World Federation of Athletic Training and Therapy World Congress 2019 Peer-Reviewed Track Abstracts May 11–12, 2019 Makuhari Messe, Chiba, Japan
Variation of Credentials and Practice Patterns by Athletic Trainers in Different Work Settings and Sports in Japan
Context: As the number of certified athletic trainers (ATs) increases, ATs need to increase their marketability through specialization on certain tasks and/or by receiving additional credentials.
Objective : To examine if differences exist in ATs' specializations and acquisition of additional credentials by work settings and sports type in Japan.
Design: Cross-sectional survey.
Setting: An online survey was distributed to certified ATs of the Japan Sport Association (JSPO) and certified members of Japan Athletic Trainers' Organization (JATO).
Patients or Other Participants: A total of 426 Japanese ATs who practice athletic training service in Japan were included in the study, and met the following criteria: (1) certified by JSPO or the Board of Certification Inc (BOC), and (2) currently employed as an AT, or (3) involved in athletic training in some form (eg, athletic training education, physical therapist, physical education teacher).
Intervention(s): The survey was created based on the questions included in the Global Practice Analysis Survey and was peer-reviewed by the JSPO board members to ensure relevance and clarity of the questions. The survey questions included items regarding participant characteristics (eg, age, sex, educational background, credentials), their current job as an AT (eg, employment type, setting, annual income), and athletic training tasks practiced.
Main Outcome Measure(s): The Pearson χ2 test (P < .05) was used to examine differences between the domain practiced and the related credentials/healthcare license (eg, Massage Therapist, Acupuncture Therapist, Physical Therapist) held by ATs in various work settings (elite, university, school organized sports, other). Then, data from 213 ATs working for four major sports (soccer [n = 79], basketball [n = 44], rugby [n = 60], and baseball [n = 30]) were extracted to examine if these differences existed by sports type. The following domains of AT tasks (n = 12) were examined in the survey: (1) prevention, (2) emergency care, (3) therapeutic intervention, (4) rehabilitation, (5) athletic rehabilitation (reconditioning), (6) conditioning, (7) performance enhancement, (8) assessment, (9) sports safety management, (10) health care administration, (11) education, and (12) communication.
Results: Differences were observed in 8 out of 12 domains (1, 2, 3, 6, 7, 10, 11, 12) of AT tasks (66.6%) among different work settings. The percentage of ATs who held massage, acupuncture, moxibustion licenses and health and fitness instructor certification were statistically different (P < .01) when comparing different work settings. No statistical differences were found in the domains of AT task practiced and related credentials/licensures held by ATs when compared by sports type.
Conclusions: Differences in AT tasks and acquisition of credentials were more prevalent when examined across employment settings than sports type. Therefore, AT educators in Japan should focus on preparing ATs to work in multiple employment settings rather than sports type for future education.
Relationship Between Physical Elements and Locomotive Ability in Elderly
Context: Locomotive abilities such as walking speed and/or step length in elderly is shown to be related to the length of health expectancy. Walking is a complex movement involving several systems, primarily musculoskeletal and nervous systems, and investigating their relationship with locomotive ability may help develop the effective training program to improve such ability.
Objective: Our purpose was to reveal the physical elements related to the locomotive ability in elderly by conducting the series of tests that measures physical fitness including locomotive ability.
Design: Cross-sectional study. Participants were over 65 years old who have no restrictions to perform physical activity. All the measurement was done in indoors.
Setting: All works were conducted in a strength and conditioning room.
Patients or Other Participants: Twenty-one elderly (72.4 ± 4.0 years old; 8 men and 13 female) had participated in the study.
Intervention(s): Maximum walking speed (MWS) and 2-step test (maximum distance (2STMD) and 2-step score) were measured to determine participant's locomotive ability. In addition, we conducted a series of tests to determine the physical fitness elements that may be related to the locomotive ability: body composition (body weight, body fat percentage, muscle mass from individual parts), flexibility (sit-and-reach (SR), hip extension), lower body strength (chair stand test), lower body power (broad jump). Muscle mass is standardized with subject's height. In order to exclude the influence of age width in the result, partial correlation coefficient with age as a control variable was calculated and the correlation of each corresponding value was examined. P value was set at .05.
Main Outcome Measure(s): We examined the variables that are related to the locomotive ability.
Results: Significant positive correlations were found between following measurements related to the locomotive abilities: 2STMD and muscle mass from individual parts (r = 0.547–0.653, P = .002–.013), 2STMD and MWS (r = 0.459, P = .042), and MWS and broad jump (r = 0.607, P = .005). Significant negative correlations were found between following measurements related to the locomotive ability: 2STMD and SR (r = −0.564, P = .010). In addition, significant positive correlations were found between SR and 1-leg chair stand test from right and left leg (r = 0.488, P = .029, and r = 0.454, P = .045, respectively).
Conclusions: From our results, it was suggested that powerful movement such as broad jump is moderately related to the locomotive ability, especially walking speed. Also, the positive relationship between SR and 1-leg chair stand test score implies the decreased hip range of motion and the lack of postural control that suggest the deficiency of gluteus muscle activation. To improve locomotive ability in elderly, they may need to improve flexibility and balance in addition to the muscle strength, suggesting the importance of strength and conditioning program.
The Protective Effect of Early Passive Motion Combined With Platelets Rich Plasma (PRP) on Articular Cartilage After Anterior Cruciate Ligament Rupture
Context: Anterior cruciate ligament (ACL) rupture is a common injury on athletes. Upon ACL rupture, it causes dramatic inflammation in in situ knee joint and may further develops posttraumatic osteoarthritis (PTOA). Therefore, how to prevent PTOA is critical. Use of early continuous passive motion (CPM) may offer an enhanced chondroprotective effect. Platelet rich plasma (PRP) also may be a method for cartilage repairs due to containing growth factors for tissue regeneration. However, it remains to be investigated whether using CPM, with or without additional intraarticular PRP injection, in early ACL injury might provide chondroprotective effects and thereby further reduce the risk of PTOA.
Objective: Comparisons of CPM with or without PRP on prevention of PTOA.
Design: Controlled laboratory study.
Setting: Laboratory.
Patients or Other Participants: Twelve rabbits were adopted. All animals received the ACL transection (ACLT) on the right knee. Contralateral (left) knee was for the sham group.
Intervention(s): The rabbits were equally and randomly allocated to four groups: (I) sedentary group (SED group). (II) CPM group. (III) PRP group. (IV) CPM + PRP group. All animals sacrificed at week 4, lateral condyle (LC), medial condyle (MC), lateral tibial plateau (LTP), medial tibial plateau (MTP), patella trochlear groove (PG), and retro patella (RP) were taken out for gross appearance, histological staining.
Main Outcome Measure(s): Gross appearance of articular cartilage, gross appearance, histological characteristics using hematoxylin and eosin for cartilage surface and cell morphological evaluations, Alcian Blue for glycosaminoglycan (GAG) distribution, in addition to quantitative osteoarthritis (OA) scores. The Kruskal-Wallis H test post hoc the Mann-Whitney U test was used to analyze the data for between-group comparisons. A significant difference was defined as a P value < .05.
Results: All animal body weight had no significant difference before and after surgery, indicating good health. Overall, the CPM groups provided protective therapeutic effects in all compartments. In gross appearance, CPM exhibited normal articular surfaces, while the SED group resulted in irregular surface abrasion. Regarding histological analysis, compared to SED group, the CPM group had significantly better histological OA scores in lateral compartment (LC<P, P = .04), but did not significant differ in medial compartment and patellar femoral compartment. Furthermore, we found that CPM + PRP had significant better scores than PRP group (P = .046). Furthermore, CPM group and CPM + PRP group showed sound chondrocyte alignment and abundant GAG content; nonetheless, others group exhibited different graded damage.
Conclusions: Early CPM with or without additional PRP shows a promising strategy for reducing the occurrence of PTOA after ACL injury. However, long-term follow up is needed.
Longitudinal Changes in Knee Kinematics Asymmetry During a Drop Vertical Jump Following ACL Reconstruction
Context: Asymmetries of knee kinematics and kinetics during landing tasks are thought as a risk factor of second injury after ACL reconstruction (ACLR). However, there is little study to investigate longitudinal changes in knee kinematics during a drop vertical jump after ACLR.
Objective: To investigate longitudinal changes in knee kinematics asymmetry during a drop vertical jump within 1 year after ACLR.
Design: A single-center cohort study.
Setting: Orthopaedic sports medicine hospital.
Patients or Other Participants: Thirty-five female patients (16.5 ± 1.7 years, 160.9 ± 6.3 cm, 56.4 ± 7.1 kg) participated in the present study. All patients underwent unilateral double-bundle ACLR with hamstring tendon autograft between May 2015 and January 2018. Inclusion criteria were as follows: age under 25 years, unilateral ACL injury and participation for sports with competitive level before injury. All subjects underwent a standardized rehabilitation protocol. Running was started at 12 weeks after ACLR. Patients were allowed jumping and sprinting from 5 months and sports specific drills from 6 months gradually. Return to play was allowed by their physicians around 9 months.
Intervention(s): Subjects performed a double-leg drop vertical jump task from 30 cm high at 6, 9 and 12 months after ACLR. Three successful trials were recorded with commercial camcorders. Knee flexion angles were calculated from the markers of greater trochanter, lateral epicondyle and lateral malleoli with using Dartfish software.
Main Outcome Measure(s): Knee flexion angle at initial contact (IC), peak knee flexion angle, and ROM of knee flexion from IC to peak were derived. A 2 × 2 repeated measures ANOVA (limb × time) and post hoc Bonferroni test were conducted to compare the knee flexion angles. The significance level was set at P < .05. Results represent mean differences (95% CI).
Results: Knee flexion angle at IC was significantly greater in ACLR limb than in contralateral limb at 6 and 9 months (3.1° [1.0 to 5.3], P = .006; 2.8° [0.8 to 4.9], P = .008). For the peak knee flexion angle, ACLR limb was significantly less than contralateral side only at 6 months (−4.0° [−6.1 to −1.9], P < .001). Knee flexion ROM was significantly less in ACLR side than in contralateral side at 6 and 9 months (−7.1° [−9.3 to −4.9], P < .001; −3.0° [−5.2 to −0.8], P =−.010).
Conclusions: The present study showed that symmetry of peak knee flexion angle during a drop vertical jump had been restored until 9 months following ACLR. On the other hand, asymmetry of knee flexion angle at IC and ROM had remained more than 9 months following surgery. These findings suggest that athletic rehabilitation to restore symmetry of knee kinematics should be emphasized to achieve symmetry on knee flexion at IC in a drop vertical jump task.
Rehabilitation Providers' Perspective on Recovery Following Autologous Chondrocyte Implantation: A Qualitative Study
Context: Autologous Chondrocyte Implantation (ACI) is an uncommon procedure that may be familiar for many rehabilitation providers. Furthermore, ACI involves a lengthy recovery process for patients. Since rehabilitation providers have a unique opportunity to positively influence outcomes in their patients, it is critical that providers' develop the tools necessary to effectively treat patients undergoing ACI, and to identify what strategies are used and how challenges are managed during the recovery process.
Objective: To explore and describe the experiences of rehabilitation providers' experiences during the rehabilitation process following autologous chondrocyte implantation and to determine what strategies they employ to improve patient outcomes, encourage rehabilitation adherence, and establish positive therapist-patient relationships.
Design: Phenomenology.
Setting: Various physical therapy clinics.
Patients or Other Participants: Seven physical therapists (3 male, 4 female) from urban and rural settings who had prior experience treating patients that had undergone ACI agreed to participate in the study. Participants were selected through convenience sampling. Participants had an average of 16 years of clinical practice, with a range of 6–30 years.
Data Collection and Analysis: Semistructured interviews were conducted with each participant, utilizing an open-ended interview guide. Participants were asked to describe their experiences treating patients that had undergone ACI. Interviews were conducted until data saturation was reached. All interviews were transcribed verbatim. The process of horizontalization was used to extract significant statements and develop themes. Rigor was established through the use of member-checks, expert checking, and epoché.
Results: Five themes emerged from therapists' experiences treating patients undergoing ACI: (1) facilitating recovery, (2) recovery is the patient's responsibility, (3) collaborative nature of recovery, (4) utilizing patient education to maximize outcomes, and (5) psychosocial factors influence recovery.
Conclusions: The relationship between a rehabilitation provider and patient is important and can have a direct impact on outcomes. Adopting a patient-centered approach is best done by devoting time to patient education, managing expectations, encouraging compliance to treatment, assessing self-efficacy, providing feedback, and promoting a collaborative environment.
Effect of Different Ankle Protection on Performance and Adaptation in College Tennis Players
Context: Ankle sprains are one of the most common injuries in tennis players. Previous researchers have shown that ankle brace or taping is effective in preventing ankle sprains. However, many players refuse to take protection because they think it will affect their performance. No authors have compared the effects of self-adherent tape and ankle brace on performance in collegiate tennis players. Also, there is no research on adaptation of taping and brace.
Objective: To investigate and compare the influence of ankle taping and brace on tennis players' athletic performance and adaptability changes.
Design: Randomized, crossover study.
Setting: Tennis court.
Patients or Other Participants: Twenty-four healthy tennis players without ankle injury for more than 6 months from Beijing Sport University were recruited and divided into brace group (BG, n = 8), taping group (TG, n = 8) and control group (CG, n = 8; age = 21.62 ± 1.07 years, height = 178.29 ± 4.55 cm).
Intervention(s): The experiment lasted for 6 weeks. The TG were carried out ankle taping and BG need to take ankle brace before each tennis training session, which was 3 times per week, and CG was not involved in any intervention.
Main Outcome Measure(s): Vertical jump (VJ), 10 meters sprint (10-mS), Left/Right sideline sliding and sprint to front (SSSF), Left/Right sideline sliding and sprint around (SSSA). The measurement was carried out before intervention (T0), immediately after the intervention (T1), 2 weeks later (T2), 4 weeks later (T4), 6 weeks later (T6) after intervention.
Results: VJ: After 4 weeks' intervention, players in brace group jumped significantly lower than taping group (P < .05). 10-mS: At time of T1, T2, T4, players in brace and taping group sprinted significantly faster than those in the CG (P < .05). Within brace group, the players sprinted faster significantly after intervention (P < .01). In taping group, players performed better than that before taping during first 4 weeks (P < .01). SSSF: Players both in brace and taping group sprinted significantly faster than CG (P < .05). Also, players in brace or taping group performed significantly better than before intervention (P < .01). SSSA: Players both in brace and taping groups sprinted significantly faster than CG immediately after the intervention (P < .05). Four weeks later, players in brace or taping group performed significantly better than that before intervention (P < .05). There are no other changes among and within three groups.
Conclusions: (1) Ankle taping and brace may improve the performance immediately after intervention. After long-term adaptation, the performance tends to be stable and gradually returns to the origin. (2) Ankle taping and brace have no difference in the athletic performance of the tennis players.
Effect of Different Ankle Protection on Hitting Ability and Adaptation in College Tennis Players
Context: Ankle sprains are one of the most common injuries in tennis players. Previous researchers have shown that wearing support or taping is effective in preventing ankle sprains. However, many players refuse to take protection because they think it will affect their hitting ability. No authors have compared the effects of self-adherent tape and ankle support on performance in tennis players. Also, there is on research on adaptation of taping or support.
Objective: To investigate and compare the influence of ankle taping and support on tennis players' hitting ability and adaptability changes.
Design: Randomized, crossover study.
Setting: Tennis court.
Patients or Other Participants: Twenty-four tennis players from Beijing Sports University were taken and divided into support group (SG, n = 8), taping group (TG, n = 8) and control group (CG, n = 8; age = 21.62 ± 1.07 years, height = 178.29 ± 4.55 cm).
Intervention(s): The experiment lasted for 6 weeks. The TG were carried out ankle taping and SG need to wear ankle support before each tennis training session, which was 3 times per week, and CG was not involved in any intervention.
Main Outcome Measure(s): International Tennis Number test (ITN) includes: Mobility test (MT), Baseline depth (BDH), Volley depth (VD), Baseline accuracy (BA) and Serve test (ST). The measurement was carried out before intervention (T0), immediately after the intervention (T1), 2 weeks later (T2), 4 weeks later (T4), 6 weeks later (T6) after intervention.
Results: Mobility test: After the intervention immediately, players both in support group and taping group sprinted significantly faster than CG (P < .01). However, 4 weeks later, players' performance in support group were significantly worse than CG (P < .05). Within taping group, players sprinted slower after 4 weeks (P < .05). There were no significant differences in baseline depth hitting, volley depth hitting, baseline accuracy hitting and sever among and within three groups.
Conclusions: Ankle taping and support may improve the mobility immediately after intervention. After long-term adaptation, the performance tends to be stable and gradually returns to the origin. Ankle taping and support have no difference in hitting ability of tennis players.
Immediate Effect of Arch Support Half Padded Insoles on Running Posture and Pain of the Anterior Knee in Female Runners
Context: The mechanism of influence of arch-support orthoses on knee injuries among female runners has not been clearly explored.
Objective: To investigate the immediate effect of arch support half-padded insoles (ASHPI) on running posture and pain of the anterior knee in female runners.
Design: Controlled laboratory study.
Setting: This study was conducted at Rehabilitation lab in Beijing Sport University in September 2017.
Patients or Other Participants: Seventeen female runners with anterior knee pain (group P, mean age = 40 years) and twenty asymptomatic female runners (group N, mean age = 42 years) participated in this study. All participants were recruited via network and physical therapy practice in Beijing, China.
Intervention(s): All participants performed a 10 km run on the track without wearing ASHPI (first run) and with ASHPI (second run), respectively.
Main Outcome Measure(s): Kinematic variables data were measured and collected using iPhone slow motion shooting before and after both run. Pain onset distance and pain intensity in group P were recorded during each run. Statistical comparisons were made using paired t test within groups and independent t test between groups (α = .05).
Results: Pelvic drop angle only in group P increased significantly during first run, but it did not obviously increase during second run. Trunk forward leaning angle and knee flexion angle only in group N significantly decreased after first run, while there was no significant difference of these two variables during second run. After wearing ASHPI, pain intensity and incidence significantly decreased, and pain onset distance was obviously postponed during second run.
Conclusions: ASHPI could effectively alleviate anterior knee pain in female runners and offer a useful and inexpensive intervention to prevent injuries by correcting their risky running posture with no stress effect on the relative proper alignment.
Effects of Increased Abductor Hallucis Muscle Activity on Subtalar Pronation and Knee Valgus Motion During Single-Leg Landing
Context: Increased abductor hallucis activity supinates the subtalar joint in the sitting position when a load is applied to the foot. It is not known whether kinetic chain motion transfer from the foot to the knee joint due to increased abductor hallucis muscle activity would occur during dynamic activities, such as single-leg landing.
Objective: To elucidate the effects of increased abductor hallucis muscle activity on ankle and knee kinematics during single-leg landing.
Design: Crossover study.
Setting: Biomechanics laboratory.
Patients or Other Participants: A total of 26 healthy young subjects (16 males: age = 22.5 ± 1.67 years, height = 171.0 ± 6.8 cm, mass = 69.3 ± 10.3 kg; 10 females: age = 21.7 ± 1.9 years, height = 159.2 ± 5.8 cm, mass = 56.7 ± 8.3 kg) with no history of lower extremity injury in the last 6 months prior to the experiment or surgeries.
Intervention(s): Subjects performed single-leg landing from a drop jump from a 30-cm high box with application of cutaneous electrical stimulation to the abductor hallucis (Experimental condition; EC) and without it (Control condition; CC). Under the EC, the intensity of cutaneous electrical stimulation to the abductor hallucis were increased till the threshold of tolerance of the subjects.
Main Outcome Measure(s): We calculated all kinematic variables at maximum calcaneal eversion. Two-way (sex × condition) repeated measures analyses of variance (RMANOVA) compared mean differences for calcaneal eversion (°) and abduction (°) relative to the tibia, as well as knee valgus (°) angles and excursion angles between the time points from the foot contact to maximum calcaneal eversion.
Results: Two-way RMANOVA showed no significant main effects (all P > .05) or interactions (all P > .05) in all targeted joint angles (CC vs EC, calcaneal eversion: −4.06 ± 6.37° vs −3.90 ± 6.75°; calcaneal abduction: −9.97 ± 7.74° vs −9.44 ± 8.20°; knee valgus: −3.95 ± 6.37° vs −4.00 ± 5.93°) and excursion angles (CC vs EC, calcaneal eversion: −8.85 ± 6.43° vs −8.86 ± 5.84°; calcaneal abduction: −11.55 ± 5.40° vs −10.95 ± 6.02°; knee valgus: −3.03 ± 4.33° vs −3.24 ± 4.04°).
Conclusions: Increasing abductor muscle activity does not affect the degree of foot pronation and frontal plane knee motion during dynamic single-leg landing motion. These results may suggest that only increasing abductor hallucis muscle activities is insufficient to control foot pronation during dynamic sharp deceleration motions, such as landing. Increasing activation of other muscles may be necessary to prevent excessive foot pronation and subsequent dynamic knee malalignment, such as excessive knee valgus, during such motions.
Vestibular Rehabilitation for Soccer Player Who Was Having Difficulty Recovering From Vertigo Due to Concussion
Background: This case is a Level 3 Exploration CASE Study. In athlete, Benign Paroxysmal Positional Vertigo (BPPV) after head injury has been reported in recent years; however, there is no reported case of physiotherapy treatment in Japan. In this case, manual treatment and exercise therapy were performed on patients who had difficulty in improving vertigo after head-and-neck injury. As a result, vertigo and balance ability was improved.
Patient: The patient is a male soccer player in his 20s, during practice, dizziness resulted from heading action and it became difficult to continue practice, so we needed to bring him to the hospital. Findings on the head CT was not abnormal so that diagnosis was a concussion and then undergoing rest and treatment was instructed. Shortly thereafter, dizziness improved temporarily, so he tried to participate in a stepwise practice. However, vertigo recurred and right ear fullness occurred, 2 weeks after onset. He was diagnosed BPPV without abnormalities on head MRI and auditory examination, at the same time, Physical therapy intervention was started to recuperate and return to competition. There was no abnormality in auditory examination on head CT and MRI; physical therapy evaluation showed no problem in the movement of the cervical vertebrae, and the security test of the vertebral artery was negative. Nystagmus and vertigo were observed in the Dix Hallpike test on the right side. Head impulse test was positive. It was difficult to maintain a stable standing position with closed eyes; in addition to that, further upset has increased in standing on an unstable surface. From the above, it was inferred that the problem of this case was vertigo similar to the right posterior semicircular canal type BPPV and the disability of balance. In this case, postural control response to the motion stimulus in the right-handed direction of the head and neck was weakened, and it was thought that intervention that improve postural control response is necessary.
Intervention or Treatment: For decreasing symptoms of vertigo, we selected the Epley maneuver as manual therapy, which is an the canalith repositioning procedure that is considered effective for right posterior semicircular canal type BPPV. When the Epley maneuver was performed, nystagmus disappeared and vertigo improved immediately. Then, vestibular rehabilitation was carried out to improve postural control response by vestibular function improvement. Vestibular rehabilitation has applied mechanisms such as adaptation, habituation and substitution that are required for recovery of vestibular function. The vestibular function improved by the vestibular rehabilitation, and he was able to return to the game based on the concussion guidelines without the appearance of vertigo even in the competition movement.
Outcomes or Other Comparisons: In general, it is thought that contact athletes' dizziness is one of symptoms of head injuries such as concussion. In this case, we found that symptom improvement can be expected by systematic differentiation and physiotherapy intervention with guidelines and appropriate stepwise athletic training approach to return to play.
Conclusions: As a result of intervention of manual therapy and vestibular rehabilitation for the patient, who were difficult to recover from BPPV after head-and-neck trauma, the symptoms of vertigo disappeared instantaneously and the return of sports smoothly based on the gradual recovery protocol has become possible.
Clinical Bottom Line: In this study, we experienced that manual therapy and vestibular rehabilitation are effective against vertigo and equilibrium dysfunction by BPPV after head-and-neck trauma.
Characteristics of the Tuck Jump in Female Basketball Athletes With Anterior Cruciate Ligament Injury
Background: Anterior cruciate ligament (ACL) injuries often occur with characteristic postures at landing, such as knee valgus, excessive ground reaction force, and the center of mass positioned posterior to the base of support at initial ground contact. The modified tuck jump assessment (Fort-Vanmeerhaeghe et al, 2017) is a tool that measures the risk of movement related to lower extremity injuries. It may be useful for evaluating risks of ACL injury. An accelerometer can also be used to evaluate the characteristics of the athletic movements and risks of injuries. Thus, in this study, we used an acceleration sensor to evaluate mechanical load and the modified tuck jump assessment to evaluate posture during landing in two athletes who sustained ACL injuries. Herein, we report our findings.
Patients: Two female athletes (player A: 16 years old, with a 3-year sport experience and player B: 17 years old, with a 9-year sport experience) incurred ACL injuries when cutting and stopping, respectively, during a basketball game 4 and 1 month after the tuck jump assessment, respectively. For comparison, 32 noninjured female basketball athletes (age = 15.9 ± 0.5 years, sport experience = 5.8 ± 2.2 years) were included. All the athletes underwent tuck jump assessment in the preseasons.
Intervention or Treatment: The participants wore a triaxial accelerometer (Sports Sensing: 100 Hz) on their upper back and performed tuck jumps repeatedly for 10 seconds. Movement was evaluated using the modified tuck jump assessment criteria (items 1–10). Then, they were graded in a scale of 0–2 for each items using a video recorded in the frontal and sagittal views. The movement assessment scores ranged from 0 (good) to 20 (poor). The peak vertical trunk acceleration was calculated from each landing during the 10-second tuck jump.
Outcomes or Other Comparisons: The vertical trunk accelerations during tuck jump were 8.15, 8.35, and 7.58 ± 1.7 G (95% confidence interval [CI] = 6.98, 8.17) in players A and B, and noninjured athletes, respectively. The modified tuck jump assessment scores were 8, 7, and 8.3 ± 2.3 (95% CI = 7.5, 9.2), respectively. The lower extremity valgus (“kissing knee”) at landing, a modified tuck jump assessment criterion, was observed in both athletes.
Conclusions: These cases demonstrate that athletes with ACL injuries tended to have greater trunk acceleration during tuck jump testing in preseason. Greater trunk acceleration during landing is related to greater ground reaction force. These two cases suggest that greater trunk acceleration during landing may induce ACL injuries. However, no obvious difference in modified tuck jump assessment score was found between the ACL injury and non-ACL injury groups. In these cases, ACL injuries were not related to the qualitative evaluation in the modified tuck jump assessment. However, the two players with ACL injuries showed knee valgus at tuck jump landing. A combination of greater acceleration and knee valgus during landing might increase the risk of ACL injury.
Clinical Bottom Line: This study shows that the female basketball players with ACL injuries had characteristic greater trunk acceleration and knee valgus during tuck jump landing before the onset of ACL injury.
Atypical Arthrogenic Quadriceps Inhibition Characteristics in a Former Female Handball Player With Three ACL Reconstruction Surgeries
Background: Athletes with ACL reconstruction (ACLR) often display quadriceps strength loss due to arthrogenic quadriceps inhibition, often preventing them from a successful return to sports (RTS) process. This case study introduced atypical arthrogenic quadriceps inhibition characteristics other than quadriceps strength loss in a woman with a history of 3 ACLRs.
Intervention or Treatment: The degree of arthrogenic quadriceps inhibition in each knee was assessed using the supra-maximum twitch interpolation technique. The subject performed maximum voluntary isometric quadriceps force (MVIQF) measurements at 90° knee flexion angle in a sitting position over 5 recorded trials on each leg. During each MVIQF measurement, the subject maximally and voluntarily extended her knee, and a supramaximum electrical stimulation was applied on the skin over the quadriceps muscle berry to evoke physiologically maximum isometric quadriceps force (PMIQF).
Outcomes or Other Comparisons: Out of the five MVIQF trials for each leg, only the first trial on the left knee and the first and third trials on the right knee showed normal force curves; the quadriceps force increased sharply, exhibited force plateau for a few seconds, and then showed a sharp increase with a supramaximum electrical stimulation. On the other hand, other MVIQF measurement trials showed atypical force curves. The quadriceps force increased sharply but dropped down steeply immediately after the first force peak (ie, MVIQF) without showing any force plateau phase; subsequently, it rose sharply again with the supramaximum electrical stimulation to a level that was higher than that of the MVIQFs. Mean MVIQFs for the left and right knees over the five trials were 404.2 N ranging from 384.9 N to 411.7 N and 376.3 N ranging from 356.5 N to 398.4 N, respectively. Mean PMIQFs for the left and right knees over the trials were 422.7 N ranging from 400.2 N to 459.2 N and 431.6 N ranging from 420.7 N to 451.3 N, respectively. Mean MVIQF/PMIQF ratios were 0.96 and 0.87 for the left and right knees, respectively.
Conclusions: Both knees exhibited smaller MVIQFs than PMIQF with much smaller differences in the left knee than in the right knee. However, both knees showed sudden quadriceps force drops right after the MVIQFs were exhibited and never showed force plateau around the level of MVIQFs in a majority of the trials. Because the quadriceps forces increased with the supramaximum electrical stimulations to levels which were higher than the MVIQFs, the sharp quadriceps force drops right after the first MVIQF should not have been caused by any localized muscle fatigue. Instead, such large force drops should be caused by some arthrogenic neurological deficits due to ACL injuries and/or ACLRs.
Clinical Bottom Line: When assessing the degree of arthrogenic quadriceps inhibition after ACLR using the supramaximum interpolation technique, it may be necessary to examine not only the values and ratio of MVIQF and PMIQF but also to evaluate the characteristics of the quadriceps force-time series changes in each MVIQF measurement trial.
Relationship Between Perineal Pain and Pubic Bone Marrow Edema, as Well as Time for Return-to-Play in Cases of Athletic Groin Pain
Context: The physical findings of athletic groin pain (GP) are found in various areas around the groin region, including pain in the perineal region. However, there have been no reports regarding the relationship between physical and MRI findings of GP, or the relationships between physical findings of GP and time to return-to-play (RTP) in athletes.
Objective: This study was performed to investigate the rate of cases with pain in the perineal region, and to examine the relationship between perineal pain and pubic bone marrow edema on MRI findings, as well as the relationship between pain in the perineal region and time to RTP in athletes.
Design: Case-control study.
Setting: Investigation was conducted at JIN Orthopaedic and Sports Clinic, Saitama, Japan.
Patients or Other Participants: The study population consisted of 651 GP patients (555 males and 96 females) ranging in age from 16 to 40 years (mean, 20 years), with an average follow-up of 40 weeks from May 2013 to September 2017. The subjects were selected from 1091 patients who consulted our clinic for sport-related GP.
Intervention(s): MRI was performed based on the physical findings and a detailed patient questionnaire. Six hundred fifty-one GP cases were classified according to physical findings into two groups: pain in the perineal region (group P) and no pain in the perineal region (group N). Six hundred fifty-one GP cases were also classified according to pubic bone marrow edema (BME) on MRI into three groups: all BME (group ABME), BME in the superior ramus (group SR), and BME in the inferior ramus (group IR). Inferior ramus stress fractures were excluded.
Main Outcome Measure(s): The relationships of group P and ABME and of groups P and SR/IR were assessed by χ2 test. We compared the time from onset to RTP between groups P and N using the Mann-Whitney U test in 365 cases, who were followed up to RTP.
Results: Group P accounted for 2% (n = 15; 15 males, 0 females; 17–32 years, mean = 20 years) of 651 cases. The sensitivity and specificity of group P were 73 and 59% for ABME (P = .012), 67% and 60% for SR (P = .038), and 73 and 73% for IR (P < .001), respectively. The time from onset to RTP was significantly longer in group P (n = 10, followed up to RTP) than N (n = 355, followed up to RTP) with medians of 55.6 (Min, Max; 11.6, 199.1) weeks and 15.1 (0.1, 256.4) weeks, respectively (P < .001).
Conclusions: Group P was related to ABME and showed higher sensitivity and specificity for group IR than group SR. In addition, group P was significantly related to long-standing GP. Pain in the perineal region provides useful information for rehabilitation to improve pelvic dysfunction in athletic GP.
Acute Sign and Symptom Predictors of Prolonged Recovery in Adolescents Following Sports-Related Concussion: A Systematic Review
Context: Sports-related concussion (SRC) continues to gather international attention as both the incidences and research increase. With estimates of over 44 million youth and adolescents participating in sports and recreation annually, this population is at especially high risk of injury and have been identified for being at higher risk of prolonged recovery (greater than 28 days).
Objective: To synthesize and critically appraise the evidence which has examined acute signs and symptoms of SRC that may predict prolonged recovery in adolescents who sustained these injuries.
Data Sources: EBSCOHost (Academic Search Complete, CINAHL, MEDLINE, PsychInfo and SPORTDiscus) and PubMed electronic databases were searched for relevant articles in English, published in peer-reviewed journals, between 2011 and 2018. The following keywords were used to identify potential studies: youth, adolescent, concussion, sports-related concussion, sport concussion, clinical predictors, predictors, prolonged recovery, delayed recovery, recovery, and resolution.
Study Selection: The data extracted from the selected studies included study design, population, definitions/diagnosis of concussion, definition of recovery, outcome measures and results of clinical evaluation and testing.
Data Extraction: A modified version of the Downs and Black Quality Index was used to assess the methodological quality of the eight included studies and to conduct a standardized risk-of-bias assessment. Reported odds ratios and 95% confidence intervals were used to draw comparisons and conclusions across the included studies. The Strength of Recommendation Taxonomy was used to determine the overall strength of recommendation based on the current evidence.
Data Synthesis: The systematic search identified eight studies that were included in the final analysis as they evaluated time to recovery or resolution of symptoms, reported odds ratios associated with potential predictors of prolonged recovery, and included an adolescent population (11–18 years old) who sustained SRC. The critical appraisal of study bias determined, 1 study was moderate quality (68.75%) and 7 studies were high quality (75–81.25%). Based upon the odds ratios from individual studies, it was determined that overall symptom burden on the Post-Concussion Symptom Scale, higher scores on the Sports Concussion Assessment Tool 2, symptom severity >20, and the presence of dizziness may be associated with prolonged recovery. No signs or symptoms were consistently identified across studies which limited the strength of the evidence. Overall, grade B evidence exists that acute signs and symptoms can predict prolong recovery in adolescents following SRC but this recommendation is not associated with any single sign or symptom.
Conclusions: The evidence suggests that there may be individual symptoms or cluster composites that have predictive odds of prolonged recovery in adolescents with SRC. However, there is inconsistent evidence across studies reporting the same variables in a similar manner. Clinicians should track symptoms and severity of concussions to best identify patients who may be at risk of a prolonged recovery.
Ultrasonographic Assessment of Femoral Articular Cartilage Response Following a Competitive Rugby Season: A Prospective Observational Study
Context: Physical activity can have a significant impact on lower extremity joint and general health. Repetitive knee joint loading during physical activity is a potential factor that leads to deleterious changes in macrostructure of the articular cartilage and cartilage composition at the knee joint. Previous studies showed acute femoral cartilage deformation following acute loads during walking and running with ultrasound. However, no study assesses chronic changes in femoral cartilage structure over the course of an athletic season. Understanding chronic response in the femoral cartilage to repetitive mechanical loads will direct clinicians and researchers to determine optimal exercise-related strategies to mediate the risk of degenerative disease of the articular cartilage.
Objective: Determine differences in chronic response in femoral articular cartilage response over the course of an athletic season in healthy collegiate rugby players.
Design: Prospective cohort design.
Setting: Collegiate athletic training facility.
Patients or Other Participants: Fifty-five male collegiate rugby players with no history of knee joint injury (age = 19.7 ± 1.0, height = 174.4 ± 6.9 cm, mass = 85.5 ± 11.5 kg) participated in this study. All athletes were cleared for full participation at the time of the study.
Intervention(s): Femoral cartilage ultrasonography assessments were performed before and immediately after an athletic season.
Main Outcome Measure(s): ImageJ software was used to assess femoral cartilage thickness, cross-sectional area, and echo intensity. Femoral cartilage thickness was measured at the intercondylar notch and 1 cm apart in the medial and lateral directions that were used as an estimate of the medial and lateral condyle cartilage thickness. The cross-sectional area was calculated as an area of cartilage between a lateral and a medial measurement points where femoral cartilage thickness was measured. Echo intensity was evaluated by the average gray-scale value across all pixels in the selected area on scale from 0 to 255. Paired t tests were used to compare femoral cartilage variables before and after the competitive season. Significance was set a priori at P < .05.
Results: There were significant decreases in the following cartilage variables in baseline when we compared with postseason values: medial cartilage thickness (P = .003) and histogram (P = .005) in the dominant side; as well as lateral (P = .003) and medial cartilage thickness (medial P = .005), cross-sectional area (P = .003), and histogram (P = .003) in the nondominant side.
Conclusions: We observed altered femoral cartilage structure following one competitive season in healthy collegiate rugby players. The results from this study indicate that long-term and higher-impact activity may have effects on femoral cartilage structure. Future researches are need to pursuit femoral cartilage response to exercises for multiple seasons to develop an effective strategy to monitor cartilage health.
An Examination of Popliteal Venous Reflux in Individuals With Chronic Ankle Instability and Ankle Sprain Copers
Context: Previous studies indicate that the soleus provides a major pumping action to return venous blood from the lower extremity to the heart. Neuromuscular impairments in the soleus muscle have been observed in individuals with CAI, which may have a negative impact on venous return and cardiovascular system. Ankle sprain copers are postulated to have adaptive abilities that limit neuromuscular impairments related to the soleus function and venous return after initial injury. However, no previous studies have examined the associations between ankle injury characteristics and venous return.
Objective: To determine if differences exist in popliteal venous reflux between individuals with CAI and ankle sprain copers, as well as if popliteal venous reflux is associated with ankle injury characteristics (ie, the number of lateral ankle sprain and self-reported instability status).
Design: A single-blinded, case-control study.
Setting: Research laboratory.
Patients or Other Participants: Eighteen participants with self-reported CAI (9M, 9F; age = 20.43 ± 1.22 years, height = 167.85 ± 6.98 cm, mass = 63.69 ± 11.07 kg) and 15 copers (9M, 6F; age = 21.00 ± 0.28 years, height = 164.81 ± 2.00 cm, mass = 59.00 ± 2.22 kg) volunteered for the current study.
Intervention(s): Doppler ultrasound was used to measure venous blood flow in an upright standing position. A 8- to 13-MHz linear-array transducer was placed over the popliteal vein at the midpoint of lateral and medial epicondyle of the femur. A 12-cm cuff attached to the calf was inflated to 100 mmHg to empty venous return, followed by rapid deflation. Three trials of the reflux measurement were performed when the cuff was deflated rapidly.
Main Outcome Measure(s): Maximal venous velocity, time-averaged maximum velocity, and venous diameter were measured during reflux. The maximal velocity and diameter values were used to calculate venous reflux volume. Independent t tests were performed to compare maximal venous velocity, time-averaged maximum velocity, and venous reflux volume between individuals with CAI and ankle sprain copers. Pearson product moment correlations were performed to examine associations of venous flow variables with ankle sprain and instability characteristics. Significance was set a priori at P < .05.
Results: There was no significant difference in maximum velocity (P = .108), time-averaged maximum velocity (P = .339), and reflux volume (P = .137) between the CAI and ankle sprain coper groups. However, a significant positive correlation was found in reflux volume and the number of lateral ankle sprains participants have experienced (r = 0.436, P < .001).
Conclusions: The results from our study indicate that ankle instability status may not influence popliteal reflux velocity and volume. However, as participants experienced higher number of ankle sprain, popliteal reflux volume increased. Therefore, recurrent ankle sprain may be a more important factor that may affect popliteal venous flow.
Assessment of Physical Functions Using the Sahrmann Core Stability Test for Athletes With Lumbar Spondylolysis
Context: Lumbar spondylolysis is generally caused by repetitive stress in pars interarticularis, especially due to hyperextension and rotation. Clinically, young athletes are often found to have trunk muscle weakness; therefore, they have difficulty keeping the spine in neutral position when they control their posture in sports activities (Thein-Nissenbaum and Boissonnault, 2005). However, there are few reports that focused on lumbar spine stability of athletes with spondylolysis using objective assessment.
Objective: The aim of this study was to evaluate the lumbar spine stability of athletes with spondylolysis using the Sahrmann Core Stability test.
Design: Cross-sectional study.
Setting: The research was taken place in a Japanese district general hospital.
Patients or Other Participants: Participants are 8 young athletes with lumbar spondylolysis (spondylolysis group: 6 men, 2 women; age = 14.6 ± 2.3 years; lumbar spondylolysis classification, 5 early, and 3 terminal-stage defects) and 8 young athletes without low back pain (control group: 3 men, 5 women; age = 15.4 ± 1.9 years) have participated.
Intervention(s): All participants were measured for the Sahrmann Core Stability Test. The spondylolysis group was measured in the first rehabilitation. The test was conducted using an inflatable pressure transducer. The transducer was placed under the individuals' lumbar spine while lying supine in a hook lying position. While keeping the pressure: (40 ± 10 mmHg) via the abdominal hollowing technique, they tried the 5 stages test from first stage (level 1) to final stage (level 5) gradually. Faries et al stated that the Sahrmann Core Stability test assesses spinal stability with or without movement of the lumbopelvic complex (2007).
Main Outcome Measure(s): The data was analyzed by descriptive analysis and Mann-Whitney U test.
Results: The median and interquartile range (IQR) of the Sahrmann Core Stability test scores was 1 (1–2) in spondylolysis group and 3.5 (3–4) in control group. There was a significant difference between the groups (P = .01).
Conclusions: By using objective assessment, we found that young athletes with lumbar spondylolysis can have poor lumbar spinal stability than controls even they often trained as athletes. It was suggested that effective rehabilitation for young athletes with lumbar spondylolysis need some exercises focused on stabilization of spine.
Clinical Characteristics of Track and Field Athletes Suffered From Lumbar Spondylolysis
Background: Lumbar spondylolysis is known to be prevalent in athletes. Lumbar spondylolysis is generally caused by repetitive mechanical stress in the pars interarticularis, especially due to hyperextension and rotation. Our research showed that the baseball and soccer players were the most likely to get injured among the athletes who were diagnosed with lumbar spondylosis (baseball: 32.2%, soccer: 18.5%), while track and field athletes only accounted for 8.0%. Track and field athletics requires not only running motions but also sprinting and endurance racing. In some motions, such as jumping and throwing, it is considered that the mechanical stresses on the lumbar region induced by repetitive leg movements are much higher than the mechanical stresses induced by a running motion. However, there are few reports that have investigated the characteristics of each track and field disciplines with lumbar spondylolysis. We aimed to clarify the characteristics of each track and field discipline with lumbar spondylolysis.
Setting: This research was taken place in a Japanese district general hospital.
Patients: Patients were 17 athletes (age = 12–18 years) who were diagnosed with lumbar spondylolysis and were treated for more than 3 months in our hospital from 2014 to 2016.
Intervention or Treatment: Their track and field disciplines and competition level were examined. Athletics disciplines include short distance, steeplechase, jumping, throwing and middle distance and long distance. The competition level was classified by 2 groups (elite and recreation). The fusion rate was assessed in 17 athletes using both MRI and CT.
Outcomes or Other Comparisons: Distribution of disciplines was 53% in short distance, 12% in steeplechase, 24% in jumping, 0% in throw, 12% in middle distance and long distance. The fusion rate was 63% in short distance, 50% in steeplechase, 100% in the jumping, 0% middle distance and long distance. By competition level, elite was 50%, and recreation was 75%.
Conclusions: The fusion rate was 0% in medium and long distances. In the track and field athletes, there was little disc degeneration. It was reported that the incidence of lumbar spondylolysis is comparable to other competitions. In this study, we investigated the characteristics of the track and field with lumbar spondylolysis. Considering the general mechanism, it is easy to think that lumbar spondylolysis is likely to onset in power disciplines. However, we found lumbar spondylolysis also in middle distance and long distance disciplines with relatively low load and small lumbar movement. Additionally, it was found that fusion rate was low in the group with elite competition level.
Identifying Factors Contributing to Triple Hop Test in Adolescent Basketball Players With Recurrent Ankle Sprain: Osaka Basketball Association Sport Injury Prevention Project
Context: Tests of functional performance, such as the triple hop test (THT), are commonly utilized to help in the decision to return to sports following ankle sprains. Functional performance in patients with recurrent ankle sprains (RAS) may be affected by deficits in dynamic postural control, muscular function, and range of motion (ROM). However, the THT does not specify which factors are associated with diminished functional performance in individuals with RAS. Identifying the factors contributing to THT will help clinicians and researchers to establish more appropriate return-to-sports criteria to reduce a risk of RAS.
Objective: Determine specific factors that make a significant contribution to the THT in adolescent basketball players with RAS.
Design: Cross-sectional study.
Setting: Middle school and high school athletic training facilities.
Patients or Other Participants: Two hundred thirty-five adolescent basketball players (M: 146, F: 89, age = 14.92 ± 2.15 years, height = 164.73 ± 9.23 cm, mass = 55.93 ± 10.12 kg) volunteered.
Intervention(s): Participants completed the THT and the SEBT in the anterior, posteriormedial, and posteriorlateral directions. Each participant underwent assessments of toe grip strength, hip abduction strength, weight-bearing (WB) and non-weight-bearing (NWB) ankle dorsiflexion ROM, hip joint ROM (extension, flexion, internal rotation, and external rotation), as well as hamstring flexibility.
Main Outcome Measure(s): Triple hop distance was measured as the distance hopped from the starting line to the point where the heel struck the ground upon completing the third hop (cm). Three trials of each SEBT direction were averaged and normalized as a percentage of stance leg length. The mean of the three directions created a composite score (SEBT-Comp). Peak force of the toe flexors was measured with a toe-grip dynamometer (kg). Raw peak hip strength values were measured in Newtons (N) and normalized to the length of the moment arm (m) and body mass (kg) to obtain a normalized torque value (Nm/kg). WB dorsiflexion were reported as degrees of tibial inclination without the heel lifting off the ground. NWB dorsiflexion and hip ROM were measured at the point of examiner perceived maximum passive ROM (°). Hamstring flexibility was assessed with the straight leg raise using a bubble goniometer (°). A multiple liner regression was performed to determine the influence of predictor variables on the THT. Significance was set a priori at P < .05.
Results: The following variables were identified as the strongest predictors of the variance in the THT: SEBT-Comp; hip internal rotation and extension ROM; and toe grip strength (R2 = 0.24, P < .001).
Conclusions: Dynamic postural control, hip internal rotation and extension ROM, and toe grip strength were the major contributors to the THT in adolescent basketball players with RAS. When deficits in functional performance is detected using the THT, data from this study suggest the need to address these contributors for players with RAS in order to improve their dynamic function.
Technical Performance Analysis of 2018 Taiwan Men's Top University Volleyball League
Context: Volleyball technology can be divided into the scoring and nonscoring technics. The scoring technics are serving, spiking, and blocking and the nonscoring technics are receiving, digging, and setting. The comprehensive relationship between the technology and athlete performance is little understood.
Objective: To estimate the relationship between the volleyball technology and athlete performance.
Design: Cross-sectional.
Setting: Field research.
Patients or Other Participants: All participants were from 12 teams of 2018 Taiwan Men's top university volleyball league.
Intervention(s): All participants were recorded their performance and technology from 66 games.
Main Outcome Measure(s): Performance was defined as getting score or not from video analysis. Technology was defined as scoring technics such as serving, spiking, and blocking and the nonscoring technics such as receiving, digging, and setting. Pearson product-moment correlation coefficients examined the relationship between the volleyball technology and athlete performance. According to the game points, 12 teams were divided into the first 6 and the last 6 groups for comparison. The independent t test examined the difference between two groups for score and nonscore technics respectively.
Results: The scoring technics, which are serve, spike and block, are highly related to the outcome of games (r > 0.7). For nonscoring technics, which are receive, dig and set, are moderately correlated to the outcome of games (r > 0.4). For the scoring technics, there were significant difference between the first six and the last six groups on the serve, spike and block technics (P < .001). For the nonscoring technics, there were significant difference between the first 6 and the last 6 groups on the dig and set technics (P < .05).
Conclusions: The scoring technics may impact athlete performance more than nonscoring technics. The information can be used as a reference of technical training for volleyball teams to improve their performance in the future. More comprehensive technical performance analysis is needed for the future training efforts.
Assessment of Physical Load During Sports Activities in Junior High School Students With Wearable Sensors
Context: Sports activities are major cause of heat illness among students around puberty, but physiological responses during sports activities in students on fields remain unclear yet. We measured physiological data by using wearable sensors to assess physical load during sports activities in junior high school students on fields.
Objective: (1) To assess physical load in junior high school students during soccer practice and game on fields. (2) To develop analytical methods evaluating the physical load.
Design: Crossover trial.
Setting: Field, athletic lawn in junior high school.
Patients or Other Participants: Healthy male junior high school students (n = 18; age = 13.5 ± 0.4 years, height = 1.64 ± 0.06 m, mass = 55.49 ± 12.06 kg).
Intervention(s): Experiments were conducted from June to October. The schedule of practices and games, including their work intensities, duration and rest were not controlled. Heart rate (HR) and acceleration (Acc) were measured by an all-in-one wearable sensor device (myBeat; WHS-1, Union Tool Co.). Wet bulb globe temperature (WBGT) was assessed on the field as an environmental factor. Based on the all HR, peak HR for each individual was assessed. HR at a given time was calculated as (HR/peakHR) × 100 (%HRpeak). HRpeak and %HRpeak were assessed as the physical load intensity. To assess thermal loads and risks of heat illness, we counted the number of data point of which Acc < 1.5 G and %peakHR > 80 % (OUT). Correlation among Acc and %HRpeak, WBGT and OUT was evaluated. The null hypothesis was rejected at the level of P < .05.
Main Outcome Measure(s): We examined correlation among Acc and %HRpeak, WBGT and OUT by Pearson correlation analysis.
Results: Linear correlation was observed between Acc and %HRpeak on each day of experiment. The correlation was not influenced by WBGT. Significant correlation was detected between WBGT and OUT (r = 0.584; P < .05).
Conclusions: It was confirmed that Acc and %HRpeak was well correlated. However, WBGT was not a factor affecting the correlation. These results suggest that Acc is useful to evaluate physical loads during sports activities on fields. Moreover, significant positive correlation was observed between WBGT and OUT. We conclude a calculating OUT is useful as a way of assessing the risks of heat illness.
Validation of a Leg Press Force Measuring Device to Assess Limb Strength Asymmetry
Context: Limb strength asymmetry is often implicated as a factor in injury recurrence and cases of long-term joint pathologies such as osteoarthritis. Measuring limb asymmetry during bilateral strength measures such as a leg press can potentially provide insight into individual limb deficiencies. However, no devices are commercially available to accurately measure limb strength asymmetry during a leg press.
Objective: The purpose of this study was to assess the ability of a low-cost modular instrument designed to interface with a standard leg press to measure limb strength asymmetry in healthy individuals.
Design: One-group, repeated measures.
Setting: Biomechanics Laboratory.
Patients or Other Participants: 15 healthy participants (4 female/11 male, age = 23.9 ± 3.1 years, mass = 81.1 ± 40.2 kg, height = 174.9 ± 23.1 cm) were recruited for this study. Participants had no significant history of or a current lower-extremity musculoskeletal injury.
Intervention(s): A one-repetition maximum was determined for the leg press utilizing normative data charts based on self-reported fitness level, age and sex. Six repetitions were recorded, starting at no weight increasing in 10% increments to 50% of their determined one-repetition maximum.
Main Outcome Measure(s): The 20, 30, 40, and 50% repetition-maximum trials were utilized for data analysis and normalized to 200 data points. Data were then split into three phases for the concentric, transition and eccentric phases of the leg press for each of the trials. Asymmetry ratios (AR) were calculated for the limbs with an AR of one indicating perfect limb symmetry and values greater than one indicating more reliance on the right limb. Repeated-measures analyses of variance (P < .05) were used to assess differences in phases across each of the 4 trials (20, 30, 40, and 50%) for each of the 3 phases. Follow-up post hoc pairwise comparison testing and Cohen d effect sizes were used to assess specific differences between trials.
Results: Significant differences in the concentric phase were found between weighted trials (F = 3.71, P = .019). Specifically, greater ARs were found in the 20% repetition-maximum trial (AR = 1.79 ± 1.56) compared to the 40% (AR = 0.84 ± 0.75, P = .007, d = 0.78) and the 50% (AR = 0.89 ± 0.54, P = .032, d = 0.77) trials. There were no significant differences in ARs for the transition (F = 0.30, P = .83) or eccentric (F = 0.45, P = .72) phases.
Conclusions: During the concentric phase of the leg press, ARs favored the right limb at the lowest level of weight whereas at higher weights participants demonstrated more symmetrical limb use patterns. As weight increases towards a 1 repetition maximum, especially during the concentric phase, we would expect participants to demonstrate more symmetrical patterns as each limb bears a greater responsibility. This preliminary assessment indicates this device may be valid to assess limb asymmetries in patients. This device may provide important objective asymmetry strength measurements to guide evidence-based decision-making throughout the injury evaluation process, rehabilitation and return to play.
Camogie Coaches' Views on Injury Prevention
Context: With reported high numbers of injury in camogie, injury prevention programs are a priority. However, anecdotal use of injury prevention programs in camogie is low. To maximize adoption and compliance to these programs, it is critical to establish coaches' views on injury prevention, identify barriers to their implementation and facilitators to enhance their use.
Objective: This study aimed to identify the use of injury prevention programs amongst camogie coaches and to explore their attitudes towards willingness and perceived abilities for wider implementation.
Design: Cross-sectional study.
Setting: Anonymous, online survey, open nationwide in Ireland. All levels of camogie coaches were eligible.
Patients or Other Participants: Ninety-eight Irish camogie coaches (43.6 ± 8.6 years).
Intervention(s): The survey was adapted from a validated survey developed for Ladies Gaelic Football coaches, a sport with a similar sports context to camogie. The survey was distributed through the Camogie Association, social media and word of mouth and remained open between July and August 2018. The survey comprised 23 questions beginning with demographics, coaching qualifications, previous coaching experience and current use of injury prevention strategies. Attitudes towards injury prevention, willingness to use an injury prevention program (8 statements) and perceived ability to conduct an injury prevention program (12 statements) were evaluated using a 5-point Likert scale. Finally, views on future coach education was examined.
Main Outcome Measure(s): Descriptive statistics are presented.
Results: Coaches were mainly female (59%) with a mean of 11.1 ± 8.3 years coaching experience. Most were involved at a nonelite level (87%) and reported having a coaching qualification (93%). Coaches believed injury prevention programs are important to implement (96%) and that coaches should have current knowledge on injury prevention programs (97%). However, just 32% were aware of a specific injury prevention program for use in camogie (of these 66% were aware of the GAA15 injury prevention warm-up and 33% the Activate GAA injury prevention warm-up). Only 34% of coaches were currently using an injury prevention program. Coaches are willing to implement injury prevention programs if they are shown to lower injury risk (98%) and improve player performance (96%). However, only 31% believe they currently have sufficient knowledge, 23% sufficient experience and 43% the skills required to put an injury prevention program in place. Coaches (92%) would like further education, particularly in the form of seminars (97%), training courses (96%), injury prevention packs (96%) or access to online resources (94%).
Conclusions: Injury prevention programs are not commonly used by camogie coaches. While they are willing to consider using them, many reported not having sufficient knowledge and experience with these programs. Thus, a national rollout of training to enhance camogie coaches' knowledge, skills and confidence in employing injury prevention programs should be completed, making use of the education formats they prefer.
Is the Frequency of High-Impact Movements During Badminton Games Predicted by Landing-Jump Characteristics?
Context: Repeated high-impact movements during a game may cause acute or chronic injuries. However, few studies have investigated the biomechanical characters related to repeated high-impact movements during games.
Objective: This study aimed to determine the relation between landing-jump characteristics and the frequency of greater impacts during actual game situations in badminton players. We hypothesize that those who experience greater impacts during jump testing will demonstrate greater frequencies of high-impact movements during the game.
Design: Cross-sectional study.
Setting: Gymnasium for badminton games.
Patients or Other Participants: Eleven female high school badminton players (age = 16.7 ± 0.5 years, height = 1.57 ± 0.05 m, mass = 52.3 ± 5.1 kg).
Intervention(s): Participants performed rebound jump testing wearing a triaxial accelerometer (100 Hz) on their upper back. They were instructed to jump five times continuously using both legs, as high as possible, and with minimal ground contact time. Each participant's peak resultant trunk acceleration was measured during the second to the fourth landing-jump procedure. They also played two singles badminton games, while wearing an accelerometer. The acceleration data from the game were used to calculate the frequency of accelerations greater than 4G (cases/min).
Main Outcome Measure(s): Univariate linear regression analysis was performed to estimate the frequency of greater trunk acceleration greater than 4G during badminton games from the average peak accelerations during rebound jump tests.
Results: The mean (SD) of the average peak accelerations during the rebound jump test was 6.2 (1.1) G, and the frequency of trunk acceleration greater than 4G was 8.1 (2.1) cases/min. The results of the regression analysis revealed that decreased peak accelerations during the rebound jump test predicted 53.1% of the variance in the frequency of greater trunk accelerations during badminton games (r2 = 0.533, F = 10.267, P = .01).
Conclusions: Contrary to our hypothesis, participants who demonstrated low impact during rebound jump tests tended to show greater frequencies of high-impact movements during the game. This suggests that individuals who do not use reaction force effectively during landing-jump procedures were frequently exposed to high-impact movements during the game. Increasing jump performance may decrease the risk of injury during badminton games.
The Comparison of Knee Cartilage Thickness Between Volleyball Athletes and Long-Distance Runners
Context: Knee cartilage health is critical to being able to perform activities of daily living. While proper mechanical loading is a key to the maintenance of cartilage function, the sports specific long-term impact on knee cartilage health is relatively unknown.
Objective: To compare in-vivo knee medial and lateral cartilage thickness between volleyball athletes and long-distance runners.
Design: Cross-sectional.
Setting: Controlled laboratory.
Patients or Other Participants: Twenty healthy male volleyball athletes (height = 1.81 ± 0.06 m, mass = 74.5 ± 7.0 kg, age = 19.6 ± 1.5 years) and 20 healthy long-distance male runners (height = 1.71 ± 0.05 m, mass = 58.1 ± 4.5 kg, age = 19.6 ± 1.5 years) with no current knee orthopedic injury or history of knee surgery in both knees.
Intervention(s): All participants underwent ultrasound measures of the medial and lateral femoral condyle articular cartilage on the right knee.
Main Outcome Measure(s): Medial and lateral femoral condyle articular cartilage thickness was obtained via ultrasound imaging. Medial and lateral cartilage measures were divided into anterior, middle and posterior regions. The independent t test examined the knee cartilage thickness between volleyball athletes and long-distance runners.
Results: There were significant differences in medial cartilage thickness of the anterior (1.6 ± 0.3 mm vs 1.4 ± 0.2 mm, P = .009), middle (1.7 ± 0.3 mm vs 1.4 ± 0.2 mm, P = .001), and in lateral cartilage thickness of anterior (2.7 ± 0.3 mm vs 2.1 ± 0.3 mm, P < .001) regions, but no significant differences in posterior region of medial cartilage (1.3 ± 0.1 mm vs 1.2 ± 0.1 mm, P = .755), and in lateral cartilage thickness of middle (1.4 ± 0.2 mm vs 1.2 ± 0.3 mm, P = .152) and posterior (1.5 ± 0.2 mm vs 1.4 ± 0.2 mm, P = .062) regions between volleyball athletes and long-distance runners were found.
Conclusions: Male volleyball athletes have thicker medial cartilage in anterior and middle regions and thicker lateral cartilage in anterior region than male long-distance runners. This work suggests that sports specific chronic loading may impact cartilage health. Future work should continue to investigate the mechanism(s) of thick cartilage on volleyball athletes.
Characteristics of ACL Injury With and Without Contact in Japanese Young Female Basketball Players
Context: Young female basketball players are at particular high risk of sustaining ACL injury. It is necessary to identify the characteristics of ACL injury in basketball to determine an effective prevention program. Objective: The purpose of this report is to identify the characteristics of ACL injury with and without contact in Japanese young female basketball players.
Design: Retrospective study (case control study).
Setting: Population-based.
Patients or Other Participants: High school and middle school female basketball players who underwent ACL reconstruction in our hospital over a period of May 2011 to August 2017. Fifty players answered our original questionnaires. Players were divided into 2 groups; Contact Injury (18 players, age = 15.4 ± 1.4 years, height = 162.4 ± 7.3 cm, mass = 53.7 ± 6.7 kg, 5.6 ± 2.2 years of experience) and Noncontact Injury (32 players, age = 15.4 ± 1.5 years, height = 161.1 ± 6.1 cm, mass = 55.8 ± 7.9 kg, 5.8 ± 2.2 years of experience).
Intervention(s): Our original questionnaires were used. Questionnaires were self-administered.
Main Outcome Measure(s): Rate of injury situation (offence or defense), injury mechanism (side cutting, taking off, stopping, or landing), and court location of players at the time of injury.
Results: In contact injury group, 13 players (78%) injured in offence and 5 players (22%) injured in defense. In offense situation, 8 players (62%) injured in the paint area, 2 players (15%) injured in the no-charge area, 2 players (15%) injured in the middle area, and 1 player (8%) injured in the 3-point area. In the paint area, 6 players (75%) injured when taking off, 1 player (17%) injured when stopping, and 1 player (17%) injured when side-cutting. In noncontact injury group, 24 players (75%) injured in offence and 8 players (25%) injured in defense. In offense situation, 9 players (38%) injured in the 3-point area, 8 players (33%) injured in the paint area, 4 (17%) players injured in the middle area, 2 players (8%) injured in the no-charge area, and 1 (4%) player injured in the center-circle. In the 3-point area, 4 players (44%) injured when stopping, 3 players (33%) injured when side-cutting, 1 player (11%) injured when taking off, and 1 player (11%) injured when landing.
Conclusions: In our study, most of contact and noncontact ACL injuries occurred in offensive play. This result is the same as the previous studies in which high school, collage, and professional female basketball players were investigated. In contact injury group, the highest risk situation was taking-off in the paint area, such as jump shot or lay-up. In noncontact injury group, the highest risk situation was stopping in the 3-point area.
Effects of Changes in Hip Extension Energy Absorption on Knee Valgus Motion and the Effect of Lower Extremity Alignments and Hip Motion During Double-Leg Landing
Context: Hip-focused neuromuscular exercises have shown to decrease patellofemporal pain (PFP). It is not known whether only increasing hip extensor activity decreases PFP risk during dynamic motion.
Objective: To elucidate whether changes in hip extensor energy absorption modulate knee valgus motion and the relationship of knee valgus motion with static lower extremity alignments (LEAs) and hip motion during double-leg landing.
Design: Crossover study.
Setting: Laboratory.
Patients or Other Participants: A total of 125 Japanese healthy volunteers (60 men, 65 women; age = 21 ± 2.9 years, height = 167.2 ± 5.4 cm, body mass = 62.6 ± 7.6 kg).
Intervention(s): Hip version, pelvic tilt, tibiofemoral angle, quadriceps angle, and navicular drop were measured for LEAs. Participants performed double-leg drop landing from a 30-cm high box onto force plates with 3 different landing styles, self-selected landing (SSL), body leaning forward to increase sagittal plane hip energy absorption (FL), and body in upright position to decrease sagittal plane hip energy absorption (UL). Three-dimensional kinetics and kinematics were recorded during all landings.
Main Outcome Measure(s): Sagittal plane total hip negative work, hip adduction and internal rotation excursion angles, and knee valgus excursion angle between the time points from the foot contact to the lowest body center of mass position were calculated. Three separate stepwise multiple regression analyses were conducted to predict knee valgus excursion angles with 6 static LEAs and frontal and transverse hip motion for each condition.
Results: Compared to that in SSL (−32.2 ± 24.2 J), total hip energy absorption in FL (−67.4 ± 30 J) and UL (−13.5 ± 7J, P < .01) was significantly different (P < .01); thus, subjects successfully modified their landing styles as required. Knee valgus excursion angles were significantly smaller in FL (−5.2 ± 7.2°) than in SSL (−7.5 ± 7°, P < .01), while no significant difference was found between UL (−8.4 ± 6.9°) and SSL (P > .05). Greater hip adduction and quadriceps angles and lesser hip internal rotation excursion angles were related to greater knee valgus excursion angles in SSL (R2 =−0.326, P < .01) and UL (R2 = 0.251, P < .05). However, greater hip adduction and tibiofemoral angles and smaller hip internal rotation excursion angles were related to greater knee valgus excursion angles in FL (R2 = 0.287, P < .05).
Conclusions: Our results indicated that increased energy absorption by the hip extensor muscles leads to decreased knee valgus motion with modification of the relationship between knee valgus motion and LEAs and hip motion, while no such changes were observed in UL compared with SSL. These results suggest that increasing hip extensor muscle activity during landing may improve dynamic knee malalignment by modulating the effect of LEAs and hip motion, possibly leading to PFP risk reduction.
Specific Risk Factors for Recurrent Ankle Sprains and an Initial Lateral Ankle Sprain in High School Basketball Players: Osaka Basketball Association Sport Injury Prevention Project
Context: Previous prospective cohort studies have identified potential risk factors that make an athlete more likely to sprain his or her ankle for the first time or suffer from recurrent ankle sprain (RAS). However, a limited prediction capability of lateral ankle sprain (LAS) still exists because of conflicting results among previous investigations, with similar outcome measures. Previous studies have assumed that the same factors increase a risk for all cases of LAS and included both athletes with and without a previous history of LAS to create the same prediction model for an initial LAS and RAS. Some of the current inconsistences among previous studies may be explained by the lack of utilization of more homogenous cohorts. No previous studies have explored a separate injury prediction model for an initial LAS and RAS.
Objective: Determine specific factors that increase a risk of RAS in high school basketball players with LAS history and initial LAS in those without LAS history.
Design: Prospective cohort study.
Setting: Athletic training facilities.
Patients or Other Participants: Three hundred fifty-eight basketball players with (510 feet) and without LAS history (206 feet) were recruited from high school that advanced to quarterfinals of the Osaka High School Basketball tournament in 2016 and 2017.
Intervention(s): Participants underwent baseline physical assessments in 2016 and 2017. A surveillance system was utilized to track initial LAS and RAS incidences over each season following the baseline evaluation.
Main Outcome Measure(s): Predictor variables assessed during the baseline evaluation consisted of body composition, triple hop distance, vertical jump height, static alignment of the lower extremity, Star Excursion Balance Test reach scores normalized as a percentage of leg length, peak force of the toe flexors, open-kinetic and closed-kinetic ankle dorsiflexion ROM, hip joint ROM (extension, hip flexion ROM, internal rotation, and external rotation), and hamstring flexibility assessed with the straight leg raise. A separate multiple logistic regression analysis was used to determine which measures predicted risk of RAS and initial LAS. Significance was set a priori at P < .05.
Results: There were 73 cases with lateral ankle sprain in 2016 and 2017 (Initial LAS: 20 cases, RAS: 53 cases). Statistically significant odds ratios for prediction of RAS were observed from logistic regression analyses for the hip internal rotation ROM (OR = 0.956, P = .033). Logistic regression analyses demonstrated no significant associations between any measures and an initial LAS.
Conclusions: Hip internal rotation ROM predicted risk of RAS in high school basketball players with LAS history. Data from this current study indicate that a specific measure of physical function may provide insight on identification of increased risk of RAS. This may lead to prevention strategies to target function at the hip joint in order to reduce the likelihood of sustaining RAS.
Effects of Contralateral Trunk Lean on Trunk and Shoulder Kinematics and Muscle Activities During Pitching
Context: Leaning the trunk toward the contralateral side to the throwing arm during baseball pitching has shown to affect shoulder loading and pitching injury risks. How such trunk lateral lean during pitching motion changes shoulder motions and muscle activities, possibly affecting shoulder loading, is unknown.
Objectives: To clarify the effects of increased contralateral trunk lean on trunk and shoulder kinematics and muscle activities during pitching motion.
Design: Crossover.
Setting: Laboratory.
Patients or Other Participants: Eight right-handed pitchers (height = 174.43 ± 6.04 cm, body mass = 70.67 ± 6.73 kg, age = 18.88 ± 0.79 years) participated in this study.
Intervention(s): Before the actual experiment, the pitching speed at which participants could lean their trunks by >30° from the vertical line contralaterally toward the throwing arm was predetermined for each participant. With the predetermined ball speed ±4 km/h, the participants threw a ball with trunk lateral lean (experimental condition [EC]) and a self-selected form (control condition [CC]) for 3 trials each. Three-dimensional trunk and shoulder kinematic and surface electromyography data from the pectoralis major, latissimus dorsi, serratus anterior, and trapezius muscle activities during pitching were obtained.
Main Outcome Measure(s): The maximum voluntary isometric contraction normalized root mean square values (%RMS) for each muscle from the cocking and acceleration phases were calculated. A paired sample t test was used to compare the mean values of the trunk and shoulder targeted kinematic variables and %RMSs for each muscle.
Results: No significant difference in ball speed (P = .27) and a significantly high positive correlation (R2 = 0.88, P < .01) were found between the conditions. The shoulder horizontal adduction angular velocity in the EC tended to be larger than that in the CC (EC vs CC: 233.0 ± 115.6°/s vs 165.7 ± 49.9°/s, P = .09). Compared with the CC, the EC exhibited significantly greater contralateral trunk lean angles at the maximum shoulder external rotation (37.7 ± 4.9° vs 27.2 ± 5.6°, P < .01) and maximum shoulder external rotation angles (75.1 ± 11.6° vs 61.0 ± 14.1°, P < .01). The %RMSs of the pectoralis major in the EC tended to be increased as compared with that in the CC at all analyzed periods (cocking phase: 158.9 ± 91.7% vs 102.8 ± 54.0%, P = .04; acceleration phase: 137.1 ± 62.5% vs 77.0 ± 34.6%, P = .02).
Conclusions: The results showed that pitching with leaning of the trunk toward the contralateral side to the throwing arm tended to increase the pectoralis major muscle activity throughout the pitching motion and the maximum shoulder external rotation angle when the ball speed was controlled. These results may indicate that pitching with an excessive trunk lateral lean may change the shoulder muscle activity to increase the anterior shear force to the humeral head, possibly increasing pitching injury risks.
Effects of 5-Minute Ice Application After Moderate Intensity Exercise on Muscle Strength, Power, Muscle Tone and Proprioception of Baseball Players
Context: Ice provides the muscle release and an analgesic effect. Most researches showed the negative effects on athletic performance after 20 minutes or more ice by means of water immersion or ice bag. Therefore, the effect of ice application on athletes' performance remains debated. For practical usage on the field, athletes may suffer a pain or discomfort during game, athletic trainer may immediately give an ice management; however, is it suitable to treat ice during exercise that may limit the exercise performance is rarely be investigated.
Objective: To investigate the changes of muscle strength, power, muscle tone and proprioception after treating short-term ice immediately after the moderate-intensity exercise.
Design: Pretest-posttest control group design.
Setting: Research laboratory.
Patients or Other Participants: A total of thirty male baseball players (age = 25.0 ± 5.0 years, body mass = 69.6 ± 32.4 kg) participated in the experiment. Participants were matched and randomly assigned into ice group or control group (no ice).
Intervention(s): All participants performed quadriceps' maximal strength and knee proprioception tests on isokinetic Biodex machine; counter movement jump (CMJ) for power assessment by My jump APP; muscle fatigue test (ie, muscel tone) by MyotonPRO before (baseline) and after icing. After baseline assessment, participants initiated a moderate intensity exercise at heart rate reserve 60%, which is simulation of a game situation. Subsequently, an ice bag was immediately applied on the dominant quadriceps muscle belly with elastic bandage fixation for 5 minutes. No ice treatment (just rest) for the control group.
Main Outcome Measure(s): The maximal muscle strength (peak torque, Nm), proprioception degree difference, muscle tone (stiffness, N/m), counter movement jump (cm).
Results: The baseline between two groups had no any significant difference. Compared to preintervention, maximal quadriceps strength, knee proprioception, counter movement jump height and muscle stiffness in the ice group had no significant difference, indicating no hampering effect. In contrast, the muscle stiffness significantly increased in control group except, indicating to produce muscle fatigue (P = .001) after moderate intensity exercise. Compared to control group, all variables showed no any significant difference, indicating that the short-term icing did not limit the exercise performance.
Conclusions: Baseball players receive a short-term ice application during moderate intensity exercise had no hampering effects on athletic performance.
The Effects of Exposure to Cold Temperatures During Warm-Ups on Muscle Temperature and Jump Performance
Context: Warm-up routines prior to competitions or exercise are practiced to prevent injuries and enhance subsequent performance. It is widely accepted that increasing muscle temperature by warming up improves muscular function and dynamic performance, especially fast velocity movement. Physical activities are impaired when humans are exposed to cold environments, so warming up is important in such environments. However, the effects of exposure to cold environments during warm-up routines on muscle temperature and performance are not well understood.
Objective: The purpose of this research was to compare the effects of warming-up on muscle temperature and jump performance in cold and warm environments.
Design: A randomized cross-over design was conducted.
Setting: Research laboratory.
Patient or Other Participants: Fifteen male university student volunteers (age = 21.3 ± 1.1 years, height = 175.8 ± 4.9 cm, mass = 71.1 ± 5.3 kg, maximal oxygen consumption (VO2max) = 51.6 ± 1.1 ml/min/kg).
Intervention(s): The room temperature was set at 10°C (cold) or 24°C (warm) and the participants was put in either condition for 30 minutes. For the warm-up, the participant was instructed to ride a stationary bike at 60%VO2max for 15 minutes.
Main Outcome Measure(s): Temperature of vastus laterallis muscle was measured with a deep tissue thermometer. Counter-movement jump (CMJ) height was assessed using a force plate. Muscle temperature and CMJ were measured immediately before and after warm-up. Muscle temperature and CMJ height were analyzed using 2-way repeated ANOVA. When any significant effects were found, post hoc (Bonferroni) tests were conducted. The significance level was set at P < .05.
Results: For muscle temperature and CMJ height, 2-way repeated ANOVA revealed significant main effects of condition and time (both P < .001). There were no 2-way interactions for muscle temperature and CMJ height (P = .130, .257, respectively). In the warm condition, muscle temperature had significantly changed after warm-up (before: 34.8 ± 0.7°C; after: 37.2 ± 0.4°C, P < .001). In the cold condition, muscle temperature had also significantly changed after warm-up (before: 33.8 ± 0.6°C; after: 36.5 ± 0.7°C, P < .001). In the warm condition, CMJ height was significantly different after the warm-up (before: 35.0 ± 4.4 cm; after: 39.7 ± 4.7 cm, P < .001). In the cold condition, there was a significant increase in CMJ height after the warm-up (before: 33.4 ± 3.9 cm; after: 37.5 ± 4.7 cm, P < .001). Muscle temperature and CMJ height after warm-up were significantly lower in the cold condition than in the warm condition (P < .01).
Conclusions: In both warm and cold conditions, warming up was effective in increasing muscle temperature and enhancing jump performance. However, the muscle temperature and jump height after warm-up were lower in cold conditions than in warm conditions. Further studies of warm-up intensity for cold conditions are needed.
Sustained Effects of a Self-Mobilization Exercise Program on Dynamic Postural Stability
Context: Balance control requires central processing of multi-sensory feedback and motor commands responsible for force production. A self-mobilization exercise program was designed to realign spinal curvature, and changes in dynamic postural stability immediately after the intervention was previously documented. However, it is unknown to what extent repeated interventions and cessation of the exercise program influence on skeletal alignment and postural stability in standing.
Objective: To examine skeletal alignment and postural stability in standing after a 1-week intervention and subsequent cessation of the exercise program.
Design: Randomized controlled trial.
Setting: Laboratory.
Patients or Other Participants: Twenty healthy adults were randomly assigned into one of two groups: exercise on a cylinder-shaped tube (Ex-T group, n = 10, female = 7, age = 21.6 ± 2.1 years, height = 1.69 ± 0.11 m, mass = 64.4 ± 10.2 kg), and a control group that rested on a flat surface (n = 10, female = 5, age = 21.6 ± 2.1 years, height = 1.69 ± 0.11 m, mass = 64.4 ± 10.2 kg).
Intervention(s): The exercise program consisted of three preparatory positions and seven small motions, and each session lasted approximately 15 min. Center of gravity (CoG) sway and posture was measured on (a) Day 0: baseline, (b) Day 1: immediately after either the intervention (Ex-T) or laying on a flat surface (Control), (c) Day 7: after 1-week exercise intervention, and (d) Day 14: after 1 week of no intervention. CoG sway was measured while standing on both static and dynamic platforms (Biodex Balance System SD) with the eyes closed. Standing posture was quantified using lateral-view photography.
Main Outcome Measure(s): The dependent variables were head and shoulder angles and sway indexes. Mixed-design ANOVAs were used to examine (1) average sway indexes and group differences, and (2) average postural angles and group differences.
Results: Head and shoulder angles of the Ex-T group on Day 1 and Day 7 (53.02 ± 1.87° and 54.35 ± 1.84°, respectively: P < .001), but not on Day 14 (51.56 ± 1.72°) were significantly different from the baseline (50.82 ± 1.77°), but there were no significant differences in the Control group. During the dynamic platform condition, sway indexes on Day 1 (4.26 ± 0.35), Day 7 (4.20 ± 0.33), and Day 14 (4.28 ± 0.37) significantly decreased from baseline (4.88 ± 0.27) in the Ex-T group (P < .01 for all comparisons), but not in the Control group. There were no significant changes in sway indexes during the static platform condition for both groups.
Conclusions: The 1-week exercise intervention altered the head and shoulder angle and improved dynamic, but not static postural stability. After 1-week cessation of the intervention, the improvement of dynamic postural stability only persisted. These may indicate that the exercise program enhances processing of sensory feedback and motor commands for dynamic postural stability, which sustains without postural changes after one week of no intervention.
Effects of Thoracic Mobility on Shoulder Range of Motion
Context: Some studies have indicated that neck and shoulder discomfort may be related with the thoracic mobility. Sports medicine clinicians advocated that proper thoracic mobility is needed for prevention of neck and shoulder discomfort.
Objective: The purpose of the study was to investigate the effects of a single thoracic mobility exercise intervention on shoulder ROM.
Design: This is a cross sectional design to identify the effect of warm up and intervention.
Setting: All test and intervention were done in the university sports science research lab.
Patients or Other Participants: Eleven healthy and leisurely active subjects, without shoulder injuries and ankylosing spondylitis, and aged 19–22 were recruited. Informed consent forms were signed by all participants.
Intervention(s): All subjects received a single session of the Open Book Exercise after a standard warm up session. Four measurements were taken: (1) after warm up, (2) after the Open Book exercise, (3) before warm up on second day, and (4) after warm up. A goniometer was used for the measurement of the shoulder ROM and the Myoton (Myoton-3) was used to assess muscle tension around the shoulder. A repeated measure ANOVA was used for data analysis α < .05 SPSS 20.0
Main Outcome Measure(s): The overall shoulder ROM in second, third, and fourth measurements were significantly (P < .05) greater than the measurement before the intervention of the Open Book exercise. No significant difference was found among the second, third, and fourth measurements. No significant difference was found in muscle tension in all measurements.
Results: Thoracic mobility intervention can improve the shoulder overall ROM and the effects may last overnight. The induced exercise did not change the muscle tension around the shoulder.
Conclusions: Shoulder overall ROMs can be improved by the introduction of a thoracic mobility exercise and may have some remaining effect after one night. However, the mechanism of the shoulder ROM improvement by the exercise is yet to be determined. It is therefore suggested by the authors that further investigation of the relationship between the shoulder and thoracic mobility.
Effects of the GAA15 Injury Prevention Warm-Up in the Gaelic Sport Camogie
Context: Camogie is a native Irish sport played exclusively by females. It is played using a stick and small leather ball and resembles sports such as lacrosse and field hockey. An injury prevention program was developed specifically for Gaelic games (GAA15), based on warmups such as the 11+. Injury prevention programs lasting 4–8 weeks have previously demonstrated improvements in neuromuscular and biomechanical function. Furthermore, season long adoption of the GAA15 showed a significant reduction in injuries in male and female players. However, its effect in camogie players solely has not been examined.
Objective: To examine the effect of a 6-week warmup (GAA15) on neuromuscular control, lower body strength, landing and squatting techniques in collegiate camogie players.
Design: Pre-post design.
Setting: Athletic therapy room.
Patients or Other Participants: Convenience sample of 20 female collegiate camogie players (age = 19.0 ± 1.3 years, height = 167.7 ± 6.4 cm, mass = 64.4 ± 6.1 kg).
Intervention(s): The GAA15 consists of three sections: running (Section 1), strength/balance/jumping exercises (Section 2) and sports-specific movements (Section 3). It was implemented prior to training (Sections 1, 2, and 3) and matches (Sections 1 and 3) twice a week for 6 weeks. Two of the investigators delivered all sessions.
Main Outcome Measure(s): Participants were tested preintervention and postintervention on a Y-balance test (YBT), isometric hamstring and adductor strength using a handheld dynamometer, the Landing Error Scoring System (LESS), overhead squats and single-leg squats (SLS). Three trials of each were performed. Mean composite and normalized YBT scores, mean dynamometry measures and the best LESS, overhead squats and SLS scores were assessed for normality and analyzed for preintervention and postintervention differences using paired t tests or Wilcoxon signed-rank tests. Significance level was set to P < .05.
Results: No significant difference was found for the LESS (mean =6.8 ± 1.4 vs 6.3 ± 1.4), overhead squat (mean = 5.9 ± 1.8 vs 5.7 ± 1.9), adductor strength (dominant side [DS]) median = 84.5 ± 18.5 vs 82.3 ± 27.1; nondominant side (NDS) median = 83.0 ± 25.6 vs 72.7 ± 22.3), composite YBT (DS mean = 97.8 ± 4.0 vs 97.8 ± 4.3; NDS mean = 97.0 ± 3.6 vs 96.3 ± 3.7), posteromedial (DS mean = 113.7 ± 5.8 vs 114.1 ± 6.9; NDS mean = 113.2 ± 4.6 vs 112.8 ± 4.2) and posterolateral (DS mean = 109.7 ± 4.7 vs 109.9 ± 5.3; NDS mean = 108.0 ± 6.5 vs 108.2 ± 5.6) YBT scores bilaterally or for DS anterior YBT score (mean = 69.9 ± 6.4 vs 69.6 ± 5.8) or hamstring strength (mean = 101.9 ± 16.8 vs 97.7 ± 18.9; P > .05). Anterior NDS YBT score significantly decreased (mean = 69.8 ± 4.6 vs 68.0 ± 5.8, P = .02, d = 0.59), however it was not clinically significant (decrease of 2.6%). NDS hamstrings strength decreased significantly (mean = 102.9 ± 17.4 vs 96.5 ± 17.8; P = .01, d = 0.61); however, the standard deviation was larger than pre-post differences. Significant differences in SLS scores on the dominant (median = 6 ± 1 vs 6 ± 1, P = .01, d = 0.56) and nondominant (median = 6 ± 1v 6 ± 1, P = .04, d = 0.46) sides were found, although these were not clinically significant.
Conclusions: Six weeks of the GAA15 warm-up is not sufficient to improve neuromuscular and biomechanical risk factors for injury in collegiate camogie players, suggesting that adoption during the preseason only is not sufficient to impact injury risk.
Contributor Notes
Disclaimer: The abstracts on these pages were prepared by the authors. The accuracy, nomenclature, form, and style of all printed abstracts here remain the responsibility of the authors. All of the abstracts published here were reviewed by at least 1 reviewer in single-blinded format to preserve the scientific quality of the submitted abstracts.