Context:

Resistance exercise training commonly is performed against a constant external load (isotonic) or at a constant velocity (isokinetic). Researchers comparing the effectiveness of isotonic and isokinetic resistance-training protocols need to equalize the mechanical stimulus (work and velocity) applied.

Objective:

To examine whether the standardization protocol could be adjusted and applied to an eccentric training program.

Design:

Controlled laboratory study.

Setting:

Controlled research laboratory.

Patients or Other Participants:

Twenty-one sport science male students (age = 20.6 ± 1.5 years, height = 178.0 ± 4.0 cm, mass = 74.5 ± 9.1 kg).

Intervention(s):

Participants performed 9 weeks of isotonic (n = 11) or isokinetic (n = 10) eccentric training of knee extensors that was designed so they would perform the same amount of angular work at the same mean angular velocity.

Main Outcome Measure(s):

Angular work and angular velocity.

Results:

The isotonic and isokinetic groups performed the same total amount of work (−185.2 ± 6.5 kJ and −184.4 ± 8.6 kJ, respectively) at the same angular velocity (21 ± 1°/s and 22°/s, respectively) with the same number of repetitions (8.0 and 8.0, respectively). Bland-Altman analysis showed that work (bias = 2.4%) and angular velocity (bias = 0.2%) were equalized over 9 weeks between the modes of training.

Conclusions:

The procedure developed allows angular work and velocity to be standardized over 9 weeks of isotonic and isokinetic eccentric training of the knee extensors. This method could be useful in future studies in which researchers compare neuromuscular adaptations induced by each type of training mode with respect to rehabilitating patients after musculoskeletal injury.

Context:

Most protocols established to treat patients with functional ankle instability (FAI) have focused on taping the ankle. Orthotic intervention is a different treatment protocol that may have a positive effect on these patients, especially after an accommodation period.

Objective:

To determine whether the use of a prefabricated orthotic affects postural stability in patients with FAI and a control group.

Design:

Randomized controlled clinical trial.

Setting:

Research laboratory.

Patients or Other Participants:

Forty patients with unilateral FAI.

Intervention(s):

Postural stability was measured on both limbs using a force plate on 3 occasions. Participants were instructed to balance on 1 limb with their eyes closed for 20 seconds. In session 1, postural stability was measured with the patient wearing his or her own athletic shoes. The control group repeated this procedure in sessions 2 and 3. When those in the orthotic group returned for session 2, they received prefabricated, full-length Quick Comfort Insoles for both feet, immediately placed the orthotics in their shoes, and were tested for postural stability. Patients in the orthotic group were instructed to wear the inserts daily and return 2 weeks later for session 3 and repeat postural stability testing.

Main Outcome Measure(s):

Center of pressure.

Results:

In the orthotic group, postural stability improved between sessions 1 and 2 and sessions 1 and 3. In session 3, postural stability was different for the orthotic and control groups. We also identified a difference between the limbs such that the FAI ankle displayed worse postural stability than did the healthy ankle.

Conclusions:

Prefabricated orthotics improved postural stability in participants with FAI. Similar to the findings of previous researchers, we found that postural stability was worse in FAI ankles than in healthy ankles.

Context:

Differences in various outcome measures have been identified between people who have sprained their ankles but have no residual symptoms (copers) and people with chronic ankle instability (CAI). However, the diagnostic utility of the reported outcome measures has rarely been determined. Identifying outcome measures capable of predicting who is less likely to develop CAI could improve rehabilitation protocols and increase the efficiency of these measures.

Objective:

To determine the diagnostic utility and cutoff scores of perceptual, mechanical, and sensorimotor outcome measures between copers and people with CAI by using receiver operating characteristic curves.

Design:

Case-control study.

Setting:

Sports medicine research laboratory.

Patients or Other Participants:

Twenty-four copers (12 men, 12 women; age = 20.8 ± 1.5 years, height = 173 ± 11 cm, mass = 78 ± 27 kg) and 24 people with CAI (12 men, 12 women; age = 21.7 ± 2.8 years, height = 175 ± 13 cm, mass = 71 ± 13 kg) participated.

Intervention(s):

Self-reported disability questionnaires, radiographic images, and a single-legged hop stabilization test.

Main Outcome Measure(s):

Perceptual outcomes included scores on the Foot and Ankle Disability Index (FADI), FADI-Sport, and a self-report questionnaire of ankle function. Mechanically, talar position was quantified by measuring the distance from the anterior tibia to the anterior talus in the sagittal plane. Sensorimotor outcomes were the dynamic postural stability index and directional indices, which were calculated during a single-legged hop stabilization task.

Results:

Perceptual outcomes demonstrated diagnostic accuracy (range, 0.79–0.91), with 95% confidence intervals ranging from 0.65 to 1.00. Sensorimotor outcomes also were able to discriminate between copers and people with CAI but with less accuracy (range, 0.69–0.70), with 95% confidence intervals ranging from 0.37 to 0.86. The mechanical outcome demonstrated poor diagnostic accuracy (0.52).

Conclusions:

The greatest diagnostic utility scores were achieved by the self-assessed disability questionnaires, which indicated that perceptual outcomes had the greatest ability to accurately predict people who became copers after their initial injuries. However, the diversity of outcome measures that discriminated between copers and people with CAI indicated that the causal mechanism of CAI is probably multifactorial.

Context:

Hormonal fluctuation as a risk factor in anterior cruciate ligament injury has been investigated with conflicting results. However, the influence of hormone fluctuations on ankle laxity and function has not been thoroughly examined.

Objective:

To examine the potential hormone contributions to ankle laxity and dynamic postural control during the preovulatory and postovulatory phases of the menstrual cycle using an ankle arthrometer and the Star Excursion Balance Test in healthy women. The cohort group consisted of male control participants.

Design:

Cohort study.

Setting:

Research laboratory.

Patients or Other Participants:

Twenty healthy women (age = 23.8 ± 6.50 years, height = 163.88 ± 8.28 cm, mass = 63.08 ± 12.38 kg) and 20 healthy men (age = 23.90 ± 4.15 years, height = 177.07 ± 7.60 cm, mass = 80.57 ± 12.20 kg).

Intervention(s):

Ankle stability was assessed with anterior-posterior and inversion-eversion loading. Dynamic postural control was assessed with the posteromedial reaching distance of the Star Excursion Balance Test.

Main Outcome Measure(s):

Female participants used ovulation kits for 3 months to determine the time of ovulation; during their preovulatory and postovulatory phases, they were tested in the laboratory with an ankle arthrometer and the Star Excursion Balance Test. Male participants were tested on similar dates as controls. For each dependent variable, a time by side by sex repeated-measures analysis of variance was performed. Statistical significance was set a priori at P < .05.

Results:

For anterior-posterior laxity, a side main effect was noted (F_1,38 = 10.93, P = .002). For inversion-eversion laxity, a sex main effect was seen (F_1,38 = 10.75, P = .002). For the posteromedial reaching task, a sex main effect was demonstrated (F_1,38 = 8.72, P = .005). No influences of time on the dependent variables were evident.

Conclusions:

Although women presented with more ankle inversion-eversion laxity and less dynamic postural control, hormonal fluctuations during the menstrual cycle (preovulatory compared with postovulatory) did not affect ankle laxity or dynamic postural control, 2 factors that are associated with ankle instability.

Context:

The prevalence of shoulder pain among competitive swimmers is high, but no guidelines exist to reduce shoulder injuries. Elucidating differences between swimmers with and without shoulder pain can serve as a basis for the development of a program to prevent shoulder injury that might lead to pain and dysfunction.

Objective:

To determine whether physical characteristics, exposure, or training variables differ between swimmers with and without shoulder pain or disability.

Design:

Cross-sectional study.

Setting:

Multisite swimming centers.

Patients or Other Participants:

A total of 236 competitive female swimmers aged 8 to 77 years.

Data Collection and Analysis:

Participants completed the Penn Shoulder Score and underwent testing of core endurance, range of motion, muscle force production, and pectoralis minor muscle length and the Scapular Dyskinesis Test. Swimmers were grouped by age for analysis: ages 8 to 11 years (n = 42), 12 to 14 years (n = 43), 15 to 19 years (high school, n = 84), and 23 to 77 years (masters, n = 67). Comparisons were made between groups with and without pain and disability using independent t tests for continuous data and χ² analyses and Fisher exact tests for categorical data.

Results:

Nine (21.4%) swimmers aged 8 to 11 years, 8 (18.6%) swimmers aged 12 to 14 years, 19 (22.6%) high school swimmers, and 13 (19.4%) masters swimmers had shoulder pain and disability. Differences that were found in 2 or more age groups between athletes with and without shoulder pain and disability included greater swimming exposure, a higher incidence of previous traumatic injury and patient-rated shoulder instability, and reduced participation in another sport in the symptomatic groups (P < .05). Reduced shoulder flexion motion, weakness of the middle trapezius and internal rotation, shorter pectoralis minor and latissimus, participation in water polo, and decreased core endurance were found in symptomatic females in single varying age groups (P < .05).

Conclusions:

Female competitive swimmers have shoulder pain and disability throughout their lives. Given that exposure and physical examination findings varied between athletes with and without substantial pain and disability, a program to prevent shoulder injury that might lead to pain and dysfunction appears warranted and might include exposure reduction, cross-training, pectoral and posterior shoulder stretching, strengthening, and core endurance training.

Context:

A single measure of knee laxity (ie, measurement of laxity in a single plane of motion) is probably inadequate to fully describe how knee joint laxity is associated with anterior cruciate ligament injury.

Objective:

To characterize interparticipant differences in the absolute and relative magnitudes of multiplanar knee laxity (ie, sagittal, frontal, and transverse planes) and examine physical characteristics that may contribute to these differences.

Design:

Descriptive laboratory study.

Setting:

University research laboratory.

Patients or Other Participants:

140 participants (90 women, 50 men).

Main Outcome Measure(s):

Using cluster analysis, we grouped participants into distinct multiplanar knee laxity profiles based on the absolute and relative magnitudes of their anterior knee laxity (AKL), genu recurvatum (GR), and varusvalgus (VV) and internal-external rotation (IER) knee laxity. Using multinomial logistic regression, we then examined associations between the different laxity profile clusters and physical characteristics of sex, age, activity level, general joint laxity, body mass index, thigh strength, and 8 measures of lower extremity anatomical alignment.

Results:

Six clusters were identified: low (LOW), moderate (MOD) and high (HIGH) laxity overall and disproportionally higher VV/IER (MOD_VV/IER), GR (HIGH_GR), and AKL (HIGH_AKL) laxity. Once all other physical characteristics were accounted for, the LOW cluster was more likely to be older, with longer femur length. Clusters with greater magnitudes of VV and IER laxity were more likely to be younger and to have lower body mass index, smaller Q-angle, and shorter femur length (MOD, HIGH, MOD_VV/IER) and less thigh strength (HIGH). The HIGH_GR cluster was more likely to be female and to have a smaller tibiofemoral angle and longer femur length. The HIGH_AKL cluster was more likely to have greater hip anteversion and navicular drop.

Conclusions:

The absolute and relative magnitudes of a person's multiplanar knee laxity are not always uniform across planes of motion and can be influenced by age, body composition, thigh strength, and structural alignment. Except in HIGH_GR, sex was not a significant predictor of cluster membership once other physical characteristics were taken into account.

Context:

Researchers have observed slower cooling rates in thigh muscle with greater overlying adipose tissue, suggesting that cryotherapy duration should be based on the adipose thickness of the treatment site. Skinfold data do not exist for other common cryotherapy sites, and no one has reported how those skinfolds might vary because of physical activity level or sex.

Objective:

To determine the variability in skinfold thickness among common cryotherapy sites relative to sex and activity level (National Collegiate Athletic Association Division I athletes, recreationally active college athletes).

Design:

Descriptive laboratory study.

Setting:

Field.

Patients or Other Participants:

Three hundred eighty-nine college students participated; 196 Division I athletes (157 men, 39 women) were recruited during preseason physicals, and 193 recreationally active college athletes (108 men, 85 women) were recruited from physical education classes.

Intervention(s):

Three skinfold measurements to within 1 mm were taken at 8 sites (inferior angle of the scapula, middle deltoid, ulnar groove, midforearm, midthigh, medial collateral ligament, midcalf, and anterior talofibular ligament [ATF]) using Lange skinfold calipers.

Main Outcome Measure(s):

Skinfold thickness in millimeters.

Results:

We noted interactions among sex, activity level, and skinfold site. Male athletes had smaller skinfold measurements than female athletes at all sites except the ATF, scapula, and ulnar groove (F_7,2702 = 69.85, P < .001). Skinfold measurements were greater for recreationally active athletes than their Division I counterparts at all sites except the ATF, deltoid, and ulnar groove (F_7,2702 = 30.79, P < .001). Thigh skinfold measurements of recreationally active female athletes were the largest, and their ATF skinfolds were the smallest.

Conclusions:

Skinfold thickness at common cryotherapy treatment sites varied based on level of physical activity and sex. Therefore, clinicians should measure skinfold thickness to determine an appropriate cryotherapy duration.

Context:

Laser therapy is purported to improve blood flow in soft tissues. Modulating circulation would promote healing by controlling postinjury ischemia, hypoxia, edema, and secondary tissue damage. However, no studies have quantified these responses to laser therapy.

Objective:

To determine a therapeutic dose range for laser therapy for increasing blood flow to the forearm.

Design:

Crossover study.

Setting:

Controlled laboratory setting.

Patients or Other Participants:

Ten healthy, college-aged men (age = 20.80 ± 2.16 years, height = 177.93 ± 3.38 cm, weight = 73.64 ± 9.10 kg) with no current history of injury to the upper extremity or cardiovascular conditions.

Intervention(s):

A class 4 laser device was used to treat the biceps brachii muscle. Each grid point was treated for 3 to 4 seconds, for a total of 4 minutes. Each participant received 4 doses of laser therapy: sham, 1 W, 3 W, and 6 W.

Main Outcome Measure(s):

The dependent variables were changes in blood flow, measured using venous occlusion plethysmography. We used a repeated-measures analysis of variance to analyze changes in blood flow for each dose at 2, 3, and 4 minutes and at 1, 2, 3, 4, and 5 minutes after treatment. The Huynh-Feldt test was conducted to examine differences over time.

Results:

Compared with baseline, blood flow increased over time with the 3-W treatment (F_3,9 = 3.468, P < .011) at minute 4 of treatment (2.417 ± 0.342 versus 2.794 ± 0.351 mL/min per 100 mL tissue, P = .032), and at 1 minute (2.767 ± 0.358 mL/min per 100 mL tissue, P < .01) and 2 minutes (2.657 ± 0.369 mL/min per 100 mL tissue, P = .022) after treatment. The sham, 1-W, and 6-W treatment doses did not change blood flow from baseline at any time point.

Conclusions:

Laser therapy at the 3-W (360-J) dose level was an effective treatment modality to increase blood flow in the soft tissues.

Context:

Conditions such as osteoarthritis, obesity, and spinal cord injury limit the ability of patients to exercise, preventing them from experiencing many well-documented physiologic stressors. Recent evidence indicates that some of these stressors might derive from exercise-induced body temperature increases.

Objective:

To determine whether whole-body heat stress without exercise triggers cardiovascular, hormonal, and extra-cellular protein responses of exercise.

Design:

Randomized controlled trial.

Setting:

University research laboratory.

Patients or Other Participants:

Twenty-five young, healthy adults (13 men, 12 women; age = 22.1 ± 2.4 years, height = 175.2 ± 11.6 cm, mass = 69.4 ± 14.8 kg, body mass index = 22.6 ± 4.0) volunteered.

Intervention(s):

Participants sat in a heat stress chamber with heat (73°C) and without heat (26°C) stress for 30 minutes on separate days. We obtained blood samples from a subset of 13 participants (7 men, 6 women) before and after exposure to heat stress.

Main Outcome Measure(s):

Extracellular heat shock protein (HSP72) and catecholamine plasma concentration, heart rate, blood pressure, and heat perception.

Results:

After 30 minutes of heat stress, body temperature measured via rectal sensor increased by 0.8°C. Heart rate increased linearly to 131.4 ± 22.4 beats per minute (F_6,24 = 186, P < .001) and systolic and diastolic blood pressure decreased by 16 mm Hg (F_6,24 = 10.1, P < .001) and 5 mm Hg (F_6,24 = 5.4, P < .001), respectively. Norepinephrine (F_1,12 = 12.1, P = .004) and prolactin (F_1,12 = 30.2, P < .001) increased in the plasma (58% and 285%, respectively) (P < .05). The HSP72 (F_1,12 = 44.7, P < .001) level increased with heat stress by 48.7% ± 53.9%. No cardiovascular or blood variables showed changes during the control trials (quiet sitting in the heat chamber with no heat stress), resulting in differences between heat and control trials.

Conclusions:

We found that whole-body heat stress triggers some of the physiologic responses observed with exercise. Future studies are necessary to investigate whether carefully prescribed heat stress constitutes a method to augment or supplement exercise.

Context:

Epidemiologic information on the incidence of youth soccer injuries in southern Europe is limited.

Objective:

To compare the incidence, type, location, and severity of injuries sustained by male subelite youth soccer players over the 2008–2009 season.

Design:

Descriptive epidemiology study.

Setting:

Twenty-eight Portuguese male youth soccer teams.

Patients or Other Participants:

A total of 674 youth male subelite soccer players in 4 age groups: 179 U-13 (age range, 11–12 years), 169 U-15 (age range, 13–14 years), 165 U-17 (age range, 15–16 years), and 161 U-19 (age range, 17–18 years).

Main Outcome Measure(s):

Injuries that led to participation time missed from training and match play prospectively reported by medical or coaching staff of the clubs.

Results:

In total, 199 injuries reported in 191 players accounted for 14.6 ± 13.0 days of absence from practice. The incidence was 1.2 injuries per 1000 hours of exposure to soccer (95% confidence interval [CI] = 0.8, 1.6), with a 4.2-fold higher incidence during match play (4.7 injuries per 1000 hours of exposure; 95% CI = 3.0, 6.5) than during training (0.9 injuries per 1000 hours of exposure; 95% CI = 0.6, 1.3) (F_1,673 = 17.592, P < .001). The overall incidence of injury did not increase with age (F_1,673 = 1.299, P = .30), and the incidence of injury during matches (F_1,673 = 2.037, P = .14) and training (F_1,673 = 0.927, P = .44) did not differ among age groups. Collisions accounted for 57% (n = 113) of all injuries, but participation time missed due to traumatic injury did not differ among age groups (F_3,110 = 1.044, P = .38). Most injuries (86%, n = 172) involved the lower extremity. The thigh was the most affected region (30%, n = 60) in all age groups. Muscle strains were the most common injuries among the U-19 (34%, n = 26), U-17 (30%, n = 17), and U-15 (34%, n = 14) age groups, whereas contusions and tendon injuries were the most common injuries in U-13 players (both 32%, n = 8). The relative risk of injury slightly increased with the age of the competitors.

Conclusions:

The higher incidence of injury during matches than training highlights the need for education and prevention programs in youth soccer. These programs should focus on coach education aimed at improving skills, techniques, and fair play during competitions with the goal of reducing injuries.

Context:

Although overuse injuries are gaining attention, epidemiologic studies on overuse injuries in male and female collegiate athletes are lacking.

Objective:

To report the epidemiology of overuse injuries sustained by collegiate athletes and to compare the rates of overuse and acute injuries.

Design:

Descriptive epidemiology study.

Setting:

A National Collegiate Athletic Association Division I university.

Patients or Other Participants:

A total of 1317 reported injuries sustained by 573 male and female athletes in 16 collegiate sports teams during the 2005–2008 seasons.

Main Outcome Measure(s):

The injury and athlete-exposure (AE) data were obtained from the Sports Injury Monitoring System. An injury was coded as either overuse or acute based on the nature of injury. Injury rate was calculated as the total number of overuse (or acute) injuries during the study period divided by the total number of AEs during the same period.

Results:

A total of 386 (29.3%) overuse injuries and 931 63.1 per 10000 AEs. The rate ratio (RR) of acute versus overuse injuries was 2.34 (95% confidence interval [CI] = 2.05, 2.67). Football had the highest RR (RR = 8.35, 95% CI = 5.38, 12.97), and women's rowing had the lowest (RR = 0.75, 95% CI = 0.51, 1.10). Men had a higher acute injury rate than women (49.8 versus 38.6 per 10000 AEs). Female athletes had a higher rate of overuse injury than male athletes (24.6 versus 13.2 per 10000 AEs). More than half of the overuse injuries (50.8%) resulted in no time loss from sport.

Conclusions:

Additional studies are needed to examine why female athletes are at greater risk for overuse injuries and identify the best practices for prevention and rehabilitation of overuse injuries.

Context:

Coaches, athletic trainers (ATs), strength and conditioning specialists (SCSs), and registered dietitians are common nutrition resources for athletes, but coaches, ATs, and SCSs might offer only limited nutrition information. Little research exists about sports nutrition knowledge and current available resources for nutrition information for athletes, coaches, ATs, and SCSs.

Objective:

To identify resources of nutrition information that athletes, coaches, ATs, and SCSs use; to examine nutrition knowledge among athletes, coaches, ATs, and SCSs; and to determine confidence levels in the correctness of nutrition knowledge questions within all groups.

Design:

Cross-sectional study.

Setting:

National Collegiate Athletic Association Division I, II, and III institutions across the United States.

Patients and Other Participants:

The 579 participants consisted of athletes (n = 185), coaches (n = 131), ATs (n = 192), and SCSs (n = 71).

Main Outcome Measure(s):

Participants answered questions about nutrition resources and domains regarding basic nutrition, supplements and performance, weight management, and hydration. Adequate sports nutrition knowledge was defined as an overall score of 75% in all domains (highest achievable score was 100%).

Results:

Participants averaged 68.5% in all domains. The ATs (77.8%) and SCSs (81.6%) had the highest average scores. Adequate knowledge was found in 35.9% of coaches, 71.4% of ATs, 83.1% of SCSs, and only 9% of athletes. The most used nutrition resources for coaches, ATs, and SCSs were registered dietitians.

Conclusions:

Overall, we demonstrated that ATs and SCSs have adequate sports nutrition knowledge, whereas most coaches and athletes have inadequate knowledge. Athletes have frequent contact with ATs and SCSs; therefore, proper nutrition education among these staff members is critical. We suggest that proper nutrition programming should be provided for athletes, coaches, ATs, and SCSs. However, a separate nutrition program should be integrated for ATs and SCSs. This integrative approach is beneficial for the continuity of care, as both categories of professionals might be developing and integrating preventive or rehabilitative programs for athletes.

Context:

Peer-assisted learning (PAL) has been recommended as an educational strategy to improve students' skill acquisition and supplement the role of the clinical instructor (CI). How frequently students actually engage in PAL in different settings is unknown.

Objective:

To determine the perceived frequency of planned and unplanned PAL (peer modeling, peer feedback and assessment, peer mentoring) in different settings.

Design:

Cross-sectional study.

Setting:

Laboratory and collegiate clinical settings.

Patients or Other Participants:

A total of 933 students, 84 administrators, and 208 CIs representing 52 (15%) accredited athletic training education programs.

Intervention(s):

Three versions (student, CI, administrator) of the Athletic Training Peer Assisted Learning Survey (AT-PALS) were administered. Cronbach α values ranged from .80 to .90.

Main Outcome Measure(s):

Administrators' and CIs' perceived frequency of 3 PAL categories under 2 conditions (planned, unplanned) and in 2 settings (instructional laboratory, collegiate clinical). Self-reported frequency of students' engagement in 3 categories of PAL in 2 settings.

Results:

Administrators and CIs perceived that unplanned PAL (0.39 ± 0.22) occurred more frequently than planned PAL (0.29 ± 0.19) regardless of category or setting (F_1,282 = 83.48, P < .001). They perceived that PAL occurred more frequently in the collegiate clinical (0.46 ± 0.22) than laboratory (0.21 ± 0.24) setting regardless of condition or category (F_1,282 = 217.17, P < .001). Students reported engaging in PAL more frequently in the collegiate clinical (3.31 ± 0.56) than laboratory (3.26 ± 0.62) setting regardless of category (F_1,860 = 13.40, P < .001). We found a main effect for category (F_2,859 = 1318.02, P < .001), with students reporting they engaged in peer modeling (4.01 ± 0.60) more frequently than peer mentoring (2.99 ± 0.88) (P < .001) and peer assessment and feedback (2.86 ± 0.64) (P < .001).

Conclusions:

Participants perceived that students engage in unplanned PAL in the collegiate clinical setting with a stronger inclination toward engagement in peer modeling. Educators should develop planned PAL activities to capitalize on the inherent desire of the students to collaborate with their peers.

Reference/Citation:

Alla S, Sullivan SJ, Hale L, McCrory P. Self-report scales/checklists for the measurement of concussion symptoms: a systematic review. Br J Sports Med. 2009;43 (suppl 1):i3–i12.

Clinical Question:

Which self-report symptom scales or checklists are psychometrically sound for clinical use to assess sport-related concussion?

Data Sources:

Articles available in full text, published from the establishment of each database through December 2008, were identified from PubMed, Medline, CINAHL, Scopus, Web of Science, SPORTDiscus, PsycINFO, and AMED. Search terms included brain concussion, signs or symptoms, and athletic injuries, in combination with the AND Boolean operator, and were limited to studies published in English. The authors also hand searched the reference lists of retrieved articles. Additional searches of books, conference proceedings, theses, and Web sites of commercial scales were done to provide additional information about the psychometric properties and development for those scales when needed in articles meeting the inclusion criteria.

Study Selection:

Articles were included if they identified all the items on the scale and the article was either an original research report describing the use of scales in the evaluation of concussion symptoms or a review article that discussed the use or development of concussion symptom scales. Only articles published in English and available in full text were included.

Data Extraction:

From each study, the following information was extracted by the primary author using a standardized protocol: study design, publication year, participant characteristics, reliability of the scale, and details of the scale or checklist, including name, number of items, time of measurement, format, mode of report, data analysis, scoring, and psychometric properties. A quality assessment of included studies was done using 16 items from the Downs and Black checklist1 and assessed reporting, internal validity, and external validity.

Main Results:

The initial database search identified 421 articles. After 131 duplicate articles were removed, 290 articles remained and were added to 17 articles found during the hand search, for a total of 307 articles; of those, 295 were available in full text. Sixty articles met the inclusion criteria and were used in the systematic review. The quality of the included studies ranged from 9 to 15 points out of a maximum quality score of 17. The included articles were published between 1995 and 2008 and included a collective total of 5864 concussed athletes and 5032 nonconcussed controls, most of whom participated in American football. The majority of the studies were descriptive studies monitoring the resolution of concussive self-report symptoms compared with either a preseason baseline or healthy control group, with a smaller number of studies (n = 8) investigating the development of a scale.

The authors initially identified 20 scales that were used among the 60 included articles. Further review revealed that 14 scales were variations of the Pittsburgh Steelers postconcussion scale (the Post-Concussion Scale, Post-Concussion Scale: Revised, Post-Concussion Scale: ImPACT, Post-Concussion Symptom Scale: Vienna, Graded Symptom Checklist [GSC], Head Injury Scale, McGill ACE Post-Concussion Symptoms Scale, and CogState Sport Symptom Checklist), narrowing down to 6 core scales, which the authors discussed further. The 6 core scales were the Pittsburgh Steelers Post-Concussion Scale (17 items), Post-Concussion Symptom Assessment Questionnaire (10 items), Concussion Resolution Index postconcussion questionnaire (15 items), Signs and Symptoms Checklist (34 items), Sport Concussion Assessment Tool (SCAT) postconcussion symptom scale (25 items), and Concussion Symptom Inventory (12 items). Each of the 6 core scales includes symptoms associated with sport-related concussion; however, the number of items on each scale varied. A 7-point Likert scale was used on most scales, with a smaller number using a dichotomous (yes/no) classification.

Only 7 of the 20 scales had published psychometric properties, and only 1 scale, the Concussion Symptom Inventory, was empirically driven (Rasch analysis), with development of the scale occurring before its clinical use. Internal consistency (Cronbach α) was reported for the Post-Concussion Scale (.87), Post-Concussion Scale: ImPACT 22-item (.88–.94), Head Injury Scale 9-item (.78), and Head Injury Scale 16-item (.84). Test-retest reliability has been reported only for the Post-Concussion Scale (Spearman r = .55) and the Post-Concussion Scale: ImPACT 21-item (Pearson r = .65). With respect to validity, the SCAT postconcussion scale has demonstrated face and content validity, the Post-Concussion Scale: ImPACT 22-item and Head Injury Scale 9-item have reported construct validity, and the Head Injury Scale 9-item and 16-item have published factorial validity.

Sensitivity and specificity have been reported only with the GSC (0.89 and 1.0, respectively) and the Post-Concussion Scale: ImPACT 21-item when combined with the neurocognitive component of ImPACT (0.819 and 0.849, respectively). Meaningful change scores were reported for the Post-Concussion Scale (14.8 points), Post-Concussion Scale: ImPACT 22-item (6.8 points), and Post-Concussion Scale: ImPACT 21-item (standard error of the difference = 7.17; 80% confidence interval = 9.18).

Conclusions:

Numerous scales exist for measuring the number and severity of concussion-related symptoms, with most evolving from the neuropsychology literature pertaining to head-injured populations. However, very few of these were created in a systematic manner that follows scale development processes and have published psychometric properties. Clinicians need to understand these limitations when choosing and using a symptom scale for inclusion in a concussion assessment battery. Future authors should assess the underlying constructs and measurement properties of currently available scales and use the ever-increasing prospective data pools of concussed athlete information to develop scales following appropriate, systematic processes.

Objective:

To emphasize the potentially harmful effects of high-intensity exercise on cardiac health and the fine line between physiologic and pathologic adaptation to chronic exercise in the elite athlete. This case also highlights the crucial need for regular evaluation of symptoms that suggest cardiac abnormality in athletes.

Background:

Sudden cardiac death (SCD) of young athletes is always a tragedy because they epitomize health. However, chronic, high-intensity exercise sometimes has harmful effects on cardiac health, and pathologic changes, such as myocardial fibrosis, have been observed in endurance athletes. In this case, a highly trained 30-year-old cyclist reported brief palpitations followed by presyncope feeling while exercising. Immediate investigations revealed nonsustained ventricular tachycardia originating from the left ventricle on a stress test associated with myocardial fibrosis of the left ventricle as shown with magnetic resonance imaging. Despite complete cessation of exercise, life-threatening arrhythmia and fibrosis persisted, leading to complete restriction from competition.

Differential Diagnosis:

Hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, myocarditis, postmyocarditis, use of drugs and toxic agents, doping, and systemic disease.

Treatment:

The arrhythmia could not be treated with catheter ablation procedure or drug suppression. Therefore, the athlete was instructed to withdraw completely from sport participation and to have a medical follow-up twice each year.

Uniqueness:

To our knowledge, no other report of left ventricle exercise-induced fibrosis associated with life-threatening arrhythmia in a living young elite athlete exists. Only postmortem evidence supports such myocardial pathologic adaptation to exercise.

Conclusions:

To prevent SCD in young athletes, careful attention must be paid to exercise-related symptoms that suggest a cardiac abnormality because they more often are linked to life-threatening cardiovascular disease.

Objective:

To describe a case of exertional rhabdomyolysis in a collegiate American football player after preventive cold-water immersion.

Background:

A healthy man (19 years old) participated in full-contact football practice followed by conditioning (2.5 hours). After practice, he entered a coach-mandated post-practice cold-water immersion and had no signs of heat illness before developing leg cramps, for which he presented to the athletic training staff. After 10 minutes of repeated stretching, massage, and replacement of electrolyte-filled fluids, he was transported to the emergency room. Laboratory tests indicated a creatine kinase (CK) level of 2545 IU/L (normal range, 45–260 IU/L), CK-myoglobin fraction of 8.5 ng/mL (normal < 6.7 ng/mL), and CK-myoglobin relative index of 30% (normal range, 25%– 30%). Myoglobin was measured at 499 ng/mL (normal = 80 ng/mL). The attending physician treated the athlete with intravenous fluids.

Differential Diagnosis:

Exercise-associated muscle cramps, dehydration, exertional rhabdomyolysis.

Treatment:

The patient was treated with rest and rehydration. One week after the incident, he began biking and swimming. Eighteen days later, the patient continued to demonstrate elevated CK levels (527 IU/L) but described no other symptoms and was allowed to return to football practice as tolerated. Two months after the incident, his CK level remained high (1900 IU/L).

Uniqueness:

The athlete demonstrated no signs of heat illness upon entering the cold-water immersion but experienced severe leg cramping after immersion, resulting in a diagnosis of exertional rhabdomyolysis. Previously described cases have not linked cold-water immersion with the pathogenesis of rhabdomyolysis.

Conclusions:

In this football player, CK levels appeared to be a poor indicator of rhabdomyolysis. Our patient demonstrated no other signs of the illness weeks after the incident, yet his elevated CK levels persisted. Cold-water immersion immediately after exercise should be monitored by the athletic training staff and may not be appropriate to prevent muscle damage, given the lack of supporting evidence.