To evaluate the quality of the evidence on the incidence of sudden cardiac arrest (SCA) and sudden cardiac death (SCD) in athletes and military members and estimate the annual incidence of SCA and SCD. We searched MEDLINE, Embase, Cochrane CENTRAL, Web of Science, BIOSIS, Scopus, SPORTDiscus, PEDro, and ClinicalTrials.gov from inception to dates between February 21 and July 29, 2019. Studies in which the incidence of SCA, SCD, or both in athletes or military members aged <40 years was reported were eligible for inclusion. We identified 40 studies for inclusion. Risk of bias (ROB) was assessed using a validated, customized tool for prevalence studies. Twelve had a low ROB, while the remaining 28 had a moderate or high ROB. Data were extracted for narrative review and meta-analysis. Random-effects meta-analysis was performed in studies judged to have a low ROB in 2 categories: (1) 5 studies of regional- or national-level data, including athletes at all levels and both sexes, demonstrated 130 SCD events with a total of 11 272 560 athlete-years, showing a cumulative incidence rate of 0.98 (95% CI = 0.62, 1.53) per 100 000 athlete-years and high heterogeneity (I2 = 78%) and (2) 3 studies of competitive athletes aged 14 to 25 years were combined for a total of 183 events and 17 798 758 athlete-years, showing an incidence rate of 1.91 (95% CI = 0.71, 5.14) per 100 000 athlete-years and high heterogeneity (I2 = 97%). The remaining low-ROB studies involved military members and were not synthesized. The worldwide incidence of SCD is rare. Low-ROB studies indicated the incidence was <2 per 100 000 athlete-years. Overall, the quality of the available evidence was low, but high-quality individual studies inform the question of incidence levels. CRD42019125560Objective
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PROSPERO Registration
To determine the effect of electrocardiogram (ECG) screening on the prevention of sudden cardiac arrest and death in young athletes and military members. MEDLINE, Embase, CENTRAL, Web of Science, BIOSIS, Scopus, SPORTDiscus, PEDro, and ClinicalTrials.gov were searched from inception to dates between February 21 and July 29, 2019. Randomized and nonrandomized controlled trials in which preparticipation examination including ECG was the primary intervention used to screen athletes or military members aged ≤40 years. Acceptable control groups were those receiving no screening, usual care, or preparticipation examination without ECG. Three published studies and 1 conference abstract were identified for inclusion. In all 4 studies, risk of bias was assessed using the Cochrane risk-of-bias tool and was found to be generally high. Two studies had data extracted for random effects meta-analysis, and the remaining study and conference abstract were included in the narrative review. The overall quality of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation approach. We included 4 nonrandomized studies (11 689 172 participants), of which all had a high risk of bias. Pooled data from 2 studies (n = 3 869 274; very low-quality evidence) showed an inconclusive 42% relative decrease in risk of sudden cardiac death (relative risk = 0.58; 95% CI = 0.23, 1.45), equating to an absolute risk reduction of 0.0016%. The findings were consistent with a potential 77% relative decreased risk to a 45% relative increased risk in participants screened using ECG. Heterogeneity was found to be high, as measured using I2 statistic (71%). Data from the remaining study and abstract were similarly inconclusive. Existing evidence for the effect of ECG screening is inconclusive and of very low quality. In our meta-analysis, we observed that screening ECG may result in a considerable benefit or harm to participants. Higher-quality studies are needed to reduce this uncertainty.Objective
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Previously, the most common treatment for a concussion was prolonged physical and cognitive rest. Recently, researchers have suggested that earlier physical activity (PA) may be better at promoting recovery. Researchers have not evaluated the relationship between free-living PA (eg, walking) and symptom reporting or recovery duration. To assess the relationship between free-living PA participation and 2 recovery outcomes in college-aged adults with a concussion. Prospective cohort. National Collegiate Athletic Association Division I and III universities. Thirty-two college-aged adults (68.8% female, age = 19.8 ± 1.4 years) with a concussion. Participants completed a postconcussion symptom evaluation at visits 1 (<72 hours from concussion) and 2 (8 days later). Between visits, each participant's PA was monitored using an Actigraph GT9X Link PA monitor and expressed as total PA (counts per minute) and percentage of PA time spent in moderate-to-vigorous intensity (%MVPA). Recovery time was the number of days from injury occurrence to medical clearance. With separate hierarchical multiple regressions, we evaluated the relationship between total PA and each recovery variable (visit 2 symptom severity, recovery time). Additionally, with separate exploratory hierarchical multiple regressions, we evaluated the relationship between %MVPA and each recovery variable. Statistical significance was set a priori at P ≤ .05. Participants averaged 2446 ± 441 counts per minute and spent 12.1% ± 4.2% of their PA performing MVPA. Participants yielded median (interquartile) symptom severities of 28 (24) and 2 (8) for visit 1 and 2, respectively. Average recovery time was 14.7 ± 7.5 days. Total PA did not significantly contribute to the model for visit 2 symptom severity (P = .122) or recovery time (P = .301). Similarly, %MVPA had little contribution to the model for visit 2 symptom severity (P = .358) or recovery time (P = .276). We suggest that free-living PA may not be enough to reduce symptoms or shorten recovery. Thus, clinicians may need to provide patients with more structured PA protocols mimicking findings from previous researchers.Context
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In 2018, the US military developed the Military Acute Concussion Evaluation-2 (MACE-2) to inform the acute evaluation of mild traumatic brain injury (mTBI). However, researchers have yet to investigate false-positive rates for components of the MACE-2, including the Vestibular-Ocular Motor Screening (VOMS) and modified Balance Error Scoring System (mBESS), in military personnel. To examine factors associated with false-positive results on the VOMS and mBESS in US Army Special Operations Command (USASOC) personnel. Cross-sectional study. Military medical clinic. A total of 416 healthy USASOC personnel completed the medical history, VOMS, and mBESS evaluations. False-positive rates for the VOMS (≥2 on VOMS symptom items, >5 cm for near point of convergence [NPC] distance) and mBESS (total score >4) were determined using χ2 analyses and independent-samples t tests. Multivariable logistic regressions (LRs) with adjusted odds ratios (aORs) were performed to identify risk factors for false-positive results on the VOMS and mBESS. The VOMS item false-positive rates ranged from 10.6% (smooth pursuits) to 17.5% (NPC). The mBESS total score false-positive rate was 36.5%. The multivariable LR model supported 3 significant predictors of VOMS false-positives, age (aOR = 1.07; 95% CI = 1.02, 1.12; P = .007), migraine history (aOR = 2.49; 95% CI = 1.29, 4.81; P = .007), and motion sickness history (aOR = 2.46; 95% CI = 1.34, 4.50; P = .004). Only a history of motion sickness was a significant predictor of mBESS false-positive findings (aOR = 2.34; 95% CI = 1.34, 4.05; P = .002). False-positive rates across VOMS items were low and associated with age and a history of mTBI, migraine, or motion sickness. False-positive results for the mBESS total score were higher (36.5%) and associated only with a history of motion sickness. These risk factors for false-positive findings should be considered when administering and interpreting VOMS and mBESS components of the MACE-2 in this population.Context
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Cold-water immersion (CWI) is the best treatment for patients with exertional heat stroke (EHS), and rectal temperature (Trec) cooling rates may differ between sexes. Previous authors have suggested that the body surface area (BSA):lean body mass (LBM) ratio is the largest factor affecting CWI Trec cooling rates in men with hyperthermia; this has never been confirmed in women with hyperthermia. To examine whether the BSA:LBM ratio and other anthropometric characteristics affect Trec cooling rates in women with hyperthermia. Cross-sectional study. Laboratory. Sixteen women were placed in either a low BSA:LBM ratio (LOW; n = 8; age = 22 ± 1 years, height = 166.8 ± 6.0 cm, mass = 64.1 ± 4.5 kg, BSA:LBM ratio = 3.759 ± 0.214 m2/kg·102) or high BSA:LBM ratio (HIGH; n = 8; age = 22 ± 2 years, height = 162.7 ± 8.9 cm, mass = 65.8 ± 12.7 kg, BSA:LBM ratio = 4.161 ± 0.232 m2/kg·102) group. On day 1, we measured physical characteristics using dual-energy x-ray absorptiometry, and participants completed a maximal oxygen consumption test. On day 2, participants walked at 4.8 km/h for 3 minutes and then ran at 80% of their predetermined maximal oxygen consumption for 2 minutes in the heat (temperature = ∼40°C, relative humidity = 40%). This sequence was repeated until Trec reached 39.5°C. Then they underwent CWI (temperature = ∼10°C) until Trec was 38°C. Rectal temperature and CWI cooling rates. The groups had different BSA:LBM ratios (P = .001), LBM (LOW: 45.8 ± 3.0 kg; HIGH: 41.0 ± 5.1 kg; P = .02), and body fat percentages (LOW: 25.7% ± 5.0%; HIGH: 33.7% ± 6.3%; P = .007) but not different BSA (LOW: 1.72 ± 0.08 m2; HIGH: 1.70 ± 0.16 m2; P = .40) or body mass index (LOW: 23.1 ± 2.1; HIGH: 24.9 ± 4.7; P = .17). Despite differences in several physical characteristics, Trec cooling rates were excellent but comparable (LOW: 0.26°C/min ± 0.09°C/min; HIGH: 0.27°C/min ± 0.07°C/min; P = .39). The BSA:LBM ratio (r = 0.14, P = .59), BSA (r = −0.01, P = .97), body mass index (r = 0.37, P = .16), and body fat percentage (r = 0.29, P = .28), LBM (r = −0.10, P = .70) were not correlated with Trec cooling rates. Body anthropometric characteristics did not affect CWI Trec cooling rates in women with hyperthermia. Therefore, clinicians need not worry that anthropometric characteristics might slow CWI treatment in women with severe hyperthermia.Context
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Swimmers are known for experiencing high training loads and a high incidence of overuse injuries, but few researchers have investigated the relationship between the two at the collegiate level. To determine the association between workload and noncontact musculoskeletal injury in collegiate swimmers. Prospective cohort study. College natatorium. A total of 37 National Collegiate Athletic Association Division III swimmers, 26 uninjured (age = 19 years [interquartile range = 3 years], height = 175 ± 11 cm, mass = 70.2 ± 10 kg) and 11 injured (age = 19 years [interquartile range = 3 years], height = 173 ± 9 cm, mass = 69.4 ± 13.5 kg) individuals. Logistic regression using generalized estimating equations was conducted to calculate odds ratios (ORs) with 95% CIs for injury relative to high workloads and high acute:chronic workload ratio (ACWRs). Injury rates for several ranges of workloads and ACWRs were also calculated. A total of 11 participants (29.7%) sustained 12 injuries, with 7 injuries occurring during the participants' winter training trip. Injury was associated with high acute workloads (OR = 27.1; 95% CI = 8.2, 89.8) and high ACWRs (OR = 25.1; 95% CI = 7.7, 81.4) but not high chronic (OR = 2.6; 95% CI = 0.3, 20.0) or overall (OR = 1.00; 95% CI = 0.99, 1.01) workloads. High acute workloads (>37.2 km/wk) and ACWRs (>1.56) increased the injury rate from ≤1% to 15% and 14%, respectively, compared with all lower acute workloads and ACWRs. Collegiate swimmers tolerated high workloads spread out during the season. However, caution should be used when prescribing high acute workloads and high ACWRs (eg, winter training trip) because of the increased odds of injury.Context
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Serum biomarkers may allow for the early identification of posttraumatic osteoarthritis after anterior cruciate ligament (ACL) injury and reconstruction. Homeostasis of matrix-metalloproteinase-3 (MMP-3) and type II collagen turnover biomarkers (C2C:CPII ratio) is believed to be compromised in individuals with ACL injury, yet the influence of sex, body mass index (BMI), and age on these biomarkers before and after ACL reconstruction remains unknown. To determine the relationship of sex, BMI, and age with serum levels of MMP-3 and C2C:CPII before and after ACL reconstruction. Descriptive laboratory study. Laboratory. Thirty-two (females = 18, males = 14) individuals with ACL injuries. Demographic variables and blood samples were collected before surgery and at return to activity. Serum was extracted from the blood and assays were used to quantify MMP-3 and C2C:CPII. Generalized linear mixed-effects regression models were used to assess the relationships between sex, BMI, age, time, and participant on the outcome variables. A significant time × sex interaction was identified for MMP-3 levels (P = .021), whereby MMP-3 levels were higher in males at return to activity (males, 2.71 ± 0.59 ng/mL; females, 1.92 ± 0.60 ng/mL; P = .017). Males also had higher MMP-3 levels at return to activity when compared with presurgery levels (P = .009). A main effect for age demonstrated that older age was associated with higher MMP-3 levels. No significant main or interaction effects were noted for C2C:CPII levels. Upregulation of MMP-3 serum levels may occur after ACL reconstruction, particularly in males, which may have deleterious consequences for the cartilage matrix. Sex, BMI, and time did not influence C2C:CPII ratios, but further research with larger sample sizes is needed to confirm these findings.Context
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Nerves or fascia may limit motion in young soccer players, thereby contributing to frequent hamstrings injuries. Nerve-gliding exercises and self-myofascial release techniques may enhance range of motion (ROM). To compare the immediate effect of foam rolling (FR) and neurodynamic nerve gliding (NDNG) on hamstrings passive stiffness, viscoelasticity, flexibility, and proprioception during the warm-up of soccer players. Crossover study. Research laboratory. A total of 15 male soccer players (age = 18.0 ± 1.4 years, height = 183.1 ± 6.0 cm, mass = 76.9 ± 7.8 kg) on the same team. The FR and NDNG consisted of 6 sets of 45 seconds with a 15-second rest between sets. Over a 2-week period, participants performed FR and NDNG on 2 separate occasions. Stiffness (between 50% and 80%, and 85% and 95% [STFmax] of maximal knee-extension ROM), viscoelasticity (stress-relaxation test), knee-extension ROM, hamstrings passive-resistance torque (PRT), hip-flexion angle (straight-leg raise test), and active knee-joint position sense. We observed an interaction between time and intervention for STFmax (F1,17 = 5.024, P = .042), knee-extension ROM (F1,17 = 7.371, P = .02), and PRT (F1,17 = 4.876, P = .044). The NDNG technique induced increases in STFmax (t17 = 2.374, P = .03), ROM (t17 = 2.843, P = .01), and PRT (t17 = 2.982, P = .008). Both NDNG and FR led to improved performance on the straight-leg raise test (F1,17 = 87.514, P < .001). No interaction or main effect was found for the stress-relaxation test or active knee-joint position sense. Adding NDNG to the warm-up routine increased ROM more than FR and may benefit soccer players.Context
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Hip pain is associated with impairments in postural control and balance. The Star Excursion Balance Test (SEBT) is a reliable and valid method for measuring dynamic postural control. To examine changes in dynamic postural control after hip arthroscopy and subsequent rehabilitation from baseline to 3 and 6 months postsurgery. Case series. Physiotherapy department. Sixty-seven individuals (47 men, 20 women; age = 31 ± 8 years, height = 1.78 ± 0.09 m, mass = 83 ± 15 kg) scheduled for hip arthroscopy to address chondrolabral conditions were matched with 67 healthy individuals serving as controls (47 men, 20 women; age = 31 ± 8 years, height = 1.77 ± 0.09 m, mass = 80 ± 16 kg). The hip arthroscopy group underwent postoperative rehabilitation including SEBT training. The SEBT reach normalized to limb length was collected before surgery (baseline) and at 3 and 6 months after arthroscopy and compared with that of the healthy matched control group. Repeated-measures analysis of variance was used to evaluate whether SEBT reach differed among the 3 time points, and t tests were used to evaluate between-limbs and between-groups differences. The SEBT reach in the hip arthroscopy group at baseline was less than that of the control group in all directions (P values < .001). At 3 months after arthroscopy, SEBT reach increased in the posteromedial (PM; P = .007), posterolateral (PL; P < .001), and anterolateral (AL; P < .001) directions from baseline. At 6 months after arthroscopy, all directions of reach had increased (P values < .001) from baseline. The anteromedial (mean difference [MD] = −2.9%, P = .02), PM (MD = −5.2%, P = .002), and AL (MD = −2.5%, P = .04) reach distances remained shorter at 6 months after surgery in the hip arthroscopy group than in the control group. No difference existed between the control and hip arthroscopy groups for reach in the PL direction (MD = −3.6%; P = .06). Dynamic balance control in the hip arthroscopy group at baseline was poorer than in a matched control group as measured using the SEBT. At 3 months after hip arthroscopy, we observed improvements in dynamic balance in the PM, PL, and AL SEBT directions. By 6 months after arthroscopy, all directions of SEBT reach had improved, but only the PL reach improved to the level of healthy control individuals.Context
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Exercise-induced muscle damage (EIMD) is associated with transient reductions in strength and athletic performance. Muscle microvascular damage and disruption of blood flow are believed to be among the causes. Previous researchers reported modulations in muscle blood flow, oxygenation, and strength with vibration therapy (VT). To observe whether local VT alleviated the impairments and hemodynamic changes associated with EIMD. Controlled laboratory study. Laboratory and public gymnasium. A total of 10 healthy participants (6 men and 4 women; age = 38 ± 15 years; height = 1.72 ± 0.48 m; mass = 72.0 ± 10.4 kg) were randomized into experimental (VT) and control groups. Both groups performed 10 sets of 10 eccentric wrist flexions at 70% of their 1-repetition maximum to induce muscle damage. Subsequent assessment of flexor carpus ulnaris muscle oxygen saturation and wrist-flexor strength occurred at 1, 24, and 48 hours postexercise. The experimental group underwent 10 minutes of local VT (45 Hz) starting 1 hour postexercise and applied twice daily (separated by 8 hours) for 48 hours during habitual waking hours. The control group received no local VT. Resting muscle oxygen saturation (SmO2), grip strength, and muscle oxygen desaturation and resaturation rates. No difference in SmO2 resaturation was evident over time (P > .05), but the VT group had a greater resaturation rate than the control group at 1 hour (P = .007, d = 2.6), 24 hours (P = .001, d = 3.1), and 48 hours (P = .035, d = 1.7) post-EIMD. No difference in grip strength was observed pre-EIMD, but the VT group demonstrated greater strength at 1 hour (P = .004), 24 hours (P = .031), and 48 hours (P = .021) post-EIMD than did the control group. Local VT successfully attenuated the effects of EIMD and increased SmO2 resaturation in flexor carpus ulnaris muscles. Including local VT as part of a recovery protocol post-EIMD could be beneficial for rehabilitation and strength training purposes.Context
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With 8 million annual US high school student-athletes, the epidemiology of sport-related injuries has garnered significant interest. The most recent studies examining overuse injury rates in high school sports were based on data from 2012 to 2013 and, therefore, may not reflect current overuse injury rates in high school sports. To (1) determine overuse time-loss (TL) and non–time-loss (NTL) injury rates among high school student-athletes using National Athletic Treatment, Injury and Outcomes Network Surveillance Program (NATION-SP) data collected from 2014–2015 to 2018–2019 and (2) compare overuse injury rates based on student-athlete sex defined by whether it was a boys' sport or a girls' sport, the sport itself, and the injury location. Descriptive epidemiology study. Online injury surveillance from 211 high schools (345 individual years of high school data). Athletes who participated in secondary school–sponsored boys' or girls' sports. Boys' and girls' overuse injury data from the NATION-SP during the 2014–2015 to 2018–2019 school years were analyzed. Overuse injuries were identified using a combination of the reported injury mechanism and diagnosis. Time-loss injuries resulted in restriction from participation beyond the day of injury; NTL injuries did not result in restriction from participation beyond the day of injury or involved no lost time due to the injury. Injury counts, rates, and rate ratios (IRRs) were reported with 95% CIs. The total overuse injury rate was 5.3/10 000 athlete-exposures (AEs; 95% CI = 5.1, 5.7), the NTL overuse injury rate was 3.4/10 000 AEs (95% CI = 3.1, 3.6), and the TL overuse injury rate was 2.0/10 000 AEs (95% CI = 1.8, 2.2). The overuse injury rate was greater in girls' sports compared with boys' sports (IRR = 1.9; 95% CI = 1.7, 2.1). The highest rates of overuse injury were observed in girls' cross-country (19.2/10 000 AEs; 95% CI = 15.0, 24.2), girls' track and field (16.0/10 000 AEs; 95% CI = 13.5, 18.8), and girls' field hockey (15.1/10 000 AEs; 95% CI = 10.2, 21.6). Overuse injury rates were higher for the lower extremity than the upper extremity (IRR = 5.7; 95% CI = 4.9, 6.7) and for the lower extremity than the trunk and spine (IRR = 8.9; 95% CI = 7.3, 10.8). Awareness of the overuse injury risk, as well as prevention and intervention recommendations, is necessary and should be specifically targeted at cross-country, field hockey, and track and field athletes.Context
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Reliability and Validity of the Functional Assessment of Neurocognition in Sport (FANS): A Paradigm Shift in Post-Concussion Return-to-Sport Decision-Making
Driving After Concussion: Clinical Measures Associated with Post-concussion
The role of shoulder posture in pitching mechanics and injury risk in high school baseball pitchers
Corticospinal Excitability during Standing and Its Association with Postural Control Following Acute Lateral Ankle Sprain.
The socio-economic cost of anterior cruciate ligament injuries and lateral ankle sprains in amateur football and basketball.
JAT eISSN: 1938-162X
JAT ISSN: 1062-6050
ATEJ ISSN: 1947-380X