Context: The influence of playing surface on injury risk in soccer is contentious, and contemporary technologies permit an in vivo assessment of mechanical loading on the player. Objective: To quantify the influence of playing surface on the PlayerLoad elicited during soccer-specific activity. Design: Repeated measures, field-based design. Setting: Regulation soccer pitches. Participants: Fifteen amateur soccer players (22.1 [2.4] y), injury free with ≥6 years competitive experience. Interventions: Each player completed randomized order trials of a soccer-specific field test on natural turf, astroturf, and third-generation artificial turf. GPS units were located at C7 and the mid-tibia of each leg to measure triaxial acceleration (100 Hz). Main Outcome Measures: Total accumulated PlayerLoad in each movement plane was calculated for each trial. Ratings of perceived exertion and visual analog scales assessing lower-limb muscle soreness were measured as markers of fatigue. Results: Analysis of variance revealed no significant main effect for playing surface on total PlayerLoad (P = .55), distance covered (P = .75), or postexercise measures of ratings of perceived exertion (P = .98) and visual analog scales (P = .61). There was a significant main effect for GPS location (P < .001), with lower total loading elicited at C7 than mid-tibia (P < .001), but with no difference between limbs (P = .70). There was no unit placement × surface interaction (P = .98). There was also a significant main effect for GPS location on the relative planar contributions to loading (P < .001). Relative planar contributions to loading in the anterioposterior:mediolateral:vertical planes was 25:27:48 at C7 and 34:32:34 at mid-tibia. Conclusions: PlayerLoad metrics suggest that playing surface does not influence mechanical loading during soccer-specific activity (not including tackling). Clinical reasoning should consider that PlayerLoad magnitude and axial contributions were sensitive to unit placement, highlighting opportunities in the objective monitoring of load during rehabilitation.
Adam Jones, Richard Page, Chris Brogden, Ben Langley and Matt Greig
Stef Feijen, Angela Tate, Kevin Kuppens, Thomas Struyf, Anke Claes and Filip Struyf
Context: The latissimus dorsi plays a major role in generating the propulsive force during swimming. In addition, stiffness of this muscle may result in altered stroke biomechanics and predispose swimmers to shoulder pain. Measuring the flexibility of the latissimus dorsi can be of interest to reduce injury. However, the reliability of such measurement has not yet been investigated in competitive swimmers. Objective: To assess the within-session intrarater and interrater reliability of a passive shoulder flexion range of motion measurement for latissimus dorsi flexibility in competitive swimmers. Design: Within-session intrarater and interrater reliability. Setting: Competitive swimming clubs in Flanders, Belgium. Participants: Twenty-six competitive swimmers (15.46 [2.98] y; 16 men and 10 women). Intervention: Each rater performed 2 alternating (eg, left-right-left-right) measurements of passive shoulder flexion range of motion twice, with a 30-second rest period in between. Main Outcome Measures: The intraclass correlation coefficients were calculated to assess intrarater and interrater reliability. Results: Interrater intraclass correlation coefficient ranged from .54 (95% confidence interval [CI], −.16 to .81) to .57 (95% CI, −.24 to .85). Results for the intrarater reliability ranged from .91 (95% CI, .81 to .96) to .94 (95% CI, .87 to .97). Conclusion: Results of this study suggest that shoulder flexion range of motion in young competitive swimmers can be measured reliably by a single rater within the same session.
Jefferson Fagundes Loss, Edgar Santiago Wagner Neto, Tatiane Borsoi de Siqueira, Aline Dill Winck, Laura Silveira de Moura and Luiz Carlos Gertz
Trunk-flexor muscle strength plays a fundamental role in athletic performance, but objective measurements are usually obtained using expensive and nonportable equipment, such as isokinetic dynamometers. The aim of this study was to assess the concurrent validity of a portable, one-dimensional, trunk-flexor muscle strength measurement system (Measurement System) that uses calibrated barbells and the reliability of the measurements obtained using the Measurement System, by conducting test–retests. As a complementary assessment, the measurements obtained during a maximum contraction test performed by a group of 15 subjects were also recorded. Four conditions were assessed: repeatability, time reproducibility, position reproducibility, and subject reproducibility. The results demonstrate that both the concurrent validity and the measured reliability (intraclass correlation coefficient > .98) of the Measurement System are acceptable. The Measurement System provides valid and reliable measures of trunk-flexor muscle strength.
Matheus Lima Oliveira, Isabela Christina Ferreira, Kariny Realino Ferreira, Gabriela Silveira-Nunes, Michelle Almeida Barbosa and Alexandre Carvalho Barbosa
Context: Strength assessment is essential to prescribe exercise in sports and rehabilitation. Low-cost valid equipment may allow continuous monitoring of training. Objective: To examine the validity of a very low-cost hanging scale by comparing differences in the measures of peak force to a laboratory grade load cell during shoulder abduction, flexion, extension, and internal and external rotations. Design: Analytical study. Participants: Thirty-two healthy subjects (18 women, age 26  y, height 172  cm, mass 69  kg, body mass index 23  kg/m2). Main Outcome Measures: The dependent variable was the maximal peak force (in kilogram-force). The independent variable was the instrument (laboratory grade load cell and hanging scale). Results: No differences were observed while comparing the results. The intraclass correlation coefficients1,1 ranged from .96 to .99, showing excellent results. The Cronbach alpha test also returned >.99 for all comparisons. The SEM ranged from 0.02 to 0.04 kgf, with an averaged SD from 0.24 to 0.38 kgf. The correlation was classified as high for all tested movements (r > .99; P < .001), with excellent adjusted coefficients of determination (.96 < r 2 < .99). Bland–Altman results showed high levels of agreement with bias ranging from 0.27 to 0.48. Conclusions: Hanging scale provides valid measures of isometric strength with similar output measures as laboratory grade load cell.
Josep C. Benítez-Martínez, Pablo Martínez-Ramírez, Fermín Valera-Garrido, Jose Casaña-Granell and Francesc Medina-Mirapeix
Context: The prevalence and negative consequences of the symptoms surrounding patellar tendinopathy constitute an important problem for sports medicine professionals. The identification of potential pain mediators is, therefore, of major interest to improve both the prevention and management of this injury. Objective: To compare the pain experienced by elite male adult basketball players and patterns of patellar tendon abnormalities. Also, to identify whether structural and vascular sonographic abnormalities (focal area of hypoechogenicity, thickening, and neovascularization [NV]) are equal in determining pain perceptions. Design: An observational study with professional basketball teams (ACB—Spanish league). Participants: A total of 73 male basketball players (mean age 26.8 y). Main Outcome Measures: Patellar tendon ultrasonography images. Pain scores were compared between the identified patterns. Multiple regression analysis was used to examine the relative importance of abnormalities. Results: Of the 146 tendons, 91 had some degree of sonographic abnormality. Three main patterns were identified: I (1 structural abnormality without NV), II (2 structural abnormalities without NV), and III (2 structural abnormalities and NV). A total of 31 tendons (21.2%) exhibited pattern I, 46 (31.5%) presented pattern II, and 13 tendons (8.9%) exhibited pattern III. The mean visual analog scale and the Victorian Institute of Sport assessment questionnaire—patellar tendon (VISA-P) scores for pattern III were significantly different (P < .05) compared with patterns I and II; however, the pain pressure threshold (PPT) scores were not. NV was significantly associated with worsened scores for all pain measures; however, the focal area of hypoechogenicity was only associated with PPT scores. Conclusion: Patterns of sonographic abnormalities, including NV, demonstrated greater pain. Although NV determined scores for the visual analog scale, VISA-P, and PPT, the presence of focal area of hypoechogenicity on its own is a determining factor for the PPT. This study suggests that the combination of 2 or more sonographic abnormalities may help explain pain variations among basketball players.
Christopher P. Tomczyk, George Shaver and Tamerah N. Hunt
Clinical Scenario: Anxiety is a mental disorder that affects a large portion of the population and may be problematic when evaluating brain injuries such as concussion. The reliance of cognitive testing in concussion protocols call for the examination of potential cognitive alterations commonly seen in athletes with anxiety. Focused Clinical Question: Does anxiety affect neuropsychological assessments in healthy college athletes? Summary of Key Findings: Three studies were included: 1 cross-sectional study and 2 prospective cohort studies. One study examined the effect of a range of psychological issues on concussion baseline testing in college athletes. Another study examined the effect of anxiety on reaction time both before and after sport competition in college-aged athletes. The final study examined the effects of psychosocial issues on reaction time during demanding tasks in college athletes. The first study reported slower simple and complex reaction times in athletes with anxiety. The second study found that athletes with high trait anxiety have slower reaction times both before and after competition. The third study reported that demanding tasks led to increased state anxiety which slowed reaction time. Overall, all 3 studies support the adverse effect anxiety can have on cognitive testing in athletes. Clinical Bottom Line: College athletes who present with anxiety at baseline may be susceptible to decreased performance on neuropsychological assessments. Strength of Recommendation: There is level B evidence that anxiety in healthy college athletes can impact neuropsychological assessments, and level C evidence that anxiety at baseline concussion assessment impacts neuropsychological testing in college athletes.
Ryan D. Henke, Savana M. Kettner, Stephanie M. Jensen, Augustus C.K. Greife and Christopher J. Durall
ClinicalScenario: Low-intensity aerobic exercise (LIAEX) below the threshold of symptom exacerbation has been shown to be superior to rest for resolving prolonged (>4 wk) symptoms following sport-related concussion (SRC), but the effects of LIAEX earlier than 4 weeks after SRC need to be elucidated. Focused Clinical Question: Does LIAEX within the first 4 weeks following SRC hasten symptom resolution? Summary of Key Findings: Two randomized controlled trials (RCT) and 1 nonrandomized trial involving adolescent athletes (10–19 y) were included. One RCT reported faster recovery time with LIAEX versus placebo stretching. Likewise, recovery time was faster with LIAEX versus rest in the nonrandomized trial, but not in the underpowered RCT, although effect sizes were similar between these studies (0.5 and 0.4, respectively). All 3 studies reported a reduction in concussion symptom severity with LIAEX; however, the magnitude of symptom reduction across the recovery timeline was greater in the LIAEX group than the rest group in the nonrandomized trial, but not the 2 RCTs. Importantly, no adverse effects or incidence of delayed recovery from LIAEX were reported in any of the studies. Clinical Bottom Line: LIAEX initiated within 10 days after SRC may facilitate a faster recovery time versus placebo stretching or rest, although additional clinical trials are strongly advised to verify this. Strength of Recommendation: Level 1b and 2b evidence suggests subsymptom exacerbation LIAEX may decrease Postconcussion Symptom Scale scores and hasten symptom resolution in adolescent athletes following SRC.
Erik A. Wikstrom, Cole Mueller and Mary Spencer Cain
Context: Lateral ankle sprains (LAS) have one of the highest recurrence rates of all musculoskeletal injuries. An emphasis on rapid return to sport (RTS) following LAS likely increases reinjury risk. Unfortunately, no set of objective RTS criteria exist for LAS, forcing practitioners to rely on their own opinion of when a patient is ready to RTS. Purpose: To determine if there was consensus among published expert opinions that could help inform an initial set of RTS criteria for LAS that could be investigated in future research. Evidence Acquisition: PubMed, CINHL, and SPORTDiscus databases were searched from inception until October 2018 using a combination of keywords. Studies were included if they listed specific RTS criteria for LAS. No assessment of methodological quality was conducted because all included papers were expert opinion papers (level 5 evidence). Extracted data included the recommended domains (eg, range of motion, balance, sport-specific movement, etc) to be assessed, specific assessments for each listed domain, and thresholds (eg, 80% of the uninjured limb) to be used to determine RTS. Consensus and partial agreement were defined, a priori, as ≥75% and 50% to 75% agreement, respectively. Evidence Synthesis: Eight domains were identified within 11 included studies. Consensus was reached regarding the need to assess sport-specific movement (n = 9, 90.9%). Partial agreement was reached for the need to assess static balance (n = 7, 63.6%). The domains of pain and swelling, patient reported outcomes, range of motion, and strength were also partially agreed on (n = 6, 54.5%). No agreement was reached on specific assessments of cutoff thresholds. Conclusions: Given consensus and partial agreement results, RTS decisions following LAS should be based on sport-specific movement, static balance, patient reported outcomes, range of motion, and strength. Future research needs to determine assessments and cutoff thresholds within these domains to minimize recurrent LAS risk.
James A. Ashton-Miller and Ronald F. Zernicke
Amy R. Barchek, Shelby E. Baez, Matthew C. Hoch and Johanna M. Hoch
Clinical Scenario: Physical activity is vital for human health. Musculoskeletal injury may inhibit adults from participating in physical activity, and this amount may be less than adults without a history of musculoskeletal injury. Clinical Question: Do individuals with a history of ankle or knee musculoskeletal injury participate in less objectively measured physical activity compared with healthy controls? Summary of Key Findings: Four studies were included. Two studies concluded patients who have undergone an anterior cruciate ligament reconstruction (ACLR) spent less time in moderate to vigorous physical activity levels when compared with healthy controls, but still achieved the daily recommended amount of physical activity. One study determined that participants with CAI took fewer steps per day compared with the control group. The fourth study determined patients with patellofemoral pain were less physically active than healthy controls as they took fewer steps per day and spent less time participating in mild and high activity. Clinical Bottom Line: There is consistent, high quality evidence that demonstrates individuals with a history of ankle or knee musculoskeletal injury participate in less objectively measured physical activity compared with healthy individuals. Strength of Recommendation: Due to nature of study designs of the included articles in this critically appraised topic, we recommend a grade of 3B.