Browse

Context: Induced mental fatigue negatively impacts sport performance and neurocognition. However, it is unclear how induced mental fatigue influences landing biomechanics. The purpose of this study was to examine the influence of mental fatigue on drop landing biomechanics in individuals with and without a concussion history. Design: Crossover design. Methods: Forty-eight (24 per group) recreationally active individuals were matched on age (±3 y), sex, and body mass index (±1 kg/m²). All participants completed an experimental (30-min Stroop task) and control (30-min reading magazines) intervention on separate days separated by a minimum of 24 hours. Drop landings were performed before and after both interventions. Outcomes included peak vertical ground reaction force (vGRF), vertical loading rate (VLR), knee flexion angle, knee abduction angle, external knee flexion moment, external knee abduction moment, and initial ground contact knee flexion and knee abduction angles. Separate 2 (group) × 2 (intervention) between-within analyses of covariance compared drop landing outcomes. Each group’s average pre-Stroop and premagazine outcomes were covariates. Results: There was a significant interaction for vGRF (P = .033, ${\eta }_{\mathrm{p}}^2=.097$) and VLR (P = .0497, ${\eta }_{\mathrm{p}}^2=.083$). The vGRF simple effects were not statistically significantly (P range = .052–.325). However, individuals with a concussion history displayed a medium effect size for greater vGRF post-Stroop compared with their own postmagazine vGRF (mean difference (95% confidence interval [95% CI] = 0.163 (–0.002 to 0.327) bodyweight (BW), p = .052, ${\eta }_{\mathrm{p}}^2=.081$. In contrast, the control group displayed a small effect size (mean difference [95% CI] = 0.095 [–0.069 to 0.259] BW, p = .251, ${\eta }_{\mathrm{p}}^2=.029$). Individuals with a concussion history displayed greater VLR post-Stroop compared with controls (mean difference [95% CI], 26.29 [6.19 to 46.40] BW/s, P = .012, ${\eta }_{\mathrm{p}}^2=.134$) and their own postmagazine values (mean difference [95% CI] = 32.61 [7.80 to 57.42] BW/s, p = .011, ${\eta }_{\mathrm{p}}^2=.135$). Conclusion: Mental fatigue leads to greater VLR for individuals with a concussion history. Athletic competition and activities of daily living can increase mental fatigue. Training programs may seek to teach mental fatigue reducing strategies to athletes with a concussion history.

Objectives: The whole-body vibration (WBV) effects on muscle strength show inconsistent results. Moreover, there is no study about the WBV effect on stiffness, elasticity, and muscle strength. Therefore, the study aimed to examine the effect of WBV exposure with static squat posture on the stiffness, elasticity, and strength of the lower-limb extensor muscles. Material and Methods: Forty healthy untrained young adults were divided into WBV and control groups. The experimental group received WBV exposure on 2 nonconsecutive days of the week, for 6 weeks. The MyotonPRO device was used for the assessment of the knee extensor and the ankle dorsiflexors’ stiffness and elasticity. Isometric muscle strength was evaluated with a hand-held dynamometer. All measurements were done by the same assessor at baseline, and the following 6 weeks. Results: Significant group-by-time interactions were found for the elasticity scores of the right (d = 0.84, P = .01) and left (d = 0.77, P = .02) ankle dorsiflexors. Similar to the elasticity measurements, significant group-by-time interactions were observed in the muscle strength scores of the right (d = 0.45, P = .046) and left (d = 1.25, P < .001) ankle dorsiflexors. No significant effects were observed in any of the evaluated muscle stiffness measurements (P > .05), and there was no significant group-by-time interaction in knee-extensor muscle strength and elasticity scores (P > .05). Conclusions: The study results indicate that if the ankle dorsiflexor strength and elasticity are desired to be increased, the 6-week WBV exposure in a static squat posture can be used in healthy individuals.

Background: The Anterior Cruciate Ligament-Return to Sport after Injury scale (ACL-RSI) is used to measure athletes’ psychological readiness in terms of their emotions, confidence in performance, and risk appraisal with respect to return to sport after ACL reconstruction. Objective: To translate and cross-culturally adapt the ACL-RSI to the Persian version and evaluate the reliability and validity of this scale in patients with ACL reconstruction. Study Design: Clinical measurement study (psychometric analysis). Methods: To assess test–retest reliability, 100 participants were asked to complete the Persian version of the ACL-RSI 2 times with a 7- to 10-day interval. In the first assessment, the patients also filled the Injury-Psychological Readiness to Return to Sport Questionnaire, Tampa Scale of Kinesiophobia, International Knee Documentation Committee Subjective Knee Form, and Knee Injury and Osteoarthritis Outcome Score. Internal consistency (Cronbach alpha, α), test–retest reliability (intraclass correlation coefficients), measurement error (standard error of measurement and minimum detectable change), and construct validity (Pearson r) were determined. Results: Our results showed good internal consistency (Cronbach alpha = .94) and excellent test–retest reliability (intraclass correlation coefficients = .90 (.85−.93)]. Standard error of measurement and minimum detectable change were 4.64 and 12.85, respectively. No significant bias was observed between test and retest. In addition, based on the results of correlation analysis, all hypotheses of this study were confirmed. The Persian version of the ACL-RSI had a strong correlation with Injury-Psychological Readiness to Return to Sport (I-PPR) (P < .001, r = .76) and Tampa scale of Kinesiophobia (TKS) (P < .001, r = −.68). Furthermore, a moderate correlation was observed between the Persian version of the ACL-RSI and the International Knee Documentation Committee Subjective Knee Form (P < .001, r = .44) and between this version of the ACL-RSI and the subscales of Knee Injury and Osteoarthritis Outcome Score (P < .001, r = .30–.55). Conclusion: Given its acceptable reliability and validity, the Persian version of the ACL-RSI seems to be a suitable tool for evaluating psychological readiness to return to sport after ACL reconstruction.

Context: Wall push-up plus (WPP) and wall slide (WS) are commonly prescribed in early rehabilitation to increase serratus anterior (SA) muscle activity. For individuals with scapular winging (SW), synergistic muscles such as upper trapezius (UT) and pectoralis major (PM) may compensate for weak SA during scapular movement. However, no studies have applied isometric horizontal abduction (IHA) during WS in individuals with SW nor have compared it with WPP with IHA. Objectives: This study compared the effects of IHA on shoulder muscle activity during WPP and WS exercises in individuals with SW. Design: Cross-sectional study; 2-way repeated-measures analysis of variance was used to assess the statistical significance of observed differences in SA, UT, PM, lower trapezius (LT), and infraspinatus (IS) muscle activities. Setting: Research laboratory. Patients: We recruited 30 individuals with SW comprising 20 men and 10 women. Interventions: The individuals performed WPP and WS exercises with and without IHA using Thera-Band. Main Outcome Measures: Surface electromyography was used to measure muscle activity of the SA, UT, PM, LT, and IS during the isometric phase of WPP and WS. Maximal voluntary isometric contractions were recorded to normalize electromyographic data. Results: There was no significant interaction between IHA application and exercise type for any of the shoulder muscles. IHA application increased SA (P = .008), UT (P = .001), LT (P = .009), and IS (P = .000) activities and decreased PM (P = .001) activity compared with those without IHA. WS exercises elicited higher PM (P = .017) and LT (P = .011) activities than WPP. Conclusion: WPP and WS with IHA may be effective in increasing the muscle activities of shoulder stabilizers and preventing overactivation of PM activity. WPP may be recommended for individuals with overactivated PM, whereas WS may be used to increase LT activity.

Context: Horse riding (HR) has gain popularity in Portugal, thereby increasing the number of related injuries. This study identifies frequently occurring injuries in Portuguese riders, the conditions under which they occur, and preventive measures. Design: A retrospective cohort study. Methods: We included 216 Portuguese riders practicing HR at the time of the study with ≥1 year of experience. Data were obtained from a questionnaire that characterized first and second rider injuries; we opted for a systematic method to assess the riders’ injuries, in a temporal order. Questions regarding demographic data, sports-related background, systematic training workload, number and characteristics of the first 2 injuries, and the need for treatment were included in the questionnaire. Results: Most first and second injuries were musculoskeletal, occurred from falling off the horse during training, and primarily affected the lower limb. Rehabilitation was required in almost 50% of all cases. The occurrence of injury was significantly associated with the number of days of training per week, years of experience, height and weight of the rider, and practice of another sport. Riding different horses was also significantly associated with the number of injuries. Conclusions: The most frequently occurring injuries during HR are musculoskeletal and in the extremities. Injury prevention is essential in HR, as most riders have at least one injury while practicing. Rehabilitation should involve a physiatrist and core strengthening exercises.

Context: Studies have illustrated that overuse injuries occur in adolescent athletes more often than previously reported. The general purpose of this study was to provide a thorough report of secondary school athletic trainers encounters, practices, and perceptions of overuse injury in adolescent athletes. Design: Cross-sectional. Methods: An anonymous online questionnaire was distributed via email to athletic trainers in the secondary school setting. The questionnaire was sent to participants during the summer of 2021 and 430 participants (highest educational degree earned: master’s degree = 66%) completed the survey. Various survey methods were used to evaluate athletic trainers (1) demographics, (2) estimations about what percentage of injuries evaluated and treated were classified as overuse, (3) methods for treating overuse injuries, (4) confidence in treating overuse injuries and the complete implementation of their treatment plan, (5) perceptions of various barriers to treating overuse injuries, and (6) perception as to why patients did not want to reduce activity to treat their overuse injuries. Results: Participants reported that about half of all evaluations and treatments in a year were overuse injuries and they were “fairly” or “completely” confident (90%) in their ability to treat these injuries. The most common treatments cited were stretching (91%) and reducing activity (90%). Only 61% of participants were “fairly” or “completely” confident in the complete implementation of their treatment plan. Participants believed that patients’ reluctance to reduce sport activities (82% “moderate” or “extreme” barrier) was the most significant barrier to treatment. Participants cited athletes’ avoidance of missing games as the most common reason athletes were reluctant to reduce sporting activity. Conclusions: Participants felt confident in treating overuse injuries yet faced significant barriers in treating these injuries. Clinicians should be prepared to have conversations about the importance of reducing sporting activity to allow proper healing for overuse injuries in adolescent athletes.

The unpredictable environments firefighters face paired with biomechanically compromising shoulder movements, such as overhead and lifting movements, place this population at an increased risk for shoulder injury. The purpose of this study was to assess firefighter trainees’ bilateral shoulder range of motion (ROM) using the Dynamic Athletic Research Institute Motion system. Retrospective anthropometric and ROM data for 31 male firefighter trainees were analyzed. Firefighter trainees’ mean shoulder ROM for bilateral external rotation, internal rotation, and extension were lower than previously published values. External rotation demonstrated the lowest percentage of trainees within normal ROM (left—6.67%, right—16.67%). Noting the susceptibility of upper extremity injuries among firefighters, establishing baseline ROM measurements for reference may improve musculoskeletal evaluations, training interventions, and injury rehabilitation.

This study examined whether table tennis as a method of sensorimotor training improves haptic and motor function and to what extent haptic function gain correlates with changes in motor ability in children with probable developmental coordination disorder (pDCD). Children with pDCD were randomly assigned to the table tennis and nontraining control groups. The children in the table tennis group received 36 sessions of table tennis training, including ball balancing, hitting the ball against the wall, strokes, and serving. Haptic sensitivity, acuity, and motor function domains were measured. The results showed a 41.5% improvement in haptic sensitivity in children exposed to table tennis training compared with 2.8% in those without training. This improved haptic sensitivity significantly correlated with motor function gain, suggesting that somatosensory gains occur simultaneously with changes in motor function in children with pDCD. This novel upper limb motor training approach may be an interesting method of sensorimotor training in neurological rehabilitation in children with pDCD.