CONTEXT:Relationships between continuous measures of walking biomechanics and post anterior cruciate ligament reconstruction (ACLR) outcomes are unclear. The purposes of this study were to: (1) determine whether continuous measures of walking vertical ground reaction force (vGRF) and knee-flexion angle (KFA) can be used to cluster patients post-ACLR and (2) compare symptom status and discrete measures of walking biomechanics between resulting clusters. DESIGN:Cross-sectional. METHODS:A Bayesian hierarchical model was used to cluster 196 patients post-ACLR (118 females; age = 21 ± 4 y; height = 1.71 ± 0.10 cm; mass = 73 ± 15 kg; time post-ACLR = 25 ± 26 mo) on involved-leg vGRF and KFA waveforms during walking. Symptom status (asymptomatic or symptomatic) was derived from Knee injury and Osteoarthritis Outcome Scores. Symptom status and discrete walking vGRF and KFA characteristics were compared between resulting patient clusters. RESULTS:Five distinct patient clusters resulted and exhibited different representative vGRF and KFA waveforms. Clusters 1 to 4 consisted of mostly asymptomatic patients (63%, n = 47; 53%, n = 49; 58%, n = 24; 74%, n = 31) and were combined to form an aggregate group. Cluster 5 consisted of mostly symptomatic patients (58%; n = 45). The aggregate group exhibited 5% greater impact peak vGRF, 42% greater excursion between impact peak and midstance vGRF minimum, greater average (18%) and instantaneous (15%) vGRF rates during early stance, and 62% greater KFA excursion between peak KFA in early stance and subsequent peak knee extension than Cluster 5. CONCLUSION:Continuous vGRF and KFA were able to cluster patients post-ACLR into distinct groups that exhibited differing symptom status and biomechanics. These results offer new insight regarding relationships between walking biomechanics and post-ACLR symptoms and can guide future research designed to manipulate walking biomechanics to improve post-ACLR outcomes.
CONTEXT:Shoulder injuries are prevalent in rugby and require sport-specific outcome measures for accurate evaluation. The Rugby Shoulder Function Questionnaire (RSFQ) is designed to assess shoulder symptoms in rugby athletes, but no validated Italian version exists. This study aimed to translate, culturally adapt, and validate the Italian version of the RSFQ (RSFQ-I). DESIGN:Cross-sectional validation study. METHODS:The RSFQ was translated following standardized forward-backward procedures and administered electronically. A total of 106 Italian rugby players completed the RSFQ-I and the Italian version of the Quick Disabilities of the Arm, Shoulder, and Hand questionnaire-I at baseline; the RSFQ-I was repeated at a second timepoint. Feasibility was evaluated through completion time, missing responses, and ceiling and floor effects. Construct validity was assessed using Spearman correlation with the Quick Disabilities of the Arm, Shoulder and Hand questionnaire-I. Internal consistency was analyzed using Cronbach α, and test-retest reliability using the intraclass correlation coefficient (ICC2,1). Measurement error was quantified using the standard error of measurement and minimal detectable change at the 95% confidence level. RESULTS:The RSFQ-I required approximately 5 minutes to complete, with no missing responses. Ceiling and floor effects were 0% and 15.1%, respectively. Construct validity was supported by significant correlations with the Quick Disabilities of the Arm, Shoulder and Hand questionnaire-I (P < .001). Internal consistency was high for both dominant (α = .92) and nondominant (α = .89) arms. Test-retest reliability was excellent for combined (ICC2,1 = .97), dominant (ICC2,1 = .96), and nondominant (ICC2,1 = .95) scores. The standard error of measurement was 2.77 points, and the minimal detectable change at the 95% confidence level was 7.7 points. CONCLUSION:The RSFQ-I demonstrates good feasibility, strong construct validity, high internal consistency, and excellent test-retest reliability. It is a valid and reliable instrument for assessing shoulder function in Italian-speaking rugby players and is suitable for use in both clinical practice and research settings.
CONTEXT:Exercise benefits people with multiple sclerosis (MS); however, most research focuses on gym or home-based aerobic and strength training. Little is known about how individuals with MS participate in dynamic sports like running. We aimed to quantify running participation over a 4-week period in individuals with MS and investigate whether running volume and training characteristics were associated with fatigue, disability, cognition, and quality of life. DESIGN:A prospective observational cohort study. METHODS:We included 29 participants from Australia who were regular runners with MS. Participants recorded their running frequency, intensity, duration, distance, and mode (indoor/outdoor/treadmill) over 4 weeks. Associations between participants' running activities, and measures of fatigue (Modified Fatigue Impact Scale), disability (Patient Determined Disease Steps), cognition (Psytoolkit online cognitive assessment), and physical and mental health (Multiple Sclerosis Quality of Life-54) were assessed using Spearman or Kendall τ b correlation coefficients. RESULTS:Participants with low to moderate disability demonstrated a broad range of running ability (range: average distance 2-13 km and 16-95 min per run). Most ran outdoors on combination surfaces (concrete, grass, and trail). Negative correlations were observed between fatigue and running distance (r = -.382, P = .041) and running duration (r = -.365, P = .052). Positive correlations were observed between running distance and quality of life, physical health (r = .380, P = .042), and mental health (r = .375, P = .045). Correlations were not significant after applying the corrected significance value of P < .0025. CONCLUSION:Regular running is feasible for individuals with MS with low to moderate disability. Participants demonstrated the ability to run despite differing levels of fatigue, cognitive function, and disability. Participants could engage in outdoor running under conditions considered challenging for those with MS. A relationship between running distance, duration, fatigue, and quality of life was identified; however, the findings were not statistically significant after correction for multiple comparisons.
CONTEXT:Effusion-synovitis commonly develops following anterior cruciate ligament reconstruction (ACLR) and may influence physical and psychological recovery. We examined the association between effusion-synovitis severity and psychological readiness to return to sport and kinesiophobia at 4 to 6 months post-ACLR. DESIGN:Cross-sectional. METHODS:We assessed 52 participants (age = 18.4 [4.0] y; 27 females; time since surgery = 5.0 [0.9] mo) between 4 and 6 months post-ACLR. We graded effusion-synovitis using the Outcome Measures in Rheumatology ordinal scale (0 = absent to 3 = severe) from suprapatellar ultrasound images and dichotomized into absent/mild (grades 0-1, n = 24) and moderate/severe (grades 2-3, n = 28) groups. We assessed psychological readiness and kinesiophobia using the ACL Return to Sport after Injury Scale and the Tampa Scale of Kinesiophobia-11, respectively. We compared outcomes between groups using analysis of covariance models adjusted for time since surgery and sex. Sensitivity analyses treated effusion-synovitis as an ordinal variable (Spearman correlations) and as a binary variable (no effusion vs any effusion). RESULTS:Effusion-synovitis grade distribution: grade 0, n = 6 (11.5%); grade 1, n = 18 (34.6%); grade 2, n = 18 (34.6%); and grade 3, n = 10 (19.2%). We observed no significant between-group in kinesiophobia (absent/mild: 21.3 [5.4], moderate/severe: 22.0 [5.7]; F1,48 = 0.01, P = .927; 95% CI, 0.000-0.041) or psychological readiness (absent/mild: 62.2 [20.2], moderate/severe: 56.0 [27.2]; F1,48 = 0.00, P = .990; 95% CI, 0.000-0.000). Sensitivity analyses yielded consistent null findings. CONCLUSIONS:Effusion-synovitis severity did not associate with kinesiophobia or psychological readiness at 4 to 6 months post-ACLR, with small effect sizes.
CONTEXT:Running is good for overall health but has a poorly understood risk of injury. Wearable technology and machine learning (ML) offer solutions to this problem. Using ML, we aimed to determine (1) the key important factors that increase the probability of classifying a run as belonging to an injured group, (2) the best-performing ML model, and (3) the sample size required for future substantive studies. DESIGN:Exploratory classification analysis. METHODS:Heart rate/inertial measurement unit/GPS data were extracted from the wristwatches of 88 recreational runners (65 injured and 23 uninjured) during a 12-week prospective cohort. Data were extracted from each run completed by participants, and each run was considered an independent event. Variance inflation factor was used to check for collinearity, and the robust normalizer was used to scale numerical features. Seven ML models were used and validated using repeated stratified 10-fold cross validation. Accuracy, precision, and recall were used to evaluate ML model performance and SHapley Additive exPlanations to determine the relative importance of the individual factors. RESULTS:The final data set had 29 numeric factors, with 4758 run instances from 80 participants. Participants completed between 6 and 148 (mean: 55.5) runs between November 2, 2022, and February 5, 2023. The 4 best-performing ML models were CatBoost, GMB, Light Gradient Boosting Machine, and GXBoost (average model performance > 0.90). CatBoost was the best-performing model, 96% correct in classifying runs from the injured groups. Critical power was the most important factor across all 4 algorithms, with higher values increasing the probability of classifying a run as belonging to the injured group. CONCLUSION:Future cohort studies using ML to explain running-related injury development should use boosting ML models, specifically CatBoost, and include critical power. We advise against interpreting these results as a causal explanation for injury development, and model performance may be overestimated due to our validation approach.
CONTEXT:Delayed recovery may affect lower-extremity kinematics and kinetics during impact activities, potentially altering movement patterns. Such changes may be associated with increased exposure to injury risk factors or impaired performance-related outcomes in runners. This study investigated whether completing a half-marathon affects 3D running kinematics. DESIGN:Within-subject repeated measures. METHODS:Fifteen trained adult runners (11 males) completed an outdoor half-marathon, aiming for their personal best time. Perceived recovery, pain perception, pressure pain threshold, and 3D running kinematics were assessed 72 hours before and 48 hours after the half-marathon. Repeated-measures analysis of variance was used to compare discrete variables, and statistical parametric mapping was applied to analyze kinematic waveforms (α = .05). RESULTS:Reduced pressure pain threshold for the vastus lateralis region and reduced perceived recovery were observed 48 hours posthalf-marathon, indicating delayed effects of the exercise on recovery. Nonsignificant differences were observed in sagittal-plane joint kinematics, with runners exhibiting slightly longer stance time (small to medium effect size, mean difference of ∼3%) and larger ankle range of motion (small to medium effect size, mean difference from 7 to 11%) in the transverse plane 48 hours posthalf-marathon. The small magnitude leg asymmetries observed in the prehalf-marathon were no longer present 48 hours posthalf-marathon. No differences were observed in joint angles waveforms pre- versus posthalf-marathon. CONCLUSION:Overall, runners maintained stable sagittal-plane lower limb kinematics 48 hours after a half-marathon, with minor changes in ankle transverse-plane motion and stance time. Although these adaptations were small, they may be considered when interpreting running mechanics during the recovery period following strenuous endurance exercise. The impact of this short-term adaptation on injury risk requires further investigation.
CONTEXT:Bowling is a widely practiced sport in the United States, both recreationally and competitively. Despite its popularity, bowling carries a risk of injury. However, comprehensive epidemiological data on bowling-related injuries are extremely limited, especially in comparison with those for other well-known sports. This study aims to provide an updated review of epidemiological patterns by age, sex, body region, and mechanism of injury for bowling-related injuries in the United States between 2014 and 2023. DESIGN:Retrospective epidemiological study. METHODS:Bowling-related injury data from 2014 to 2023 were extracted from the National Electronic Injury Surveillance System. Variables included age, sex, body region, diagnosis, disposition, and injury mechanism. Weighted national estimates were calculated. Statistical analyses included linear regression, t-tests, analysis of variance, and chi-square tests, with significance set at P < .05. RESULTS:A total of 3299 injuries were identified, corresponding to a national estimate of 141,844 injuries. The mean age was 34 years; 51.6% were male. Adults (19-64 y) had the highest injury rates. Trunk (21.9%), head/neck (13.4%), and finger (12.6%) were the most commonly injured regions across all age groups. Sprains/strains were the most frequent diagnosis (29.9%). Falls were the leading mechanism (27.5%), especially in children and seniors. Most patients (95%) were treated and released. Injury incidence declined over the study period, with a sharp drop in 2020, likely due to the COVID-19 pandemic and declining bowling participation. CONCLUSION:Bowling-related injuries most commonly affect the trunk and upper extremities, with falls and overexertion as leading mechanisms. Injury patterns vary by age, with children and seniors demonstrating higher rates of falls and acute injuries, and adults demonstrating higher rates of overuse injuries. Understanding the epidemiology of bowling-related injuries can inform targeted prevention strategies, including supervision and equipment for children, conditioning for adults and seniors, and education on safe techniques for all bowlers.
CONTEXT:Clinical tests, such as the Ober, and modified Ober tests are commonly used to assess iliotibial band (ITB) stiffness. Whether these tests can be used to evaluate ITB stiffness in vivo, or whether alternatives are available remains unclear. We aimed to investigate whether commonly used and alternative clinical tests reflect ITB stiffness in vivo. DESIGN:Cross-sectional. METHODS:Thirty-five healthy males underwent the traditional Ober and modified versions of the Ober tes, including variations performed with the tested hip in extension, as well as a hip extension test with tibial external rotation. We defined positive cutoff values as < 0° of hip adduction for the Ober test and Ober test with the tested hip in extension, <10° of hip adduction for the modified Ober test and modified Ober test with the tested hip in extension, and <0° of hip extension for the hip extension test with tibial external rotation. Shear wave elastography was used to assess the stiffness of the ITB, rectus femoris, tensor fascia lata, gluteus medius, and gluteus minimus. Multivariable logistic regression analyses were performed to investigate associations between positive clinical test findings and tissue stiffness. RESULTS:Higher ITB stiffness was associated with positive findings in the modified Ober test performed with the tested hip in extension (odds ratio = 1.03, 95% confidence interval = 1.00-1.06, P = .04) and the hip extension test with tibial external rotation (odds ratio = 1.04, 95% confidence interval = 1.00-1.07, P = .03). The traditional Ober and modified Ober tests were not associated with ITB stiffness. CONCLUSIONS:Traditional Ober-based tests may have limited utility for evaluating ITB stiffness in vivo. Modified testing positions, particularly the modified Ober test with the tested hip in extension and the hip extension test with tibial external rotation, may better reflect ITB stiffness.
Context : Lateral ankle sprains are among the most common musculoskeletal injuries, and in specific sporting populations, up to 70% of cases may progress to chronic ankle instability (CAI). This study explored qualitative sensations during the Weight-Bearing Lunge Test (WBLT), a reliable and valid dorsiflexion range of motion assessment, to identify differences among CAI patients, individuals who have recovered from ankle sprains (copers), and healthy controls. Design : Cross-sectional study. Methods : A total of 147 active adults classified as controls (n = 55), copers (n = 52), and CAI (n = 40) performed the WBLT. Two blinded raters independently collected and coded participant-reported sensations by type (eg, pain, stretching) and localization (eg, Achilles tendon, talus). Sensations were aggregated at the participant level and were analyzed using chi-square or Fisher’s Exact Tests with Bonferroni correction and effect size estimation. Results : Stretching was the most common sensation across all groups (77.6%), typically localized to the posterior (61.9%) and anterior (51.7%) aspects of the leg and ankle. CAI participants reported pain more frequently than controls (42.5% vs 12.7%, P = .003) as well as sensations on the lateral side of the leg and ankle more often (25% vs 3.6%, P = .001). No other categories differed significantly between groups after adjustment. Conclusions : CAI participants have distinct WBLT sensation profiles, underscoring the importance of qualitative assessment during the WBLT for tailoring rehabilitation strategies in this population.
CONTEXT:To examine the association between unilateral and bilateral perceived ankle instability and proprioceptive acuity and the stability of the measures over a time period of 1 week. DESIGN:Repeated-measures study. METHODS:We categorized 134 physical education students into "no," "unilateral," or "bilateral" perceived ankle instability groups based on Cumberland Ankle Instability Tool (CAIT) scores and assessed ankle proprioception using Active Movement Extent Discrimination Assessment for each leg at 2 time points (T1 and T2) 1 week apart. The lower limbs for each participant were identified as "more unstable" for the lower CAIT score and "less unstable" for the leg with the higher CAIT score. RESULTS:Two-way analysis of variance showed significant main instability effect (P < .001), with the bilateral group demonstrating the lowest proprioceptive acuity overall. In the more unstable leg, the no instability group scored significantly higher than the unilateral instability (mean difference [MD]: 0.043; 95% CI, 0.015 to 0.071) and bilateral instability groups (MD: 0.059; 95% CI, 0.024 to 0.094). In the less unstable leg, the no instability group performed better than the bilateral instability group (MD: 0.057; 95% CI, 0.022 to 0.091), whereas there was no significant difference versus the unilateral instability group (MD: 0.019; 95% CI, -0.009 to 0.047). A significant main time effect (P = .019 less unstable leg; P = .034 more unstable leg) showed a mean improvement of 0.015 in both limbs upon retesting. CONCLUSION:We found a significant association between bilateral perceived ankle instability and reduced proprioceptive acuity in both legs. The lack of variance between the less unstable and the more unstable legs in either group suggests that these deficits are not localized to a peripheral joint. Consequently, rehabilitation strategies should consider a holistic, bilateral approach, addressing both ankles regardless of which side is perceived as unstable.
CONTEXT:Early sport specialization is associated with increased risk of injury and sport attrition. There may be a relationship between early sport specialization and chronic injuries, and these injuries may in turn impact future sport participation. Our aim was to investigate the relationship between the degree of early specialization and the odds of reporting a chronic injury. A second aim was to explore the influence that chronic injuries had on an athlete's decision to discontinue participation in their sport. STUDY DESIGN:Cross-sectional study. METHODS:Retrospective data was obtained from a questionnair e given to 322 college students currently enrolled in their institution's general education wellness course. The degree of early sport specialization for each participant was calculated using a 4-point specialization scale. Odds ratios with 95% CIs were calculated for chronic injury's association with early sport specialization. Frequency and weighted average rank of options were used to determine which factors had the most influence on specialization and discontinuation decisions. RESULTS:Of the 322 athletes surveyed, degree of early sport specialization was determined for 214 (66%). When compared with the referent ("No early sport specialization"), all degrees of early sport specialization (low, moderate, and high) had significantly higher odds (2.32; 95% CI, 1.07-5.04; 3.64; 95% CI, 1.74-7.64; and 4.86; 95% CI, 2.14-11.01, respectively) of reporting a chronic injury. "Personal enjoyment" was the most common reason given for choosing to specialize in a sport (n = 198, average rank = 1.5). "Loss of motivation or enjoyment" was the most common reason for quitting a sport (n = 98, average rank = 1.62). CONCLUSIONS:Early sport specialization is associated with significantly greater odds of reporting a chronic injury. Factors pertaining to personal enjoyment are the primary drivers of both the decision to specialize and the decision to discontinue a sport.
CONTEXT:Weakness of the quadriceps and hamstrings often persists following rehabilitation after anterior cruciate ligament reconstruction (ACLR). Yet, recovery of the gastrocnemius muscle following ACLR remains unclear. Thus, we aimed to compare the cross-sectional areas (CSAs) of the calf (lateral and medial gastrocnemius) muscle in individuals 1 year after ACLR with uninjured controls and to investigate longitudinal CSA changes up to 5 years post-ACLR. DESIGN:Secondary analysis of a longitudinal cohort study. METHODS:Existing knee MRI axial scans of 78 individuals, 1 year after ACLR, and 17 uninjured controls were segmented to obtain lateral and medial gastrocnemius muscle CSAs. Follow-up MRIs at 5 years post-ACLR were also segmented. Cross-sectional areas were compared in participants 1 year post-ACLR and controls using analysis of covariance, adjusting for age, sex, and body mass index. Changes in CSAs from 1 to 5 years post-ACLR were evaluated using paired t tests. Supplementary analyses included sex-stratified analyses. RESULTS:Individuals 1 year after ACLR had smaller lateral gastrocnemius muscle CSA than controls (mean difference: -3.86 cm2; 95% CI, -5.71 to -2.00), but no differences were found in the medial gastrocnemius muscle CSA (-1.02 cm2; 95% CI, -2.95 to 0.91). Lateral (0.54 cm2; 95% CI, -0.18 to 1.27) and medial (0.30 cm2; 95% CI, -0.43 to 1.03) gastrocnemius muscle CSA did not change between 1 and 5 years post-ACLR. The supplementary analyses revealed increases in both lateral (0.85 cm2; 95% CI, 0.24-1.47) and medial (0.53 cm2; 95% CI, 0.16-0.90) gastrocnemius muscle CSAs in females from 1 to 5 years post-ACLR, but not in males. CONCLUSION:Calf muscle atrophy exists 1 year after ACLR, suggesting that postoperative rehabilitation should target muscles beyond the thigh. Moreover, sex-specific changes in calf muscle size over time underscore that muscle size recovery may differ by sex.
CONTEXT:Historical underrepresentation of female athletes in sports medicine and rehabilitation research has limited the understanding of long-term postretirement health outcomes and the development of female-specific athlete care systems. This study aimed to (1) describe the mental health, brain health, cardiovascular health, musculoskeletal health, and general well-being of elite retired Australian female athletes; (2) compare these characteristics with the Australian general population where possible; and (3) explore retired athletes' perception of how sport has impacted their health and well-being. METHODS:Data were collected through a larger online cross-sectional survey co-created with female athletes and disseminated to Australian retired elite (international- and national-level) female athletes aged ≥18 years old and retired from elite competition ≥2 years. RESULTS:One hundred and ninety-nine retired athletes (mean [SD]: age 44 [10] y; retired for 16 [9] y; competed for 10 [5] y) across 31 different sports responded to the 147 questions. Athletes had lower odds of depression than the general population (odds ratio = 0.65; 95% CI, 0.49 to 0.86). Nearly all athletes (94%) reported witnessing or experiencing harassment/abuse during their career. A greater proportion of athletes (8%) reported atrial fibrillation/flutter than the general population (2%). Eighty-one athletes (41%) reported retiring due to injury-most commonly involving the knee, the most common source of ongoing pain. Despite the impact of injuries, most athletes (81%) would compete at the same level again if given the choice. They recommended current developing athletes prioritize individual health needs and foster a sense of self beyond sport. CONCLUSION:We identified a high prevalence of harassment and abuse, atrial fibrillation/flutter, and knee injuries. These findings highlight the need for sex- and gender-specific tailored mental health and injury prevention systems-moving beyond reliance on male-centric data-to protect all athletes' long-term health and well-being.
CONTEXT:Chronic low back pain (CLBP) is common among baseball players. However, physical factors associated with CLBP in collegiate players remain unclear. This study aimed to identify these factors. DESIGN:Cross-sectional study. METHODS:This cross-sectional study included collegiate baseball players. Of the 153 players surveyed, 118 were included in the final analysis (29 with CLBP and 89 without CLBP). Based on questionnaire responses, players were classified into CLBP and non-low back pain groups. Body composition, trunk flexibility, hip range of motion, trunk muscle strength, and baseball-related training loads were assessed. Groups were compared using appropriate parametric or nonparametric tests, effect sizes were calculated, and multivariate logistic regression was performed to identify factors associated with CLBP. RESULTS:The prevalence of CLBP was 18.9%. Compared with the non-low back pain group, the CLBP group demonstrated significantly reduced standing trunk flexion and lead-leg hip internal rotation with small effect sizes. In the multivariate analysis adjusted for body mass index, reduced standing trunk flexion (odds ratio = 0.94; 95% CI, 0.889-0.997) and reduced lead-leg hip internal rotation (odds ratio = 0.93; 95% CI, 0.877-1.000) were independently associated with CLBP. CONCLUSIONS:Reduced trunk flexion and limited lead-leg hip internal rotation were associated with CLBP in collegiate baseball players, suggesting the usefulness of assessing trunk and hip mobility in identifying affected players.
CONTEXT:The athletic shoulder (ASH) test traditionally evaluates upper limb isometric strength in a prone position using a force platform. However, this position may lack functional relevance, and the force platforms are not portable. A functional electromechanical dynamometer may provide a potentially valid, reliable, portable, and standardized seated alternative. DESIGN:Randomized, repeated-measures design to assess the between-session reliability and concurrent validity of the Modified Seated ASH Test using an electromechanical dynamometer compared with the prone ASH test using a force platform. METHODS:Thirty-four active university students (15 males, 19 females; 19.73 [3.68] years) completed ASH assessments using a force platform (prone) and an electromechanical dynamometer (seated). We evaluated between-session reliability using intraclass correlation coefficients and coefficients of variation and concurrent validity using Pearson correlations (r) and Bland-Altman analyses. RESULTS:The electromechanical dynamometer demonstrated excellent reliability across the 180° (I), 135° (Y), and 90° (T) positions (intraclass correlation coefficient = .91-.97, coefficients of variation = 7.25%-11.33%). The force platform also showed good to excellent reliability but with higher variability (intraclass correlation coefficient = .83-.91, coefficients of variation = 12.43%-15.89%). Electromechanical dynamometer and force platform forces correlated strongly across positions (r = .77-.87, P < .001). However, Bland-Altman analyses revealed the electromechanical dynamometer yielded systematically higher forces (bias = 18-28 N) with nontrivial limits of agreement, indicating scores differ meaningfully between devices. CONCLUSIONS:The Modified Seated ASH test, using an electromechanical dynamometer, has good to excellent reliability for assessing upper limb isometric strength and is strongly associated with the traditional force platform-based ASH test. The presence of systematic bias and nontrivial limits of agreement indicates that electromechanical dynamometer- and force platform-derived forces should not be considered interchangeable for absolute strength quantification.
CONTEXT:Scapular dyskinesis is frequently associated with subacromial pain syndrome (SAPS), and clinicians increasingly use inertial sensors as a portable, low-cost option to assess scapular kinematics. However, the reliability of these measurements in individuals with SAPS and scapular dyskinesis remains unclear. This study aimed to report the reliability of scapular kinematic variables obtained using inertial sensors during arm elevation and lowering in individuals with SAPS and scapular dyskinesis. DESIGN:Test-retest study. METHODS:Fifty-two adults with unilateral SAPS for at least 3 months and clinically diagnosed scapular dyskinesis performed arm elevation and lowering in the scapular plane across 2 sessions separated by 48 to 72 hours. Five inertial sensors (Xsens) recorded 3-dimensional scapular upward rotation, internal rotation, and scapular tilting at 30°, 60°, 90°, and 120° of humeral elevation on both limbs. Within- and between-day reliability were quantified using intraclass correlation coefficients, standard error of measurement, and minimal detectable change. RESULTS:Within-day reliability was excellent, with intraclass correlation coefficients ranging from .91 to .97 for all scapular angles. Between-day reliability ranged from .63 to .89 across movements and angles, with higher values on the dominant side and at lower elevation angles. Standard error of measurement values ranged from 0.67° to 4.55°, and minimal detectable change values from 1.87° to 12.61°, indicating low-to-moderate measurement error. CONCLUSIONS:Inertial sensors provide reliable within- and between-day measurements of scapular kinematics during arm elevation and lowering in individuals with SAPS and scapular dyskinesis, particularly on the dominant limb and at lower elevation angles, supporting their use as a clinical assessment tool.
CONTEXT:Early-onset osteoarthritis and associated symptoms are common after anterior cruciate ligament reconstruction (ACLR), but evidence for effective treatments is limited. We aimed to assess the feasibility of a slim-fit knee brace in young adults with a symptomatic knee post-ACLR. DESIGN:6-week feasibility randomized controlled trial. METHODS:Participants (aged 18-45, 1-8 y post-ACLR) with a symptomatic knee were randomized (2:1) to (1) a slim-fit knee brace group, to wear ≥1 hour daily and during aggravating activities; or (2) a no brace control group. Feasibility was assessed via eligibility, enrollment, recruitment, dropouts, adverse events, and adherence (temperature sensor). Acceptability was assessed via treatment satisfaction (100-point scale) and explored in semistructured interviews and analyzed thematically. Secondary outcomes included 6-week change in Knee injury and Osteoarthritis Outcome Score, Tampa Scale of Kinesiophobia, and hop performance. RESULTS:Of 48 participants screened, 24 (50%) were eligible and 21 (88%) enrolled over 6 months (52% male, mean age 31 [6] y, n = 14 brace, n = 7 control). One control participant was lost to follow-up (5% dropout). In the brace group, there were 2 serious and 3 minor unrelated adverse events, and 6 minor skin-related events; the control group had 2 minor events. Brace adherence averaged ≥1 hour per day on 43% of days (participant range 0%-78%). For acceptability, satisfaction was rated 70/100 (19). Fourteen interviews identified themes of perceived effectiveness (eg, improved confidence, pain relief), practical challenges to brace wear (eg, fit, clothing compatibility), and integration into daily life (eg, ease of use, social perceptions). The brace showed potential for worthwhile treatment effects for hop performance, and most Knee injury and Osteoarthritis Outcome Score subscales, but not for kinesiophobia. CONCLUSIONS:A full-scale randomized controlled trial is feasible, as recruitment and retention targets were met, although adherence requires refinement. The brace showed promising functional benefits, supporting further evaluation as a low-burden intervention for young adults with a symptomatic knee post-ACLR.
CONTEXT:Persistent neuromuscular deficits and physical activity limitations are common after traumatic knee injuries. While biomedical literature focuses on measurable strength, there is a lack of depth regarding how individuals navigate the long-term journey of recovery including the psychological and social adaptations required in daily life. This study explored individuals' lived experiences of rehabilitation and long-term recovery following traumatic knee injury, focusing on their perceptions of physical function, symptom management, and the evolution of their physical activity engagement. DESIGN:Qualitative study. METHODS:We used semistructured, one-on-one interviews conducted online with 19 individuals (9 females, median age = 34 [interquartile range: 28-40], median = 7 [3-14] y postinjury) who had sustained a traumatic knee injury. Participants were purposively selected for maximum variation. Data were analyzed using reflexive thematic analysis. RESULTS:Three themes were identified that characterize recovery as a nonlinear journey of identity reconstruction. (1) An unreliable limb: initial neuromuscular silence and permanent limitations-participants described an early state of bodily alienation where the muscle was perceived as disconnected from control. Long-term deficits were framed by participants as a fragility of progress. (2) The pendulum of recovery: balancing progress, symptoms, and systemic friction-recovery was reported as an oscillation between progress and setbacks. Participants identified visceral barriers and a clinical void in health care guidance as primary deterrents to sustained engagement. (3) The forever knee: acceptance and stewardship-participants described a transition toward lifelong stewardship involving the psychological labor of mourning the preinjury self and accepting a new normal of good enough function and exercise routines. CONCLUSIONS:Neuromuscular recovery is a multifaceted psychosocial process rather than a linear biological event. Participants identified that a lack of long-term guidance often results in permanent activity reduction. To optimize outcomes, rehabilitation should focus on fostering self-efficacy and support the long-term stewardship of the "forever knee."
CONTEXT:Transcranial direct current stimulation (tDCS) can enhance cortical activity and improve motor performance, potentially inducing synergetic effects when coupled with balance training. Yet, its effects during balance training in individuals with chronic ankle instability (CAI) remain unclear. This study aimed to evaluate whether tDCS has additive effects on static postural control, neural excitability, and perceived ankle function in individuals with CAI compared with sham stimulation. DESIGN:Double-blind, pilot randomized controlled trial. METHODS:Nineteen individuals with CAI were included. Participants were randomized to either active tDCS or sham tDCS. Participants and experimenters were blinded to group allocation. Twenty minutes of anodal tDCS (2 mA) was applied over the contralateral motor cortex of the CAI-injured side during balance training, 3 times a week for 4 weeks. The primary outcome was static postural control, assessed by center of pressure velocity and area during unipedal stance with eyes open and closed. Secondary outcomes included corticospinal and spinal reflexive excitability (soleus, fibularis longus, and tibialis anterior), evaluated via transcranial magnetic stimulation and Hoffmann reflex methods, respectively, during unipedal stance. Self-reported outcomes were assessed. All outcomes were assessed at baseline, during, and following a 4-week intervention. Individual analyses were conducted. RESULTS:Individual analyses show changes in static balance, soleus corticospinal excitability, and ankle function over time, regardless of tDCS group. Effect size estimates indicated small group differences at weeks 2 and 4 in the active-tDCS group compared with sham for most measures. However, the center of pressure area under the eyes-closed condition and fibularis longus corticospinal excitability demonstrated potential moderate (d = -0.62) and large (d = -0.88) effects, respectively. CONCLUSION:This pilot study indicates that tDCS applied during balance training appears to provide no added benefit. However, potential changes in selected outcomes (center of pressure area and corticospinal excitability) warrant a larger clinical trial.
Context (Aim): To estimate the test-retest reliability of performance metrics, heart rates, and symptoms collected during the Multimodal Exertional Test (MET) in healthy interuniversity athletes. STUDY:Test-retest reliability. METHODS:Twenty-five participants (n = 14 males, n = 11 females) completed the MET twice, 1 week apart. Participants' performance metrics and symptom severity scores were obtained following each task, and average and maximum heart rates were collected prior to the MET and during each stage. RESULTS:In both females and males, the completion times for 7 out of 9 MET tasks were performed between 1 and 6 seconds faster at time point 2 in comparison with time point 1; however, the majority of the concordance correlation coefficients (CCC) fell within the range of good agreement (.61 < CCC < .80). Males performed all 9 tasks faster compared with females. All MET count data performance metrics (ie, number of words, step-down + lateral jumps, and jump-overs) were consistent between time points as no differences were observed. Average and maximum heart rates were consistent between sessions, typically differing by approximately 2 beats/min, with good agreement (CCCs of .64-.74). Male and female symptom severity scores did not differ between instances. CONCLUSIONS:The MET demonstrates good reliability across key domains, including symptom reporting, physiological responses, and several performance-based metrics. Clinicians should consider potential practice effects in task completion times and account for sex differences when applying these findings to concussion assessment and establishing clinical benchmarks.
