Context : The Copenhagen Adduction (CA) exercise is commonly prescribed to field-sport athletes and has been proven as effective in strengthening the hip adductor muscles and reducing groin problems. The aim of this study was to compare maximal isometric torque in the isometric CA exercise with various loads, and at various lever-lengths, in a cohort of male and female field-sport athletes. Design : Cross-sectional study. Methods : Hip adduction torque was assessed in the short-lever, mid-lever, and long-lever testing positions during the isometric CA exercise with body mass-only, and with various loads, in 48 field-sport athletes. Results : A 2-way repeated-measures analysis of variance revealed no significant interaction between added external weight and lever length on torque ( F 4 = 1.366, P = .248, η 2 = .033), indicating that the effect of added external weight on torque during the CA exercise was consistent across lever length positions. Added external weight demonstrated a significant main effect on torque ( F 2 = 114.494, P ≤ <.001, η 2 = .741), with significantly greater torque evident with 20% body mass added compared with 10% body mass added (mean difference: 0.28 N·m/kg) and body mass-only (mean difference: 0.53 N·m/kg), and significantly greater with 10% body mass compared with body mass-only (mean difference: 0.25 N·m/kg). Lever-length demonstrated a significant main effect on torque ( F 2 = 89.403, P ≤ .001, η 2 = .691), with significantly greater torque evident in the long-lever position compared to the mid-lever position (mean difference: 0.22 N·m/kg) and short-lever position (mean difference: 0.52 N·m/kg), and significantly greater in the mid-lever position compared to the short-lever position (mean difference: 0.30 N·m/kg). Conclusions : Added external weight conditions and lever-length have a significant effect on torque during the isometric CA exercise, with large effect size. This data can inform exercise selection criteria for the CA exercise, based upon hip adduction torque requirements.
Context : Up to 75% of lateral ankle sprain cases experience long-term impairments and suffer chronic ankle instability (CAI), a condition characterized by impaired ankle proprioception. This study aims to investigate ankle proprioceptive performance during functional tasks with increasing movement control and ankle joint load in individuals with and without CAI. Design : Cross-sectional study. Methods : Twenty individuals with CAI and 19 healthy controls completed 4 proprioceptive tasks: standing, walking, landing (double-leg drop), and stair descent. In each task, their ability to discriminate between 4 ankle inversion angles was assessed using a task-specific discrimination apparatus. Results : CAI participants had significantly lower ankle proprioception scores than controls (mean difference = 0.047, 95% CI, 0.031–0.063). Proprioceptive acuity varied by task ( P < .001, ), with no significant group-by-task interaction ( P = .220, ). Trend analysis showed a linear improvement in proprioceptive performance with increasing ankle load and challenge in controls ( P < .001, ), whereas the CAI group showed both significant linear ( P < .001, ) and quadratic ( P = .001, ) trends, reflecting a rise followed by a significant downturn as load peaked. Conclusions : Both groups improved with greater load, but during stair descent, individuals with CAI exhibited a significant decline. This suggests that proprioceptive processing in CAI is impaired and may be overloaded during highly challenging tasks.
Context : Individuals with anterior cruciate ligament (ACL) injury are at high risk of knee osteoarthritis. Black individuals with osteoarthritis have worse pain and disability than White individuals. Racial disparities in ACL treatment use (ACL reconstruction and physical therapy) may contribute to disparities in long-term osteoarthritis-related disability. However, factors influencing ACL injury disparities are unknown. We explored facilitators and barriers to treatment access and use in Black individuals with ACL injury. Design : Qualitative (semistructured interviews). Methods : We included Black or African American individuals who self-reported ACL injury up to 5 years prior to recruitment, no longer seeking care for the injury, and 16–50 years old. We conducted one-on-one semistructured interviews and topics included facilitators and barriers to care, perceived communication, medical trust, and perceived discrimination. We used a reflexive thematic analysis approach to analyze the interviews. Results : We included 10 participants (age 21–49 y, 8 women). We generated 4 themes: (1) path to diagnosis, (2) patient approach to treatment, (3) patient–provider interactions, and (4) life demands. ACL injury recovery was often complex with frustrations particularly common during the diagnosis process due to lack of an accurate diagnosis and poor communication on next steps. Participants took various approaches to treatment use including active, passive, and more autonomous approaches. Family obligations and transportation barriers posed challenges to accessing treatment. Lack of health insurance was a barrier affecting multiple aspects of recovery. Participants often desired shared decision making. Several types of perceived discrimination were discussed including race, gender, insurance, and weight. Facilitators were often related to positive communication or athletic program resources. Conclusion : Facilitators included shared decision making, provider empathy and encouragement, and athletic program resources. Barriers included a lack of listening to patients’ concerns, lack of health insurance, transportation challenges, and perceived discrimination.
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:Handheld dynamometry is common for isometric strength testing, but the high cost and import barriers of commercial devices (eg, MicroFET II) limit access. Three-dimensional (3D) printing enables low-cost, customizable instruments. We developed the 3D-printed PhysioCode and examined its measurement properties for knee strength. DESIGN:Methods and Technical Report evaluating concurrent validity and test-retest reliability versus a reference handheld dynamometer. METHODS:Forty-nine healthy adults (23.2 [3.9] y; body mass index 21.9 [2.8] kg/m2) performed 3 isometric trials of dominant-limb knee extension and flexion with both devices in randomized order, assessed by 2 trained novice raters under blinded analysis. Concurrent validity was evaluated using Pearson correlation coefficients (r) and root mean square error, and agreement between devices was assessed using Bland-Altman analyses. Reliability was assessed using intraclass correlation coefficients (ICC[2,1] and ICC[2,k]), along with the standard error of measurement and minimal detectable change at 95% confidence. We compared single and repeated test strategies. RESULTS:All mean values differed by ≤21 N between devices across knee extensors and flexors. Concurrent validity was strong-very strong (r = .88-.95; P < .001), with lower root mean square error for averaged repetitions. Bland-Altman showed small, direction-specific bias: PhysioCode slightly overestimated extensor force values (-17 to 21 N) and underestimated flexor force values (-12 N). Reliability was excellent: PhysioCode ICC(2,1) = .93 to .95 and ICC(2,k) = .98 to .98; MicroFET II ICC(2,1) = .89 to .94 and ICC(2,k) = .96 to .98. Averaging 2 to 3 trials reduced standard error of measurement and minimal detectable change at 95% confidence relative to single trials or maxima. CONCLUSIONS:The 3D-printed PhysioCode showed adequate concurrent validity and excellent test-retest reliability for knee extensor/flexor strength, with performance comparable to the MicroFET II in this sample of young, healthy adults. Averaging 2 or 3 repetitions improved precision. These findings suggest that PhysioCode may represent an option for strength assessment, warranting further evaluation in target clinical populations.
