ABSTRACT
BACKGROUND: After an anterior cruciate ligament reconstruction (ACLR), only 47% of military members return to full duty, possibly due to persistent neuromuscular asymmetries. Psychological factors may also contribute to reduced return to duty in military members. HYPOTHESIS: Psychological factors and time since surgery would be associated negatively with neuromuscular asymmetries, asymmetries would be greater in cadets postsurgery when compared with healthy controls, and asymmetries would be greater at earlier timepoints after ACLR. STUDY DESIGN: Case control. LEVEL OF EVIDENCE: Level 4. METHODS: This study examined the relationship between psychological factors and time since surgery with neuromuscular asymmetry, compared neuromuscular asymmetries between cadets with and without a history of ACLR, and explored differences in neuromuscular asymmetries at different timepoints in cadets with a history of ACLR. A total of 37 cadets post-ACLR (18.3 ± 9 months) and 28 controls participated. Psychological factors were assessed using the Tampa Scale of Kinesiophobia and Anterior Cruciate Ligament-Return to Sport after Injury scale (ACL-RSI). Participants performed a drop-jump landing, joint positioning sense (JPS), and isometric quadriceps strength testing. Peak vertical ground-reaction forces (vGRF), absolute angle of replication, peak quadriceps torque, rate of torque development (RTD), and RTD time torque interval 200 ms (TTI200) were analyzed. RESULTS: The ACL-RSI score was significantly related to limb symmetry index (LSI) peak quadriceps torque (r = 0.617, P < 0.01), LSI RTD (r = 0.367, P = 0.05), and LSI TTI200 (r = 0.0489, P < 0.01), but not time since surgery, JPS, or LSI peak vGRF. Cadets with a history of ACLR had significantly lesser ACL-RSI scores and greater asymmetries compared with controls. CONCLUSION: Reduced psychological readiness was associated with increased neuromuscular asymmetries after ACLR. CLINICAL RELEVANCE: Clinicians should assess psychological readiness during rehabilitation after ACLR.
ABSTRACT
Background: Static balance is often impaired in patients after ankle sprains. The ability to identify static balance impairments is dependent on an effective balance assessment tool. The Sway Balance Mobile Application (SWAY App) (Sway Medical, Tulsa, OK) uses a smart phone or tablet to assess postural sway during a modified Balance Error Scoring System (mBESS) assessment and shows promise as an accessible method to quantify changes in static balance after injury. Purpose: The primary purposes of this study were to determine the ability to differentiate between those with ankle sprain versus controls (construct validity) and ability to detect change over time (responsiveness) of a mBESS assessment using a mobile device application to evaluate static balance after an acute ankle sprain. Study Design: Case-control study. Methods: Twenty-two military academy Cadets with an acute ankle sprain and 20 healthy Cadets were enrolled in the study. All participants completed an assessment measuring self-reported function, ankle dorsiflexion range of motion (via the weightbearing lunge), dynamic balance, and static balance. Static balance measured with the mBESS using the SWAY App was validated against laboratory-based measures. Cadets with ankle sprains completed their assessment twice: once within two weeks of injury (baseline) and again after four weeks of rehabilitation that included balance training. Independent and paired t-tests were utilized to analyze differences over time and between groups. Effect sizes were calculated and relationships explored using Pearson's correlation coefficients. Results: The mBESS scores measured by the SWAY App were lower in participants with acute ankle sprains than healthy Cadets (t = 3.15, p = 0.004). Injured participants improved their mBESS score measured by SWAY at four weeks following their initial assessments (t = 3.31, p = 0.004; Baseline: 74.2 +/- 16.1, 4-weeks: 82.7 +/- 9.5). The mBESS measured by the SWAY App demonstrated moderate to good correlation with a laboratory measure of static balance (r = -0.59, p \< 0.001). Conclusion: The mBESS assessed with a mobile device application is a valid and responsive clinical tool for evaluating static balance. The tool demonstrated construct (known groups) validity detecting balance differences between a healthy and injured group, concurrent validity demonstrating moderate to good correlation with established laboratory measures, and responsiveness to changes in static balance in military Cadets during recovery from an acute ankle sprain. Level of Evidence: Level 3.
