An Adaptive Knee Brace Is Associated With Improved Dynamic Stabilization Compared With a Standard Passive Brace in Anterior Cruciate Ligament‐Deficient Men During a Functional Hop Task

Purpose To compare the dynamic knee stabilization effects of an adaptive dynamic brace (ADB) with those of a standard passive brace in anterior cruciate ligament (ACL)‐deficient men. Methods ACL‐deficient participants were included. The subjects performed 3 single‐leg functional hop tests: drop jump, crossover hop, and 90° rotational hop. Each task was performed once while wearing the ADB and once while wearing a traditional passive brace. Three‐dimensional kinematic data were collected using an 8‐camera optoelectronic motion‐capture system. Repeated‐measures analysis of variance was used to evaluate the effects of brace condition and time. An a priori power analysis indicated that a minimum of 12 participants were required. Results Twelve ACL‐deficient participants were included (age: 30.2 ± 3.4 years; time since injury: 32 ± 6 months; ACL‐Return to Sport after Injury score: 70 ± 3). No significant differences in knee flexion angles were observed between braces. Knee flexion during landing was significantly lower in the crossover hop compared with the drop jump and rotational hop tasks ( P < .01). During the drop jump task, the ADB significantly reduced knee valgus angles ( P < .01). In the crossover hop task, the ADB significantly reduced both knee valgus and rotational angles ( P < .01). During the rotational hop task, a significant brace‐by‐time interaction was observed for knee valgus ( P < .05) and rotational angles ( P < .05). Conclusions The ADB showed improved dynamic stabilization particularly during high‐risk landing and rotational movement compared with a standard passive brace. Clinical Relevance The ADB may enhance the effectiveness of rehabilitation strategies in ACL‐deficient individuals by improving dynamic knee stability during functional activities.