Altered neural control of gait and its association with pain and joint impairment in adults with haemophilic arthropathy: Clinical and methodological implications.

Introduction: It is unknown whether altered neural control is associated with clinical outcomes in people with haemophilic arthropathy (PWHA). The dynamic motor control index during walking (Walk‐DMC) is a summary metric of neural control. Aims: The primary aim of this study was to apply the Walk‐DMC to assess if people diagnosed with haemophilic arthropathy have impaired neural control of gait and investigate the association of Walk‐DMC with pain and joint impairment. Method: The Walk‐DMC was assessed using surface electromyography in 11 leg muscles. Twenty‐two PWHA and 15 healthy subjects walked on a 30‐m walkway at 1 m/s. In addition, pain (visual analogue scale), knee flexion contracture (degrees) and joint impairment (Haemophilia Joint Health Score, HJHS) were assessed. The clinical outcomes were correlated with the Walk‐DMC. Multiple regression analysis was performed to predict the Walk‐DMC using the clinical outcomes. Results: In 13 PWHA the Walk‐DMC was beyond the normal range (80–120 pts). PWHA with an altered Walk‐DMC showed more years with arthropathy, more pain, higher knee flexion contracture and a higher HJHS score (P <.05, effect size >.8). Significant negative moderate associations between Walk‐DMC and pain, knee flexion contracture and HJHS were found (P <.05). The model that best predicted the Walk‐DMC was the pain with knee flexion contracture (R2 =.44; P =.004). Conclusions: PWHA with abnormal neural control of gait also has more years with arthropathy, more pain, and more impaired joints. Our results indicate an association between the Walk‐DMC index and joint damage, specifically with pain in combination with knee flexion contracture. [ABSTRACT FROM AUTHOR]