Impact of Becker muscular dystrophy on gait patterns: Insights from biomechanical analysis

Current research on muscular dystrophy primarily focuses on Duchenne muscular dystrophy (DMD) with early onset. However, studies on gait characteristics in Becker muscular dystrophy (BMD) patients with later onset, particularly those diagnosed after the age of 16, remain limited. The late onset of symptoms may disrupt previously established gait patterns, potentially leading to unique compensatory mechanisms and clinical outcomes.

This study aims to investigate gait characteristics and plantar pressure distribution in BMD patients with symptom onset after the age of 16.

Seven male BMD patients diagnosed after the age of 16 and ten healthy male controls were recruited. Changes in gait kinematics and kinetics were analyzed using statistical nonparametric mapping (SnPM), plantar pressure was measured, and symmetry angles (SA) were calculated.

BMD patients exhibited greater anterior pelvic tilt and increased hip flexion during the stance phase (StP), along with higher peak hip extension moments in the early StP, knee hyperextension and insufficient knee extension moments in the early StP, higher knee flexion during the swing phase, and sustained ankle dorsiflexion at the end of the StP. Plantar pressure was increased at the heel, while pressures in the medial and lateral metatarsal regions, as well as the hallux and lesser toes, were significantly lower. SA results indicated a tendency to apply greater pressure on the non-dominant leg.

BMD patients with symptom onset after the age of 16 exhibit gait compensation patterns similar to those observed in some DMD patients, with distinct differences in ankle joint behavior that warrant further investigation. Plantar pressure distribution may serve as potential clinical indicators for assessing disease progression.