Altered gluteus medius contraction during gait in chronic ankle instability versus coper and healthy groups

Musculoskeletal ultrasound imaging (USI) was used to assess gluteal muscle activity throughout walking gait among healthy individuals, patients with chronic ankle instability (CAI), and lateral ankle sprain “copers”. While gluteus maximus activity was comparable across groups throughout the gait cycle, the CAI group presented with significantly decreased gluteus medius activity throughout the gait cycle when compared to copers and healthy counterparts. Copers and healthy groups presented similarly with increased gluteus medius activity above resting thickness levels. As gluteus medius inactivity was unique to CAI patients, this proximal muscle deficit may exacerbate lower extremity dysfunction during walking gait.