Foot Varus in Stroke Patients: Muscular Activity of Extensor Digitorum Longus During the Swing Phase of Gait

Background: Hemiparetic patients often present an abnormal leg muscles balance that can lead to foot deformities like equinovarus or varus.

Objective: To assess whether a muscle imbalance between tibialis anterior and extensor digitorum longus was associated with a varus deformity of the foot during the swing phase of gait in stroke patients.

Methods: Twenty hemiparetic patients presenting a foot varus during the swing phase of gait were compared to 16 healthy subjects. Gait was analyzed by video recording and by surface electromyography. Duration and magnitude of electromyographic signal were collected for tibialis anterior and extensor digitorum longus. Presence of an activity of the calf muscles during the swing phase was also evaluated.

Results: Hemiparetic patients exhibited more often premature activity of the calf muscles (p<0.05) and greater duration and amplitude asymmetry between tibialis anterior and extensor digitorum longus (p<0.05). These asymmetries were explained by a decrease in extensor digitorum longus activity (p<0.05).

Conclusions: The activity of extensor digitorum longus muscle during the swing phase of gait is important to balance the foot in the frontal plane. The activation of that muscle should be included in rehabilitation programs.