Dynamic Motor Control Changes after Botilinum Toxin Treatment in Cerebral Palsy Patients

INTRODUCTION Cerebral palsy (CP) is caused by an injury to the brain and causes problems with movement and coordination due to impaired voluntary motor control. Past research has shown that muscle activity during human movement can be described by a small set of weighted simultaneous muscle activations known as synergies. Synergies are estimated by measuring muscle activations with electromyography (EMG) and using algorithms, such as nonnegative matrix factorization (NNMF), to identify muscles that are consistently activated together [1]. Applying these techniques to patients with CP has shown that fewer synergies are required to describe muscle activity during gait than unimpaired individuals [2]. However, it remains unclear if current treatments to improve movement for individuals with CP alter neuromuscular control or synergies. Botulinum toxin type A (BTA) is a common treatment for individuals with CP and aims is to improve mobility by reducing muscle spasticity and normalizing gait kinematics. The purpose of this study was to evaluate whether synergies change after BTA treatment. Secondarily we sought to determine if positive changes in gait kinematics are correlated with changes synergies.