Association between botulinum toxin injection into the arm and changes in gait in adults after stroke

Botulinum toxin (BTX) is often used to improve arm function in persons with hemiparesis after stroke. Persons injected into the arm sometimes report changes in their gait. The purpose of this open-labeled pilot study was to investigate the association between injecting BTX into the upper limb and ankle and knee range of motion (ROM) and paretic-leg stride-time, defined as the time in seconds required to move the hemiparetic leg from initial contact of the foot to initial contact of the same foot. Gait parameters were recorded before and 4 to 6 weeks after the hemiparetic arm was injected with BTX in 13 adults with hemiparesis secondary to stroke, using a three-dimensional computerized motion analysis system. BTX injection into the paretic arm was associated with a decrease in stride-time of the paretic leg in all participants. Slower striding participants improved knee and ankle ROM in the paretic leg. There was no change in ankle and knee ROM in faster striding participants. Injection of BTX into the upper extremity is associated with a change in hemiparetic leg stride-time and ankle and knee ROM. There is a variability of response, with slow striders improving to a greater extent than fast striders.