Effect of botulinum toxin injection in the rectus femoris on stiff-knee gait in people with stroke: a prospective observational study

OBJECTIVE: To study the effect of botulinum toxin type A (BTX-A) injection in the rectus femoris on the decreased knee flexion during the swing phase of gait (stiff-knee gait) in people with stroke. DESIGN: Intervention study (before-after trial) with an observational design. SETTING: Outpatient rehabilitation clinic and gait laboratory. PARTICIPANTS: Nineteen chronic hemiparetic adults presenting with stiff-knee gait. INTERVENTION: Injection of 200 U of BTX-A (Botox) into the rectus femoris. MAIN OUTCOME MEASURES: Before and 2 months after BTX-A rectus femoris injection: Stroke Impairment Assessment Set (SIAS), Duncan-Ely test, and an instrumented gait analysis. RESULTS: Median SIAS score improved from 53 (range, 36-65) to 57 (range, 42-70) (signed-rank test, P=.005) and the Duncan-Ely score from 3 (range, 1-3) to 1 (range, 0-3) (P10 degrees)