Motor branch block of the rectus femoris: its effectiveness in stiff-legged gait in spastic paresis

OBJECTIVE: To verify the efficacy of motor branch block of the rectus femoris for stiff-legged gait in spastic patients. DESIGN: Before-after treatment trial. SETTING: University hospital physical medicine and rehabilitation department outpatient clinic. PATIENTS: Thirty-one adult spastic patients with stiff-legged gait. INTERVENTION: Motor branch block of the rectus femoris with 2% lidocaine and 5% phenol. OUTCOME MEASURES: Subjective assessment of gait performance by patients themselves and objective assessment of gait speed and sagittal knee kinematics. RESULTS: Seventy-four percent (23/31) of patients felt an improvement (improved knee bending, disappeared toe dragging) after nerve block with lidocaine. Sixteen of 17 patients with an abnormal swing phase activity of the rectus femoris without that of the vastus medialis or lateralis and 20 of 23 patients with a sufficient hip flexor strength expressed an improvement subjectively. Gait analysis showed increased maximal knee flexion at swing phase and increased slope of knee flexion curve at toe off (p < .05). Phenol block was performed in 19 of 23 patients who had had a subjective improvement in their gait performance after nerve block with lidocaine. Gait speed, maximal knee flexion angle at swing phase, and slope of knee flexion curve at toe off increased significantly after phenol block (p < .05). CONCLUSION: Motor branch block of the rectus femoris can be an effective treatment in stiff-legged gait. Its effect is varied with hip flexor strength and dynamic electromyographic findings of quadriceps.