Effect of the rectus femoris motor branch block on post-stroke stiff-legged gait.

Six hemiparetic stroke patients presenting with a stiff-legged gait underwent a motor branch block of rectus femoris (RF). A gait analysis, including synchronous kinematic, dynamic, energetic recordings was performed before and after motor branch block of RF. The electrical activity of RF, Vastus Medialis, Vastus Lateralis, Vastus Intermedius was also recorded. Before nerve block, the sagittal kinematic data showed a decrease in both the mean maximum knee angular displacement during swing phase and the mean angular knee velocity at toe-off. In the sagittal kinetic data, the mean knee extension moment was increased. The mean mechanical work, internal and external work, was increased and the mean energy cost was also decreased. After the motor branch block of Rectus Femoris, the sagittal mean knee angular displacement and the mean internal work of the gait were significantly improved.