Purpose: To characterize the effects of botulinum toxin A treatment of spastic plantar flexors in stroke on joint mobility and gait kinematics and kinetics.
Method: Nine patients with hemiparetic stroke presenting with ankle hypertonicity participated in this exploratory open-label case series study. Comprehensive gait analysis provided bilateral kinematic and kinetic information for the ankle, knee, and hip joints throughout the stance phase. Data were obtained at baseline, 2 weeks, and 10 weeks post botulinum toxin injection of the spastic plantar flexors.
Results: Passive ankle range of motion increased post injection (p < .05). The amount of plantarflexion in late stance was significantly reduced (p < .05) while the maximum dorsiflexion increased in midstance at 10 weeks post treatment. The angular displacement profiles for the knee revealed that patients tended to display less hyperextension following treatment (p = .053). No significant changes in kinetic measures were found; however, case-by-case observations suggested that most patients experienced improvements in positive work production.
Conclusions: The findings indicate that botulinum toxin treatment results in improved joint mobility and ankle kinematics and, in some patients, increases in positive work, suggesting better gait performance.