Gait analysis using three-dimensional motion and ground reaction force systems in patients with hemiplegia treated with botulinum toxin type A in ankle plantar flexors.

Objective: The efficacy of botulinum toxin type A (BoNT-A) injection on spasticity has usually been measured using the range of motion (ROM) of joints and Modified Ashworth Scale (MAS); however, they only evaluate muscle tone at rest. We objectively analyzed the gait of three patients with hemiplegia using three-dimensional motion analysis and ground reaction force (GRF) systems to evaluate muscle tone during gait. Materials and Methods: We measured passive ankle dorsiflexion ROM with knee extension and the MAS score for clinical evaluation, and gait speed, stride length, single-leg support phase during the gait cycle, joint angle, joint moment, and GRFs for kinematic evaluation before and one month after BoNT-A injection. Results: All patients showed an increase in ankle dorsiflexion ROM, improvement in MAS score, and increase in stride length. Case 1 showed an increase in gait speed, prolongation of the single-leg support phase, increase in hip extension angle and moment, and improvement in the vertical and anterior-posterior components of the GRFs. Case 2 showed an increase in gait speed, improvement in double knee action, increase in ankle plantar flexion moment, and improvement in propulsion in the progressive component of the GRFs. Case 3 exhibited a laterally directed force in the GRFs. Conclusion: We evaluated the effects of BoNT-A injections in three patients with hemiplegia using three-dimensional motion analysis and GRFs. The results of the gait analysis clarified the improvements and problems in hemiplegic gait and enabled objective explanations for patients.