Walking assessment with instrumented insoles in patients with lower limb spasticity after botulinum toxin infiltration.

Introduction: Botulinum toxin A (BTA) improves the kinematic parameters of gait in patients with spasticity of lower limbs, but there are no studies in which kinetic parameters are measured with instrumented insoles. We therefore used instrumented insoles to perform a functional assessment of therapeutic results in patients with lower limb spasticity after brain injury or spinal cord infiltration indicating BTA.

Material And Methods: Ten patients (11 lower limbs) seen in a Neurorehabilitation Unit. The tests carried out included clinical examination, gait assessment (Functional Ambulation Categories (FAC); Hospital de Sagunto Gait Scale), and biomechanical assessment (Biofoot / IBV version 5.0), before and three weeks after infiltration with BTA.

Statistics: t-test for related samples of clinical variables, functional variables and biomechanical variables before and after infiltration. Level of significance P< .05. Qualitative method to assess whether changes in the biomechanical variables tended toward normal values.

Results: BTA improves muscle tone, joint arch and frequency of spasms (P<.01). The patient sample showed a high level of satisfaction with the improvement in symptoms. There were no changes in walking ability after injection. There were no statistically significant changes in biomechanical parameters, but there was improved gait cadence. The relatively small statistical significance close to P=.1 of the peak pressure in the heel after injection indicates the need for further studies with instrumented insoles in people with spasticity due to central nervous system injury.

Conclusions: With the decrease in muscle tone after infiltration with BTA the clinical symptoms associated with muscle tone improved without any functional changes in gait scales. The changes in the biomechanical parameters show that larger studies using instrumented insoles should be performed in the population with spasticity after a central nervous system injury treated with BTA infiltration.