Effects of botulinum toxin–A on gait velocity, step length, and base of support of patients with dynamic equinovarus foot

Objective: The aim of this study was to identify if botulinum toxin typeA is a drug able to modify walking velocity, step length, and width of thebase of support of adult patients with dynamic equinovarus foot deformityresulting from upper motor neuron syndrome.Design: This retrospective study analyzed data from 20 patients’ filesselected from 448 consecutive charts. The main inclusion criteria werethe presence of dynamic equinovarus foot deformity due to upper motorneuron syndrome, age between 20 and 80 yrs, evaluation of temporospatialparameters of gait by the Gait Mat II before and 4 wks afterbotulinum toxin type A injection to the calf muscles, and the ability to walkbarefoot, unassisted, and without braces. For data analysis, based onwalking velocity, we divided the patients into two groups, slow walkingvelocity (0.18–0.49 m/sec) and medium walking velocity (0.50–0.99m/sec).Results: Width of the base of support was significantly reduced afterbotulinum toxin type A treatment, both for the affected (P 0.005) andthe unaffected limbs (P 0.002), in the group of subjects walking atmedium velocity. Walking velocity or step length of either group ofpatients was not significantly modified by botulinum toxin type A treatment.Conclusions: Based on this study, a significant effect of botulinumtoxin type A on width of the base of support is evident and seems to be theresult of a better position of the affected foot during the stance phase oflocomotion leading to increased body stability and consequent reductionof width of the base of support of the unaffected limb. No change wasevident in step length or walking velocity for this patient population.