Are gait and mobility measures responsive to change following botulinum toxin injections in adults with lower limb spasticity?

Purpose: To determine whether gait and mobility measures are responsive to change following botulinum toxin (BoNT) injections in adults with lower limb spasticity. Method: Independently ambulant adults who attended a spasticity clinic for lower limb BoNT injections were eligible to participate. The 10 m walk test (shoes on and off), timed up and go test and 6-min walk test were performed before injection and 1 month later. Participants completed a global rating of change scale (GRCS) at follow up. Comparisons were made between participants' ratings of change and change in walking performance. Effect sizes (ES) and standard error of measurement (SEM) were calculated for each outcome. Results: Thirty-nine patients (22 female, 17 male; mean age 51 +/- 12 years; range 26-74 years) with a median spasticity duration of 53 months participated. Statistically significant changes were found in all gait and mobility measures at 1 month following injection. All ES were small (<0.2) and SEM for each measure was large. The global rating of change scale (GRCS) indicated that 66% of participants perceived that their walking had improved. However, there was a significant relationship between GRCS and performance on walking tests for the 10 m walk test with shoes off (p = 0.01) and timed up and go test (p = 0.02) only. Conclusion: Commonly used walking tests may not be responsive to change following BoNT injection. The small ES suggest that BoNT has a modest effect on walking ability. Tests of walking performance may not be sufficient to capture all clinically relevant changes in walking ability following BoNT injection of the lower limb.