Gait velocity and joint power generation after stroke: Contribution of strength and balance

Objective The aim of the study was to assess the degree to which isometric strength of multiple lower limb muscle groups and balance is associated with gait velocity and joint power generation during gait after stroke. Design Sixty-three participants in a multisite, multinational, cross-sectional, observational study underwent assessment of gait velocity (10-m walk test), standing balance (computerized posturography), and isometric strength (hand-held dynamometry). Twenty-seven participants had joint power generation assessed (three-dimensional gait analysis). Bivariate associations were examined using Spearman’s correlations. Regression models with partial F tests were used to compare the contribution to gait between measures. Results Although all muscle groups demonstrated significant associations with gait velocity (ρ = 0.40–0.72), partial F tests identified that ankle plantar flexor and hip flexor strength made the largest contribution to gait velocity. Ankle plantar flexor strength also had strong associations with habitual and fast-paced ankle power generation (ρ = 0.65 and 0.75). Balance had significant associations with habitual and fast gait velocity (ρ = −0.57 and −0.53), with partial F tests showing that the contribution was independent of strength. Conclusions Ankle plantar flexor and hip flexor strength had the largest contribution to gait velocity. Future research may wish to refocus strength assessment and treatment to target the ankle plantar flexors and hip flexors.