Differences in self-selected and fastest-comfortable walking in post-stroke hemiparetic persons

Abstract

Post-stroke hemiparetic walking is typically asymmetric. Assessment of symmetry is often performed at either self-selected or fastest-comfortable walking speeds to gain insight into coordination deficits and compensatory mechanisms. However, how walking speed influences the level of asymmetry is unclear. This study analyzed relative changes in paretic and non-paretic leg symmetry to assess whether one speed is more effective at highlighting asymmetries in hemiparetic walking and whether there is a systematic effect of speed on asymmetry. Forty-six subjects with chronic hemiparesis walked at their self-selected and fastest-comfortable speeds on an instrumented split-belt treadmill. Relative proportions (paretic leg value/(paretic + non-paretic leg value)) were computed at each speed for step length (PSR), propulsion (PP), and joint moment impulses at the ankle and hip. Thirty-six subjects did not change their step length symmetry with speed, while three subjects changed their step length values toward increased asymmetry and seven changed toward increased symmetry. Propulsion symmetry did not change uniformly with speed for the group, with fifteen subjects changing their propulsion values toward increased asymmetry while increasing speed from their self-selected to fastest-comfortable and eleven decreasing the asymmetry. Both step length and propulsion symmetry were correlated with ankle impulse proportion at self-selected and fastestcomfortable speed (c.f., hip impulse proportion), but ratios (self-selected value / fastest-comfortable value) of the proportion measures (PSR and PP) showed that neither step length nor propulsion symmetry correlated with the ankle impulse proportions. Thus, the individual kinetic mechanisms used to increase speed could not be predicted from PSR or PP.

Symmetry of corticomotor input to plantarflexors influences the propulsive strategy used to increase walking speed post-stroke

“…Peak ankle plantarflexion moment was the biomechanical variable of interest in this study due to its temporal correlation with peak soleus muscle EMG activity during walking (Bogey et al 2005; Buchanan et al 2005), its relationship to self-selected and fastest walking speeds (Beaman et al 2010), and, in contrast to plantarflexion power or anterior ground reaction forces, its relative independence from other joint segments (e.g. hip flexion moment on ankle joint power or the trailing limb position on anterior ground reaction forces) (Hsiao et al 2015a; Hsiao et al 2015b).…”

Fast gait speed and self-perceived balance as valid predictors and discriminators of independent community walking at 6 months post-stroke – a preliminary study

“…Walking at comfortable and fast speeds provide complementary information on walking function after stroke [17,18]. Subjects with a significant difference between comfortable and fast speeds have greater potential to adapt to different modes of locomotion and, consequently, are more likely to be able to walk in the community.…”

Walking speed, unilateral leg loading, and step symmetry in young adults

“…One factor that is known to affect gait variables is speed, and it is well established that walking should be tested under a range of speeds, rather than just self-selected speed [9,10]. However, most reports on over-ground gait symmetry in healthy individuals are limited to self-selected speed (e.g.…”