Effects of loading the unaffected limb for one session of locomotor training on laboratory measures of gait in stroke

Background Walking following stroke involves compensatory strategies by the unaffected leg to cope with the deficits in the hemiparetic leg. Recently, training paradigms based on the principles of task-oriented repetitive exercise have provided a valuable insight regarding the influence of restraining compensatory movements to improve motor performances. We investigated changes in the walking movements of each lower extremity after weighting the unaffected leg. Methods. Ten individuals early after a stroke (range: 3-7 months) who were able to walk 10 m with no aids, participated to this study. Subjects were instructed to walk on a treadmill with an external mass attached around the non affected ankle during a single session. The short-term effects on gait performance were quantified by a 3D-gait analysis system before, immediately after and 20 min after the walking technique. Findings. A one factor repeated measures model revealed that stroke participants significantly improved in walking speed (P < 0.001), step length (P < 0.01) and cadence (P < 0.01). Weight-bearing on the paretic leg increased (P < 0.01) along with kinematic modifications including greater hip and knee excursion. When the mass was removed, these adaptations were maintained 20 min later. Interpretation. Preliminary findings suggest that even brief gait training using a treadmill with a restrictive weight placed on the distal extremity of the non-hemiplegic lower limb can improve laboratory measures of gait ability in a sample of stroke subjects. Future studies must evaluate the effect of this technique in longer-term locomotor retraining. (C) 2008 Elsevier Ltd. All rights reserved.