Kinematic analysis of lower-limb movement during ergometer pedaling in hemiplegic and nonhemiplegic subjects.

The purpose of this descriptive study was to examine bicycle pedaling as a model for studying motor control dysfunction in persons with hemiplegia. Results of a kinematic analysis of the involved lower extremity of 10 hemiplegic patients were compared with the lower-extremity kinematic data of 10 "normal" (nonhemiplegic) subjects. Subjects pedaled at a constant work load at two pedaling rates. Hip, knee, and ankle angular-displacement variables were studied. Statistical comparisons for variables at the hip and knee were not significantly different between groups or between pedaling speeds. Ankle dorsiflexion and total ankle excursion were significantly different across pedaling speeds, but not between groups. Phase-plane analyses of angular-displacement and angular-velocity variables revealed that the most striking difference between the hemiplegic and the normal subjects was the control of ankle displacement and velocity of the lower extremity during pedaling.