Kinematic and kinetic asymmetries in hemiplegic patients' gait initiation patterns.

OBJECTIVE: To assess the kinetic and kinematic characteristics of hemiplegic stroke patients' gait initiation patterns during the various gait initiation phases. DESIGN AND SUBJECTS: Gait initiation was studied in 3 hemiplegic subjects with a spastic equinus varus foot and 3 control subjects. METHODS: Temporal and kinetic analysis of gait initiation was performed with 2 AMTI force plates, and kinematic analysis of gait initiation with an ELITE optoelectronic system. A one-way ANOVA was performed directly on the phase durations, forces, centre of pressure displacements, stride length, and ankle motion range. RESULTS: Duration of the monopodal phase was shorter in hemiplegic patients when the affected leg rather than the sound one was used as the supporting leg. Propulsion forces were exerted by the hemiplegic patients' sound leg during the postural phase. Hemiplegic patients' body weight was supported more by the sound leg than by the affected leg. Knee was lifted higher on the affected side during the swing phase to compensate for the equinus. Initial contact was performed with a flat foot on the affected side. CONCLUSION: Quantitative data obtained on the gait initiation phase suggest that hemiplegic patients develop asymmetrical adaptive posturo-motor strategies to compensate for their impairments.