Characteristics of Stability Limits and Foot Pressure Distributions during Reaching Movements by Stroke Patients

[Purpose] The purpose of this study was to investigate the effects on maximum displacements of center of pressure (COP) and the characteristics of foot pressure distributions induced by external rotations of the affected lower limb during standing and reaching movements performed by patients with stroke. [Subjects] Nine patients and ten age-matched healthy subjects participated in this study. [Methods] The displacements of COP and foot pressure distributions were measured during multi-directional reaching movements with foot rotation. The ranges of foot rotation were set at 10, 30 and 45°. [Results] The range of COP displacements did not increase, even though the base of support was increased by the foot rotation of the stroke patients. In addition, the front foot pressures of the affected lower limb decreased and the heel pressures of the unaffected one were increased in the stroke patients compared to the healthy subjects. [Conclusion] Our conclusion is that external rotations of the affected lower limb did not contribute to postural stability of the stroke patients, because of the decrease in weight shifts onto the front of the foot.