INTERFACE PRESSURE AND GAIT ANALYSIS IN DIFFERENT WALKING SPEEDS AND ON THE BELOW-KNEE AMPUTEES WITH MULTIPLE AXIS PROSTHETIC FOOT PROSTHESIS

摘要

Interface stresses are an important consideration in stump and socket for a prosthetic limb to a person with transtibial amputation. During stance phase of the gait cycle, the prosthetic socket is expected to support and distribute the entire body weight of the patient. Excessive stresses between stump and socket will induce pain, discomfort and breakdown of soft tissues. The objectives of this study are to investigate the differences of gait, the maximum forces and pressures between stump and socket during different walking speed. Motion analysis system was applied to investigate the kinematics and kinetics of the gait and the Pedar system was used to measure the maximum forces and pressures between stump and socket during different walking speeds. Fifteen male subjects with transtibial amputation were collected in this research. These subjects were required to walk in three different speeds (85 steps/min, 95 steps/min, 115 steps/min). The maximum force, pressure and force-time integrals in head of fibula, patellar ligament, medial condyle of tibia, tibial end and fibular end were recorded. The results showed that, the range of motion and the moment in hip, knee and ankle joint increased as the walking speed. Maximum forces and pressures in the measured areas had no significant difference in multiple axis prosthetic foot when the walking speed increased. The distributions of the force-time integrals were the same when compared with maximum force and the pain scale of subjects' subjective feeling. Walking speed would not influence the maximum force and pressure when subjects were in single axis prosthetic foot. This study provided the objective and subjective data for prosthetist or physician when applied on amputees.