Recognizing that outcome assessments are necessary to justify new and costly prosthetic components, the authors have compared the gait characteristics of a single transfemoral amputee using two prosthetic knee units: the Total Knee and the DAW 4Bar pneumatic knee. All other components of the prosthetic systems were identical, and the patient was given sufficient time to adapt to each system. The authors conducted the research and collected kinematic and kinetic data at the Motion Analysis Laboratory of Children's Hospital in San Diego. Movement measurements varied slightly between the two prosthetic knee units and differed markedly from normal. The gait using the Total Knee unit demonstrated slight movement of the knee into flexion during stance while the gait using the 4Bar pneumatic unit demonstrated full extension throughout stance. During the loading response of the prosthetic limb, a relatively large initial external extension moment occurred with the 4Bar pneumatic knee unit; the Total Knee demonstrated an initial external flexion moment at this same phase. The vertical force and fore/aft shear curves were closer to normal with the Total Knee. Walking velocity and stride length were improved with the Total Knee, but cadence was unchanged. Overall, the gait parameters were more favorable with the Total Knee unit. A single trial such as this does not provide statistically significant data but can serve as a model for multiple studies to obtain objective information about prosthetic systems.
- Force Plate
ASJC Scopus subject areas
- Biomedical Engineering
- Orthopedics and Sports Medicine