Gait study of dysvascular lower limb amputees in early stage of rehabilitation
The study has investigated some load aspects of the gait of elderly, vascular, lower limb amputees in early stage of rehabilitation, in day to day realistic conditions. The aims were: 1) to understand the gait of recent vascular amputees better, 2) to quantify mechanical loads with two different assistive walking devices. To reach these targets: a removable novel pylon transducer was designed; a fully portable data acquisition system and instrumented canes were used. The new pylon transducer comprised two main parts so that the prosthesis did not need to be altered: 1) an valuminium. bell)) placed within the prosthetic shank tube, having a flange at its base on which the tube of the prosthesis comes to bear; 2) the body of the transducer located inside the bell with an upper contact flange and having clearance to allow the bonding of strain gauges in four levels. A full calibration of the six channels followed by static and dynamic validation tests has been undertaken. They showed a mean accuracy of 7% with a sufficient linearity to be confident in the provided results. Data were recorded through an eight channels 12-bit data acquisition system. At a sampling frequency of 6411z, the recording duration was I hour. Two series of patients have been included in the sample: 30 transtibial and 10 transfemoral amputees. A new pattern for the vertical ground reaction force is described: the second peak was absent, evidently transmitted by the load on the walking devices. The mean load on the walking devices was 35 percent of the body weight. It was also shown that the walking devices not only transmitted axial load but also assisted in the forward acceleration of the body. Three typical gait patterns have been found in the temporal parameters of the gait but none could be discerned for the load distribution.