Loading Between the Socket and the Residual Limb of Below-Knee Amputees (BKA): Pilot Investigation
J. R. ENGSBERG, Ph.D., M. J. N. SPRINGER, B.Sc., AND J. A. HARDER, M.D.
The most important aspect of a prosthesis for a BKA is the fit and comfort of the socket. The purpose of this pilot investigation was to test a method of quantifying the load between the socket and the residual limb of BKAs as an attempt to determine an objective, as opposed to a subjective method of evaluating socket fit and comfort. Thin pressure sensors were taped to four different positions on the residual limb (anterior, posterior, medial and lateral) of a 30 year old male (Subject 1) and a 10 year old boy (Subject 2). Then wearing their prostheses, subjects stood with their feet on separate force platforms while two trials of data were collected from both the pressure sensors and the force platforms. The sum of the magnitudes of normal forces for specific high pressure sites were determined and divided by the vertical ground reaction force to yield high pressure site ratios (Table 1 ).
The results indicated that the sensors measured areas of high pressure that were aligned with the goals of the prosthetists. This technique may become a method to quantitatively determine socket fit and comfort.
University of Calgary, Human Performance Laboratory, Calgary, Alberta, Canada T2N 1N4