Weight Distribution Between Below-Knee-Amputee (BKA) Children During Standing

J. A. HARDER, M.D., M. J. N. SPRINGER, B.Sc., K. G. TEDFORD, R.P.T., AND J. R. ENGSBERG, Ph.D


The purpose of this investigation was to compare weight distributions of a large number of BKA children during standing. Twenty-one BKA children volunteered as subjects. Three trials of data for two different foot positions (i.e., feet together and feet 20 cm apart) were collected from each subject while standing on a pressure plate. The amount of force applied by each foot to the pressure plate was determined for the trials and normalized by dividing by subject weight. Pressure output was also separated into forefoot and rearfoot areas, forces were calculated and normalized by dividing by total force from that foot. Resulting ratios for the two standing conditions and for nonprosthetic (NP) and prosthetic (P) feet were compared using paired t-tests (p less than 0.05).

Results for distribution of weight between NP and P feet indicated that significantly more weight was placed on the NP foot than the P foot (NP = 0.56, P = 0.44). Results for distribution of weight between forefoot and rearfoot indicated that for the NP foot the load was evenly distributed.

However, for the (P) foot results showed that over 90% of the load was applied to the forefoot. In all cases, no differences were found between foot positions.

If the children of this investigation are indicative of BKA children in general, it can be stated that during standing for `feet together' or for `feet 20 cm apart' positions; 1) BKA children place slightly more weight on their NP limb than their P limb, 2) the majority of the load on the P foot is placed on the forefoot, and 3) the load on the NP foot is evenly distributed between the forefoot and rearfoot.

University of Calgary, Human Performance Laboratory, Calgary, Alberta, Canada T2N 1N4