Sense of Feel for Lower-Limb Amputees: A Phase-One Study

Abstract

To determine the effects of a sensory feedback device developed at Sabolich Prosthetic & Research Center for lowerlimb amputees, 12 transfemoral (aboveknee) and 12 transtibial (below-knee) unilateral amputees were recruited from a convenience population for testing. Pre- and post-testing procedures included: symmetry of weight distribution, duration of single limb standing balance over the involved side, and symmetry of step length and of stance phase times.

After subjects completed the pre-testing protocol, the Sense-of-Feel (SOF) device was incorporated into the pre-test socket and five- to six-hour familiarization periods were provided. Post-testing was performed while wearing the SOF.

Weight distribution symmetry scores increased by 7% (p<.01) overall while the transtibial (below-knee) group improved by 11 percent (p<0.01). The transfemoral (above-knee) subgroup demonstrated a 24 percent increase (p<0.04) in standing balance duration. Scores for symmetry of stance phase time increased significantly (p<0.04) for the transfemoral (above-knee) subgroup. For step-length symmetry scores, overall subjects increased by 11 percent (p<0.05), and the transfemoral (above-knee) subgroup improved by 29 percent (p<0.04). Despite the relatively short acclimation period, results suggest that significant change toward improved symmetry was effected by using the SOF. A future study, including a larger sample population using the device for extended periods, is planned to fully understand the benefits of this type of sensory feedback.