Changes in interface pressure and stump shape over time: preliminary results from a trans-tibial amputee subject

Interface stresses and stump shape were measured during sessions over a two -month interval on a trans-tibial amputee subject. Results fi om thirteen t ransducer sites monitored during four sessions showed greater interface pre ssure changes over time at anterior sites than at lateral or posterior loca tions. There was a trend of decreased pressure with stump swelling and incr eased pressure for stump atrophy. During one session in which stump shape w as monitored over a 23.1 min interval after ambulation, stump swelling was localised. Swelling tended to increase in the regions of initial enlargemen t, as opposed to redistributing through different areas over time. Regions of swelling were anterior lateral and posterior proximal, al eas of thick u nderlying soft tissue. Identification of localised areas of swelling and at rophy and understanding of their effects on interface pressures could be us ed to improve individual socket design.