A Pneumatically Controlled Prosthetic Socket for Transfemoral Amputees.

Amputees typically experience changes in residual limb volume in their daily lives. It causes an uncomfortable fit of the socket by applying high pressure on the sensitive area of the residual limb or by loosening the socket. In this study, we developed a transfemoral prosthetic socket for above-the-knee amputees that ensures a good socket fit by maintaining uniform and constant contact pressure despite volume changes in the residual limb. The socket has two air bladders in the posterior femoral region, and the pneumatic controller is located on the tibia of the prosthesis. The pneumatic system aims to minimize unstable fitting of the socket and improve walking performance by inflating or deflating the air bladder. The developed socket autonomously maintains the air pressure inside the prosthetic socket at a steady-state error of 3 mmHg or less by adjusting the amount of air in the air bladder via closed-loop control. In the clinical trial, amputee participants walked on flat and inclined surfaces. The displacement between the residual limb and socket during the gait cycle was reduced by up to 33.4% after air injection into the socket. The inflatable bladder increased the knee flexion angle on the affected side, resulting in increased stride length and gait velocity. The pneumatic socket provides a stable and comfortable walking experience not only when walking on flat ground but also on slopes.

Short-Term Walking Outcomes in Diabetic and Non-Diabetic Unilateral Transtibial Amputees.

This study compared short-term walking outcomes in diabetic amputees after prosthesis fitting compared to that in non-diabetic amputees. We retrospectively investigated walking outcomes at 3 months after starting gait training with a prosthesis. Forty-four unilateral transtibial amputees with (n=18) and without diabetes (n=26) were included. At 3 months after gait training with a prosthesis, only 2/18 (11.1%) and 3/18 (16.7%) diabetic amputees were capable of independent outdoor and indoor walking without cane, respectively. However, 21/26 (80.8%) and 24/26 (92.3%) non-diabetic amputees were capable of independent outdoor and indoor walking without cane, respectively. With assistance of cane, most of non-diabetic amputees (n=24, 92.3%) were capable of walking in both outdoor and indoor but only seven (38.9%) and nine (50.0%) diabetic amputees were capable, respectively. Thus, short-term walking outcome were poor in transtibial amputee with diabetes compare to those without diabetes, and these results suggest intensive rehabilitation would be needed to them.