Residual muscle contraction and prosthetic socket interface force in a transtibial amputee upon the osteomyoplastic procedure — A preliminary study

In the Transtibial Osteomyoplastic Amputation (TOA) technique, the fibular end and the tibial end are connected to each other by a bone bridge in order to stabilize the bony anatomy of the residual limb. In addition, during the myoplasty procedure, the ends of the muscles are secured to one another and to the bony foundations to re-establish the length-tension relationship. In contrast to conventional amputation techniques in which the muscles are cut and the length-tension relationship is lost overtime, the TOA procedure is anticipated to allow muscles to actively contract and return blood to the heart more efficiently [1]. In this study, the outcomes of the TOA procedure were investigated by measuring electromyography signals from the tibialis anterior and gastrocnemius muscles on the amputated leg as well as the interface force inside the prosthetic socket at the end-bearing level of a transtibial amputee. The subject had undergone the TOA procedure and the study was conducted while the subject walked on different terrain (level ground with different speeds, stairs, and incline) with two different kinds of prosthetic feet. Preliminary results showed that (1) the residual muscles appeared to be active while walking on various terrain, and (2) the activation level of the residual tibialis anterior muscle was found to be related to the force variation inside the prosthetic socket.