Towards quantifiable prosthetic gait: socket fit and prosthetic alignment
Towards quantifiable prosthetic gait: socket fit and prosthetic alignment
A lower-leg prosthesis can be attached either via a socket or through direct anchoring to the bone. For both systems, the fitting (how well the prosthesis connects to the residual limb) and the alignment (the orientation of the prosthetic limb relative to the residual limb) are crucial. This thesis of Niels Jonkergouw focuses on measuring and improving these aspects.
In socket-suspended prostheses, kinetic outcome measures, such as the moment around the socket or knee, proved to be more sensitive to alignment changes than kinematic parameters (e.g., step characteristics). Although the moment around the socket can be used to guide alignment adjustments, minimizing those does not necessarily lead to optimal results. Following those result ultrasound has been used to capture the motion between the residual bone and the prosthetic socket during dynamic. This measurements revealed considerable motion within the “pseudo-joint,” offering new opportunities to study socket fitting and biomechanics.
For bone-anchored prostheses, a radiographic method was developed to objectively determine static alignment. This approach allows the alignment of the intact limb to be accurately replicated, resulting in improved static symmetry. However, this did not automatically lead to better dynamic symmetry during walking, indicating that additional dynamic alignment remains necessary.
The results of this thesis provide deeper insight into the processes of prosthetic fitting and alignment in clinical practice. The applied techniques may, in the future, be further developed into methods suitable not only for research but also for everyday clinical use to enhance prosthetic performance.