Article

Limb movement between the residuum and socket continues to be an
underlying factor in limb health, prosthetic comfort, and gait performance yet
techniques to measure this have been underdeveloped. OBJECTIVES: Develop a method
to measure motion between the residual limb and a transtibial prosthetic socket.
STUDY DESIGN: Single subject, repeated measures with mathematical modeling.
METHODS: The gait of a participant with transtibial amputation was recorded using
a motion capture system using a marker set that included arrays on the anterior
distal tibia and the lateral epicondyle of the femur. The proximal or distal
translation, anterior or posterior translation, and angular movements were
quantified. A random Monte Carlo simulation based on the precision of the motion
capture system and a model of the bone moving under the skin explored the
technique's accuracy. Residual limb tissue stiffness was modeled as a linear
spring based on data from Papaioannou et al. RESULTS: Residuum movement relative
to the socket went through ~30 mm, 18 mm, and 15 degrees range of motion. Root
mean squared errors were 5.47 mm, 1.86 mm, and 0.75 degrees when considering the
modeled bone-skin movement in the proximal or distal, anterior or posterior, and
angular directions, respectively. CONCLUSION: The measured movement was greater
than the root mean squared error, indicating that this method can measure motion
between the residuum and socket. CLINICAL RELEVANCE: The ability to quantify
movement between the residual limb and the prosthetic socket will improve
prosthetic treatment through the evaluation of different prosthetic suspensions,
socket designs, and motor control of the prosthetic interface.
CI - (c) The International Society for Prosthetics and Orthotics 2015.

Langue : ANGLAIS