Estimating prosthesis energy storage and return using wearable sensors

We propose and evaluate a method for measuring energy exchange between a transtibial prosthesis and the residual limb using only wearable sensors. We reconstruct leg movement from inertial sensors on the foot and shank, and incorporate force and moment from a pylon load cell to compute energy storage and return using a deformable body model. Results show discrepancies between wearable and lab-based estimates of energy exchange, attributable to small errors in reconstructed shank velocity. The deformable body model is sensitive to these errors, rendering current inertial motion reconstruction with commodity sensors inadequate for this method.