A prosthetic lower leg uses one or more generally C-shaped spring elements between the patient's socket and a footplate assembly. The respective connections between (a) those one or more elements and (b) that socket and that footplate can be configured to provide a lightweight and economic prosthesis that effectively mimics the feel and performance of a normal human foot. The prosthetic spring element is generally C-shaped, and can have a substantially constant thickness along its length, lending itself to being fabricated by automated processes such as filament winding. One or more of the generally C-shaped spring elements can be incorporated into other prostheses and/or other devices.