US Patent 7794506 Multi-axial prosthetic ankle

A prosthetic foot includes a rod having a substantially spherical head and a shank extending from the head. A connector is pivotally coupled to the spherical head of the rod. The connector has a coupling configured to attach to the stump of an amputee. A wear plate is disposed on the shank of the rod adjacent the connector. The wear plate is sized and shaped to contact the connector as the connector pivots on the spherical head of the rod. A spring is removably disposed on the shank of the rod and spaced apart from the wear plate a predetermined distance. The spring is compressible by the rod when the rod is disposed in a prosthetic foot and an axial load is applied to the rod.