Sach foot - a prosthetic foot with a solid ankle and a cushion heel.
Safe foot - a prosthetic foot with a stationary attachment and a flexible endoskeleton.
Sinistropedal - using the left foot in preference to the right.
Splayfoot - flatfoot; talipes valgus.
Supinate - the act of turning the palm forward or upward, or of raising the medial margin of the foot.
Syme's amputation - disarticulation of the foot with removal of both malleoli. tarsal bones of the foot.