Fig. 1From: Design principles, manufacturing and evaluation techniques of custom dynamic ankle-foot orthoses: a review studyThe four main types of PD-AFOs. Where: (1) is the calf strap; (2) is the calf shell; (3) is the foot plate, and (4) is the ventral shell. H is the variable or fixed-stiffness hinge joint connecting the foot plate to the calf or to the ventral shellBack to article page