Figure 8 : Close-up view of the CAD model of the prototype with the right Arm and the anterior Brace removed (refer to Figure 7 for names of each part).  The two pillow block Bearings attach to the Foot Plate and house the Shaft (not shown), which serves as the axis of rotation for the ankle.  The two Arms also rotate about the Shaft and are held vertical by the two Soft Bumpers.  In between the Arms is the Base (which is held vertical by the Stiff Bumpers) which also rotates about the Shaft.  The Arms hold a pin (not shown) which serves as the axis of rotation for the Cam. This axis is slightly offset from the center of the Cam, allowing backward rotation of the Arms with respect to the Base, but when engaged the Cam jams into the Base, preventing forward rotation.  The Arms also hold the four Shoulder Bolts in place.  The Adaptor (which connects to the user’s prosthetic pylon) is attached to the Upper Housing; these two pieces can slide up and down the Shoulder Bolts and have the four Compression Springs under them to resist contact between the Upper Housing and the Arms.  Four Set Screws protrude from the bottom face of the Upper Housing and their length determines the maximum distance that the Upper Housing can travel towards the Arms (the Upper Housing “bottoms-out” when the Set Screws hit the Arms).  The Upper Housing holds a pin (not shown) which pins the proximal end of the Link.  The distal end of the Link is pinned (not shown) to the Cam, so that as the Upper Housing moves downwards, the Link forces the Cam to rotate onto the Base.