A joint orthosis includes upper and lower members, and a joint mechanism. The joint mechanism includes a shielding cover and at least one of modular front and rear inserts. Each of the modular front and rear inserts is disposed to limit movement of a joint of a human body in a flexion/extension direction. The shielding cover is removably attached to a mounting frame of the joint mechanism and is configured to conceal and prevent access to the at least one or the modular front and rear inserts.