Abstract: A dynamic orthosis incorporating proportional resistance across a major joint connecting proximal and distal body portions (e.g., the elbow connecting the upper arm and forearm), includes a first orthotic coupler for grasping the proximal body portion for movement therewith and a second orthotic coupler for grasping a distal body portion for movement therewith. A connector connects portions of said pair of couplers and permits said first and second couplers to pivot freely relative to one another about the pivotal axis of the major joint. A resistance is disposed between and operatively connects the couplers for creating a bidirectional velocity proportional resistance in both tension and compression modes to relative pivotal movement of the couplers, whereby rapid dysmetric relative movement of the proximal and distal body portions is dampened more by the resistance than is slow controlled relative movement thereof.