Abstract: The present invention provides an orthotic appliance for the carpus of a human hand for the treatment of carpal tunnel syndrome using co-dynamic, rather than traditional static or dynamic, techniques. The appliance may apply a 2 pound dorsally directed force about the region of the pisiform bone in the neutral carpal position of a human hand upon co-contraction of the hand and up to 8 pounds dorsally directed during arc of motion in carpal flexion, as the wrist and hand is encouraged to actively move in all planes of motion without negatively affecting the normal activities of daily living. The appliance may comprise a biasing structure for applying the dorsally directed force and a base structure for maintaining the biasing structure in its proper configuration during normal hand motion.