Patent ID: 7857780

Claim:
A system for applying traction to a patient's limb, comprising: an orthopedic traction apparatus that attaches to a patient's limb, the traction apparatus including a plurality of constant-force springs supported rotatably by the traction apparatus such that each spring is extendable by unwinding, the plurality of constant-force springs including one or more main springs operatively disposed to apply a base tractive force to the limb, wherein the plurality of constant-force springs also includes at least one supplementary spring that is changeable between an uncoupled configuration that does not apply a supplementary tractive force to the limb and a coupled configuration that applies the supplementary tractive force to the limb, and wherein the at least one supplementary spring is changeable reversibly between the uncoupled and coupled configurations while the base tractive force is applied continuously to the limb and without repositioning the limb, thereby providing discrete adjustment of traction force while the limb remains in traction.