Abstract: An active-passive rehabilitation device is disclosed providing natural and relatively unconstrained motion of the treated joint, which promotes drainage and mitigates edema in the extrema. This active-passive rehabilitation device enables the application of adjunctive therapeutic modalities such as cryotherapy units and pneumatic sequential compression devices. Electronic controls allow the active-passive rehabilitation device to be programmed to provide resistive load for Active Range of Motion or Active Resistive Range of Motion (AROM or ARROM) for prescribed therapeutic cycles. Speed, range of motion and therapeutic torque limitations are some of the parameters that may be user controlled and/or programmable. Historical data can be stored in the device and can be downloaded electronically in real-time or at discrete intervals, allowing caretakers to monitor progress and even modify load cycles via electronic communication means.

Abstract: Difficulty in disconnecting two coupled shafts (38, 40) is avoided through the use of a retractable shaft coupler which includes a sleeve (22) which can engage respective shafts (38, 40) at each of its ends and having at least one spring (28) coaxially positioned inside of the sleeve (22). The spring (28) is sandwiched and contained inside of the sleeve (22) by washers (24, 26) which are retained by splines (32, 34). The construct allows retraction from one of the shafts (40) by moving the tubular member (22) in the axial direction away from the shaft (40) against the bias of the spring 28.