Continuous Passive Motion (CPM) Devices - OptiFlex-K1 Knee CPM with Comfort Hand Control : Continuous Passive Motion is a postoperative procedure designed to aid in the recovery after joint surgery. After extensive joint surgery, if a patient fails to move their joint, the tissue around the joint will become stiff and scar tissue will form, resulting in a joint with limited range of motion, which often takes months of physical therapy to recover. OptiFlex-K1 Knee CPM has interchangeable hand controls for maximum versatility.