A Continuous Passive Motion (CPM) machine is a specialized medical device used in rehabilitation to gently move a joint through a controlled range of motion. This motorized equipment supports the limb, enabling movement without requiring the patient’s active muscle engagement. CPM therapy is typically initiated after surgery or injury to help prevent joint stiffness and aid in recovery.
How CPM Machines Work
CPM machines provide continuous, controlled movement to a joint without patient effort. The motorized device moves the affected joint repetitively through a predetermined arc, maintaining flexibility and preventing stiffness. It consists of a motor, a limb-supporting frame, and adjustable settings for range of motion, speed, and duration. For example, a knee CPM machine gently bends and straightens the leg, with its pivot point aligned to the patient’s knee joint. Patients simply place their limb into the machine for the prescribed motion.
Common Medical Uses
CPM machines are frequently prescribed following joint surgeries to help restore mobility and deter complications. They are most commonly used after knee procedures, such as total knee replacement or anterior cruciate ligament (ACL) reconstruction. Beyond the knee, CPM devices are also employed for other joints, including the hip, shoulder, and elbow. For example, they may be used after hip impingement surgery or rotator cuff repair to assist in regaining motion and preventing stiffness. The machine’s design is adapted to conform to the specific joint being treated, ensuring appropriate and controlled movement.
Patient Benefits and Experience
The continuous movement helps to reduce pain and swelling by promoting circulation and preventing fluid accumulation around the joint. It also works to prevent the formation of scar tissue, which can otherwise limit joint mobility and lead to stiffness. By gently moving the joint, the machine helps maintain the elasticity of tissues and ligaments, supporting a quicker return to normal activities.
Patients typically use the CPM machine while lying down, often for several hours a day, depending on their healthcare provider’s instructions. The machine is designed for comfort, with adjustable straps and padding to secure the limb. While some minor discomfort might be experienced, the therapy should not cause outright pain; settings can be adjusted if needed. The duration of use can vary, with some protocols suggesting several hours daily for a few weeks, or even continuous use in “comfort mode” overnight.