Skip to main content

Continuous Passive Motion Machine

Medically reviewed by Last updated on Jan 5, 2023.

What is a continuous passive motion machine?

A continuous passive motion (CPM) machine is a device that slowly and gently moves your joint while you are in bed. You may need to use a CPM machine for any of the following:

  • After surgery such as a total knee replacement or rotator cuff repair
  • After excision of scar tissue from a joint with manipulation for stiffness
  • For conditions such as osteoarthritis or after a fracture in your arm or leg

How can a CPM machine help me?

Your healthcare provider may tell you use a CPM machine with other treatments such as physical therapy. A CPM machine may help you recover from surgery or injury in the following ways:

  • The range of motion (ROM) of your arm or leg will increase. The CPM machine will flex (bend) your joint for you. Your healthcare provider may program the CPM machine to increase the amount that your joint is flexed over time. ROM may prevent scar tissue from forming. This may also prevent pain and stiffness in your knee.
  • Your muscles may get stronger more quickly. The CPM machine will gently exercise your arm and leg muscles to prevent them from getting weak. Your tendons and ligaments, the tissue that connects your muscles and bones, may also get stronger by using a CPM.
  • You may have less pain. A CPM machine will elevate your leg or arm and decrease swelling. You may have less pain if your swelling is decreased.
  • You may have increased blood flow in your arm or leg. Increased blood flow to your tissues will help you heal faster.

How do I use a CPM machine safely?

Your healthcare provider will show you how to set up your CPM machine. Your provider will also show you how to change the amount of flexion, speed, and time. You may need to use your CPM machine for up to 2 hours at a time, 3 to 4 times per day. If you use a machine for your shoulder, you may use the machine for only 20 to 30 minutes at a time. Ask your healthcare provider how to use the type of CPM machine that you have. The following are safety precautions:

  • Place your CPM machine against your headboard or a heavy object. This will prevent it from moving while you use it.
  • Plug in the CPM machine. Move the cord under the bed or secure it to the ground to prevent falls.
  • You may need to remove a shoulder or knee immobilizer before using a CPM machine. Ask your healthcare provider how to remove an immobilizer.
  • If using a CPM machine for your knee, place your leg so that the middle of your knee rests where the CPM machine bends, and the bottom of your foot is against the foot pad.
  • If using a CPM machine for your shoulder, place your elbow so that it rests where the CPM bends. Place your hand around the hand grip.
  • Attach your leg to the machine by wrapping the machine's straps around your thigh, shin, and foot.
  • Attach your arm to the machine by wrapping the machine's strap around your lower arm.

What else do I need to know about a CPM machine?

  • Take pain medicine before using your CPM machine. Control your pain so it is more comfortable to use your machine. Wait 20 to 30 minutes after taking pain medicine to use your machine.
  • Do not leave your CPM machine on the floor. Keep floors and pathways clear to prevent falls.
  • Do not use a CPM machine when smoking. Smoking, or using your CPM machine near open flames and heat, may cause a fire.
  • Keep your CPM machine dry. Do not use water or cleaners directly on your machine. This may cause damage to the CPM machine. Ask your healthcare provider how to clean your machine.

When should I stop using a CPM machine?

Your healthcare provider will tell you when to stop using a CPM machine. You may need to use a CPM machine for up to 6 weeks. Stop using a CPM machine and call your healthcare provider immediately if:

  • Your arm or leg feels warm, tender, and painful. It may look swollen and red.
  • You have a fever or chills.
  • Your wound is red, swollen, or draining pus.
  • You have more pain than usual when you use the CPM machine.
  • Your stitches come apart.

When should I seek immediate care?

  • Your leg or arm is larger than normal and more painful.
  • Any part of your arm or leg is numb.
  • Your leg or arm is pale and cool to the touch.
  • Your knee or ankle is turned inward or outward.
  • Your elbow or shoulder is turned inward or outward.
  • Your stitches come apart.

When should I contact my healthcare provider?

  • You have a fever or chills.
  • Your wound is red, swollen, or draining pus.
  • Your skin is itchy, swollen, or you have a rash.
  • You have questions or concerns about how to use your CPM.

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your healthcare providers to decide what care you want to receive. You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

© Copyright Merative 2022 Information is for End User's use only and may not be sold, redistributed or otherwise used for commercial purposes.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.