For continuous passive motion, what is the initial knee flexion range?

• A. 0-20 degrees
• B. 20-40 degrees
• C. 40-60 degrees
• D. 60-80 degrees

Answer: (B)

Continuous passive motion is used to keep the knee moving without requiring muscle effort, protecting healing tissues while encouraging motion to reduce stiffness and improve circulation. Starting with a modest bend, about 20 to 40 degrees, provides enough flexion to promote synovial fluid movement and nutrient delivery to the joint surfaces while staying gentle on the surgical repair. This range helps prevent adhesions and stiffness early on, without overloading healing structures. As healing progresses and tolerance improves, the range is increased gradually according to the surgeon’s protocol, moving in small increments to continue advancing ROM. If pain or swelling limits the motion, adjustments are made to protect the joint.