Maximising Knee Range of Motion After Replacement Surgery
Range of motion is one of the most important outcomes after knee replacement surgery. The ability to fully straighten the knee (extension) and bend it adequately (flexion) determines your ability to walk normally, climb stairs, sit comfortably, and perform daily activities. Achieving good range of motion requires consistent, focused effort, particularly in the first six weeks.
Two range of motion goals are critical. Full extension (the ability to straighten the knee completely) is the first priority — a knee that cannot fully straighten causes an abnormal gait, fatigue, and poor function. Extension is achieved through prolonged stretching: lying with the ankle on a pillow or rolled towel and allowing gravity to gently straighten the knee. This should be done for ten to fifteen minutes, several times daily.
Flexion (bending the knee) is the second goal. Functional flexion targets are: ninety degrees by two weeks (enough to sit comfortably and get in and out of a car), one hundred to one hundred and ten degrees by six weeks (enough for stairs and most daily activities), and one hundred and fifteen to one hundred and twenty-five degrees eventually (enough for most activities including stair descent).
Flexion exercises include: heel slides (lying on the back, sliding the heel towards the buttocks), wall slides (lying on the back, feet on a wall, letting gravity bend the knee), sitting knee flexion (sitting on a chair and sliding the foot back), and stationary cycling (once sufficient flexion is achieved, cycling provides excellent range of motion exercise).
Several factors affect range of motion achievement. Swelling limits motion — aggressive swelling management (ice, elevation, compression) is essential. Pain management allows more effective exercise — take your medication as prescribed. The timing of exercise matters — range of motion exercises are often most effective after a warm shower or heat application, when tissues are more pliable.
Patellar mobilisation — gently moving the kneecap in all directions — prevents adhesions between the kneecap and underlying tissues. Your physiotherapist will teach you this technique.
If range of motion plateaus despite intensive effort, discuss this with your surgeon. Sometimes manipulation under anaesthesia (a procedure to break adhesions while you are asleep) is needed, but this is uncommon with consistent physiotherapy.
Our knee replacement physiotherapy service provides intensive, home-based range of motion rehabilitation. The home environment allows for frequent practice throughout the day — essential for achieving optimal range. Our post-hospital rehabilitation service supports the early recovery period, while our elderly physiotherapy service addresses the needs of older patients.