After a knee replacement exercises
A knee replacement resurfaces a worn knee joint, capping the ends of the bones with metal and adding a smooth plastic bearing between them. It is one of the most successful operations there is for pain and function, but the surgery is only half of it: the result depends heavily on the rehabilitation you do in the weeks and months afterwards.
Two things matter most early on. The first is movement, especially getting the knee fully straight and gaining enough bend to walk, sit, climb stairs and get in and out of a car. The second is switching the thigh muscle back on, because the quadriceps becomes very weak very quickly after surgery. Some swelling and mild warmth around the knee are normal for weeks to months, as long as they are settling week by week and eased by elevation, movement and pacing. A knee that becomes hotter, redder or more painful rather than less is different, and is a reason to contact your surgical team.
Expect the first two weeks to be hard work, with sleep often disturbed. Most people are walking comfortably indoors within a few weeks, off walking aids by around six weeks, and back to most daily activities by three months. Improvement usually continues for a full year. The knee often still feels different from a natural one - tight at the end of range, mildly warm, sometimes clicky - which is expected rather than a problem.
This programme follows that usual arc: gentle range and muscle activation in the first weeks, progressive strengthening through the middle phase, then a return to walking distance, stairs and daily activities. Always follow the specific instructions from your surgical team, which take priority over any general guidance, and contact them if the knee becomes hot, increasingly swollen or suddenly much more painful.
Who this programme is for
People recovering from a total or partial knee replacement. In the early weeks, follow the programme your hospital team gave you. Sessions with us start once your surgical team has confirmed you have no restrictions. The early-phase exercises below are shown for reference only; this page complements, and does not replace, the specific advice and any hospital physiotherapy you have been given.
Get urgent help now if
- Sudden breathlessness or chest pain - call 999 or go to A&E, this could be a blood clot in the lungs, especially if you also have pain or swelling in a leg. Do not drive yourself.
- The area is hot, very swollen and red, especially if you also feel feverish or unwell - go to A&E now, or call NHS 111 straight away if you are not sure where to go. Do not drive yourself if you feel very unwell.
Get checked by a clinician first if
- Throbbing or cramping pain, swelling, warmth or redness in one calf or leg with no clear cause - ask for an urgent GP appointment or call NHS 111 to rule out a blood clot
- Wound that opens, leaks, or becomes increasingly red, hot and painful, with or without a fever - possible infection: contact your surgical team, or ask for an urgent GP appointment or call NHS 111
- A sudden increase in pain, swelling or inability to bear weight after a fall or twist
- The knee will not straighten or bend at all, or feels unstable and gives way
- The pain followed a significant accident, fall or direct blow and you have not been checked over
- You feel unwell with the pain - a fever, night sweats, or losing weight without trying
- Pain that is severe, steadily getting worse, or keeps you awake every night and does not ease with a change of position
The staged programme
First days and weeks
For reference only: in the early weeks, follow the programme your hospital team gave you. Sessions with us start once your surgical team has confirmed you have no restrictions. Hospital programmes at this stage often focus on full straightening, gradually increasing bend, ankle pumps for circulation, and reactivating the thigh muscle. Do little and often through the day, and elevate the leg to manage swelling.
Build strength
From around 4 to 6 weeks, as the wound heals and range improves. Add sit-to-stand practice, stationary cycling for movement and fitness, and gentle squats, building the effort gradually.
Return to activity
From around 3 months. Rebuild step and stair strength, walking distance, and the strength for hobbies and daily tasks. Continue for 6 to 12 months to get the most from the joint.
How long recovery takes
The NHS says it may take several months or longer to fully recover from a knee replacement. Rehab starts once your surgical team has confirmed you have no restrictions. It depends on your condition; your physiotherapist will give you an estimate after your assessment. We review your progress regularly and adjust your plan.
Knowing when to progress
Prioritise full straightening early - it is harder to regain later. Expect the knee to feel warm and swollen after exercise in the first months; that is normal if it settles overnight. Progress load as pain and swelling allow, and keep going with strengthening well beyond the point where you feel recovered.
Common questions
How much knee bend should I aim for?
Around 90 degrees is needed for comfortable walking and sitting, and roughly 110 to 120 degrees for stairs and getting in and out of a car easily. How quickly you get there depends on your operation and your recovery, and your physiotherapist will give you an estimate after your assessment.
Is it normal for the knee to be warm and swollen for months?
Yes. Warmth and swelling that fluctuate with activity are expected for 6 to 12 months as the joint settles. Elevation, ice, and pacing your activity help. Swelling that comes on suddenly with throbbing or cramping calf pain can be a blood clot: ask for an urgent GP appointment or call NHS 111. With breathlessness or chest pain, call 999 or go to A&E, and do not drive yourself.
When can I kneel on it?
Kneeling is safe once the wound has fully healed and is comfortable, often around 3 months, though many people find it uncomfortable for longer. It does not damage the replacement. A cushion helps.
What activities can I go back to?
Walking, swimming, cycling, golf, bowls and doubles tennis are all encouraged. High-impact running and contact sport are generally advised against to avoid wearing the components. Your surgeon can advise on your specific case.
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