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Exercise for a Stiff Knee After Surgery

When you have a total replacement of your knee, you may be left with s stiff knee after surgery. If so, specific interventions can help you feel more comfortable and get back to your normal activities. There are some activities you need to avoid, though, so let’s look carefully at what will help.

Exercising and stretching regularly helps to restore the mobility and strength in your knee for a gradual return to all your regular activities after a total replacement. Your surgeon and physical therapist from Summit Physical Therapy in Merrick, NY, will recommend a specific, customized exercise regime. It is essential that your Physical Therapist spend time manually stretching your knee to return the flexibility. 

You will probably need to exercise and stretch 20 to 30 minutes every day, at least once. This is in addition to seeing the PT for manual stretching 2-3x weekly. Many times, the recommendaition is to perform the exercises 2 to 3 times daily. You’ll probably also receive a recommendation to walk for half an hour, 2 to 3 times a day during the early recovery period.

Your exercise program will be designed and supervised closely by your physical therapist and surgeon. Always check with your PT or surgeon before performing any exercises.

Here are some common exercises that physical therapists recommend after total replacement knee surgery.

Initial Exercises After Surgery

Initially, it is important to increase circulation to your feet and legs to prevent blood clots, strengthen muscles and improve your knee’s mobility. Start exercising as soon as possible, even in the recovery room right after surgery. Many of these exercises feel a bit uncomfortable when you start out, but they do help speed recovery and lower your postoperative pain.

Ankle Pumps

  • Rhythmically move your foot up and down using your shin and calf and muscles
  • Repeat for 2 to 3 minutes, several times an hour, starting in the recovery room
  • When you watch TV, do ankle pumps during commercial breaks
  • Do ankle pumps any time you notive ankle or lower-leg swelling
  • Continue doing ankle pumps until you have full recovery after your surgery

Quadriceps Sets

  • Start by tightening your thigh muscle
  • Straighten your knee as much as possible
  • Hold 5 to 10 secs
  • Repeat approx 10 X over 2 mins
  • Rest for 1 min
  • Repeat
  • Continue until your thigh is too fatigued

Straight Leg Raises

  • Straighten your leg as you sit on the bed
  • (Optional – Straighten your leg while sitting on a chair and perform the exercise while sitting)
  • Tighten your thigh muscle like the quadriceps set above, but with your leg straight
  • Lift the leg a few inches holding your knee straight with your leg unsupported
  • Hold for 5 - 10 secs
  • Slowly lower your leg and put it back on the bed (or your foot on the floor if you are sitting)
  • Repeat until your leg is too fatigued – approx. 3 minutes
  • Repeat
  • Continue regularly until you have full strength in your thigh

Knee Straightening Exercise

  • Sit up in bed as much as possible
  • Use a small rolled towel to support just above your heel, so that it doesn’t touch the bed
  • Tighten your thigh muscles
  • Work to straighten your knee fully. Try to touch the back of your knee to the mattress.
  • Hold your leg straight for 5 to 10 secs
  • Repeat until your thigh is too fatigued – about 3 mins

Knee Bends – Bed-Supported

  • Straighten your leg on the bed
  • Move your foot along the bed towards you with your foot flat on the mattress to bend your kne as much as possible
  • Hold your leg with your knee bent for for 5 to 10 secs.
  • Straighten out your leg again
  • Repeat several times over 2 minutes until your leg feels fatigued or you can bend your knee completely

Knee Bends – Sitting Supported

  • Sit at your bedside or in a chair
  • Keep your thigh supported
  • Put your other foot behind the heel of the leg you had surgery on, for support
  • Slowly bend your knee as far as possible.
  • Hold for 5 to 10 secs
  • Repeat until your leg is too fatigued or you can bend your knee completely – about 2 mins

Knee Bends – Sitting Unsupported

  • Sitting at bedside or in a chair
  • Keep your thigh supported
  • Bend your knee as far as possible until your foot sits on the floor
  • As your foot sits on the floor, slide your body forward on the chair
  • Increase the bend of your knee
  • Hold for 5 to 10 secs
  • Straighten your knee out completely
  • Repeat until your leg is too fatigued or you can bend your knee completely – about 3 mins

Continue to perform these exercises for as long as your surgeon and physical therapist recommend.

Activities Soon After Knee Surgery

Soon after your total replacement surgery, you soon walk short distances and get involved in your normal, everyday activities. The early activities support your recovery by helping your knee regain mobility and strength.

Walking Helps a Stiff Knee After Surgery

Walking is critical to help your knee recover. First, you use a walker or crutches and avoid putting too much weight on your leg. Your surgeon or physical therapist will explain how much weight you can safely put on your leg.

Your leg’s muscle strength and endurance will improve as you spend more time walking. Plus, you can put more weight down very soon. Once you are able to walk and stand for over 10 minutes and you don’t need your walker or crutches, you can shift to one critch or a cane. This is usually only 2 or 3 weeks after surgery. Always use a cane on the opposite side from your surgery, being careful not to limp or lean away in an unbalanced gait.

Stairs – Going Up and Coming Down 

Stair climbing strengthens muscles, increases flexibility, and builds endurance. Start with a supportive handrail moving only one step at a time. Lead up stairs with your good knee. Go down stairs with the operated knee first. Over time, you can climb stairs foot over foot, but always be very careful when you are using a critch or cane.

More Advanced Exercises and Activities After Knee Surgery

Once your knee heals more, your physical therapist will offer more exercises. These are some options.

Standing Knee Bends

  • Stand with your walker, crutches or cane
  • Lift your thigh
  • Bend your knee as much as possible
  • Hold 5 to 10 secs
  • Straighten knee – touch the floor heel first
  • Repeat until fatigued – about 2 mins

Assisted Knee Bends

  • Lie on your back
  • Put a folded towel over your knee and drop it to your foot
  • Bend knee, applying gentle pressure through the towel
  • Hold 5 to 10 secs
  • Repeat until fatigued – about 2 mins

Resistance Exercises

Put light weights on your ankle and repeat any of the exercise outlined 4 to 6 weeks after surgery. Start with 1 to 2lb weights. Increase weight as strength returns.


Exercise bikes are excellent to help regain strength and mobility. Adjust the seat height so the sole of your foot touches the pedal when your knee is almost straight.

  • First, peddle backwards
  • Peddle forward only after backwards is comfortable
  • Increase the tension as your strength increases.
  • Start with 10 to 15 minutes daily, and build to 20 to 30 minutes
  • 3 to 4X/ week

If you have pain or swelling, elevate your leg and apply ice for 20 minutes and remove for 20 minutes, repeated for 2 hours.

Exercise and activity should consistently improve your mobility and strength, reducing issues with a stiff knee after surgery. Contact a physical therapist at Summit Physical Therapy in Merrick, NY, for more information.

Summit Physical Therapy