Every person who undergoes knee replacement surgery will do physical therapy exercises to strengthen the muscles around the new knee. These exercises:

  • Increase muscle flexibility and strength, which helps protect the new knee and other joints
  • Promote healing by increasing blood flow

Below are knee-strengthening exercises that doctors and physical therapists commonly recommended to knee replacement patients.

See Knee Strengthening Exercises

Patients may be advised to do 10 or 15 repetitions of each exercise a few times a day. About 6 weeks after surgery, most patients are able to scale back and do exercises 3 or 4 times a week.

Quad squeezes
The knee joint is supported and controlled by the quadriceps muscles, which are located at the front of the thigh. To do quad squeeze exercises, a patient will:

  • Lie on his or her back with legs extended
  • Contract the quadriceps muscles at the front of the thigh
  • During the contraction, the leg should be kept straight, so that it may seem the back of the knee is pressing down
  • Hold for 5 seconds and release

Quad squeezes can strengthen the quadriceps muscles without moving or putting strain on the knees.

See Total Knee Replacement Surgery Recovery


Ankle pumps
Exercising the muscles of the lower leg will help maintain their strength and improve blood circulation. To do ankle pump exercises, a patient will:

  • Lie on his or her back with legs extended and ankle propped up on a rolled towel or blanket
  • Flex foot, pushing the heel away from the body and toes pointing up and towards the body
  • Hold for 5 seconds
  • Point the toes, moving the heel towards the calf and toes pointing away from the body
  • Hold for 5 seconds

By stimulating blood flow, ankle pumps help decrease leg swelling and decrease the risk of blood clots.

Short arc quad
Short arc quad exercises improve strength and range of motion in the hip and knee. To do short arc quad exercises, a patient will:

  • Lie on his or her back with legs extended and the knee supported by a rolled towel or blanket (the knee will be slightly bent)
  • Keeping the knee on the towel, straighten operated leg at the knee by lifting the heel off the bed
  • Hold for 5 seconds
  • Slowly lower the heel back down

The four quadriceps muscles are essential to knee stability and movement; they prevent the knee from buckling and are involved in standing and walking.

See Knee Exercises for Arthritis

Heel slides
These exercise engage both the quadriceps muscles and the gluteal muscles. To do heel slides, a patient will:

  • Lie on his or her back with legs extended
  • Flex the hip and the new knee, bringing the knee off the bed and sliding the foot along the bed
  • Keep the other leg straight
  • Hold for 10 seconds

Heel slides work both the quadriceps and hamstring muscles, and will help improve the patient’s range of motion.


Knee extensions
These exercises can be done sitting upright in a firm chair. To do knee extensions, a patient will:

  • Raise the foot and extend the knee until the leg is straight
  • Hold for 5 seconds
  • Slowly lower the foot until it rests on the floor again

Knee extensions help strengthen the quadriceps and improve knee and knee flexibility.

Straight leg raises
These exercises are typically introduced a few weeks after surgery. To do straight leg raises, a patient will:

  • The patient should lie on his or her back
  • Bend the unoperated leg so that the knee is up and the bottom of the foot is resting on the floor
  • Straighten the operated leg so that it is flat against the bed
  • Lift the straightened leg up, raising the toes toward the ceiling
  • Gently lower the leg to the bed

Because muscles are cut (and later repaired) during knee replacement surgery, straight leg raises can be challenging at first.

This list of exercises is not exhaustive. In fact, there are dozens knee- and leg-strengthening exercises that may be appropriate for knee replacement patients. An orthopedist or physical therapist can develop an exercise program tailored to an individual patient’s needs.

See Total Knee Replacement Surgery Recovery

Dr. K.C. Owsley is an orthopedic surgeon specializing in sports medicine with Arch Health Medical Group. He has several years of experience performing arthroscopy and reconstructive surgery of the shoulder, elbow, knee, and ankle.