Knee Strengthening Exercises

Written By: Chloe Wilson, BSc(Hons) Physiotherapy
Reviewed by: KPE Medical Review Board

Knee strengthening exercises are one of the best ways to cure knee pain and stop it from coming back.

People who do knee strengthening exercises have less pain, recover quicker from injuries, function better and have less recurrences of pain.

Whenever there is weakness in the leg muscles, it means the knee joint is less well supported, resulting in more weight going through the bones and making knee problems much more likely. Knee strengthening exercises help to combat that¹.

All the exercises here are easy to perform, quick, effective and suitable for most people, whether you are looking for knee strengthening exercises for runners, after an injury, with arthritis or almost any knee problem.

The first of our knee strengthening exercises helps maintain and strengthen the quads muscles without moving the knee and helps enable full straightening of the knee. 

• Lie flat on your back or sitting up. Leg and knee straight
  
  
• Tighten the muscle on the front of the thigh by pushing your knee down. You should feel your thigh muscles clench. Hold for 3 secs.
  
  
• Repeat 10-20x every 3-4 hours
  
  
• If you are struggling to get your knee to straighten fully, place a rolled up towel underneath the ankle so that your leg is lifted slightly on the bed. Then do the exercise as described. Lifting the knee up slightly lets gravity help the knee to straighten.

• Lie flat on your back or sitting up with your leg horizontal on a flat surface such as a bed. Place a rolled up towel (approx 10cm diameter) under the knee
  
  
• Pull your toes towards you and clench you thigh muscles. Slowly lift your foot up off the bed until your knee is straight (keep your knee resting on the towel). Hold for 3-5 secs and slowly lower
  
  
• repeat 10-20 times, 3x daily
  
  
• You can challenge yourself further by
  a. Increasing the size of the towel under the knee 2)
  b. Add a weight e.g. by wearing a shoe, or using a light ankle weight
  c. Progress further by using a heavier weight.

This knee strengthening exercise works to strengthen the quads without needing to bend the knee. NB Do not do this if you have a history of back problems.

• Lie flat on your back. Leg and knee to be worked straight, other leg bent
  
  
• Pull your toes towards you and tighten/clench the muscle on the front of the thigh, locking your knee straight. Lift your foot up about 6 inches off the bed. Hold for 3-5 secs and slowly lower
  
  
• Ensure your knee stays straight the whole time
  
  
• Repeat 10-20 times, 2x daily
  
  
• To work harder, add a weight e.g. by wearing a shoe.

• Lie on your tummy (on the floor or bed) with your legs straight
  
  
• Lift your foot off the floor and bring it towards your bottom as far as you can. Slowly return to the starting position
  
  
• Repeat 10-25x, 3x daily
  
  
• You are aiming to get your heel all the way to your bottom
  
  
• Make the exercise easier by hooking your good leg underneath the bad and using it to help lift the bad leg up
  
  
• Make the exercise harder by using a weight e.g. a shoe or ankle weight.

• Lie on your side with your hip and knees bent approx 90°, feet together
  
  
• Keeping your feet together, lift the top knee up as high as you can. Hold for 3 seconds and slowly lower
  
  
• Repeat 10-25x on each side, 2x daily
  
  
• For more of a challenge, squeeze your heels together while doing the exercise to work the glutes harder
  
  
• Do not let your top hip roll backwards.

• Lie on your back with both knees bent about 90° and your feet on the floor/bed
  
  
• Clench your buttocks and lift your bottom off the bed as high as you can without arching your back. Hold for 3-5 seconds and slowly lower
  
  
• Repeat 10-25 times, 1-2x daily
  
  
• Keep your back straight – don’t let it arch as you lift up, it should be your bottom doing the work 
  
  
• Don’t hold your breath – keep breathing normally.

• Sit in a chair with your heel against the leg of the chair and your feet firmly on the floor
  
  
• Press your heel firmly backwards into the chair leg feeling the back of your thigh tightening/clenching. Hold for 3-5 secs
  
  
• Repeat 10-20x, 2x daily
  
  
• NB The foot shouldn’t move during this knee exercise.

• Sit on a firm chair with your knee bent and your foot on the floor
  
  
• Lift your foot up and straighten your knee as much as possible. Hold for 3-5 secs and slowly lower
  
  
• Repeat 5-20 times, 3x daily
  
  
• Strengthen further by adding an ankle weight. 

9.  Buttock Clenches

Buttock clenches are the perfect place to start if you want to strengthen your glutes.

• Start lying down or sitting up
  
  
• Clench your buttocks together as tightly as you can and hold for 3 seconds. You should feel yourself rise up from the chair slightly
  
  
• Repeat 10-20x every 3-4 hours
  
  
• If you find this uncomfortable, try doing this knee exercise lying down, either with your legs out straight or your knees bent.

Knee Marching is one of those knee strengthening exercises that works the quads without having to put any weight through the knee joint, making it perfect in the early stages of recovery from a knee injury or surgery.

• Sit in a chair with your feet on the floor
  
  
• March your legs up and down one at a time. Lift your knee and foot up and then back down
  
  
• Repeat for about 1 minute, 2x daily and any time you are sitting for more than 20 minutes to stop your knee getting stiff
  
  
• Progress knee strengthening exercises by adding an ankle weight or shoe.

• Stand up straight holding on to something stable e.g. chair or table
  
  
• Lift your foot up as far as you can towards your bottom, bending the knee. Hold for 3-5 secs
  
  
• Repeat 5-25 times, 2x daily
  
  
• For more challenge, add a weight e.g. shoe or ankle weight
  
  
• Don’t bend forwards - keep your body upright
  
  
• Keep your knees in line with each other- don’t let your thigh come forwards.

• Stand with your feet slightly apart, weight equally distributed, holding onto something solid for balance if needed such as a chair or the wall
  
  
• Rise up onto your toes lifting your heels as high as possible. Keep your body upright as you do this, don’t bend forwards. Hold for 3-5 secs and slowly lower
  
  
• Repeat 10-30 times, 2x daily
  
  
• Try and push up equally through each leg.

Sit To Stand is another one of my favourite knee strengthening exercises! Whilst it might sound simple, this exercise helps to improve knee mobility, strengthens the quads, hamstring and glutes all at the same time, and improves general fitness and knee function.

I love knee strengthening exercises that work two or three muscle groups at the same time - it's like buy one get one (or two) free! 

• Sit in a firm chair, feet on the floor
  
  
• Lean forwards, lift your bottom and stand up straight and then sit back down
  
  
• Repeat 10-30x
  
  
• You can make this exercise easier by:
  a. pushing up through your arms too
  b. The higher the chair, the easier the exercise
  
  
• You can make this exercise harder by:
  a. Not using your arms
  b. Using a lower chair
  c. Increasing the speed you do knee strengthening exercises at
  d. Hold a heavy weight – e.g. bag of books during this knee exercise.

14. One Leg Standing: Stage 1

Balance and stability are often affect by knee pain so it is really important to work on regaining both to ensure good control at the knee and help preventing further knee injuries.

A quick way to tell whether you should be doing balance exercises as part of your knee strengthening exercises program is to try standing on one leg with your eyes closed. If you can’t do it for one minute, you should do some balance exercises. 

• Stand near a wall or chair for support
  
  
• Lift up your good leg and stand on one leg for as long as you can.  It is normal to wobble a bit
  
  
• Spend 5 minutes doing this 2x daily e.g. when brushing your teeth
  
  
• To work harder, close your eyes and perform the exercise as above - you'll be surprised how much harder it is. Or try Stage 2.