Knee Strengthening Exercises

Knee strengthening exercises should form part of a full knee rehabilitation program. Here we demonstrate early, mid and late stage knee rehabilitation exercises following injury.

We recommend seeking professional advice before beginning any knee strengthening exercises. View more detailed information with our specific knee rehabilitation programs.

Early stage knee exercises

Depending on your injury, these exercises are done as soon as pain allows. In some cases, this may be within a day or so of injury after the acute stage has passed.

Isometric quads

Isometric quad exercises aim to strengthen the quads by contracting the muscle, with no, or very little movement of the knee joint. The athlete can be sitting or supine depending on the degree of injury. Being seated increases the difficulty.

• Keeping the uninvolved knee in place, the athlete tightens the involved knee pushing it into the table.
• To position the knee in partial flexion the athlete places a towel or roll under the knee.
• The knee is straightened (keeping the other knee flexed) and held in full extension.
• Hold the position for about 5 seconds and return to the starting position.
• This can be further progressed by raising the angle of the knee using a foam roller.

Isometric hamstring exercises

Static or isometric hamstring exercises can be used in the early stages of rehabilitation for a knee injury, or a hamstring strain to help prevent muscle wasting.

• The athlete lies on their front with the knee slightly bent and the therapist grasps around the back of the ankle.
• The athlete then tries to bend their knee against the therapist’s resistance.
• Start with a gentle contraction and gradually increase force as pain allows.
• The knee should not move.

If a therapist or friend is not available, this can be achieved in a seated position. Sitting on a chair with the knee bent, push the heel back against a chair or table leg or wall.

Sit to stand exercise

This is a simple exercise that works the quadriceps in the early stages of rehabilitation after a knee injury. It is also helpful for the elderly to maintain quad strength.

• The athlete sits with the knees bent and feet directly under the knees.
• In a slow and controlled manner, the athlete moves from seated to standing and then back to seated as shown.
• Ensure the knees do not fall inwards.

Mid stage knee exercises

These knee exercises progress form the main part of any knee rehabilitation program. They gradually increase the load through your knee joint, without damaging injured tissues.

Wall squats

The wall squat exercise is a slightly easier alternative exercise to the squat. By using the wall some of the bodyweight is supported.

• The athlete stands with their back against a wall and the feet moved forwards.
• They perform a squat by sliding the back down the wall and ensuring that the knees do not move forward past the toes.
• The squat position can be held for added difficulty, or performed on a single leg only.
• A Swiss ball between the back and the wall can also be used for smooth movement.

Terminal knee extension

This exercise increases the weight-bearing strength of the quadriceps. A resistance band is wrapped around the knee and anchored to a table leg or similar upright object.

• The athlete starts with the knee slightly bent and body weight on the involved leg.
• The knee is then straightened backward, against the resistance of the band.
• The knee should not be locked straight.

Standing hamstring curl

Standing single leg hamstring curl (leg curl). Start slowly then get faster as you gain in confidence.

• The athlete stands and flexes the involved knee.
• Ankle weights can be used to increase difficulty or offer resistance with the hands, or incorporate a resistance band.
• The athlete may use the hands-on to support the body.

Squat with band

The resistance band provides lateral or sideways resistance to add another dimension to the squat exercise.

• Starting with the feet shoulder-width apart, the athlete squats down to no more than a right angle at the knee.
• The knees should not fall inwards and the back should remain straight throughout.
• This can be performed with a bar over the shoulders or dumbbells in the hands.

Straight leg ball pick up

The straight leg ball pick up strengthens the hamstring muscles in a stretched position.

• The athlete stands with the heel of the involved leg raised.
• The uninvolved leg is moved back to provide balance.
• Ensuring that the back is kept straight the athlete bends to pick up the medicine ball.
• All motion involves the pelvis moving around the femurs rather than lumbar flexion.

Plie

The Plie is a wide squat exercise with the knees pointing outwards. The back should remain straight during the exercise and the pelvis should not til backward.

• The athlete stands with the feet turned out.
• The knees should be bent as if performing a squat, ensuring they do not move forward past the toes

Knee extension with a band

Knee extension exercise (or leg extension) using a resistance band to strengthen the thigh muscles.

• The athlete sits on the edge of the table (or on a chair) with the knees over the edge.
• The resistance band is placed around the ankle and anchored under the furthest table/chair leg on the side of the leg being worked on.
• The athlete lifts the foot upwards to straighten the knee, then returns to the starting position.
• If the pain is felt do not continue with this exercise.

Seated hamstring curl

Seated or supine hamstring curl exercise using a resistance band.

• The athlete sits with a resistance band around the ankle with both legs straight.
• A partner holds the band in both hands until it is taut.
• The partner must not move the band from the starting position.
• The athlete draws the ankle in towards the buttocks increasing the resistance of the band, then returns to the starting position

Hamstring curl in prone

This exercise works the hamstring muscles and can be progressed to use weights depending on the state of the injury. 

• Lying on their front with the foot pointing down over the edge of the couch, the athlete fully bends the knee.
• Provided this is pain-free, a resistance band or ankle weight can be used to increase difficulty.

Hamstring catches

Single leg catch exercises for hamstrings. This starts to strengthen the hamstrings eccentrically or as they lengthen.

• In a prone position, the athlete lifts both legs to a 90-degree angle.
• Ensuring that the leg and the foot are not turned outwards the athlete drops the leg attempting to stop or ‘catch’ the lower leg reaching full extension.
• Alternate the legs.

The athlete can increase the difficulty of this exercise either by adding ankle weights or speeding up the rate of the leg catch.

Advanced knee exercises

Late-stage or advanced knee exercises are more functional and sport-specific. The aim is to restore full strength and mobility to the joint and bridge the gap between basic knee rehabilitation exercises and full competition fitness.

Lunge with ball

A ball can be used with a lunge to help with balance and to add extra weight.

• The athlete stands with the injured leg a wide stance in front of the other.
• The athlete holds a medicine ball close to the chest with the weight shifted onto the front leg, the back knee is slowly bent and dropped down towards the floor.
• This exercise works the Glutes, Quads, and Hamstrings.

Lunge on step

By raising the uninvolved leg on a step the athlete adds more weight to the leg being worked on.

• The athlete stands with the injured leg a wide stance in front of the other.
• The uninvolved leg is raised on a step with weight on the toes.
• With the weight shifted onto the front leg, the back knee is slowly bent and dropped down towards the floor.

Lateral Lunge

By using a medicine ball in the lateral lunge (side lunge) the athlete is able to add weight to the exercise as well as using it to aid balance.

• The athlete steps to the side keeping the toes forwards and the feet flat.
• Whilst keeping the involved leg straight, squat through the hip of the involved leg ensuring that the knee is in line with the foot.
• The athlete holds the ball out to help maintain balance.
• Squat as low as possible and hold for 2 seconds.
• Push back to the starting position.

Eccentric squats

Eccentric squat knee exercises target the hamstrings, glutes, and quads.

• The athlete raises the heels using half a foam roller.
• Keeping the back straight the athlete lowers themselves down slowly.
• The athlete returns to the starting position then repeats.
• To increase the level of difficulty the athlete can lower the body closer to heels.
• This exercise can also be executed on one leg.

Norwegian hamstring curl

The Norwegian hamstring curl (or Nordic curl) requires either a partner or gym equipment to lock the lower legs securely. This is a very advanced exercise isolating hamstring muscles.

• A partner anchors the athlete’s calves.
• A straight line must be maintained from knee to shoulder.
• The athlete lowers the body as controlled as possible to the floor.
• At the point whereby the move becomes uncomfortable, the athlete lets the body fall to the floor using the hands to control their landing.
• As the hamstrings get stronger less upper body push can be used the athlete can raise themselves back to the start position.