ACL injury: Exercises to do before treatment

The anterior cruciate ligament (ACL) is one of four knee ligaments that connect the upper leg bone (femur) with the large lower leg bone (tibia). The ACL stabilizes knee movement by:

• Preventing the lower leg bone from sliding forward or turning inward when the leg is straight.
• Preventing the knee from being stretched or straightened beyond its normal limits (hyperextended).
• Supporting the knee ligaments that keep the knee from bending sideways.

See a picture of the knee and the ACL .

When the ACL tears, the blood vessels around the ligament tear and blood can fill the knee joint, causing swelling. This can result in both pain and loss of motion. The inactivity following an ACL injury often results in weakening of the muscle in the front of your thigh, the quadriceps. If nothing is done after an ACL injury, you may develop chronic ACL deficiency—your knee may become less stable, leading to abnormal knee joint movement and premature osteoarthritis.

Treatment is needed for an ACL injury. Treatment is either a rehab program or ACL surgery followed by a rehab program. Surgery is generally more successful if you condition your knee and surrounding muscles before starting your treatment. This can be achieved by doing a few simple exercises. Your doctor will help you decide when to start these exercises.

Continue to Why?

It is important to begin doing some simple exercises after injuring your ACL and before treatment begins. Regaining leg strength and knee motion will help your treatment be more successful, whether your rehab program is done in conjunction with surgery or not.

Continue to How?

Quad sets, straight-leg raises, and heel slides are common exercises used after an ACL injury. As symptoms decrease and you are able to bear weight, side-lying leg lifts, glute sets, bridges, mini-squats against a wall, heel raises, and prone hamstring curls might be added. But your doctor may want you to tailor exercises to your specific injury. Check with your doctor before you do any exercises.

You should start slowly and gradually increase the intensity of the exercises. Do not push yourself to the point that you feel pain. Talk to your doctor about how to best progress.

All of the following exercises are done with your injured leg.

Quad sets

Quad sets help you maintain and build strength in the muscles on top of your thigh (quadriceps). Do 8 to 12 repetitions several times during the day.

1. Sit on the floor with your injured leg straight out in front of you.
2. Tighten the muscles on top of your thigh by pressing the back of your knee flat down to the floor.
3. Hold for 10 seconds.

If you feel discomfort under your kneecap, try putting a small towel roll under your knee during this exercise.

Straight-leg raises to the front

Straight-leg raises to the front help you strengthen the muscles on top of your thigh and around your hip. Do 8 to 12 repetitions.

1. Lie on your back with your good knee bent so that your foot rests flat on the floor. Your injured leg should be straight. (During this exercise, your low back should have a normal curve. Your back has a normal curve if you can slip your flat hand in between the floor and the small of your back, with your palm touching the floor and your back touching the back of your hand.)
2. Tighten the thigh muscles in the injured leg by pressing the back of your knee flat down to the floor. Hold your knee straight.
3. Keeping the thigh muscles tight, lift your injured leg up so that your heel is about 12 in (32 cm) off the floor. Hold for 5 seconds, then lower slowly.

Heel slides

Heel slides help you regain your range of motion by stretching the muscles on top of your thigh. Do 2 to 4 repetitions several times during the day.

1. Lie down on the floor or the bed with your leg flat.
2. Slowly begin to slide your heel toward your buttocks, keeping your heel on the floor or bed. Your knee will begin to bend.
3. Continue to slide your heel and bend your knee until it becomes a little uncomfortable and you can feel a small amount of pressure inside your knee.
4. Hold this position for 10 seconds.
5. Slide your heel back down until your leg is straight on the floor or bed.

Straight-leg raises to the outside

Straight-leg raises to the outside help you strengthen the muscles around your hip. Do 8 to 12 repetitions.

1. Lie on your side, with your injured leg on top.
2. Tighten the muscles on the front of the thigh of your injured leg to keep your knee straight.
3. Keep your hip and your leg straight in line with the rest of your body, and keep your knee pointing forward. Don't drop your hip back.
4. Lift your injured leg straight up toward the ceiling, about 12 in (32 cm) off the ground. Hold for 5 seconds, then slowly lower your leg.

Glute sets

Glute sets strengthen the buttock muscles. The buttock muscles are important in rotating and extending your legs. Do 8 to 12 repetitions several times during the day.

1. Lie on your back and prop yourself up on your elbows.
2. Squeeze your buttocks together as tightly as possible and hold for 10 seconds.

Bridging

The heel dig bridging exercise works your hamstrings and the muscles around your hip. Do 8 to 12 repetitions.

1. Lie on your back with both knees bent and your ankles bent so that only your heels are digging into the floor. At this point, your knees should be bent about 90 degrees.
2. From here, push your heels into the floor, squeeze your buttocks, and lift your hips off the floor until your shoulders, hips, and knees are all in a straight line.
3. Hold briefly, and then slowly lower your hips back down to the floor.

Standing knee bends

Shallow standing knee bends (also called mini-squats or half squats) build strength in the muscles on top of your thigh. This exercise should only be done if you have very minimal pain; if you have no clicking, locking, or giving way in the injured knee; and if it doesn't hurt while you are doing 8 to 12 repetitions.

1. Stand with your hands lightly resting on a counter or chair in front of you with your feet shoulder-width apart.
2. Slowly bend your knees so that you squat down just like you were going to sit in a chair. Make sure your knees don't go in front of your toes.
3. Lower yourself about 6 in (15 cm). Your heels should remain on or barely off the floor.
4. Rise slowly to a standing position.

Heel raises

Heel raises strengthen the calf muscles. Do 8 to 12 repetitions several times during the day.

1. Stand with your feet a few inches (several centimeters) apart, with your hands lightly resting on a counter or chair in front of you.
2. Slowly raise your heels off the floor while keeping your knees straight. Hold for 3 seconds, then slowly lower your heels to the floor.

Hamstring curls

Prone hamstring curls strengthen the hamstrings (the muscles in the back of the thigh). Do 8 to 12 repetitions.

1. Lie on your stomach with your knees straight. If your kneecap is uncomfortable, roll up a washcloth and put it under your leg just above your kneecap.
2. Lift the foot of your injured leg by bending the knee so that you bring the foot up toward your buttocks. If this motion hurts, try it without bending your knee quite as far, in order to avoid any painful motion.
3. Slowly lower your leg back to the floor.
4. With your doctor's permission, you may also want to add a cuff weight up to 5 lb (2.3 kg) to your ankle, or use soup cans in a plastic bag with the loops around your ankle. With weight, you don't have to lift your leg more than 12 in (32 cm) to get a hamstring workout.

Continue to Where?

For more information about exercises for an ACL injury, talk to:

• Your doctor.
• A sports medicine specialist.
• A physical therapist.