8 Exercises for a Torn ACL

The ACL is a large ligament that stabilizes the knee from within the knee joint. This ligament can tear with various movements, such as quickly changing direction or landing after jumping. Symptoms of a torn ACL include pain, swelling, knee instability, and reduced range of motion.

Treatment for a torn ACL involves rehabilitation exercises to strengthen your knee. But some exercises can cause more harm if performed too soon. Learn more about exercises for a torn ACL, including how to do them safely. 

What are the best exercises for a torn ACL? 

Exercise is one of the most effective treatments for recovering from a torn ACL, which stands for anterior cruciate ligament. Rehabilitation for a torn ACL follows a series of steps to restore proper function of your knee. Exercises will first focus on improving your range of motion and strength while staying off of your feet. Afterwards, you can progress to standing exercises that work on balance, coordination, and further strengthening.

1. Heel slides

A torn ACL can cause pain and swelling that can limit your normal range of motion. Restoring the range of motion of your knee is one of the first goals of ACL rehabilitation. Heel slides help improve your ability to fully bend your knee.

• Step 1: Lie on your back with your legs straight.

• Step 2: Slide the heel of your injured leg closer to your body by slowly bending your knee. Don’t lift your leg. And make sure to keep your heel touching the floor throughout the movement.

• Step 3: Once your knee is bent as much as possible, hold this position for 5 seconds.

• Step 4: Then, slowly straighten your knee and slide your heel away from you.

• Step 5: Complete 20 repetitions.

2. Quadriceps sets

The quadriceps muscles are four muscles located in the front of the thigh that straighten the knee. Properly activating these muscles is key to stabilizing the knee joint after an ACL injury. Quadriceps sets activate the quadriceps and also improve your ability to fully straighten your knee.

• Step 1: Lie on your back with your legs straight. Place a small rolled up towel under your knee.

• Step 2: Contract the quadriceps muscles to tighten your thigh and fully straighten your knee. Press the back of your knee down into the towel.

• Step 3: Hold this contraction for 5 seconds, then relax.

• Step 4: Complete 20 repetitions.

3. Straight leg raises

Straight leg raises also strengthen your quadriceps muscles but with your knee straight. Being able to perform a straight leg raise without the knee bending is an indicator of good quadriceps strength and muscle activation. You’ll need to master this in order to move onto more challenging ACL rehabilitation exercises.

• Step 1: Lie on your back with one leg bent and the injured leg straight.

• Step 2: Contract the thigh muscles of your straightened leg to maintain a locked out knee.

• Step 3: Slowly lift your straightened leg up, keeping your knee straight throughout the movement. Stop when your knee is level with your other knee.

• Step 4: Then, slowly lower your leg back down to the starting position. Maintain your knee straightened the entire time.

• Step 5: Complete 20 repetitions.

4. Side-lying leg lifts

Side-lying leg lifts also target your quadriceps to maintain your knee straightened with movement. They also work your glute muscles, which are important for stabilizing your leg and keeping your knee joint in good alignment.

• Step 1: Lie on your side with your injured leg on top. Your hips should be stacked on top of each other, as well as your legs and feet.

• Step 2: Contract the thigh muscles of your top leg to straighten your knee.

• Step 3: Slowly lift your top leg up, keeping your knee straight throughout the movement. Keep your toes pointing forward and don’t rotate your hips or body.

• Step 4: Then, slowly lower your leg back down to the starting position. Keep your knee straight the entire time.

• Step 5: Complete 20 repetitions.

EXPERT PICKS: WHAT TO READ NEXT

• What exactly is the ACL and how does it tear? Learn the basics, including injury classification, diagnosis, and treatment options. 

• Meniscus tears: ACL injuries and meniscus tears often occur at the same time. Here’s what to know about meniscus injury. 

• How to prevent pain from cycling: Cycling is a common activity for people recovering from ACL injury. Try these tips to avoid knee pain from cycling.

5. Half squats

When your pain, strength, and range of motion start to improve, you can begin to challenge yourself with standing exercises. Half squats work many muscles of the leg together to strengthen the hips and knees. A full squat with deep knee bending can stress the ACL, so be sure to only perform a partial range of motion when starting out. It might help to perform this exercise in front of a mirror.

• Step 1: Start in a standing position. Your toes should be pointing forward and your feet should be hip-width apart.

• Step 2: Contract your abdominal muscles to engage your core. Pretend that you’re sitting down in a chair and lean your hips back. Your knees will bend slightly but will not pass over your toes.

• Step 3: Lower your hips down until you form a 45-degree bend in your knees.

• Step 4: Then, push through your legs to straighten your knees and hips to return to a standing position.

• Step 5: Complete 20 repetitions.

6. Single-leg balance

With a torn ACL, your knee is less stable. This can affect your balance. Practicing single-leg balance can strengthen the leg muscles that support and stabilize your knee (and ankle).

• Step 1: Start in a standing position. You may want to hold onto a chair or counter for support.

• Step 2: Lift the foot of your uninjured leg and stand on your injured leg. You may want to keep your hands close to the railing or counter for support in case you lose your balance.

• Step 3: Start by trying to hold this position for 10-15 seconds. As it gets easier, you can increase your time to 30-60 seconds.

• Step 4: Repeat 3-5 times.

Read more like this

Explore these related articles, suggested for readers like you.

Exercises for a Torn Meniscus: 8 Moves to Help You Recover

8 Runner’s Knee Exercises and Stretches for Pain Relief

5 Exercises for Knee Pain (With Visual Examples)

8 Knee Exercises for an MCL Sprain

View more

7. Step-ups

As you get more comfortable with standing exercises, you’ll want to challenge your strength more. Step-ups improve your leg strength, balance, and ability to support weight through your knee joint. You can start with a short step, or curb, and gradually move up to a higher step height over time as you build up strength and stability. Start with just your body weight at first. As this exercise gets easier, you can hold dumbbells to make this move more challenging.

• Step 1: Start in a standing position in front of a step or curb.

• Step 2: Place the foot of your injured leg on top of the step or curb.

• Step 3: Lean forward and push through your injured leg to step up onto the step or curb. Keep your uninjured leg lifted so that you’re balancing on one leg.

• Step 4: Then, slowly bend your standing leg and lower your lifted leg to step your foot back down to the floor.

• Step 5: Complete 20 repetitions.

8. Single leg sit-to-stand

This challenging move relies on your injured leg only to help you stand up from a chair. If you can perform this exercise, it’s a sign of good strength and stability in your knee. Be sure to use a stable chair to avoid falling. You can start with a higher seat height to limit the range of motion. Once you build up more strength, you can gradually make the seat lower.

• Step 1: Start in a seated position at the edge of a chair. Keep your arms extended out in front of you or crossed across your chest.

• Step 2: Extend your uninjured leg to straighten your knee. Keep this foot lifted from the floor. 

• Step 3: Keep your uninjured leg lifted while you lean forward and push through your injured leg to stand up. Stay balanced on your injured leg.

• Step 4: While keeping your uninjured leg lifted, slowly lean your hips back and sit down in the chair.

• Step 5: Complete 20 repetitions.

What exercises should you avoid if you have a torn ACL?

In the beginning of your recovery, avoid running, jumping, and playing sports. Performing high-impact exercises can stress your still-recovering knee. These exercises also require proper knee stability, which will take time to gain back after an ACL tear. 

What else can you do to recover from a torn ACL?

There’s no way to speed up recovery from a torn ACL. Ligaments, in general, are slow to heal. It takes several months for the ACL to fully recover, whether you have surgery or not. Recovery from a torn ACL requires consistent rehabilitation to achieve goals of building up strength and stability. Everyone recovers a little differently, so some people may progress at a faster rate than others.

It’s important to not rush into sports or other high-impact activities too soon. Doing this can stress the ACL before it fully heals. This can increase the risk of tearing it again and accelerating the onset of osteoarthritis.

Why trust our experts?

Written by:

Kristen Gasnick, PT, DPT

Kristen Gasnick, PT, DPT, practices outpatient rehabilitation focusing on orthopedic injuries and post-operative recovery.

Edited by:

Lauren Savage, MA

Lauren Savage, MA, is a health editor at GoodRx, where she focuses on movement, exercise, and healthy aging. She aims to provide readers with the information they need to live healthier, more active lifestyles.

Reviewed by:

Mandy Armitage, MD

Mandy Armitage, MD, has combined her interests in clinical medicine with her passion for education and content development for many years. She served as medical director for the health technology companies HealthLoop (now Get Well) and Doximity.

Our editorial standards

Meet our experts