Physical Therapy for an ACL Tear: How Does It Work?

Can an ACL Tear heal with physical therapy? How does physical therapy for an ACL work? Can you recommend ACL exercises to avoid surgery?

ACL injuries are tears and ruptures sustained by the anterior cruciate ligament in the knee joint. Listed above are the top three questions patients ask when they begin treatment at our clinic. Know that ACL injuries affect the strength and stability of the injured knee. This can be debilitative for anyone leading an active lifestyle, especially those that participate in sports or perform manual labor.

As far as ACL treatment is concerned, there are several options out there. The treatment plan varies from person to person based on their current symptoms and medical history. One thing that provides safe results without significant risk of complications is physical therapy.   

This comprehensive guide gives you an insight into how physical therapy for an ACL tear works and its importance before and after surgery.

Let’s begin.

The Basics: What Is ACL Tear?

The Anterior Cruciate Ligament (ACL) crosses through the middle of the knee. The ligament is attached between the femur and tibia within the knee joint. It offers stability, flexibility and maintains a full range of motion during joint movements. 

The ACL can tear during high-impact sports activities, traumatic accidents, and strenuous fitness routines. Alternatively, you can sustain injuries with a sudden movement or quick change of direction or when a collision puts unbearable stress on the ligament. As a result, the ligament can get strained, fully rupture, or tear partially.

Causes of ACL Tears

ACL Tear in a soccer player
Soccer is one of the leading causes of ACL injuries

Most ACL injuries occur when a high-risk activity or sudden movement causes a shift in pressure and impacts the anterior cruciate ligament.

Here’s a preview of the most common causes of ACL tears:

  • Gender

Females usually have lower muscle mass and greater instability as compared to males. Hence, they are more susceptible to experience ACL tears than their male counterparts in the same sports/profession.

Moreover, females have a great ‘Q-angle’ (the angle at the knee measured between the femur and tibia). It causes greater instability in the knee joint, especially when combined with weakness in the hip musculature.

  • Sports Injuries

High-risk contact sports, such as soccer, basketball, ice hockey, skiing, football, and gymnastics, are among the leading causes of ACL tears. Approximately 70% of ACL tears happen without direct contact with the knee. Examples include sudden twisting or cutting, quick change of direction while running, and knee hyperextension when coming down from a jump.

Athletes and sports enthusiasts who use worn-out equipment and improper training techniques are at a greater risk of ACL injuries. Playing on artificial turf may also increase risk when the foot gets stuck while performing a quick cutting or sideways drill/movement.

  • Collisions and Trauma Injuries

ACL tear can also occur when you sustain a direct hit to the knee during a physical fight or an automobile accident.   

  • Footwear

Wearing footwear that doesn’t fit properly is another common cause of ACL tears. Sports players and laborers who engage in physical activities wearing shoes that are too tight or too loose are at risk of experiencing an ACL injury.

  • Muscle Weakness and Imbalances

Weakness in hip muscles, primarily in the gluteus maximus and gluteus medius, contributes significantly to ACL tears.

Apart from this, your ACL can tear when you are cutting (i.e., changing directions), pivoting incorrectly, or when you make a sudden stop mid-movement. These scenarios cause you to land on your feet awkwardly and place unexpected strain on the knees. Lack of coordination is another reason for sustaining ACL injuries.


Major tell-tale signs of an ACL tear include intense knee pain, difficulty in straightening and bending the knee, tenderness, and swelling in a localized area. You might experience your knees ‘giving away’ when you stand up or walk. In addition, there’s an evident reduction in joint mobility and range of motion. Difficulty in walking is followed by loss of strength and weakness. 

All of this has a debilitative effect on everyday movement and activities. 

Without medical intervention, patients with a torn ACL might develop osteoarthritis due to the accelerated wear and tear of the injured ligaments placing a greater strain on the patellofemoral and tibiofemoral joint.

ACL Tear Exercises without Surgery: Can It Help Heal Your Torn ACL?

Can a torn ACL heal with physical therapy?

Whether you are undergoing ACL surgery or need help regaining joint strength and mobility, physical therapy can help. There are varied exercises that you can perform to prevent further deterioration of the injured ligament, strengthen the surrounding musculature, and improve balance/stability.

Physical therapy rehabilitation programs offer several benefits for people undergoing ACL surgery. A few weeks of physical therapy in the pre-operative phase can work wonders in promoting joint health and mobility.  

Alternatively, patients with partial ACL tears or ACL strains are advised to use physical therapy as the primary form of ACL treatment.  In these cases, exercises target muscles surrounding the knee (i.e., hamstrings and quadriceps), strengthening and stabilizing the lower extremity.

We aim to:

  • Prevent excessive compression of the affected area
  • Increased/improved muscle strength
  • Use strengthening and stretching exercises to preserve your range of motion and flexibility
  • Reduce swelling and loss of muscle mass

These advantages avert the possibility of a ‘frozen’ knee joint. Additionally, regular exercising and gentle movements promote the natural recovery of the torn ligament.

Structured ACL physical therapy treatments can include the following exercises: 

1. Isometric Quad Contractions (Quad Sets)

These exercises are performed when you are seated. Remember to keep shoulders straight and prevent slouching when you get into position.

You must:

  1. Sit on the floor with your affected leg extended and the uninjured leg bent.
  2. Gently contract the quadriceps muscles of your injured knee. Make sure that your leg doesn’t move during these movements.
  3. Hold this position for 5-10 seconds, depending on your muscle strength.
  4. Relax.
  5. Repeat these movements 10 times before switching to another exercise.

2.  Heel Slides

It’s a type of exercise that does not require any weight when you extend the knee for stretching.

 For this to work, you should:

  1. Sit upright, on the floor with outstretched legs.
  2. Your body must be positioned at a 90° angle.
  3. Gently bend the injured knee and slide the heel across the surface. Your heel should move towards you during this step.
  4. Slowly slide the foot back into the initial position.
  5. Repeat this back and forth movement for a couple of minutes (approx. 10-15 minutes).

3. Prone Knee Flexion

Prone knee flexion supports muscle contraction and relaxation of your knee joint.  Use a floor mat to perform this exercise.

Here’s a step-by-step you can follow:

  1. Lay on your stomach and place your legs straight.
  2. Bend the affected knee and bring it towards your buttocks.
  3. Hold the position for a couple of seconds (no less than 5 seconds).
  4. Relax.
  5. Repeat actions 10-12 times in one session. 

4. Heel Raises

You may increase the intensity of your exercises once the knee pain and swelling subside. Once you regain stability, you can move onto standing exercises like heel raises.

Here’s what you need to do:

  1. Place one hand on the back of a chair or countertop for balance.
  2. Stand on your tiptoes as you gently lift the heel of your affected leg upwards.
  3. Maintain this position for 5 to 10 seconds.
  4. Gradually bring your heel down and lower it to the starting position.
  5. Repeat these motions at least 10 times in one session.

Track your progress by timing how long you can hold a position and how many times you can perform an exercise each day. Patients performing these rehabilitation exercises at home can use tracking sheets to receive further guidance from physical therapists. 

Your observations can help them adjust exercise routines according to the needs and requirements of your body. Furthermore, it can ensure that you don’t overstrain your muscles during rehabilitation.

5. Shallow Standing Knee Bends

Shallow standing knee bends build muscle strength in the upper thigh region.  This exercise is only suitable for patients with mild knee pain and small ACL tears. 

  1. Position yourself in front of a chair or counter.
  2. Your feet must be placed shoulder-width apart. Place your hands gently on the surface in front of you for balance.
  3. Gradually bend knees to squat down. It should feel like moving downwards to sit in an invisible chair. Ensure that your knees are aligned with the front of your toes.
  4. Lower your body (approximately 6 inches). Keep your heels flat on the floor when you are squatting.
  5. Stand slowly to return to the initial position.
  6. Repeat these steps 5-10 times, depending on your condition.

Like the other ACL tear exercises without surgery, this routine maintains mobility and strength.


Physical Therapy After ACL Surgery: What to Expect?

Assessing range of motion and strength after an ACL tear

ACL surgery revolves around surgical reconstruction or replacement of the injured anterior cruciate ligament (ACL) in the knee. Recovery after surgery is gradual and often facilitated with post-operative physical therapy

The treatment plan includes rehabilitation exercises chosen according to your individual needs and movement goals. They help restore lost range of motion along with rebuilding knee joint stability and strength.

Here’s a preview of exercises you will need to perform during physical therapy after ACL surgery:

1. Range of Motion Exercises

After the initial consultation, physical therapists teach movement-based exercises during the first week of the treatment program. Here you will receive instructions to regain lost motion in the affected area. Common exercises include lunges, heel slides, hamstring stretches, knee slides, popliteus/knee stretch, etc.

ACL physical therapy timeline begins with rehabilitation exercises that are often gentle and non-strenuous.  We aim to alleviate knee pain, reduce swelling, and support everyday movement (i.e., walking, sitting, and climbing stairs).

2. Strengthening Exercises

The first month of rehabilitation and physical therapy after ACL surgery features a varied range of weight-bearing and non-weight-bearing exercises. 

A special emphasis is placed on your thigh muscles with hamstring and quadriceps exercises. 

For example:

  • Bend and straighten your knee.
  • Move your knee between 0-30° and stop softly.
  • Repeat these actions several times.
  • You can use knee/ankle weights to make the exercises more challenging after a few weeks.

The intensity and frequency of strengthening exercises increase with time. This ACL physical therapy protocol protects the reconstructed ACL from experiencing any unwanted strain and/or pressure.

Additionally, it facilitates the transition towards full recovery and range of motion. 

3. Balance Exercises

Balance training after ACL surgery revolves around exercises that aim to strengthen muscles that ensure that you stay upright without loss of balance or swaying.  These exercises usually target your knees, legs, and core muscles.

You will receive guided instructions on how to shift your weight on the affected leg post-operation. This is done through a series of activities. Each one of them is performed on varied surfaces to effectively test your balance.

Before this phase begins, physical therapists will assess your current joint strength and balance.  It typically involves a quick test, as detailed below.

For example:

You might be asked to stand up straight with both feet placed firmly on the ground. After this, you will have to gradually lift your uninjured leg and stand unassisted on the affected leg for a designated time.

This can be 10-30 seconds or longer.

Many patients find this challenging. Practicing balance exercises every day can help regain stability.  After this, you might have to perform more challenging balance exercises to return to an optimal functioning level.

4. Electrical Muscle Stimulation (EMS)

Physical therapy after ACL surgery often includes Electrical Muscle Stimulation (neuromuscular electrical stimulation). This modern technique uses electric impulses to restore muscle contractions and sensation in targeted areas.

A study reveals that advanced technology used in EMS can be ‘more effective in improving quadriceps strength than exercise alone’.

Physical therapists opt for EMS during ACL rehabilitation to facilitate natural recovery. It can help you regain lost muscle strength and knee movement with more precision. 

EMS manages to do that by reducing post-surgery stress and discomfort felt during physical activity. Additionally, it boosts healthy blood flow and circulation. Consequently, it ensures that the area surrounding the reconstructed receives sufficient nutrients for rejuvenation. 

More importantly, EMS can minimize and reverse the loss of muscle atrophy (i.e., loss of muscle mass and tissue).

We also often utilize Neuro Biological Electrical Stimulation (NEUBIE) for patients with ACL tears. NEUBIE is a state-of-the-art electrical stimulation device used to activate muscles and engage the nervous system to help patients heal faster.     

5. Functional Exercises for Patients Returning to Sports (or Other Physically-Demanding Activities)

As you regain joint strength and improve your balance, we shift focus towards functional exercises.  Our physical therapists have specific return to sports rehabilitation programs tailored to meet individual requirements, usually dependent upon the sport you are returning to.

This phase of the treatment includes jumping, hopping, running, and other sport-specific movements. For instance, soccer athletes receive functional training to perform quick jumping and cutting drills safely while minimizing the risk of injury.

In turn, this prevents relapse and complications after surgery for ACL.

Besides this, you might have to wear a brace to support your knee movements post-surgery. Our physical therapists can fit you properly for a brace and provide practical instructions for safe usage. 


Bottom Line

Overall, physical therapy for ACL tears can positively impact recovery with (and without) surgery. We recommend seeking an orthopedist if you observe more serious signs of injury, such as instability, severe weakness, or the knee giving out.

Early intervention can control knee pain and retain mobility to facilitate your road towards recovery.  With proper support and personalized treatment, you may return to sports and everyday activities sooner than most.

If you have experienced an ACL tear or recently ACL reconstruction, give us a call @ 201-773-8851 or email us HERE to start treatment.

To learn more about ACL Tear Physical Therapy, what we treat, and our services, please do not hesitate to contact us.