Pre-ACL Surgery: 5 Best Exercises (with Pictures!)

published by: Debbie Luna
Last Updated:
December 16, 2022

Among the most common physiological injuries that require surgery is that of the ACL tear, a type of soft-tissue injury often caused by excessive impact or strain being placed on the joint of the knee.

Often, before rehabilitative surgeries such as ACL reattachment surgery, physicians will instruct the patient to perform preparatory exercises that can aid in retaining the mobility and strength of the damaged ligament despite the severity of their injury.

The majority of pre-ACL surgery exercises revolve around rotation and extension of the knee joint, as these are the biomechanics that are directly governed by the anterior cruciate ligament or the ACL.

What is ACL Surgery?

ACL surgery is a rehabilitative surgery that aims to reattach or otherwise graft new tissue onto the joint in a manner that allows the patient to return to their original quality of life and full level of mobility. 

what is acl surgery

In most instances of ACL injury, excessive torsion, resistance or impact is placed on the anterior cruciate ligament of the knee joint while it is in a disadvantageous state - resulting in partial or full tearing or otherwise damage of the aforementioned ligament.

This, in turn, causes instability, pain or loss of effective range of motion within the knee joint, especially in regards to full knee extension.

How do Exercises Help With ACL Surgery?

Invasive surgeries are often traumatic to the tissues of the body, requiring significant periods of recovery and often coming with their own inherent risks and disadvantages. 

One particularly large risk when undergoing reconstructive ACL surgery is the fact that this reattachment may be otherwise ineffective due to insufficient stimulus being placed on the knee joint, thereby permanently limiting the range of motion or strength of the ACL structure.

This is counteracted by performing prehabilitative and rehabilitative exercises surrounding the time of the operation, with prehabilitative work meant to aid in reducing the risks involved in the surgery and rehabilitative work meant to maximize the benefits achieved through the same surgery.

Should You Exercise Before ACL Surgery?

Unless otherwise specifically instructed by your physician - no, it is not a good idea to exercise the injured area in any capacity.

Pre-surgery exercises are specifically performed under the supervision or instruction of medical professionals, and are carefully designed and picked in such a manner that they do not worsen or otherwise interfere with recovery from the injury.

Exercises Prior to ACL Surgery

Pay especially close attention to the volume of repetitions prescribed by your physician, as well as their instructions on how to perform these exercises, as excessive volume or improper execution of any sort of exercise could potentially worsen ACL tear symptoms.

1. Seated Knee Extension Exercise

The seated knee extension exercise is the quintessential pre and post ACL surgery exercise, as it directly targets the anterior cruciate ligament as well as any surrounding tissue structures that may also be impacted by weakness of the ACL within the knee.

knee extension

This exercise is not to be confused with the resistance machine exercise also known as knee or leg extensions, as this exercise is entirely inappropriate for pre-surgery preparation.

Remember that if you experience pain or any symptoms that are out of the ordinary, it is best to cease performing the exercise and to speak with your physician.


Sitting on a table or bed with the legs hanging over the ground, the patient will place their uninjured leg beneath the injured leg, hooking the foot behind the injured leg’s calf.

Ensuring that the injured leg is relaxed and that the knee is not exerting any force whatsoever, the patient will then try to raise the injured leg into a state of extension with their uninjured leg, stopping once they have reached as far as their injury will allow.

They will hold this position for a count before returning to the starting position once more.

2. Lying Heel Slide Exercise

A favorite for pre-ACL surgery exercise plans due to its very low risk of injury and impact, the lying heel slide involves the patient lying upon their back and simply affecting the ACL in a manner that requires little mobility or technical exercise knowledge.

This particular exercise is especially useful for individuals who cannot stand or sit upright due to concurrent injuries or a high risk of the ACL tear worsening in severity.


To perform the lying heel slide exercise, the patient will lie on their back with their chest facing upwards and the injured leg bent at the knee, pressing the heel against the bed or flooring.

As carefully as possible, the patient will then attempt to slide their heel across the floor, extending the knee in a supported and slow manner until the maximum range of motion has been reached.

This exercise may be made easier by giving the patient a sock to wear so as to reduce friction between the heel and the ground.

3. Standing Hamstring Curl Exercise

Not to be confused with the resistance machine hamstring curl exercise, the standing hamstring curl exercise is an excellent pre-ACL surgery movement that is better suited for more moderate or low risk injuries of the ACL, as it involves the patient standing and will otherwise place some level of resistance on the knee joint as a whole.

standing hamstring curl

Crutches or parallel rehabilitation bars may be used so as to support the body as this exercise is performed, reducing pressure placed on the opposite leg and ensuring that the patient can better control the movement of their injured knee.


To begin performing the standing hamstring curl exercise, the patient will stand with one or both sides of their body supported through their arms.

Then, the patient will gently pull the heel of their injured leg upwards, exercising the knee flexion biomechanic in a manner that stretches the ACL.

Once they have drawn the heel as high as the knee joint can reach, they will then slowly allow the foot of the injured leg to return to its original position, thereby completing the exercise.

4. Lying Hamstring Curl Exercise

A lower resistance variation of the standing hamstring curl, the lying hamstring curl is more appropriate for patients with concurrent injuries that limit their capacity to stand, or otherwise do not wish to place any sort of pressure on the injured leg whatsoever.

lying hamstring curl


Lying the patient stomach-down with the thigh supported by a small pillow or roller, the patient will then contract the muscles of the hamstring within the injured leg, slowly drawing the heel of the same side upwards until it is above the plane of the gluteus muscles.

Holding this position for a moment, the patient will then lower the foot back to the ground, thereby completing the exercise.

5. Lying Hip Abduction/Adduction Exercise

An exercise either utilized for concurrent injuries alongside ACL tears or otherwise to account for hip muscle deficits caused by unbalanced gaits from ACL injury, the lying hip adduction/abduction exercise is low enough in resistance and impact to be included into the majority of pre-ACL reconstruction surgery programs.

lying side hip abduction

This preparatory exercise is also employed in rehabilitative programs so as to aid in the patient fully regaining their capacity to walk or otherwise utilize a full hip joint range of motion.


Laying the patient on their uninjured side, the patient will then fully extend their injured leg (as much as they are able) before contracting the hip rotator muscles, pulling the leg upwards in a straight line.

Once reaching the maximum comfortable range of motion of the hip joint, they will then reverse the motion and draw the leg back to the floor, rotating the leg somewhat behind themselves as they do so.

This completes the exercise.

Other Factors to Control Before ACL Surgery

Though following the prescribed exercise routine of your physician is absolutely vital in importance, it is not the only responsibility you must account for in the time leading up to your ACL reconstruction surgery.

Other matters like maintaining a healthy diet, consuming your prescribed medication (if any) in the correct manner and ensuring that the injury does not worsen are all just as important as exercising the injured ligament properly.

As always, if you are unsure of whether something will affect your ACL injury, it is best to consult your physician.

In Conclusion

As painful or limiting as an injury of the anterior cruciate ligament may be, remember that it is relatively common and therefore also quite well-researched within clinical medicine. 

This means that the rate of success in reconstructive surgery of even the most severe ACL injuries is actually quite high, and that performing the correct preparatory exercises will only multiply these chances of a successful recovery.

In the event that your physician or physical therapist has prescribed an exercise that is not listed in this article, it is best to clarify with them as to how to perform such an exercise so as to avoid incorrect form leading to any worsening of your injury.


1. Cunha J, Solomon DJ. ACL Prehabilitation Improves Postoperative Strength and Motion and Return to Sport in Athletes. Arthrosc Sports Med Rehabil. 2022 Jan 28;4(1):e65-e69. doi: 10.1016/j.asmr.2021.11.001. PMID: 35141537; PMCID: PMC8811524.

2. Paschos NK, Howell SM. Anterior cruciate ligament reconstruction: principles of treatment. EFORT Open Rev. 2017 Mar 13;1(11):398-408. doi: 10.1302/2058-5241.1.160032. PMID: 28461919; PMCID: PMC5367541.

3. Granicher P., Scherr J. Do athletes benefit from preoperative physical therapy before ACL-reconstruction? Sports Orthopaed Traumatol. 2021;37:126–131.

Debbie (Deb) started powerlifting and Olympic lifting in High School as part of her track team's programming; She continues to train in order to remain athletic. Inspire US allows Deb to share information related to training, lifting, biomechanics, and more.
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