ACL Tear: Rehab Before and Without Surgery

By Nova Physical Therapy, an outpatient physical therapy clinic in North Hollywood, CA | Published November 2026

You planted your foot to cut during a pickup basketball game, or landed awkwardly coming down from a rebound, and felt a pop inside your knee. Within a few hours, the knee swelled up. Now it feels unstable, like it might buckle if you turn too fast, and you're wondering if your ACL is torn and whether you need surgery.

ACL tears are one of the most common serious knee injuries in sports. Treatment has more options than many people realize. This article explains what the ACL does, the signs of a tear, why rehab before surgery matters, what research says about rehab with and without surgery, and when to see a physician.

The short answer

The anterior cruciate ligament (ACL) is a key stabilizing ligament inside the knee. Tears often happen with a pivot, cut, or awkward landing, and commonly cause a pop, swelling within hours, and a feeling of the knee giving way (Logerstedt et al., 2017). In a randomized trial of 121 active adults aged 18 to 35 with acute ACL tears, those who started with structured rehab, with surgery later only if needed, had similar knee function at two years to those who had early surgery, and only about 40% of the rehab-first group needed reconstruction (Frobell et al., 2010). Whether surgery is right for you is a decision to make with an orthopedic surgeon. Either way, physical therapy is a core part of recovery. In California, you can see a physical therapist without a referral.

What does the ACL do?

The ACL runs diagonally through the middle of the knee, connecting the thighbone to the shinbone. It:

• Keeps the shinbone from sliding too far forward
• Controls rotation of the knee
• Helps the knee stay stable during cutting, pivoting, and landing

That's why ACL tears are common in sports like basketball, soccer, football, skiing, and pickleball, which involve quick changes of direction.

What are the signs of a torn ACL?

The APTA knee ligament guideline lists these common signs (Logerstedt et al., 2017):

• A "pop" at the time of injury
• Swelling that develops quickly, often within the first 12 hours
• A history of the knee giving way
• Looseness in the knee on specific clinical tests

Many people can walk after an ACL tear, especially once the swelling settles, so walking doesn't rule one out. ACL tears can also happen with injuries to the meniscus or other ligaments. A physical exam is key, and imaging decisions are made by your physician.

Do I need surgery for a torn ACL?

Not always, and the answer depends on your knee, your sport, and your goals. The KANON trial in Sweden compared two approaches for young, active adults with acute ACL tears (Frobell et al., 2010):

• Early surgery: 62 people had ACL reconstruction within 4 to 6 weeks, plus rehab.
• Rehab first: 59 people did structured rehab, with surgery later only if needed.
• At two years: knee function, activity level, and well-being were similar between the groups.
• Surgery later: only about 40% of the rehab-first group went on to have reconstruction.

Some people, especially those returning to cutting and pivoting sports or whose knee keeps giving way, may do better with surgery. Others can return to many activities with a strong, well-trained knee. That decision is made with an orthopedic surgeon.

Why does rehab before surgery matter?

Whether or not you have surgery, the first weeks of rehab set you up for a better recovery. Early goals usually include:

• Calming swelling
• Getting the knee fully straight and bending well
• Waking up and strengthening the quadriceps
• Walking normally without a limp

Going into surgery with good motion and strength often makes recovery afterward smoother.

How can physical therapy help?

The APTA knee ligament guideline recommends (Logerstedt et al., 2017):

• Neuromuscular electrical stimulation alongside strengthening, to help rebuild quadriceps strength
• Neuromuscular training (balance, landing, and movement control) combined with strengthening
• Progressive strengthening, with rehab after reconstruction often lasting about 6 to 10 months
• Supervised rehab, moving to a home program you can do on your own
• Hop testing to check side-to-side differences and readiness to return to sport

A physical therapy evaluation may include:

• How the injury happened and what your sport or job demands
• Swelling, knee motion, and knee stability tests
• Quadriceps, hamstring, and hip strength
• Balance, squatting, and hopping when ready
• Screening for other injuries that need a physician

Physical therapy doesn't guarantee a specific result or timeline. At Nova Physical Therapy in North Hollywood, sports injury rehab and rehab after knee surgery are among our core services, and every plan starts with an evaluation so treatment fits what we find. For other knee injuries, read our post on meniscus tears.

When should I see a doctor?

See a physician promptly if you have:

• A pop at injury followed by rapid swelling
• A knee that gives way or feels unstable
• A knee that locks and won't straighten
• Inability to put weight on the leg
• A deformed-looking knee or severe pain
• Numbness, tingling, or a cold or pale foot
• Calf swelling, warmth, or redness

We screen for these signs during every evaluation and refer you to a physician when findings call for medical assessment.

Do I need a referral for physical therapy in California?

Not to get started. California allows direct access to physical therapy. A physical therapist can evaluate and treat you without a referral for up to 45 calendar days or 12 visits, whichever comes first. After that, a physician or podiatrist needs to sign the plan of care for treatment to continue. Your insurance plan may have its own referral rules, so check your coverage or see our insurance page.

Frequently asked questions

Can you walk with a torn ACL?
Often, yes, especially after the swelling settles. Walking doesn't rule out a tear. A knee that gives way or feels unstable should be evaluated.

Can a torn ACL heal without surgery?
A fully torn ACL usually doesn't heal back together on its own, but many people regain good knee function with structured rehab. In one trial, only about 40% of people who started with rehab later needed surgery.

How long is rehab for a torn ACL?
It varies. After reconstruction, rehab often lasts about 6 to 10 months. Without surgery, many people progress over several months depending on their goals.

Should I do physical therapy before ACL surgery?
Usually, yes. Reducing swelling and restoring motion and quadriceps strength before surgery often makes recovery afterward easier.

Can I play sports again after an ACL tear?
Many people do, with or without surgery. Returning to cutting and pivoting sports should be based on strength, hop testing, and your surgeon's guidance.

How do I know if I tore my ACL or meniscus?
Both can cause swelling and pain. An ACL tear often comes with a pop and a feeling of the knee giving way. A physical exam, and sometimes imaging ordered by a physician, sorts it out.

Do I need a referral to see a physical therapist?
No, not to start. California allows direct access within the limits described above.

About Nova Physical Therapy

Nova Physical Therapy is an outpatient physical therapy clinic in North Hollywood, California, led by a Doctor of Physical Therapy. We help people recover from sports injuries, back and neck pain, work injuries, auto accident injuries, knee pain, and shoulder problems, and we also work with balance problems and rehab after surgery. Patients come to us from North Hollywood, Burbank, Studio City, Toluca Lake, Valley Village, and across the San Fernando Valley. Learn more about Nova or see our services.

Schedule an evaluation

If you think you’ve torn your ACL, or you’re preparing for surgery, an evaluation can help you start rehab and plan your return to sport.

Nova Physical Therapy
4795 Vineland Ave #E, North Hollywood, CA 91602
Call (818) 639-3402 | Book an appointment online

Disclaimer

This article is for general education only. It is not medical advice, a diagnosis, or a treatment recommendation for any individual. Knee injuries vary, and only an in-person evaluation, sometimes with imaging ordered by a physician, can determine what is right for you. No treatment guarantees symptom resolution, and results vary. Physical therapists evaluate movement and function within their scope of practice and refer to physicians when findings warrant. Physical therapy in California is regulated by the Physical Therapy Board of California.

References

1. Logerstedt DS, et al. Knee Stability and Movement Coordination Impairments: Knee Ligament Sprain Revision 2017. J Orthop Sports Phys Ther. 2017;47(11):A1–A47. Link
2. Frobell RB, Roos EM, Roos HP, Ranstam J, Lohmander LS. A randomized trial of treatment for acute anterior cruciate ligament tears. N Engl J Med. 2010;363(4):331–342. Summary: Link