Physical Therapy Guide to Anterior Cruciate Ligament Tear
An anterior cruciate ligament tear is an injury to the knee. ACL tears commonly affect athletes, such as football players, soccer players, basketball players, and skiers. Nonathletes can also experience an ACL tear due to injury or accident. Around 150,000 ACL injuries are diagnosed in the United States each year. About 70% of ACL tears in sports are the result of noncontact injuries, and 30% are the result of direct contact (player-to-player, player-to-object). Women are more likely than men to experience an ACL tear, especially at a younger age. Physical therapists help people with ACL tears reduce pain and swelling, regain strength and movement, and return to desired activities.
Physical therapists are movement experts. They improve quality of life through hands-on care, patient education, and prescribed movement. You can see a physical therapist directly for evaluation and treatment without a physician’s referral.* To find a physical therapist in your area, visit Find a PT.
*A referral may still be required by your insurance plan (some states may limit the type or duration of treatment without a referral).
What Is an ACL Tear?
The ACL is one of the major ligaments connecting the thigh bone (femur) to the shin bone (tibia) at the knee joint. It can tear if you:
- Twist your knee while keeping your foot planted on the ground.
- Stop suddenly while running.
- Suddenly shift your weight from one leg to the other.
- Jump and land on an extended (straightened) knee.
- Stretch the knee farther than its usual range of movement.
- Experience a direct hit to the knee.
How Does It Feel?
When you tear the ACL, you may feel a sharp, intense pain or hear a loud "pop" or snap. You might not be able to walk on the injured leg because you can’t support your weight through your knee joint. Usually, the knee swells immediately (within minutes to a few hours). You might feel that your knee "gives way" when you walk or put weight on it.
How Is It Diagnosed?
Right after an injury, you may be examined by a physical therapist, athletic trainer, or orthopedic surgeon. If you see your physical therapist first, they will conduct a thorough evaluation that includes reviewing your health history. Your physical therapist will ask questions such as:
- What were you doing when the injury occurred?
- Did you feel pain or hear a "pop" when the injury occurred?
- Did you experience swelling around the knee in the first two to three hours after your injury?
- Does your knee buckle or give out when you try to rise from a chair, use stairs, or change direction while walking?
Your physical therapist may perform gentle hands-on tests to determine the likelihood that you have an ACL tear. They also may conduct other tests to assess possible damage to other parts of your knee.
An orthopedic surgeon may order further tests, including magnetic resonance imaging, or MRI, to confirm the diagnosis and rule out other possible damage to the knee.
Surgery
Most people who sustain an ACL tear will undergo surgery to reconstruct the ligament. However, some people may avoid surgery by modifying their physical activity to relieve stress on the knee. A select group can return to vigorous physical activity following rehabilitation without having surgery.
Your physical therapist, together with your surgeon, can help you determine if rehabilitation without surgery is a reasonable option for you. If you elect to have surgery, your physical therapist will help you prepare for surgery and recover your strength and movement after surgery.
How Can a Physical Therapist Help?
If you receive an ACL tear diagnosis, you will work with your surgeon and physical therapist to decide if you need surgery or if you can recover without it. If you don’t have surgery, your physical therapist will work with you to restore your muscle strength, agility, and balance so you can return to your regular activities. They may teach you ways to modify your physical activity to put less stress on your knee. If you decide to have surgery, your physical therapist can help you before and after the procedure.
Treatment Without Surgery
Research has identified a specific group of patients (called "copers") who have the potential to heal without surgery following an ACL tear. These patients have injured only the ACL. They also have not experienced episodes of the knee "giving out.” If you are in this category, based on the specific tests your physical therapist conducts, your physical therapist will design a personalized physical therapy treatment program for you. It may include treatments such as gentle electrical stimulation applied to the quadriceps muscle, muscle strengthening, and balance training.
Treatment Before Surgery
If your orthopedic surgeon determines that your injury requires surgery, your physical therapist can work with you before and after surgery. Some surgeons refer their patients to a physical therapist for a short course of physical therapy before surgery (prehabilitation). Your physical therapist will help you decrease swelling, increase the range of movement of your knee, and strengthen your thigh muscles (quadriceps).
Treatment After Surgery
Your orthopedic surgeon will provide postsurgery instructions to your physical therapist. Your physical therapist will tailor a treatment program based on your specific needs and goals. Your treatment program may include:
Bearing weight. Following surgery, you will use crutches to walk. The amount of weight you are allowed to put on your leg and how long you use the crutches will depend on the type of reconstructive surgery you had. Your physical therapist will design a treatment program to meet your needs and gently guide you toward full weight bearing.
Icing and compression. Immediately after surgery, your physical therapist will control your swelling with a cold application, such as an ice sleeve, which fits around your knee and compresses it.
Bracing. Some surgeons will give you a brace to limit your knee movement (range of motion) after surgery. Your physical therapist will fit you with the brace and teach you how to use it safely. Some athletes will be fitted for braces as they recover and begin to return to their sports activities.
Movement exercises. During your first week after surgery, your physical therapist will help you begin to regain motion in the knee area. They also will teach you gentle exercises you can do at home. The focus will be on regaining full knee range of motion. Early exercises help with increasing blood flow, which also helps reduce swelling.
Electrical stimulation. Your physical therapist may use electrical stimulation to help restore your thigh muscle strength. Electrical stimulation also can help you achieve those last few degrees of knee motion.
Strengthening exercises. In the first four weeks after surgery, your physical therapist will help you increase your ability to put weight on your knee. This will involve guiding you through a combination of weight-bearing and non-weight-bearing exercises. The exercises will focus on your thigh muscles (quadriceps and hamstrings) and might be limited to a specific range of motion to protect your new ACL. Next, your physical therapist may increase the intensity of your exercises and add balance exercises to your program.
Balance exercises. Your physical therapist will guide you through exercises on varied surfaces to help restore your balance. Initially, the exercises will help you gently shift your weight onto the surgical leg. These activities will progress to standing on the surgical leg while on firm and unsteady surfaces to challenge your balance.
Return to sport or activities. As athletes regain strength and balance, they may begin running, jumping, hopping, and doing other exercises specific to their sport. This phase varies greatly from person to person. Physical therapists design return-to-sport treatment programs to fit each person’s needs and goals. It may take the athlete over a year to regain the strength, stability, and power to return to their sport safely.
Can This Injury or Condition Be Prevented?
Most studies on ACL tears have been done with female college athletes, because women are four to six times more likely to experience this injury. Preventive physical therapy programs are highly effective in reducing the risk of ACL tears in female athletes. An analysis of multiple studies found a 67% reduction in non-contact ACL injuries in females who participated in prevention programs. Researchers recommend the following for a preventive exercise program:
- The program should be designed to improve power, strength, and sports performance. Strengthening your core (abdominal) muscles is key to preventing injury, in addition to strengthening your thigh and leg muscles.
- Exercises should be done two or three times per week and should include sport-specific exercises.
- The program should last no fewer than six weeks.
- The program should start in preseason and continue throughout the season.
Although most exercise studies have been conducted with female athletes, the findings may benefit male athletes as well.
What Kind of Physical Therapist Do I Need?
All physical therapists are prepared through education and clinical experience to treat a variety of conditions or injuries. You may want to consider:
- A physical therapist who is experienced in treating people with orthopedic (musculoskeletal) problems or who has a practice focus on sports physical therapy.
- A physical therapist who is a board-certified clinical specialist or who has completed a residency or fellowship in orthopedic or sports physical therapy. This physical therapist has demonstrated advanced knowledge, experience, and skills that may apply to your condition.
You can search for physical therapists with specific experience or expertise using the American Physical Therapy Association’s Find a PT tool.
General tips when you're looking for a physical therapist (or any other health care provider):
- Ask family, friends, or other health care providers to recommend a physical therapist.
- Ask about the physical therapists' experience in helping people with ACL tears when you contact the clinic for an appointment.
- Be prepared to describe your symptoms in as much detail as possible. Make a note of what makes your symptoms better or worse.
The American Physical Therapy Association believes consumers should have easy access to clear, reliable information that helps them make informed health care decisions and feel prepared for visits with their providers.
These resources offer the latest scientific evidence on the physical therapy treatment of ACL tears. They cover recent research and standards of practice in the United States and globally. Whenever possible, they link to PubMed* abstracts (some of which offer free full-text access) or to other resources. Read these materials to learn more or share them with your health care provider.
Evans J, Mabrouk A, Nielson Jl. Anterior cruciate ligament knee injury. In: StatPearls [Internet]. StatPearls Publishing; 2025. Article Summary on PubMed
Raj S, Ridha A, Umar H, et al. Injury prevention programmes (IPPs) for preventing anterior cruciate ligament injuries. Cochrane Database Syst Rev. 2024;12(12):CD016089. Article Summary on PubMed
Brophy RH, Lowry KJ. American Academy of Orthopaedic Surgeons Clinical Practice Guideline Summary: Management of Anterior Cruciate Ligament Injuries. J Am Acad Orthop Surg. 2023;31(11):531–537. Article Summary on PubMed
Arundale AJH, Bizzini M, Dix C, et al. Exercise-based knee and anterior cruciate ligament injury prevention. J Orthop Sports Phys Ther. 2023;53(1):CPG1–CPG34. Article Summary on PubMed
Brinlee AW, Dickenson SB, Hunter-Giordano A, Snyder-Mackler L. ACL reconstruction rehabilitation: clinical data, biologic healing, and criterion-based milestones to inform a return-to-sport guideline. Sports Health. 2022;14(5):770–779. Article Summary on PubMed
Knee ligament sprain guidelines: Revision 2017: Using the evidence to guide physical therapist practice. J Orthop Sports Phys Ther. 2017;47(11):822–823. Article Summary on PubMed
*PubMed is a free online resource created by the National Center for Biotechnology Information. It contains millions of citations to biomedical literature, including those in the National Library of Medicine's MEDLINE database.
Expert Review:
Jul 12, 2025
Revised:
Mar 24, 2026
Content Type: Guide
Anterior Cruciate Ligament Tear
PT, DPT, MS
Laura Thornton
PT, DPT, Board-Certified Clinical Specialist in Orthopaedic Physical Therapy, Fellow of the American Academy of Orthopaedic Manual Physical Therapists
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