Iliotobial (IT) Band Syndrome
An ACL injury affects the anterior cruciate ligament in the knee. This ligament connects the thigh bone to the shin bone and helps keep the knee steady when you move. It is especially important for twisting, turning, and quick changes in direction. When the ACL is injured, the knee may feel painful, swollen, and unstable during everyday activities and sports.
On this page, you will find out how common ACL injuries happen, the different types and levels of tears, and how they are diagnosed. We also cover treatment options, recovery timelines, and what to expect during each phase of ACL rehab. The goal is to help you understand your injury, know what comes next, and feel confident moving forward.
OVERVIEW
The anterior cruciate ligament (ACL) is a strong band of fibrous tissue located deep in the center of the knee. It connects the thigh bone, called the femur, to the shin bone, known as the tibia. The ACL plays a key role in stabilizing the knee during movement.
ANATOMY
An ACL tear can happen with or without contact from another person. It usually occurs when the knee twists suddenly or bends too far backward. These strong forces put too much stress on the ligament and cause it to tear. These strong forces put too much stress on the ligament and cause it to tear. When sustaining an acute ACL tear, 68% of athletes were injured by a non-contact mode of injury, 32% were injured by a contact mode of injury. Overall, female athletes are 2 to 8 times more likely to experience an ACL tear than their male counterparts. This range is dependent on age, hormone levels, sport, level of intensity of sports competition, and individual risk factors. Understanding how these variables interact helps explain why ACL injuries are so common in athletics and why prevention strategies often focus on movement patterns, strength training, and neuromuscular control, especially for female athletes.¹
MECHANISM OF INJURY
An ACL tear can happen with or without contact from another person. It usually occurs when the knee twists suddenly or bends too far backward. These strong forces put too much stress on the ligament and cause it to tear. These strong forces put too much stress on the ligament and cause it to tear. When sustaining an acute ACL tear, 68% of athletes were injured by a non-contact mode of injury, 32% were injured by a contact mode of injury. Overall, female athletes are 2 to 8 times more likely to experience an ACL tear than their male counterparts. This range is dependent on age, hormone levels, sport, level of intensity of sports competition, and individual risk factors. Understanding how these variables interact helps explain why ACL injuries are so common in athletics and why prevention strategies often focus on movement patterns, strength training, and neuromuscular control, especially for female athletes.¹
TYPES OF INJURY
An ACL tear can happen with or without contact from another person. It usually occurs when the knee twists suddenly or bends too far backward. These strong forces put too much stress on the ligament and cause it to tear. These strong forces put too much stress on the ligament and cause it to tear. When sustaining an acute ACL tear, 68% of athletes were injured by a non-contact mode of injury, 32% were injured by a contact mode of injury. Overall, female athletes are 2 to 8 times more likely to experience an ACL tear than their male counterparts. This range is dependent on age, hormone levels, sport, level of intensity of sports competition, and individual risk factors. Understanding how these variables interact helps explain why ACL injuries are so common in athletics and why prevention strategies often focus on movement patterns, strength training, and neuromuscular control, especially for female athletes.¹
DIAGNOSIS
TREATMENT TIMELINE
Conservative Treatment (3-12 months): means helping the knee heal without surgery, usually over 3 to 12 months. It can include rest and protection, using crutches to reduce weight on the knee, wearing a brace, taking medicine for pain and swelling, and doing physical therapy. As healing improves, treatment also includes strength training and exercises to help the person safely return to sports.
Surgical Reconstruction (9 to 18 months): means having surgery to rebuild a torn ACL, and recovery usually takes about 9 to 18 months. The new ligament can be made using tissue from your own body, called an autograft, such as the hamstring, quad, or patellar tendon, or from a donor, called an allograft. Your doctor will choose the best option based on your age, activity level, body type, and what will help you heal and return to sports safely.
ACL REHAB PHASE - II
You should have received an ACL Rehabilitation Protocol from your surgeon, if not please ask your physical therapist as they may have a copy to share with you.GOALS: Week 2 - 4
1. Maintain full extension, knee flat.
2. Gradually increase bending to 90+ degrees based on your protocol.
3. Diminish swelling and pain with elevation, compressing, ice, and pain medications if needed.
4. Initiate muscle control, activation, and neuromuscular control with therapeutic exercise.
5. Initiate proprioception (knowing where your body and joints are in space) , if full weight bearing is allowed based on your protocol.
ACL REHAB PHASE - I
You should have received an ACL Rehabilitation Protocol from your surgeon, if not please ask your physical therapist as they may have a copy to share with you.GOALS: Week 1
Follow weight bearing and brace precautions on your protocol.
Recover full passive extension (knee flat to the bed/floor).
Reduce inflammation and swelling with elevation, compression, and ice.
Control pain levels with prescription and or over the counter pain medications.
Restore knee cap movement (patellar mobility) by doing the exercises your physical therapist shows you.
Slowly work on bending your knee again using gentle passive and active assisted techniques your therapist shows you.
Get your thigh muscle (quadricep) working again by reducing swelling and doing the exercises your physical therapist gives you.
ADDITIONAL RESOURCES
Teenage Girls Are Most Likely To Tear Their ACLs. Parents Say More Must Be Done To Protect Them. San Francisco Chronicle · Marc Levy, Associated Press
Why Are Women More Likely to Get ACL Injuries? Instagram · @natgeoscience
Protect Your ACL Instagram · @teamacl_ and @fckruisband
¹ Tjong V. Why Women Have More ACL Injuries Than Men. Northwestern Medicine HealthBeat. https://www.nm.org/healthbeat/healthy-tips/why-women-have-more-acl-injuries-than-men. Accessed March 9, 2026.