ACL Sprain

ACL sprain, or anterior cruciate ligament sprain, is a common knee injury that occurs when the ACL is stretched or torn.

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Your Guide to Understanding ACL Sprain

ACL Sprain

What is ACL Sprain?

ACL sprain, or anterior cruciate ligament sprain, is a common knee injury that occurs when the ACL, one of the major ligaments in the knee, is stretched or torn. The ACL is responsible for providing stability to the knee joint, particularly in activities that involve sudden changes in direction or pivoting motions.

An ACL sprain can happen due to various reasons, such as sudden stops, twisting movements, direct impact to the knee, or landing awkwardly from a jump. Athletes participating in sports like soccer, basketball, football, and skiing are at higher risk of ACL injuries.

When the ACL is sprained, it can result in symptoms such as immediate pain, swelling, instability, and difficulty bearing weight on the affected leg. It is important to seek medical attention if you suspect an ACL sprain, as proper diagnosis and treatment can help prevent further damage and promote recovery.

Treatment for an ACL sprain typically depends on the severity of the injury and the individual's activity level. In less severe cases, conservative management may be recommended, which involves rest, ice, compression, and elevation (RICE), along with physical therapy exercises to strengthen the surrounding muscles and improve stability. A knee brace may also be used for additional support during the healing process.

For more severe ACL sprains, surgical intervention may be necessary. ACL reconstruction surgery involves replacing the torn ligament with a graft from another tendon in the body, often from the hamstring or patellar tendon. This procedure aims to restore stability to the knee joint and allow individuals to return to their pre-injury level of activity.

Following surgery or conservative treatment, a comprehensive rehabilitation program is crucial for optimal recovery. This includes a gradual return to activity, strengthening exercises, balance training, and functional exercises to regain strength, stability, and range of motion in the knee.

How can Physiotherapy help treat ACL Sprain?

Physiotherapy services play a crucial role in the treatment and recovery of ACL sprains. Physiotherapists employ various techniques to alleviate symptoms and promote healing. They may start with initial rest, ice, compression, and elevation (RICE) to reduce pain and inflammation. Then, they design personalized exercise programs to strengthen the knee muscles, enhance stability, and improve range of motion.

Additionally, physiotherapists use modalities like electrical stimulation or ultrasound to aid in pain relief and tissue healing. By providing targeted treatment and rehabilitation protocols, physiotherapy helps individuals with ACL sprains regain function, prevent further injury, and return to their desired level of activity.

What causes ACL Sprain?

ACL sprains are typically caused by sudden and forceful movements or trauma to the knee joint. The most common causes of ACL sprains are sports-related activities that involve quick changes in direction, jumping, landing, or sudden stops. For example, pivoting, cutting, or twisting motions during sports like soccer, basketball, football, skiing, or gymnastics can put significant stress on the ACL and lead to injury.

ACL sprains can also occur due to non-sports-related incidents, such as a direct impact to the knee, falling, or accidents that cause the knee to forcefully bend or twist beyond its normal range of motion. These types of movements can result in the stretching or tearing of the ACL ligament.It's important to note that ACL sprains are more common in certain situations, such as when an individual lands from a jump with improper technique or when they participate in high-impact sports without proper conditioning or warm-up exercises.

Additionally, factors like weak muscles, previous knee injuries, and anatomical factors can increase the risk of ACL sprains. Understanding the common causes of ACL sprains can help individuals take preventive measures to reduce the risk of injury. This includes practicing proper techniques, wearing appropriate protective gear, maintaining good physical fitness, and participating in regular strength and conditioning programs that focus on strengthening the muscles around the knee joint.

What treatments might help ACL Sprain?

The treatment for an ACL sprain aims to improve the condition and promote healing. Here are some common approaches used:

Rehabilitative Therapy

Medical treatment often begins with several weeks of rehabilitative therapy. A physical therapist will guide you through exercises that help regain strength, stability, and range of motion in the knee.

Rest and Rehabilitation

Depending on the severity of the ACL sprain, treatment may involve a period of rest and rehabilitation exercises. These exercises help to regain strength and stability in the knee joint.

Surgery (If necessary)

In some cases, surgery may be recommended, especially for combined injuries or severe ACL tears. Surgery aims to repair or reconstruct the damaged ligament using various techniques.

Muscle Strengthening

Physical therapy plays a crucial role in the treatment process. Strengthening the muscles around the knee is important for supporting the joint and improving its stability and function.

Pain Management

Pain relief measures such as ice application, pain medications (under medical guidance), and other modalities can help manage pain and inflammation during the healing process.

Activity Modification

It may be necessary to modify activities and avoid those that can put excessive stress on the knee joint. This helps in preventing further damage and promoting optimal healing.

Use of Braces

In some cases, the use of braces or supportive devices may be recommended to provide additional stability and protection to the knee.

Signs of ACL Sprain:

The signs of an ACL sprain include various symptoms that can indicate the presence of an injury to the anterior cruciate ligament. These signs can include:


Individuals may experience pain on the outside and back of the knee following an ACL sprain.


Knee swelling is a common symptom that typically occurs within the first few hours after the injury."Pop" Sensation: Some people may recall hearing or feeling a "pop" in the knee at the time of the injury.


If the ACL is completely torn, individuals may experience a sense of instability in the knee, causing sudden shifting or buckling.

Difficulty Bearing Weight

In some cases, individuals may be unable to bear weight on the affected leg due to the pain and instability.

Limited Range of Motion

ACL sprains can lead to decreased flexibility and range of motion in the knee joint.

Symptoms of ACL Sprain:

The symptoms of an ACL sprain can vary from person to person but generally include:

  • A "pop" or popping sensation at the time of the injury.
  • Severe pain in the knee.
  • Swelling in the knee.
  • Instability or a feeling that the knee cannot support weight.
  • Trouble walking or difficulty bearing weight on the affected leg.
  • Limited range of motion in the knee joint.
  • Tenderness and sensitivity around the knee.
  • Loss of full function and strength in the knee.
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When is the right time to see a Physiotherapist for ACL Sprain?

It is generally recommended to see a physiotherapist as soon as possible after an ACL sprain. Seeking professional care early on can help in the proper assessment, diagnosis, and initiation of appropriate treatment strategies.

In the case of an ACL sprain, prompt attention from these healthcare professionals can ensure a comprehensive evaluation of the injury, including assessing the extent of ligament damage and identifying any associated injuries or complications. They can also provide valuable guidance on managing pain, reducing inflammation, and preventing further damage to the knee.

Early intervention with a physiotherapist allows for the implementation of personalized treatment plans that address specific needs, considering factors such as the severity of the sprain, individual goals, and lifestyle considerations. These healthcare practitioners can provide targeted therapies, exercises, and recommendations tailored to the individual's condition, helping to promote healing, restore function, and prevent long-term complications.

Meet our Lead Registered Physiotherapist

Brittany Pereira

Brittany Pereira

Registered Physiotherapist

Registered Physiotherapist with a degree from the University of Toronto

Brittany enjoys working with patients across age groups and backgrounds to help them move better, get stronger, understand their bodies and ultimately, feel more confident. She combines her knowledge and clinical experience to best serve her patients.

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Physiotherapist Brittany Pereira working with client at Anchor Health and Performance Clinic Mississauga
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