Anterior Cruciate Ligament (ACL) Sprain or Tear

The anterior cruciate ligament (ACL) is 1 of the 4 major ligaments in the knee and provides stability. A common ACL injury is a sprain or tear.

The ACL is commonly injured in pivoting and twisting sports like football, soccer, basketball, tennis.

Download the overview and exercises PDF


There are a number of reasons why an ACL sprain or tear may occur. Some common ones include:

  • Improper warm up

  • Overtraining

  • Participating in sport when fatigued

  • Lack of strength and flexibility training

  • Twisting, where the foot is planted and the body pivots

  • Hyperextending, where the knee straightens out too much

  • Changing direction too fast

  • Slowing down suddenly

  • Landing awkwardly after a jump

  • A hard hit during a contact sport with a twisting motion


Common symptoms related to an ACL sprain or tear are:

  • Immediate, rapid swelling

  • Pain

  • Inability to weight bear

  • Unable to move knee

  • Popping sound or sensation at time of injury

  • Feeling of knee “giving out” when in use


To determine if your child has an ACL tear, our specialists will perform a physician exam that includes flexibility tests, stress tests, muscle tests and gait analysis. These tests will help our specialized team better understand your child’s condition, assess range of motion and identify abnormalities that might occur in bone alignment or muscle function. After a physical exam, our specialists may order x-rays or advanced imaging tests.


ACL tears often require surgery to reconstruct the torn ligament. This is done in order to get your child back to sports and activities, treat symptoms of giving out/locking/clicking/instability, and prevent long term damage to the lead that could lead to arthritis, pain and disability. ACL surgery is commonly done by using tissue from somewhere else on the knee to replace the torn ACL.

At-Home Care

Common at-home treatment options for ACL injuries include:

  • Icing the Area:

    Put ice packs wrapped in a towel or thin cloth on your child’s knee for 20–30 minutes every 3-4 hours for the first 2-3 days. If pain does not go away, contact your healthcare provider.

  • Elevating the Injured Limb:

    Elevate your child’s lower leg by placing it on a pillow when your child is lying down. Elevating it above the heart level can help reduce swelling and pain.

  • Taking Non-Prescription Medication:

    Take a non-steroidal, anti-inflammatory drug (NSAID), such as ibuprofen as recommended by your healthcare provider.

  • Exercising:

    Your doctor may recommend doing exercises at home. These are designed to stretch the affected knee, maintain range of motion in the joint and strengthen your child’s knee.

Rehabilitation Exercises

Below are common exercises a doctor may recommend to help your child recover after an ACL injury. Always check with your doctor to find out which exercises are right for your child.


Standing Calf Stretch

  • Facing a wall, put hands against the wall at about eye level.

  • Keep the uninjured leg forward and the injured leg back about 12-18 inches.

  • Keep the injured leg straight and the heel on the floor.

  • Keep toes pointed towards the wall.

  • Next, do a slight lunge by bending the knee of the forward leg. Tell your child to lean into the wall until they feel a stretch in the calf muscle.

  • Hold for 30-60 seconds. Repeat 3 times.

Standing Soleus Stretch

  • Facing a wall, put hands against the wall at about eye level.

  • Keep the uninjured leg forward and the injured leg back about 4-6 inches behind the uninjured leg.

  • Tell your child to keep both heels on the ground and gently bend their knees until they feel a stretch in the calf muscle.

  • Hold for 30-60 seconds. Repeat 3 times.

Hamstring Stretch

  • Lie on back and bring the affected leg towards the chest.

  • Grab the back of the thigh and try to extend the leg.

  • Your child may also try this with a towel around the foot if it is more comfortable.

  • Hold for 30-60 seconds. Repeat 3 times.

Quadriceps Stretch

  • Stand sideways to a wall, about an arm’s length away, with injured leg towards the outside.

  • Face straight ahead, keep the hand nearest the wall against it for support.

  • Grasp the ankle of injured leg and pull heel up toward buttocks, using other hand.

  • Do not arch or twist back.

  • Hold for 30 seconds. Repeat 3 times.

Alternative Quadriceps Stretch

  • Place the affected leg on a sturdy chair or low stool.

  • Place the opposite hand on a wall to your child’s side

  • Bend front leg slowly.

  • Hold for 30 seconds. Repeat 3 times.


Vastus Medialis Oblique Quadriceps Sets

  • Sit on the floor with injured leg straight in front.

  • Press the back of the knee down while tightening the muscles on the top of the thigh.

  • Concentrate on tightening muscles on the inner side of kneecap.

  • Hold for 5 seconds. Complete 3 sets of 10.

Straight Leg Raise

  • Sit on the floor with the injured leg straight and the other leg bent, foot on the floor.

  • Pull the toes of the injured leg in as far as possible, while pressing the back of the knee down and tightening the muscles on the top of the thigh.

  • Raise the leg six to eight inches off the floor and hold for 5 seconds.

  • Slowly lower back to the floor.

  • Complete 3 sets of 10.

Abduction Leg Lifts

  • Lie on the uninjured side and lean on the elbow of the uninjured side.

  • Use the arm of the injured side in front to stabilize the body.

  • Slowly with the injured leg up, hold for 5 seconds then lower slowly.

  • Be sure to keep hips steady and don’t roll forwards or backwards.

  • Complete 3 sets of 10.


  • Lie on the injured side with top leg bent and a foot placed in front of the injured leg, which is kept straight.

  • Raise the injured leg as far as possible, while remaining comfortable.

  • Hold for 5 seconds keeping hips still while lifting leg.

  • Slowly lower leg.

  • Complete 3 sets of 10.

Prone Hip Extension

  • Lie on stomach.

  • Squeeze buttocks together and raise injured leg 5-8 inches off the floor.

  • Keep back straight and the hip of the lifted leg on the floor. Hold leg up for 5 seconds, then lower it. Do not let hip roll open while lifting the leg.

  • Repeat 10 times. Do 3 sets of 10.


  • Lie on side with knees slightly bent, keeping legs and ankles together.

  • Open and close knees like a clam by lifting the top knee up until it’s parallel with the hip.

  • Keep feet together throughout the exercise.

  • Move slowly and controlled as if someone is pushing against the knee while your child is pressing it up.

  • Complete 3 sets of 10.

Side Steps with Latex Resistance Band

  • Place a band around ankles.

  • Lower down into a half squat with knees bent and toes pointing forward.

  • Step to the right with the right foot while staying low in squat position.

  • Bring left foot in.

  • Repeat 10 times in each direction. Do 3 sets.

When Will My Child Return to Play?

After your child has had a musculoskeletal injury like an ACL injury, it’s normal to want to know how long the injury will take to heal and what you can expect.

Every child is unique, every injury is different. Your doctor will be able to give you guidelines as to when your child may be able to return to play. Collaboration between sports medicine team and each patient and family will help ensure safe and successful return to their sports and hobbies.

The best thing you can do for your child is to make sure you consistently follow your doctor’s instructions, including doing at-home exercises regularly. When it is okay to do so, our doctors and staff will let you know when your child can return to play at a controlled level.

How to Prevent ACL Injuries

  • Practice proper landing techniques

  • Don’t overtrain

  • Do exercises to strengthen the hamstrings and quadriceps

See more information

Sports Medicine

Orthopedic Rehabilitation