ACL Injuries and Rehabilitation
This article covers ACL injuries and rehabilitation

5 Knee Strengthening Exercises To Help With Knee Pain and Instability

By Steve on April 14th, 2015

ACL Injuries and Recovery

One of the most common knee injuries in the world, especially among athletes, is an anterior cruciate ligament sprain or tear. Athletes who play sports like football, soccer, and basketball are much more likely to injure their ACL due to the intensity and speed required. This puts stress on the ligaments and tendons holding the knees together, which could possibly lead to an injury like an ACL tear. This type of injury will typically require surgery to rectify, but that depends on the severity of the tear and a number of other factors such as your activity level and the amount of pain you experience.

Anatomy of the Knee

The knee joint is the product of three bones meeting: The femur, shinbone, and kneecap. The kneecap provides some protection of the joint. Ligaments are what connect our bones to each other. They are essentially like ropes, and they work to hold our bones together and keep them stabilized. There are four main ligaments in the knee:

Collateral ( Lateral and Medial ) – Found on the sides of the knee. They control the side to side motion of the knee and protect it from unordinary movements.

Cruciate ( Anterior and Posterior ) – Found on the inside of the joint. These cross over one another in the shape of an “X”. They assist with the forward/backwards motion of the knee.

The anterior cruciate ligament runs diagonally across the middle of the knee. This prevents the tibia from sliding in front of the femur, and provides rotational stability to the knee.

(Picture model of a healthy knee)

Types of ACL injuries

About 50% of all injuries to the ACL occur in tandem with additional injuries to other parts of the knee such as the meniscus, articular cartilage, and other ligaments.

There are 3 grades of sprains:

Grade 1 Sprain: The ligament is mildly to moderately damaged. Slightly stretched, but still has the ability to keep the knee joint stable

Grade 2 Sprain: The ligament has been stretched to the point that it has become loose. Sometimes referred as a partial tear of the ligament ( partial tears are much more uncommon than full tears )

Grade 3 Sprain: Complete tear of the ligament. It has been split in two. Knee joint is unstable.

The ACL can be injured in many ways, including:

o Rapid change of direction

o Suddenly stopping

o Awkward landing from a jump

o Collision

(picture model of a torn ACL)


When the ACL is injured you may hear a distinct “popping” sound and may feel your knee give out underneath you. Other symptoms include pain and swelling, loss of range of motion, Tenderness along the joint, walking becomes uncomfortable.

If you have any of these symptoms your doctor will want to talk with you. He may want to do an X-ray or MRI scan.


A torn ACL will not heal properly without surgery, but nonsurgical treatment may be beneficial for elderly patients with low activity levels. If the stability of the knee is still sufficient, your doctor may recommend a nonsurgical recovery program.

Bracing is ideal for instability and recovery to further protect the knee. Popular knee braces like the DonJoy Everyday Knee Brace, Ossur Cti, Breg Recover provide extreme stability and may allow the user to regain a normal life with minimal surgery. After surgery, a knee brace may be prescribed by a physician to help stabilize and protect the knee joint while it heals.

Physical therapy is ideal once the swelling subsides. Exercises made specifically for your injury will restore function and strength in the muscles that support the knee.


Your treatment may or may not involve surgery, but the rehab process will play a vital role in your overall outlook. As well as physical therapy to help get your strength and function back. If surgery is advised, the physical therapy afterwards will be focused on getting motion in the joint back. Then it will be followed by a strengthening program as your function increases. The final phase of the rehab will be aimed at getting the athlete or patient back to their desired sport or in the patients case, daily activities.