What is Causing the Pain in Your Knee?

Learn about the Real Source of Knee Pain

Physical therapist massaging patient knee in examination room
Hero Images/Getty Images

Knee pain due to physical activity is common, and the location and associated symptoms can tell us a lot about the type of injury sustained. Common knee injuries are listed below and are grouped into: acute knee injuries, pain in the anterior (front), lateral (outside), medial (inside), and posterior (back) area of the knee.

Acute Knee Injuries:

Contact sports commonly result in serious injuries and often involve severe twisting or sudden changes in direction.

If the onset of the pain occurs abruptly after the trauma and includes rapid swelling, you should immediately implement RICE (rest, ice, compression and elevation) for your injury. Common acute knee injuries include:

ACL sprain: occurs when twisting of the knee due to impact or trauma causes a tear in the anterior cruciate ligament. MCL sprain: occurs when the medial ligament, located on the inner knee, is torn due to excessive stretching of the ligament after trauma.

Patellar dislocation: occurs when the kneecap dislocates, usually around the perimeter of the knee. It is possible for the kneecap to dislocate and pop back into its normal position. Medial meniscus tears occur when there is an injury in the cartilage inside of the joint.

PCL sprain occurs when the posterior cruciate ligament is torn by twisting or bending the knee backwards. This ligament crosses the ACL in the center of the knee and keeps the shin bone from and knee from moving in the wrong directions.


Knee Pain: Front

With anterior knee pain, the symptoms tend to occur gradually and there is often no obvious cause. Common injuries in this area of the knee are:

Patellofemoral pain syndrome: onset is gradual and symptoms include aching pain in the joint and around the knee cap. This happens when the patella rubs on the underlying bone and the knee will most likely appear swollen.

Patella tendinopathy: also known as patella tendonitis, this involves inflammation or deterioration of the tendon that attaches the kneecap and the shin bone.

Quadricep tendinopathy: an inflammation and degeneration of the tendon that connects the quadriceps muscle to the front part of the thigh. Pain will occur on or above the kneecap, and the onset is gradual.

Fat pad impingement: occurs when the fat pad becomes pinched. The bottom of the knee and under the kneecap become tender, and there may be a history of having the ability to overextend the knee.

Knee Pain: Outside

This pain usually also has a gradual onset and is often caused by overuse. Other common causes are:

Iliotibial band friction syndrome: is swelling of the iliotibial band that is caused by friction when it rubs the bone. It is a long tendon in the hip that runs down the outer side of the thigh.

Lateral meniscus tear: this can be caused by an acute tear that hasn’t healed properly or can happen through deterioration of the cartilage meniscus that functions to cushion and support the joint

Knee Pain: Inside

Medial knee pain usually occurs gradually and is not as common as pain on the front or outer knee. Common causes are:

Patellofemoral pain: symptoms are most often felt in the front  side of the joint but can also occur on the inside.

Medial meniscus tear: occurs when there is damage to the knee.

Medial ligament sprain: happens after the medial ligament is torn, and it is often an acute injury but occasionally occurs gradually.

Osteoarthritis: occurs due to gradual wear and tear in the joint. There is often pain and swelling.

Knee Pain: Back

Pain on the backside of the knee can be referred pain from an injury in front side of the knee, the back, or a nerve in the hip or buttocks. Other common causes are:

Biceps femoris tendinopathy: an inflammation or degeneration of a tendon from the hamstring muscles where it connects to the backside of the knee.

Baker’s cyst: is caused by injury within the joint and creates a golf ball sized swelling behind the knee.

Continue Reading