Why does knee pain occur when running? Here are 4 reasons to know

Many people experience knee pain when running. This situation is related to many factors. In addition to problems with the knee joint, knee pain when running may also be caused by personal reasons. For example, some people suffer from patellar pain syndrome, which can cause knee pain when running.

1. Runner’s knee

Runner's knee is also known as patellar pain syndrome. Generally speaking, it is pain on the inner side of the patella, or obvious friction pain between the patella and femur. The pain worsens when you press your hand on the patella to extend and flex the knee, and it worsens when you go up and down stairs. During running, factors such as excessive intensity and inappropriate shoes cause the patella to bear too much external force from the front perpendicular to the knee joint, resulting in excessive wear of the contact surface between the patella and femur and causing lesions.

2. Meniscus injury

The meniscus is a cartilage pad between the femur and tibia that relieves and disperses pressure and provides lubrication for the movement of the knee joint. It is divided into the medial and lateral sides. Generally speaking, the most common meniscus injury in running is the medial meniscus tear, which can cause slight knee swelling and pain when bending the knee. During running, at the moment of sudden stop and change of direction, or at the moment of taking off and landing, an external force perpendicular to the inner side of the knee joint acts on the flexed knee joint.

3. Iliotibial band syndrome

The iliotibial band is located on the outside of the thigh, at the same level as the greater trochanter of the femur. It starts from the outside of the thigh below the buttocks and ends on the outside of the knee joint on the calf. It can help reduce the pressure of the body weight on the knee joint. Iliotibial band syndrome presents as pain on the outside of the knee. During running, the tense iliotibial band constantly rubs against the lateral epicondyle of the femur when the knee extends and flexes.

4. Patellar injury

The patella is located in front of the knee joint. It plays the role of force transmission and fulcrum in knee joint movements, such as jumping, squatting, standing up, etc., and is the main part to maintain the stability of the knee joint. Patellar injury is also one of the more common causes of knee pain during running. During running, the knee joint often needs to flex and extend, and the patellar articular surface will be squeezed and rubbed against the femoral articular surface for a long time. Over time, it will cause patellar cartilage damage, such as cartilage degeneration, softening, fragmentation, uneven articular surface, etc., causing knee pain.