The knee is the largest most complicated joint in the body, and knee injury is the most common complaint among runners. Running increases the risk for acute knee injuries. The knee, which provides stability, is held together by muscles, tendons and ligaments. Given how many parts make up the knee, pain during running could be from a variety of injuries.
Tendonitis
The tendons attach the muscle to the bone. Thick, fibrous cords that create the tendon can become irritated and inflamed by being stretched beyond its limits. Runners are prone to inflammation of the patellar tendon, which connects the muscle of the thigh to the lower leg bone. Tendonitis causes pain and stiffness, and possible swelling located below the knee. Rest is required for tendonitis to heal.
Ligaments
The knee has four ligaments. The two most common in knee injuries are the anterior cruciate ligament, or ACL, and the posterior cruciate ligament, or PCL. Injury to one of the ligaments is often referred to as a sprain or strain. A tear of the ACL can happen when slowing down during running. Injury of the PCL and the medial collateral ligament, or MCL, occurs from a blow to the knee. A torn ligament brings about immediate pain, possible swelling, popping sounds and an inability to use the injured leg. Depending on the severity of the injury, a strain or sprain is treated with ice to reduce swelling, exercises to strengthen the muscle, a brace to help with stability or surgery.
Meniscus
Knee joints have pads of connective tissue that act like shock absorbers, called menisci. They are shaped like a C and also help with stability. Tearing of the meniscus often accompanies strains of the ligaments. A partial tear keeps the meniscus attached to the knee while a larger tear leaves it hanging by a thread. The meniscus can tear due to excessive wear and cause pain, swelling and an inability to straighten the knee. A tear can be treated with exercise or electrical stimulation to strengthen the muscles, rest and ice or in complete tears, surgery.
Runner's Knee
Runner's Knee is Chondromalacia of the knee cap, which occurs when the cartilage softens. It may be caused from a misalignment of the knee cap, overuse or an imbalance of muscle. The pain and tenderness that ensues is between the knee cap and the thigh bone. The knee may make a grinding, grating or popping sound and the pain worsens after sitting, taking the stairs, running or jumping. In order to correct Runner's Knee, physical therapy, strength training and proper footwear may be needed.
Iliotibial Band Syndrome
Distance runners are vulnerable to Iliotibial Band Syndrome, which occurs when the iliotibial band rubs against the outside of the lower leg bone. The iliotibial band extends from the pelvic bone to the lower knee and over time can become stretched too tight. This often occurs in sports and can cause the knee to swell. The rubbing of the band creates a sharp, burning pain on the outside of the knee. Treatment is based on increasing flexibility of the iliotibial band. Rest, stretching, running on flat surfaces and gradually increasing your exercise routine can help with this syndrome.
