What are shin splints?
Shin splints are defined as damage to one or more areas along the shinbone that causes pain. One of the most common sports injuries, they are often associated with runners or any athlete who has repetitive strain on the muscles in this area. As the tendons around the tibia (shinbone) become inflamed, they can cause pain, usually on the inside of the shin. Shin splints account for approximately 17 percent of all running injuries.
While this injury can happen to anyone, it occurs nearly twice as often in women. This is thought to be because women have lower bone mass density and can injure themselves more easily. People who have flat feet are especially prone to this condition because of the added shock they put on the bones with each step while running or changing direction.
While treatment of shin splints typically requires rest and ice, without seeing a doctor the condition can worsen and lead to more severe injuries. Shin splints need to be differentiated from stress fractures or other conditions by an orthopedic surgeon.
Anatomy of the shin
The shin is the lower part of the leg, between the knee and the ankle. It consists of the following:
- Tibia (the larger shinbone)
- Fibula (the smaller shinbone)
- Tibialis anterior (muscle)
- Tibialis posterior (muscle)
Types of shin splints
Shin splints are typically divided into two main types of injury:
- Anterior shin splints—This type of shin splint occurs in the tibialis anterior. The tibialis anterior is the muscle that is used to lift the foot up and is covered by a thin sheath. When a person walks and rotates their foot outward, it causes the muscle to rub along the sheath, creating irritation. Over time, the pain worsens whenever weight is put on the foot and without treatment, this can lead to the muscle detaching or to a stress fracture.
- Posterior shin splints—These injuries occur in the tibialis posterior, which is the muscle that runs from the foot up the back of the leg to the knee. It is the muscle that is responsible for pointing the toes. When a person pronates as they walk, they cause the muscle to twist gradually. If left untreated, this can lead to the muscle detaching or to a stress fracture.
Symptoms of shin splits always include some level of pain due to the number of nerve endings in and around the muscles that connect to the bone. The following are common shin splint symptoms. Depending on how the injury occurred and how physically strong a person is, symptoms can vary, including:
- Tenderness or pain along the inside of the shinbone
- Slight swelling
- Pain at the beginning of exercise
- Pain at the end of exercise
- Pain as toes are pointed
Shin splint symptoms occur because the muscles around the shinbone become inflamed. While this injury is minor and can be treated easily, without the help of an orthopedic surgeon, it can lead to more significant injuries down the road, such as muscles detaching or stress fractures.
There are a few causes of shin splints:
- Overuse of the muscles—When a person runs or plays a sport that requires changing directions quickly, a lot of strain is put on this muscle group. As this strain builds up, the muscles begin to twist and rub. That eventually leads to irritation and causes the nerve endings in the leg to become inflamed.
- Muscle imbalance—As the body begins increased physical activity, it needs time to allow muscle groups to catch up and work in tandem with one another. Core muscles are some of the last to develop, and a weakened core can mean more pressure put on the lower extremities, including the shinbone. When this happens, people can experience shin splints as their muscles strengthen.
- Tightness in the shin muscles—If a person does not stretch properly, this can lead to tighter shin muscles that ultimately cause more friction and stress, leading to the pain associated with shin splints.