I have shin splints, what does this mean?

I decided to write about shin splints after discovering it was the most read topic on my website this past month. On reflection, I should not really be surprised, because spring weather leads to increased physical activity and overuse injuries.

Shin splints are common among runners, race walkers and individuals who participate in soccer, football, lacrosse and dance. Shin splints are a non specific diagnosis for lower leg pain. One common cause of shin splints is periostitis. Periostitis is an inflammation of the periosteum. The periosteum is a dense connective tissue covering the shin bone or tibia. Periostitis results from an overuse injury that usually develops gradually over a period of weeks to months. Periostitis can also occur after one excessive bout of exercise. The periosteum serves as an attachment site for the muscles originating on the tibia. Muscle overuse causes the periosteum to pull away from the tibia causing inflammation.
Periostitis of the tibia has also been classified as medial tibial stress syndrome. Medial tibial stress syndrome is associated with an overuse of the anterior and posterior tibial muscles. Both of these lower leg muscles have attachments via tendons to the foot bones. The origin of these two muscles is where you will complain of pain. The locations of pain are the lower inside half of the tibia and, less commonly, the upper outside portion of the tibia.  You will usually notice the pain when you start exercising and it decreases or goes away as you continue to exercise. Your pain maybe worse after you stop exercising or it will bother you the next morning.

The pain from periostitis of the tibialis posterior muscle is located on the lower inside half of the tibia. Abnormal foot and lower leg alignment can cause excessive flattening of the foot that requires excessive work from the posterior tibial muscle to help stabilize the arch. This stress causes microtears and inflammation in the periosteum attached to the lower inside half of the tibia. Custom foot orthotics paired with the appropriate running shoes is quite successful in treating posterior tibial muscle periostitis due faulty foot mechanics.

Pain from periostitis of the anterior tibial muscle is located on the upper outside portion of the tibia. Anterior shin splints often occur in both legs. Anterior shin splints is caused from over-training or improper training, especially, if your running program includes a lot of excessive downhill running or a sport requiring rapid starts and stops.
You may also have an imbalance between the weaker anterior muscle group and the larger and stronger posterior group. Tightness of the calf muscles may further aggravate this condition. These stresses result in microtears and inflammation in the periosteum attached to the upper outside portion of the tibia. Successful treatment includes modified rest with changes in your training program. Physical therapy to address muscle weakness, tightness and imbalance is paramount. Foot orthotics will be indicated if abnormal foot mechanics are the cause of the muscle tightness or imbalance.
In some cases of periostitis there can be a progression to micro-fractures or stress fractures along the tibia. Generally there is not a sudden break of the bone but usually you will complain of a gradual increase in pain until it becomes quite severe.

There are a number other causes of lower leg pain that can mimic periostitis. They include: tendonitis, a partial muscle tear, growth plate inflammation, referred lower back pain, lower leg muscle imbalance, a leg length difference and compartment syndrome.
Compartment syndrome can occur in muscles originating from the tibia. Muscles are surrounded by fascia which allows for a separation between adjacent muscles. This fascia does not stretch. Pressure within the muscles can increase due to activity. The fascia does not allow the pressure to diminish. This can lead to muscle damage and pain. If you have shin splints a proper diagnosis via a thorough history and physical examination is essential to rule out causes other than periostitis.

Conservative treatment for tibial periostial injuries usually consists of modified activity, ice, immobilization, compression and elevation, physical therapy, foot orthotics, appropriate footwear, and proper training techniques. However, the most important part of the treatment is educating you on the tissue(muscle, tendon, fascia, ligaments, periosteum and bone) injury process. I discuss the concept that everyone has a unique biomechanical yield point where tissue injury occurs, even if you have the best training technique, footwear and equipment.  In other words, you have to listen to your body and give yourself enough time to recover from any tissue injury (minor or major) before you resume exercising. If you continue to exercise without adequate tissue recovery, the tissue injury yield point becomes lower when compared to the previous exercise session. This means even less activity can more tissue damage. This is why less activity can make your shin splints worse if tissue recovery is not allowed to occur during a rest period.  For more information on the treatment protocol for shin splints please visit www.painfreefeet.ca