Whether you're a novice runner or a seasoned veteran, shin pain and bruising can rear its ugly head from time to time, interfering with your training and competition schedules. However, shin pain caused by running is not inevitable. Learning to identify the possible causes can set you on the path to recovery and improved performance.
Pain and Bruising of the Shin
Impact stress from running normally affects the tibia, the large bone at the front of the shin that absorbs repetitive motion forces as your foot strikes the ground. According to Mark Jenkins, MD, of Rice University, muscle fatigue leads to greater force applied to the fascia, the tissue that fuses the tibialis muscle to the bone, causing pain and inflammation within it, and eventually leading to bone stress and even stress fractures. Visible bruising is indicative of bleeding and inflammation, a condition the American Academy of Orthopedic Surgeons calls chronic compartment syndrome. Shin pain can be treated and avoided with corrections in running mechanics and the use of proper protective footwear.
Foot Strike and Running Mechanics
The way your foot strikes the ground and then pushes off can influence the amount of stress placed on the shin during running. If you strike with your heel and roll through, you may be over-striding, leading to the poor distribution of body weight during impact. If you strike with the toe or ball of your foot, you absorb less impact with your calf and Achilles tendon, shifting the brunt of impact to your shin. Striking with the mid-foot shifts shock absorption to the large muscles of the calf and away from the shin. Foot strike is typically a habit that can be corrected with training.
Foot Type and Running Mechanics
Your foot type can influence how shock is distributed when you land. According to Jenkins, individuals with high, inflexible arches tend to experience more impact stress on the tibia, while individuals with flat feet tend to experience greater muscle fatigue when pushing off, gradually leading to stress on the fascia. Both extremes can predispose you to shin pain and bruising. To determine your foot type, do the "wet test." Stand on a wet towel, then step onto a colored piece of paper. Examine the imprint of your foot. If it is broad and triangular, you have a flat foot. If the imprint is slightly curved on the inside, you have a normal or neutral foot, and if your imprint is C-shaped, you have a high arch.
Running Shoe Selection
Competitive bodybuilder and sports doctor David Ryan, MD, emphasizes the importance of finding the right shoe for your foot type and running style, a process he likens in difficulty to finding the right life partner. Ryan notes that individuals with high arches, men weighing over 200 pounds and women weighing over 150 pounds may require a stability shoe with a rigid midsole that provides good arch support. Flat-footed individuals whose feet tend to roll inward, or pronate when running, will do better with a motion control shoe. While highly cushioned shoes offer more shock absorption, they are generally less supportive of high arches and flat feet.