Jose Iglesias is not the first athlete to ever suffer from a case of shin splints, and he will not be the last. He is, however, the most prominent Detroit figure to be dealing with them at the moment. With Andy Dirks already sidelined for three months due to a microdiscectomy, the last thing the Tigers need is another long-term injury to an everyday player. Unfortunately for Jose, we do not know how long he will be affected by this particular ailment.
Medial tibial stress syndrome -- more commonly known as shin splints -- is an injury that affects the front of the tibia, the larger and more prominent of the two bones in your lower leg, as well as the surrounding muscles. It is almost exclusively seen in athletes and most often due to running and/or over-training. The injury itself is due to a chronic remodeling of the muscle, tendon, and bone tissue in the affected area -- basically, the tissue is inflamed and has not been given ample time to heal.
While the specific cause of shin splints in each individual can differ, the injury is most often a result of some combination of muscle tightness (especially in the calf muscles), limited ankle joint motion, and poor foot position. The latter is likely why Iglesias has reportedly been using orthotics; if the foot is malaligned, the biomechanics of the entire leg are affected. A sudden increase or change in training methods can also be the culprit. Some have opined that the shift from training on other surfaces to infield dirt caused Iglesias' flare up, but I would venture a guess that the change from running shoes to baseball spikes also played a role.
The pain that results from medial tibial stress syndrome can be anywhere from mildly debilitating to wildly excruciating. The specific activity that caused the injury -- running, most often -- is typically the most painful, and should be avoided to give the body time to heal. Continuing to run and "play through the pain" can lead to increased inflammation and possibly the formation of stress fractures within the tibia bone. Iglesias' prognosis will depend on how quickly the Tigers training staff can get his symptoms to subside, but this could be an injury that hampers him periodically until they are able to find a long-term solution to the underlying problem.