“Shin splints” refers to the pain that develops along the inside of your shin (the tibia bone)
Also known as medial tibial stress syndrome (MTSS), it commonly affects runners, aerobic dancers, and people in military boot camp because it is an exercise-related overuse injury. In such injuries, your repeated movements during exercise cause muscle fatigue. This fatigue leads to additional forces applied to the tissue (called the fascia) that attaches muscles to the bone. The muscles that attach to the tibia, which include the soleus muscle (ankle flexor) and the flexor digitorum longus (toe flexors), are what actually hurt during MTSS (injury to the bone itself does not cause pain).
Early in the condition, pain is experienced at the beginning of a training session and disappears as the exercising continues. As your injury progresses, the episodes of pain lengthen.
With repeated stress-related injuries, the bone itself can be affected and may eventually develop multiple microfractures — what is referred to as a stress fracture. The pain associated with a stress fracture will be sharp and focused on a very small area of your bone. Stress fractures are more serious and typically require you to restrict your activities to ensure proper healing.