Shin Splints - What are they?
Shin splints-we’ve all heard the term and maybe even experienced the symptoms but what is this mysterious overuse injury?
Medial tibial stress syndrome (MTSS), commonly referred to as “shin splints”, is an overuse injury typically seen in running and jumping athletes. It manifests as pain and tenderness along the anterior (front) and medial (inside) aspect of the tibia. The tibia is the weight bearing bone in the lower leg often called the shin bone. Symptoms tend to be worst on the distal portion of the bone just above the ankle.
There are two theories as to what causes these symptoms but both tend to involve a recent increase in high impact activity along with other factors including muscular weakness, limited flexibility, and/or elevated BMI.
The first theory involves an irritation and subsequent inflammation of the periosteum-the thin membrane lining around our bones full of blood vessels and nerves. This membrane gets pulled on repeatedly by muscles in the lower leg with each step. Without adequate strength and mobility relative to the volume of exercise the periosteum becomes inflamed and painful.
The second theory speculates that MTSS is an injury from repetitive bony microtrauma caused by the high number of impacts that occur with forces multiple times the individual’s body weight. These small amounts of damage can typically be repaired assuming adequate rest and nutrition. However, increased running volume and frequency can create a state where damage is outpacing the natural repair.
In either case shin splints can be a predecessor of more severe bony injury including stress fracture. It is typically managed initially with rest followed by gradual and calculated progression of activity after any other deficits have been addressed. In addition to remaining strong and mobile, rotating and replacing running shoes regularly is beneficial. Most experts recommend retiring running shoes after 200-400 miles.