Baseball has been America’s pastime since its early beginnings. Over time, fans have watched the game evolve. In many cases, the game seems to boil down to a battle between pitchers. Franchises competing for a spot in the World Series seem to know this, and many (such as the San Francisco Giants) have heavily stacked their pitching rosters with notable talent. So, physiologically speaking, how do pitchers do what they do, pitch after pitch after pitch? And what parts of their bodies are most prone to injuries?
These are complex questions. The obvious place to begin is with the arm, shoulder and back muscles. The most vulnerable joint in pitching is the glenohumeral joint, which is commonly known as the ball and socket of the shoulder. This joint has the greatest range of motion of any joint in the body. It is directly supported by four rotator cuff muscles that attach with tough, sinuous tendons. The pectoral muscle group and the lassitimus dorsi are larger muscles, located in the front and back of the shoulder. They help stabilize the joint and help keep it from over-rotating and causing injury.
These and other muscle groups work to gather and release energy during a pitch, and others counter the whipping motion of throwing the ball, acting to decelerate and prevent the arm from injury. In addition to the muscles used in the back and shoulder, leg and core body muscles significantly contribute to the power behind the pitch. It is this symphony of muscles working in tandem that allows pitchers to throw 100 mph pitches.
Read more about the basics of pitching and physiology or learn the technical physiology behind pitching.
Articles by Josh Silvernagel.