Avoid shoulder and elbow injuries with proper pitching mechanics

By Jason Hutchison, M.D.

As winter gives way to spring and basketball gives way to baseball, orthopedic surgeons see a change in the type of injuries in our office. During basketball season, we are riddled with knee and ankle injuries, which are often an unavoidable result of participating in a jumping sport.

This is not the case with baseball. During baseball season, the majority of athletes who present to the orthopedic surgeon have shoulder and elbow complaints. Contrary to the often unavoidable injuries associated with basketball, many of the shoulder and elbow injuries associated with pitching could be avoided with proper pitching mechanics.

Pitching mechanics have been the subject of many studies in sports medicine and bio-mechanics over the last 10 years due to the increased incidence of shoulder and elbow injuries in throwing athletes. Pitching coaches who devote their life to studying and instructing proper pitching mechanics also have contributed immensely to the evolution of thought regarding proper mechanics. Some areas certainly are still in debate, and conflicting theories of proper mechanics are yet to be worked out. However, the intent of this article is to work through some of the less controversial topics and hopefully impart some basic concepts that are generally agreed upon.

The myths
First, it is important to debunk a couple of myths with regard to pitching mechanics.

One common misconception is that arm strength is the primary source of power when pitching. In fact, the pitcher’s arm strength has very little to do with the power and velocity in pitching. The core strength in the lower torso and upper legs are the muscles that provide the primary source of power in all pitchers. Arm strength is secondary at best.

This is well understood when we compare pitching to the swing of a golf club. No one would argue that the strength in one’s arm determines how far you can drive a golf ball. Similarly, the strength in the arm does not determine how hard one can throw a baseball. With both of these maneuvers, the power is primarily determined by the flexibility and strength of the core musculature involving the lower torso and upper legs.

Another misunderstood principle by pitchers is the concept of the arm slot and what determines it. Arm slot is simplified into straight overhand, three quarters and side arm. A common misunderstanding is that the angle of flexion of the elbow determines the arm slot. In other words, straight overhand requires that the elbow be flexed at 90 degrees and similarly for straight side arm, the elbow must be extended to 180 degrees.

With this line of thinking, pitchers may be taught that the shoulders should remain level during this pitching motion, thus allowing the elbow to be the sole determinant of the arm slot. This is an over simplification, and biomechanically, this is not what happens. The elbow is fully extended at the release point, regardless of the arm slot. Careful analysis of professional pitchers supports this finding and notes that the arm slot is primarily determined by the tilt of the pitcher’s shoulders rather than the degree of flexion at the elbow.

Another misconception is that leading with the elbow is one of the main causes of injury to the elbow in young pitchers. This is contradicted by the fact that almost all professional pitchers, at some point during their motion, do lead with their elbow.

However, there is a difference between leading with the elbow and a pitcher who gets his upper torso and shoulder motion significantly behind his footwork and ends up rushing to get the ball delivered. This certainly can increase the risk of injury to the shoulder and elbow.

This phenomenon of rushing is best determined by the position of the forearm when the glove-side foot lands. If the forearm is not yet vertical when the foot lands, it leads to the shoulders and elbow being significantly behind the lower body. This creates increased forces across the shoulder and elbow, which then can increase shoulder and elbow injuries.

Good mechanics
As we have already noted, the lower body and the lower torso are so vitally important in pitching that we want to make sure to emphasize the good mechanics of the lower body.

Beginning with the leg lift, it varies from pitcher to pitcher. There remains some debate whether, at the top of the leg lift, that the pitcher should come to an exact balance at this point or if the hip should already be moving sideways towards the target line at the top of the leg lift.

The stride should approximate the height of the pitcher, and we want to keep the hips closed as long as possible during the stride.

During the stride, it is important that the forearm is in the high cocked position by the time the gloved-side foot is planted. Again, this has been shown to significantly reduce the stress across the shoulder and elbow in pitchers and should not be confused with the arm slot of the pitcher.

The next phase is the release point. At the release point, the weight is primarily on the front leg, which is somewhat flexed and not locked in full extension. This reduces the joint reaction forces, which are transferred from the foot up through the knee, hip and spine.

The final phase of pitching involves the finish and follow through. It is at this phase that we want the pitcher to be back into a field-ready position in order to protect himself from balls hit back at him and to better field his position.

Comparing pitchers
Many of these principles and mechanics can only be attained through careful attention to timing, study and proper instruction. It is often helpful to look at the motions of professional pitchers who do things well and also those who do not do things well.

We can then understand why some pitchers seem to have unyielding endurance and others spend more time on the injured reserve than on the mound. Pitchers who give us excellent mechanics for study include Greg Maddux, Tom Glavin, Roger Clemmons, Nolan Ryan and Justin Burlander.

We also can look at pitchers, such as Chris Carpenter, Mark Pryor and Carey Wood, whose mechanics leave something to be desired. These pitchers have had significant injuries that plagued them throughout their careers.

Comparing the mechanics of these two groups will help young and aspiring pitchers comprehend not only the concept of good pitching mechanics, but also the need to prevent injury.

As an orthopedic surgeon, I see more and more young athletes come in with shoulder and elbow problems. As a former college pitcher who tore his ulnar collateral ligament, I hope that we can continue to improve our understanding of proper pitching mechanics so that fewer athletes end up with these potentially career-ending injuries.