Too Much Elbow Flexion Raises Pitcher Injury Risk

Baseball pitchers with increased elbow flexion at ball release are at greater risk of injury, according to a new study.

In the study, “Increased Elbow and Olecranon Injury History in Professional Pitchers With Increased Elbow Flexion at Ball Release,” the researchers compared elbow and shoulder injury incidence among professional baseball players.

The findings were published online on February 2, 2022, in The American Journal of Sports Medicine.

“Elbow flexion at late portions of the pitch has been associated with increased elbow varus torque, a kinetic surrogate associated with injury risk. Direct examinations of injury incidence with elbow flexion angles have not been conducted in professional pitchers,” the researchers wrote.

“This study attempts to associate injury incidence with a modifiable, kinematic variable for an at-risk population.”

For the study, 314 professional pitchers pitched between 8 and 12 fastballs while being evaluated using motion capture technology. Then they were interviewed about upper extremity injuries. The pitchers were divided into 3 groups based on increasing elbow flexion at ball release.

Overall, 116 pitchers had a previous upper extremity injury. Elbow injuries were the most common.

Pitchers with the smallest elbow flexion at ball release had less peak elbow flexion torque than those with the greatest elbow flexion at ball release (3.8 ± 0.5 vs 4.1 ± 0.6% weight x height, p = .003).

Pitchers with greater than average elbow flexion at ball release were more likely to have a history of elbow injury (OR, 1.97; 95% CI, 1.14-3.40; p = .015) and olecranon spur formation or stress fracture (OR, 5.79; 95% CI, 1.25-26.85; p = .025).

“Increasing elbow flexion has been shown to place the medial elbow in a position to carry a greater amount of load, which may be exacerbated during the final moments of the pitching motion. Professional pitchers can consider decreasing elbow flexion at ball release as a potential, modifiable risk factor for elbow injury, in particular for olecranon spur formation and fracture,” the researchers reported.

The study authors included Joseph E. Manzi of Weill Cornell Medical College in New York, Michael C. Ciccotti, M.D., of Rothman Orthopaedic Institute in Philadelphia, Nicolas Trauger of Cornell University in New York, Grant G. Black of Weill Cornell Medical College in New York, Ryan R. Thacher, M.D., of the Sports Medicine Institute, Hospital for Special Surgery in New York, Venkat Boddapati, M.D., of Columbia University and Joshua Dines, M.D., also of the Sports Medicine Institute, Hospital for Special Surgery.