Take Home Points
The Ulnar collateral ligament (UCL) is the main stabilizer in the elbow during the pitching motion. When a pitcher brings his arm forward in the acceleration phase of the throwing motion, the hand lags behind the elbow as it rotates over the top. This motion puts a lot of “valgus stress” on the elbow. When you add, warm up throws, bullpen sessions and games a lot of stress is placed on the UCL. Pitchers in their playing careers starting from playing little league to the MLB throw the ball millions of times. This volume without proper injury prevention and rehabilitation results in injuries. Combine these factors plus having bad mechanics or poor arm strength this can lead to weakness and damage in the ligament. “The theory is that these high performance athletes who throw in the upper 80s or 90s accumulate microscopic damage to the ligament over time through the high number of repetition of pitches. At some point, the combined stresses overwhelm the UCL, causing it to rupture (Jiang 2014)”.
- Jiang JJ, Leland JM. Analysis of Pitching Velocity in Major League Baseball Players Before and After Ulnar Collateral Ligament Reconstruction. Am J Sports Med. 2014 Feb 4