Preventing Tommy John Surgery: The Identification of Trends in Pitch Selection, Velocity, and Spin Rate Before Ulnar Collateral Ligament Reconstruction in Major League Baseball Pitchers

Abstract

Background: Ulnar collateral ligament (UCL) reconstruction is a common surgery among Major League Baseball (MLB) pitchers that results in a significant number of missed games. Little has been reported regarding game-by-game trends that can identify those on the verge of becoming injured. Purpose: To determine if there is a patterned change in MLB pitchers’ pitch selection, velocity, or spin rate in games leading up to Tommy John surgery that may predict subsequent UCL surgery. Study Design: Case series; Level of evidence, 4. Methods: A retrospective review of MLB pitchers who underwent primary UCL reconstruction between 2009 and 2019 was performed. Pitch characteristics were evaluated on a game-by-game basis for the 15 games leading up to surgery. A Mann-Kendall trend test was used to identify trends in pitch selection, velocity, and spin rate for multiple pitch types. A Kendall τb correlation coefficient was identified, with values closer to 1 or –1 signifying a stronger monotonic trend. Results: A total of 223 MLB pitchers underwent UCL reconstruction in the time period. In the 15 games leading up to surgery, decreases in pitch velocity for 4-seam fastballs (τb = –0.657; P < .001), 2-seam fastballs (τb = –0.429; P = .029), and sliders (τb = –0.524; P = .008) were significantly associated with game number closer to injury. There was a significant positive association in the spin rate for cutters (τb = 0.410; P = .038) and a significant negative association in spin rate for 4-seam fastballs over the course of these 15 games (τb = –0.581; P = .003). In addition, there was a significant positive association in the percentage of curveballs thrown (τb = 0.486; P = .013). Conclusion: The study results suggest that there is a patterned change in certain pitch statistics in MLB pitchers in the games leading up to Tommy John surgery. Although the absolute change from game to game may be small, it may be possible for these trends to be monitored before a player becomes injured, thus reducing the significant burden Tommy John surgery places on these athletes.

Ulnar Collateral Ligament Reconstruction Does Not Decrease Spin Rate or Performance in Major League Pitchers

“…The authors looked at the previous 15 games before UCL injury and reported a statistically significant decrease in 4FB, 2FB, and SL velocity, as well as a significant decrease in 4FB spin rate leading up to injury. 20 The study hypothesized that the drop in velocity and spin rate may be related to muscle fatigue or altered pitching mechanics before impending injury. 20 In the present study, there were no significant differences in 4FB or SL velocity after RTP after UCLR, although a significant decrease was seen for 2FB in the first year after return (which returned to a nonsignificant difference in the second year).…”

“…20 The study hypothesized that the drop in velocity and spin rate may be related to muscle fatigue or altered pitching mechanics before impending injury. 20 In the present study, there were no significant differences in 4FB or SL velocity after RTP after UCLR, although a significant decrease was seen for 2FB in the first year after return (which returned to a nonsignificant difference in the second year). Of note, that difference was less than a mile per hour, so from a performance standpoint it is difficult to determine if this would have an effect.…”

“…14,19,20,22,27,29 A recent development in baseball analytics is the concept of pitch spin rate, which has garnered tremendous interest in the baseball and medical communities. 20,21,24,25,30,31 Higuchi et al 10 demonstrated that increasing spin rate on an FB at the same velocity…”

“…In addition to velocity, factors such as pitch accuracy, pitch movement or action, and pitch selection have been investigated in the setting of UCLR. 14,19,20,22,27,29 A recent development in baseball analytics is the concept of pitch spin rate, which has garnered tremendous interest in the baseball and medical communities. 20,21,24,25,30,31 Higuchi et al 10 demonstrated that increasing spin rate on an FB at the same velocity changed the expected trajectory of the ball and led to worsening performance in a group of skilled batters.…”

“…14,19,20,22,27,29 A recent development in baseball analytics is the concept of pitch spin rate, which has garnered tremendous interest in the baseball and medical communities. 20,21,24,25,30,31 Higuchi et al 10 demonstrated that increasing spin rate on an FB at the same velocity changed the expected trajectory of the ball and led to worsening performance in a group of skilled batters. In particular, increased FB spin rate led to a pitch that drops less than a pitch at the same velocity, but with less spin.…”