Table 5.

Studies Evaluating Preinjury Risk Factors for UCL Injury in MLB Pitchers Who Underwent UCL Reconstruction ^a

First Author (Year)	Risk Factors Evaluated	Significant Findings Associated With UCL Injury
Chalmers (2016) 6	Preinjury mean and peak velocity, height, weight, BMI, pitch selection, age, years in league	Higher mean and peak pitch velocity, weight, BMI, and use of breaking balls vs controls; younger age and fewer years in league vs controls
DeFroda (2016) 11	Timing of injury during season, preinjury velocity	More tears in first half of season and higher FB velocity vs controls
Hodgins (2018) 28	Previous forearm flexor tendon injury	Higher rate of previous forearm flexor tendon injury vs controls
Keller (2016) 32	Preinjury pitch selection and velocity by pitch type	Higher FB % vs controls
Mayo (2021) 42	Pitch selection, velocity, and spin rate over the course of 15 games before injury	Velocity decrease for 4FB, 2FB, and sliders; significant decrease in 4FB spin rate; higher % of curveballs thrown
Portney (2019) 53	Pitch type, release location, and velocity	More lateral pitch release, lower vertical release location, and higher % of curveballs vs controls
Prodromo (2016) 55	Preinjury pitch selection and velocity by pitch type	Higher FB, slider, curveball, changeup, split-finger FB velocity vs controls
Whiteside (2016) 66	Age, height, mass, position, innings, FIP, number of pitches in repertoire, mean days between games, mean pitchers per inning and game, mean pitch speed and spin rate, mean horizontal and vertical release location	Fewer days between outings, smaller repertoire of pitches, less pronounced horizontal release, smaller stature, higher mean pitch speed, and higher mean pitch counts per game vs controls

^a 2FB, 2-seam fastball; 4FB, 4-seam fastball; %, pitch percentage; BMI, body mass index; FB, fastball; FIP, fielding independent pitching; MLB, Major League Baseball; UCL, ulnar collateral ligament.