Using a lighter baseball would not significantly increase batted-ball impact injuries to position players in youth baseball, but would likely increase such injuries to pitchers, suggests a first-of-its-kind study.
Studying reaction time among youth baseball players ages 9 to 13 in laboratory tests intended to mimic game conditions, researchers reported that the 10% reduction in time to respond to a batted ball expected from reducing ball weight by 20% would lead to less than a 5% increase in impact probability to nonpitchers, but increase impact probability for pitchers by more than 25%.
Previous research indicated that either reducing the weight of a baseball or its stiffness could result in a decrease in injuries or injury severity, but the effect of reducing ball weight on the speed at which a ball comes off a bat had not been directly studied.
Around half of baseball-related injuries occur from ball-player impact, with the majority affecting defensive or fielding players. While many are minor, ball impacts with the head or chest can lead to costly dental injuries (about 10% of youth baseball injuries) and eye injuries (baseball is a leading cause of sports-related eye injuries in 5- to 14-year old children).
Impacts to the chest are the most dangerous, due to the risk of commotio cordis (death from a sharp, ill-timed blow to the chest leading to sudden cardiac arrest). Commotio cordis was the cause of death in a third of deaths of baseball pitchers in one ten-year period and account for 2 to 4 deaths a year in youth baseball.
The new study appears to support concerns that reducing the weight of the baseball, while it may limit the severity of ball-player impact injuries or elbow and shoulder overuse injuries in youth players, may actually increase injury rates for pitchers, because they are standing closer to home plate and have signficantly less time to get out of the way of a batted ball than infielders.
Matta PA, Myers JB, Sawicki GB. Factors Influencing Ball-Player Impact Probability in Youth Baseball. Sports Health: A Multidisciplinary Approach 2015; 7:154-160; published online before print August 1, 2013, doi:10.1177/1941738113498209