Matthew Robert Poczatek, Billy Lozowski, Anthony W. Fava, Gretchen D. Oliver, FACSM. The Auburn University, Auburn, AL.

BACKGROUND: Scaling of equipment is commonplace across various sports and has been shown to enhance skill acquisition and aid the development of better motor patterns. In baseball, bat size, field size, and protective equipment are modified to meet the needs of younger players, except for the size of the baseball. As such, hand anthropometry for each playing level has not been considered. Therefore, the purpose of this study was to investigate the differences in the hand size of males from 6 to adult (18+), in order to offer recommendations for a suitably sized baseball for each playing age group (per the United States Specialty Sports Association’s guidelines). METHODS: PubMed, Google Scholar, and EBSCO Host databases were searched for studies including the terms: “hand size”, “hand dimensions”, “hand length”, “hand width”, “hand span”, “male”, and “adolescents” from 2002-2022. In total 56 studies were found, with 9 meeting the inclusion criteria by presenting hand length and width measures. Mean hand size values from a total of 3833 data points were calculated before being grouped by age. Mean hand size was then established for each playing age group: 7-8y, 9-10y, 11-12y, 13-14y, 15+, and the difference in hand size (HS, length × width) and ball coverage (BC, hand size ÷ ball surface area) was calculated. RESULTS: Relative to the adult group, HS was: 41.2% smaller (with 40.5% less BC) for 7-8 years; 31% smaller (with 30.5% less BC) for 9-10 years; 19.9% (with 19.5% less BC) for 11-12 years; 7.2% (with 7.1% less BC) for 13-14 years; and 3% (with 2.9% less BC) for 15+ years. CONCLUSION: These findings demonstrate that hand size differs considerably between adult and youth age-group players, and indicate that younger players are using a ball that is too large. If the baseball is appropriately scaled for younger players, then the sport will be comparable in all facets of the game that their senior counterparts play. This might allow youth players to mimic a more mature throwing style and help them to learn proper mechanics as early as possible. Future work should investigate how scaling a baseball can influence throwing kinematics and kinetics in youth athletes. By scaling down the baseball for younger players then the game (or sport) may be more replicable (or comparable) to the version played by their senior counterparts.

This document is currently not available here.