Original Research

A speed distance-based classification system for injury prevention and research in international and domestic youth baseball players.

Authors: Axe MJ, Strube M, Osinski D, Andrews JR, Snyder-Mackler L

An objective classification system for studying youth baseball players in the U.S.A. was published in 1996. Professional baseball is composed of greater than 25% international players, the majority of whom come from five countries. Many youth baseball players are injured in their early years of play, both in the U.S.A. and internationally. There is currently no international classification system to study youth baseball pitching injuries, biomechanics, or maturation, but one is needed in order to compare and combine data from pitchers in multi-center studies. Uniform domestic and international pre-injury normative data is optimum. Ideally, data collection should be practical requiring inexpensive equipment and limited time demands. The authors' hypothesis was that the mathematical model, developed in 1996 would be internationally applicable, allowing easy classification of youth baseball pitchers and levels throughout the world. The authors studied international pitchers between the ages of 8-14, from the Dominican Republic, Venezuela, Puerto Rico, Japan, the Phillipines, Mexico, Brazil, Peru, and Columbia. Players threw five full-speed pitches that were recorded with a calibrated radar gun and four maximum distance throws on a marked field. The mathematical model developed in 1996 was used to generate predicted distances for this sample for comparison with actual distances. The authors found that the correlation between predicted distance using the mathematical model and actual distance was 0.90. There was no systematic over or under prediction indicating that both relative and absolute fit for the model was excellent. The clinical relevance is that pre-injury distance/speed data allows for classification of youth baseball player of multiple levels between the ages of 8-14. International and regional comparisons are now possible for multi-center studies in order to better define risk factors, compare studies, and combine data based upon pre-injury maximum long toss data.

Abstract  |  Full Article (subscribers only)  |  Purchase Article