Comparison of pitching kinematics between youth and adult baseball pitchers: a meta-analytic approach

Coaches teach proper mechanics at a young age in an effort to increase pitching efficiency (i.e., proper pitching mechanics). Unfortunately, the mechanics taught to beginning pitchers are based on the findings from adult pitchers and may result in techniques that are detrimental to younger pitchers. The purpose of this study was to compare kinematics published for pitchers across various ages in an effort to determine whether the pitching techniques vary across developmental periods. A meta-analysis of papers published describing pitching kinematics for youth and adult pitchers was conducted. Maximal rotational velocity of the trunk and maximum external rotation of the shoulder were observed during the arm cocking phase. Peak magnitudes for abduction, horizontal adduction, and shoulder internal rotation were observed during the deceleration phase of the movement. In addition, by comparing previously published data across youth and adult pitchers, valuable insight into the differences in mechanics was gained. The results demonstrated that there are some distinct differences between youth and adult pitching mechanics. This finding may allow increased focus to be applied to those parameters observed to differ across age, increasing the knowledge base available for coaches to properly instruct youth pitchers.