(41) RELATIONSHIP BETWEEN ISOMETRIC ARM STRENGTH TO PITCHING METRICS AND GAME PERFORMANCE IN DIVISION I COLLEGIATE BASEBALL PITCHERS

Purpose: To determine the relationship between isometric arm strength to pitching metrics and game pitching performance for collegiate baseball pitchers.

Methods: Thirteen Division I pitchers (age = 20.5 ± 1.5 yr; height = 185.8 ± 6.5 cm; body mass = 93.5 ± 11.6 kg; lean body mass (LBM) = 77.6 ± 6.8 kg; body fat percentage = 16.6 ± 4.4%) participated in this study. Isometric data for shoulder internal rotation (IR), external rotation (ER), and scaption (S) strength, and fastball grip (FBG) strength for the throwing arm as well as a total arm (TA) strength (combined IR, ER, S, and G) and arm score (TA strength value divided by body mass) were acquired before and after competitive games using the ArmCare dynamometer according to the manufacturer directions. Additionally, each isometric arm strength score was divided by the pitcher’s body mass and LBM to provide relative strength values. Pitching metrics were recorded using Rapsodo In-Stadium unit during the competitive baseball season and included velocity, top spin, side spin, total spin, true spin, spin efficiency, horizontal break, and vertical break recorded for three pitch types: fastball (FB), breaking ball (BB), and change-up (CH). Game performance data (wins, losses, earned-run average, innings pitched, hits, hits per inning pitched, hits per 9 innings pitched, runs, earned runs, walks, walks per inning pitched, walks per 9 innings pitched, strikeouts, strikeouts per inning pitched, strikeouts per 9 innings pitched, walks plus hits per inning pitched, walks plus hits per 9 innings, and opponents’ batting average) were acquired after the competitive season through the official university athletics website. Pearson product-moment correlations were run with an alpha level of 0.05.

Results: Multiple statistically significant relationships were observed between isometric strength values and pitching metrics and game pitching performance (Table 1).

Conclusions: Meaningful significant relationships existed between isometric FBG strength, relative strength, and relative LBM strength and FB top spin, BB velocity, and CH top spin. Pitchers with greater arm score relative to LBM, TA strength, IR strength, FBG strength had more wins, innings pitched, strike outs, and less walks per inning pitched and walks per 9 innings pitched. PRACTICAL APPLICATIONS: An isometrically stronger arm relates to better pitching metrics and game pitching performance, which could improve team success. Strength and skill coaches should make a conscientious effort to promote the importance of data-led and individualized throwing arm strength programming beyond injury prevention, as lower arm strength could translate to poor game pitching performance and lack of team success.

Acknowledgements: We would like to thank the Louisiana Tech baseball pitchers for participating in this study as well as Chris Watson and Elise Bordlee for assisting with data collection.