Correlation of static and dynamic trunk muscle endurance and bat swing velocity in high school aged baseball players

BACKGROUND: Trunk muscle endurance training is used by most high school baseball or softball coaches. However, evidence demonstrating a relationship between trunk muscle endurance and batting performance is lacking. OBJECTIVE: This study aimed to establish a relationship between trunk muscle endurance and bat swing velocity in a high school baseball team. METHOD: Sixty-one high school (15-18 years old) baseball players, taken from the same team, with 6.5 ± 1.3 years of training experience, participated in the following tests: static trunk flexion/extension endurance tests, dynamic trunk flexion/extension endurance tests and a maximum bat swing velocity test. RESULTS: Bat swing velocity showed significant low-to-moderate negative correlations with static trunk flexor endurance (P=0.001, r=-0.404), dynamic trunk flexor endurance (P=0.016, r= -0.308) and the ratio of static flexor/extensor endurance (P=0.021, r=-0.298). CONCLUSIONS: These findings support the concept that better trunk flexor endurance might not benefit batting performance. Trunk flexor endurance training should not be over-emphasized when the targeted training goal is to enhance bat swing velocity.