Relationship between upper-limb muscle strength in limb position similar to the zero position and lower trapezius muscle thickness

Abstract

Objective: This study aimed to investigate the relationship between upper-limb muscle strength in limb position similar to the zero position and lower trapezius muscle thickness in high school baseball players.

Methods: Shoulder external rotator strength (zero external rotator strength) and elbow extension muscle strength (zero release muscle strength) in limb position similar to the zero position, lower trapezius (LT) muscle strength, and resting and contracted LT muscle thickness were measured on the pitching side in high school baseball players. The relationship between zero external rotator or release muscle strength and LT muscle thickness was examined using Pearson’s correlation coefficient and Spearman’s rank correlation coefficient (significance level was set at p＜0.05).

Results: Significant positive correlation was found between zero release muscle strength and resting LT muscle thickness (r＝0.52, p＝0.01), and a weak positive correlation was found between zero external rotator strength and resting LT muscle thickness (r＝0.4, p＝0.05).

Conclusion: Our results suggested that LT muscle thickness is related to shoulder external rotator and elbow extension strength in limb position similar to the zero position.