Lower-body muscle structure and jump performance of stronger and weaker surfing athletes

Purpose: To identify whether there are any significant differences in the lower-body muscle structure and countermovementjump (CMJ) and squat-jump (SJ) performance between stronger and weaker surfing athletes. Methods: Twenty elite male surfers had their lower-body muscle structure assessed with ultrasonography and completed a series of lower-body strength and jump tests including isometric midthigh pull (IMTP), CMJ, and SJ. Athletes were separated into stronger (n = 10) and weaker (n = 10) groups based on IMTP performance. Results: Large significant differences were identified between the groups for vastus lateralis (VL) thickness (P =.02, ES = 1.22) and lateral gastrocnemius (LG) pennation angle (P =.01, ES = 1.20), and a large nonsignificant difference was identified in LG thickness (P =.08, ES = 0.89). Furthermore, significant differences were present between the groups for peak force, relative peak force, and jump height in the CMJ and SJ (