Kinematics That Differentiate the Beach Flags Start Between Elite and Non-Elite Sprinters

Abstract

This study differentiated the kinematics of the beach flags sprint start between five elite (three males, two females; age = 21.2 ± 2.6 years; height = 1.71 ± 0.04 m; mass = 66.2 ± 5.9 kg) and five non-elite (three males, two females; age = 20.4 ± 1.7 years; height = 1.69 ± 0.08 meters [m]; mass = 61.6 ± 5.7 kilograms) sprinters. A high-speed camera filmed the start. Timing gates recorded the 0-2, 0-5, and 0-20 m intervals. Data included body position during the start and at take-off; start time; first step length; and sprint times. A Mann-Whitney U-test determined significant (p < 0.05) between-group differences; effect sizes (ES) were also calculated. Elite sprinters had a greater take-off trajectory angle (p = 0.01; ES = 2.57), and were faster over the 0-2 (p = 0.02; ES = 1.77), 0-5 (p = 0.05; ES = 1.20), and 0-20 m (p = 0.02; ES = 1.83) intervals. Large effects were found for: greater take-off swing leg hip flexion (ES = 1.13) and trunk lean (ES = 1.37); longer duration start time (ES = 1.33); and longer first step length (ES = 1.23) in elite sprinters. A longer start time assists with force generation, which in conjunction with increased hip flexion, could translate to a longer first step. Increased trunk lean shifts the take-off trajectory angle towards the horizontal. A greater trajectory angle at start take-off, which could be advantageous for force production during sprint performance, is likely necessary for beach flags.

Effects of Whole Body Vibration on Strength and Jumping Performance in Volleyball and Beach Volleyball Players

“…During the sprinting performance on a sand surface, successful sprinters are characterized by a greater angle of trajectory at start take-off than in non-elite sprinters. As Lockie and Vickery suggested, this could be facilitated by a longer start time that allows for more force generation, and a greater degree of hip flexion of the swing leg and trunk lean at start take-off [ 14 ].…”

Resisting arrest: Analysis of different prone body positions on time to stand end engage

“…is hip height was used to con rm that the participant had nished the movement a er they stood up from the prone position and was displayed through the rest of the footage to provide a reference. For each trial, initiation of movement was visually determined from the video footage (Gruen, 1997;Lockie et al, 2012b).…”