LANDING ChARACTERISTICS OF DOUBLE BACK SOMERSAULTS ON THE FLOOR

Abstract

One of the most frequently used components of a floor exercise are the landings which occur at the beginning, anywhere in between, and at the finish of the exercise. This study examined the biomechanical characteristics of double back somersault landings at the beginning, during, and at the end of a floor exercise. Performances of ten selected male gymnasts at the World Gymnastic Championships 1994 in Brisbane, were chosen. Kinematic data was captured at50 Hz through 3-D videorecordings during competitions, with the videocameras positioned on the catwalks above the floor of the competition venue. The analysis included mean and standard deviations of selected kinematic and temporal parameters in order to identify the biomechanical characteristics in landings, and to establish a profile for stable competition landings on floor, which should also comply with specific competition guidelines as set out by the FIG code of points. Analysis of the data revealed, that the displacement h m maximum CM height before the landing (2.18 ±0.16 m) to CM height at landing (0.88±0.13 m) was 1.3 ±0.1 1 m. The vertical and horizontal impact velocities were 4.2±0.46 and 3.21±0.49 m/s. The mean knee angles at landing (touch-down) were 153" and at minimum CM height were 98", a 55"knee angular landing force absorption over 0.12 sec. landing phase duration. The videorecordings of the individual landing performances were carefully reviewed to qualitatively investigate the completion of the second salto of the double back somersault before the landing. The better performances showed a reasonable extension of the body or a kick out before the landing, and the landing was actively anticipated through proper feet placement. Poor performances resulted in a slow second salto extending the hip and knee joints hurriedly into the landing surface. The mean angles between CM to toe and the horizontal at landing (touch-down) were 69". The mean angles between trunk and the horizontal and thigh to the horizontal at landing (touch-down) were 22and 84", respectively. Selected parameters of the results presented in this study may be used to form a representative biomechanical profile for floor landings.