THE INFLUENCE OF SELECTED BODY DIMENSIONAL PARAMETERS ON THE MECHANICAL PARAMETERS OF THE VERTICAL JUMP

Abstract

INTRODUCTION: The purpose of the present study was to determine the influence of body fat, as well as selected limb lengths and proportions, on the maximal mechanical power and height of the countermovement jump. The effect of countermovement depth, body mass and jump height on maximal power, known from our previous study, was taken into consideration as well. METHODS: Untrained physical education students (56 female and 38 male) volunteered to take part in the CMJ jumping test, consisting of 3 jumps of different countermovement depths performed at one-minute intervals on a computerized Kistler force plate. Results of the highest jump were selected for each subject for further processing. The following variables were included in the statistical analysis: the maximal mechanical power (Pmax) developed during take-off, the height of the jump (h), the counter-movement depth (d), body mass (m) and height (H), lengths of the foot (F), shank (S), leg (L), trunk (T), shank to leg length ratio (s) and fat mass. The Shapiro-Wilk test was used to examine the distributions of the tested variables. Pearson’s correlation matrix and multiple regression analysis were employed to identify the relationships between the tested variables. RESULTS AND CONCLUSIONS: In both female and male groups the multiple regression procedure (the forward stepwise method) pointed the height of the jump, the countermovement depth and the body mass as variables having an effect on maximal power. Significant effects of the fat mass and the shank-to-leg length ratio on the height of jumps were found. REFERENCES: Aura, O., Viitasalo, J. T. (1989). Biomechanical Characteristics of Jumping. Intertional Journal of Sport Biomechanics 5, 89-98. Bobbert, M. F., Gerritsen, K. G. M., Litjens, M. C. A., Van Soest, A. J. (1995). Explanation of Differences in Jump Height Between Countermovement and Squat Jumps. Book of Abstracts. XV ISB Congress. Jyväskylä Dowling, J. J., Vamos, L. (1993). Identification of Kinetic and Temporal Factors Related to Vertical Jump Performance. J. Appl. Biomech. 9, 95-110. Harley, R. A., Doust, J. H. (1994). Effects of Different Degrees of Knee Flexion During Continuous Vertical Jumping on Power Output Using the Bosco Formula. Journal of Sports Sciences 12, 2, 139-140. Gajewski, J., Janiak, J., Eliasz, J., Wit, A. (1996). Determinants of the Maximal Mechanical Power Developed During the Countermovement Jump. In J. Abrantes (Ed.), XIV International Symposium on Biomechanics in Sports (pp.420-423). Lisbon.