GENDER DIFFERENCES IN JOINT MOMENTAND POWER MEASUREMENTS DURING VERTICAL JUMP EXERCISES

INTRODUCTION Gender differences are apparent not only in the absolute maximum force level but also in the rates at which the force and/or power is produced(Koml et al., 1978). The predominant requirement for success in a large number of athletic skills IS explosive power. For the lower body, this IS perhaps best exemplified by vertical jump. Vertical jumps a complex ballistic multi-joint movement, where the musculature around the hip, knee and ankle joints collectively operate to produce patterned movements. The purpose of this study was to assess the effect of gender on the mechanical output of the lower limb joints (moments and powers), during vertical jumping exercise. Methods: Eight male (age 22.4 yrs) and eight female ( age 21.7yrs) athletes served as subjects. After 20 min. of standard warm-up, the subjects performed 20 maximal vertical jumps with the arms behind the back. The 3-D coordinates of ten anatomical landmarks ( five per leg) were detected by the opt electronic ELITE system (Ferringno & Pedotti, 1985) with a sampling frequency of 100 HzS simultaneously, the GRF signals were measured and acquired with a sampling frequency of 500 Hz. Internal joint centres and the corresponding moments and powers were estimated from anthropometric and kinematic data using a special software package Group differences were assessed by the Wilcoxon signed rank test Statistical significance was assessed at pground reaction forces showed that the male subjects had greater peak forces and longer times of force application. The kinetic variables concerning the performance of the two groups are shown in table 1 and 2 For moments, the values of men are significantly higher than those of women. For powers, significant differences exist at the hip joint. When the values were normalized, dividing them by body weight and height, significant dlfferences were found for hip moment and ankle power CONCLUSION Despite the large Inter-subject variability observed in both groups, the test proposed here allows to point out significant gender effects onmost of the examined parameters REFERENCES Ferringno G , Pedotti A (1 985) ELITE a digital dedicated hardware for movement analysis via real time TV signal processing IEEE Trans B~omed3, 2,943-950Komr P V , Kartsson J (1 978) Skeletal muscle fiber types, enzyme activities and physical performance in young males and females Acta Physrol Scand, 103, 210-