Analysis of effectiveness of free segment actions and antero-posterior and lateral body displacements during the take-off phase of high jump (flop style)

Abstract

The aim of this study is to analyse frontal and lateral displacements, as well as free segment actions in a sample of 10 athletes (7 in national categories and 3 at an international level) in order to compare them with optimal reference levels and determine their current technical level. To achieve this, all jumps were recorded during an official competition by 6 synchronised cameras, previously validated with a 24 control point reference system. Calculations were based on the sum of all 14 angular momenta in relation to the body's centre of mass.From the results, it can be concluded that, in the highest jumpers, jump height was correlated to vertical displacement in the sagittal plane (r = -0.60), free leg arm velocity (r = -0.56) and frontal plane angle momentum (r = -0.59). The main technical errors in the assessed athletes were identified as body inclination in the analysed planes at the beginning of take-off (frontal and sagittal) and excessively low free leg activity. These mistakes could be improved with training in curved run-up and transition to take-off.