Validity of a new contact mat system for evaluating vertical jump.

Jonathan Ache Dias,Marcelo Diederichs Wentz,Raquel Petry,Susana Cristina Domenech,Noé Gomes Borges Junior,Daniela Junckes Da Silva Mattos,Lucas Borges

doi:10.5016/1980-6574.2011v17n1p26

Abstract

The purpose of this study was to verify the validity of the flight and ground contact time measurement of a contact mat, SaltoBras (SB), comparing it to an oscilloscope (OS) and to a force plate (FP). For that, the SB was placed upon a FP. At first, four male and two female performed 15 jumps on the SB and the flight times were obtained. After, they performed six consecutive jumps and the ground contact times were obtained. SB software was valid in comparison with the OS, but underestimated the flight (~0.30 %) and ground contact (~1.01 %) time measurements when comparing it to the FP. Despite the differences, the error found between SB and FP was systematic, and two prediction equations were defined and added to the software for correction. The results suggest that SB is a valid instrument for the evaluation of vertical jump.

Highlights

The vertical jump is a fundamental skill extensively studied in the literature (DAVIS et al 2003; HASSON et al, 2004)
According to Baca (1998), the three methods used in scientific studies to evaluate the jump height are: the video-based method (VID), the method based in the vertical ground reaction force (VRF) and the flight time method (FT)
Two prediction equations were defined and explained ~99% of the variation of the flight and ground contact times of the Force plates (FP). It can be observed in table 1 and 2 the measure of central tendency and variability, as well as the absolute differences of flight and ground contact times obtained in the sequence of jumps of all the participants, by SB and FP

Summary

Introduction

The vertical jump is a fundamental skill extensively studied in the literature (DAVIS et al 2003; HASSON et al, 2004). The most utilized parameter for the evaluation of the vertical jump is the jump height which is considered as the displacement of the center of mass (CM) of the body from the standing position to the highest vertical position and several protocols and systems are currently employed to measure it (GARCÍA-LOPEZ et al, 2005; JAGGER et al, 2008; MUSAYEV, 2003). According to Baca (1998), the three methods used in scientific studies to evaluate the jump height are: the video-based method (VID), the method based in the vertical ground reaction force (VRF) and the flight time method (FT). Force plates (FP) have been used and allow the vertical jump height to be estimated integrating the kinetic and temporal variables produced by the force-time curves, by analyzing the VRF which allow the jump impulse to be calculated as well as the take-off velocity and power (CORDOVA; AMSTRONG, 1996; JAGGER, 2004; LARKINS; SNABB, 1999; SACCO et al, 2004; LINTHORNE, 2001)

Objectives

Methods

Results

Conclusion