Kinematical and Dynamic Differences by Executing Basic Steps on Stable and Unstable Surface

Anatoli Ioannidou, Evaggelos Dakis, Thomas Nikodelis, & Georgios Papaiakovou

Biomechanics Lab, Dept. of Physical Education and Sports Sciences, Aristotle University of Thessaloniki, Hellas

Abstract

The purpose of the study was to investigate if the characteristics of the centre of pressure (CoP) and ground reaction forces (Fz) are altered during the basic step, when using a stable and an unstable stepper. Thirty (30) healthy female students of physical education, participated in the study executing the basic step on a stable step and on the unstable Reebok Core Board. The results showed a greater displacement of the CoP in both axes (CoPx stab: 45.1 ± 4cm, CoPx unstab: 48.4 ± 3.2cm and CoPy stab: 49.6 ± 6.3 cm, CoPy unstab: 51.8 ± 6.7 cm). The force developed in the vertical axis was also greater when using the unstable step (Fzmax (N): stab: 934.13± 121.90, unstab: 973.60 ± 114.71). It can be concluded that the use of an unstable stepper is connected with increased demands on balance, force application and possibly more energy cost, facts that should be taken in account when introducing several populations in this kind of exercise.

Key words: Step exercise, stabile-instable surface, force development