Balance control during lateral arm raising in humans

Abstract

The aim of the present study was to determine (i) whether the centre of gravity (CG) shift resulting from the mechanical effect of arm raising in the frontal plane is minimized in standing subjects and (ii) whether this putative minimization is affected by the support conditions (unipedal vs bipedal) and/or by adding a load (3.5 kg) to the moving hand. Our results indicate first that a CG control does exist during bipedal stance (compensating for 31% of the mechanical shift), which increases markedly in unipedal stance (73%) and secondly, that an additional load is compensated for solely in the case of unipedal stance (81%).