Various studies have shown that training with free weights or machines without movement restrictions ensure more muscle strength and balance [1 t / m 4]. Training on a machine with a restriction of the movement also provides more balance and strength of the muscles [4,5]. Until 2008, no investigation had yet been done on the impact of the difference in muscle strength and balance of the two.

A study by the University of Minnesota has done research in 2008 into the two different methods [7]. When examining three different groups were compared. A group of ten participants who had to perform the exercises on a machine with a fixed movement (FX). Group two consisted of ten participants had to perform exercises on a machine without movement restriction (FF). And a control group who performed no fitness exercises.
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