INFLUENCE OF AFTER-MOVEMENT ON MUSCLE MEMORY FOLLOWING ISOMETRIC MUSCLE-CONTRACTION

The existence of the so-called Kohnstamm phenomenon indicates that muscular activity influences a subsequent movement. The aim of this investigation, therefore, was to elucidate the influence of a previous isometric muscle contraction on the ability to relocate a certain point without using the eyes. A preceding isometric muscle contraction using 50 per cent of the maximum isometric strength maintained for 30 seconds was found to have little influence on muscle memory. The distance from the marks on the targets to bull's-eye decreased from first to third marking. SD of the marks was larger after the effort than after rest and the feeling of uncertainty in the subjects was larger after the effort. It seems that the largest effect of an isometric muscle contraction on a subsequent movement performed without using the eyes is the increased uncertainty after effort compared to after rest.