Glycerinated psoas muscle fiber is a good biochemical and mechanical model of the intact muscle. The ATP-hydrolysis cycle runs on ms time scale, so we need a very rapid technics to investigate it. We can make a long-living intermediate states with the help of different phosphate analogues with life time which fits to the measuring time of other techniques (e.g.: EPR and DSC). This way we are able to investigate the molecular dynamic and thermal stability of these states for the better understanding of muscle function.