Maximal frequency, amplitude, and elbow joint stiffness in cyclic movements

Most of research projects on cyclical motor activity focus on locomotion. They provide ambivalent data on the considered theme. Saito et al. [1] present the results of their research on the relationship between step length and frequency in sprint, which was not a decreasing one. Laurent and Pailhous [2] observed that step length and frequency both correlate with walking speed but are relatively independent of each other. Martin et al. [3] observed an inverse relationship between crank length (amplitude) and pedaling frequency. Peper and Beek [4] noticed a slight amplitude decrease with frequency increase of forearm movements. The question may thus be asked whether cyclical movements performed by the human motor system are characterized by an unequivocal relation between movement amplitude and frequency. If this is the case, then what is the nature of this relationship, within what amplitude or frequency ranges and in what way can it manifest itself in complex movements? The objective of this study derives from the questions posed above and consists in researching hypothetical relations between the amplitude of cyclical joint movement and its frequency, as well as the conditions in which such relations exist and, possibly, the mechanisms lying at the basis of such relationships.