Purpose:
The aim of this investigation was to look for relationships between the repeatability of forces generated during the movement rhythm present in step aerobics and the movement to a rhythm by the upper and lower limbs alone. As step aerobics requires the symmetric involvement of both the upper and lower limbs, it appears to be important to examine whether a relationship exists between repeatability of a rhythm and a repeatability of forces generated when moving to a rhythm. As step aerobics is considered an endurance activity, the repeatability of the force reproduced by the lower limb muscles may be important in the prevention of injury.

Methods:
The study involved using a mock step bench which consisted of two Kistler force plates. The 29 female subjects of the study executed two motor tasks. The first task was hitting the plate with the dominant and the non-dominant upper and lower limb to a musical rhythm. The second task consisted in performing the basic step of step aerobics on the bench. The rhythm in both tasks was dictated by the beat of a metronome.

Results:
No statistically significant differences were found between respectability of producing a rhythm by the dominant and non-dominant upper and lower limbs. No correlation was found between the rhythm reproduction error of the limbs and the accuracy of moving to a rhythm during the step aerobics task. This second task was characterized by a high repeatability of the generated forces and a high variability in following a musical rhythm.

Conclusions:
Body mass does not influence the force generated during rhythm reproduction with the upper and lower limbs. During step walking, the study participants were characterized with a high repeatability of generated force and also by a high variability in following a musical rhythm.