Introduction: We investigated the effect of workload and the use of pedal straps on the spatial distribution of neuromuscular activation within the rectus femoris (RF) muscle during pedaling movements.
Methods: Eleven healthy men performed submaximal pedaling exercises on an electrically braked ergometer at different workloads and with or without pedal straps. During these tasks, surface electromyograms (SEMGs) were recorded from the RF using 36 electrode pairs, and central locus activation (CLA) was calculated along the longitudinal line of the muscle.
Results: CLA moved markedly, indicating changes in spatial distribution of SEMG within the muscle, during a crank cycle under all conditions (P < 0.05). There were significant differences in CLA among different workloads and between those with and without pedal straps (P < 0.05).
Conclusion: These results suggest that neuromuscular activation within the RF is regulated regionally by changes in workload and the use of pedal straps during pedaling.
Keywords: bi-articular muscles; cycling; high-density surface electromyography; multichannel surface electromyography; neuromuscular compartment; quadriceps femoris muscle.
© 2014 Wiley Periodicals, Inc.