Displacement Mechanomyography Reflects Mechanical Pedaling Force of Muscle Associated with Changes in Cadence and Work Rate During Pedaling

• Published in: Journal of medical and biological engineering Vol. 42; no. 6; pp. 889 - 897
• Main Authors: Fukuhara, Shinichi, Oka, Hisao
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.12.2022; Springer Nature B.V
• Subjects: Biological Techniques; Biomedical and Life Sciences; Biomedical Engineering and Bioengineering; Biomedical Engineering/Biotechnology; Biomedicine; Cyclic loads; Electromyography; Mechanical properties; Muscle strength; Original Article; Pedals; Regenerative Medicine/Tissue Engineering; Waveforms; Mechanomyography; Displacement MMG; Pedaling; Cadence; Electromyography
• ISSN: 1609-0985; 2199-4757
• DOI: 10.1007/s40846-022-00752-1

Purpose The combined approach of electromyography (EMG) and mechanomyography (MMG) in cyclic exercise, such as pedaling, is not completely understood. The aim of this study was to investigate the effect of changes in cadence and work rate during pedaling on EMG and displacement MMG (dMMG) of the vastus medialis (VM) measured simultaneously using our developed MMG/EMG simultaneous measurement device. Methods The primary endpoints were the change in EMG and dMMG for each cadence and load conditions (9 patterns) during pedaling. The study participants were 15 healthy men. EMG and dMMG of the right VM were measured at 1 kHz sampling for 30 s with a cadence of 30, 60, and 90 rpm and a work rate of 30, 60, and 90 W. Total powers were calculated based on the time domain waveforms of EMG and dMMG. Results The effect of increased work rate responded only to EMG (p < 0.001), but with increasing cadence, EMG (increase) and dMMG (decrease) showed a contrasting relationship. Additionally, dMMG and theoretical pedaling torque had a significant strong positive correlation (p < 0.001). Conclusion The results of this study revealed that the dMMG measured during cyclic exercise with different loads and cadence reflect the mechanical properties and states of net muscle strength during pedaling. Accordingly, the dMMG may be considered as a biological index for representing the transmission mechanical force on the cyclist's pedals, that is, the net muscle strength during pedaling.