Erschienen in:
13.01.2022 | Original Article
Muscle stiffening is associated with muscle mechanoreflex-mediated cardioacceleration
verfasst von:
Nobuhiro Nakamura, Naoki Ikeda, Peng Heng, Isao Muraoka
Erschienen in:
European Journal of Applied Physiology
|
Ausgabe 3/2022
Einloggen, um Zugang zu erhalten
Abstract
Purpose
Although the muscle mechanoreflex is an important mediator to cardiovascular regulation during exercise, its modulation factors remain relatively unknown. Therefore, the purpose of this study was to investigate the effect of muscle stiffness on the muscle mechanoreflex.
Methods
Participants were divided based on their median muscle stiffness (2.00 Nm/mm) into a low group (n = 15) and a high group (n = 15), and the muscle mechanoreflex was compared between the groups. After a 15-min rest in the supine position, heart rate (HR), blood pressure (BP), stroke volume (SV), and cardiac output (CO) were measured at rest for 3 min and during static passive dorsiflexion (SPD) at 20° for 1 min. Following a 15-min re-rest, muscle stiffness and passive resistive torque were evaluated in the distal end of the muscle belly of the medial gastrocnemius.
Results
Peak relative changes in HR (low group: 6 ± 4% and high group: 12 ± 4%) and CO (low group: 8 ± 10% and high group: 13 ± 9%) were greater in the high group than in the low group (both, P < 0.05). A significant positive correlation was found between resistive torque during SPD and muscle stiffness and peak relative changes in HR (r = 0.51 and 0.61, both P < 0.05). However, there was no correlation between muscle elongation during SPD and peak relative changes in HR (r = − 0.23, P = 0.20).
Conclusion
These findings suggest that muscle stiffness may be modulatory factor of muscle mechanoreflex.