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Does different activation between the medial and the lateral gastrocnemius during walking translate into different fascicle behavior?
- Source :
- Journal of Experimental Biology, Journal of Experimental Biology, 2021, 224 (12), pp.jeb242626. ⟨10.1242/jeb.242626⟩, Journal of Experimental Biology, The Company of Biologists, 2021, 224 (12), ⟨10.1242/jeb.242626⟩, Journal of Experimental Biology, Cambridge University Press, 2021, 224 (12), ⟨10.1242/jeb.242626⟩
- Publication Year :
- 2021
- Publisher :
- The Company of Biologists, 2021.
-
Abstract
- The functional difference between the medial gastrocnemius (MG) and lateral gastrocnemius (LG) during walking in humans has not yet been fully established. Although evidence highlights that the MG is activated more than the LG, the link with potential differences in mechanical behavior between these muscles remains unknown. In this study, we aimed to determine whether differences in activation between the MG and LG translate into different fascicle behavior during walking. Fifteen participants walked at their preferred speed under two conditions: 0% and 10% incline treadmill grade. We used surface electromyography and B-mode ultrasound to estimate muscle activation and fascicle dynamics in the MG and LG. We observed a higher normalized activation in the MG than in the LG during stance, which did not translate into greater MG normalized fascicle shortening. However, we observed significantly less normalized fascicle lengthening in the MG than in the LG during early stance, which matched with the timing of differences in activation between muscles. This resulted in more isometric behavior of the MG, which likely influences the muscle–tendon interaction and enhances the catapult-like mechanism in the MG compared with the LG. Nevertheless, this interplay between muscle activation and fascicle behavior, evident at the group level, was not observed at the individual level, as revealed by the lack of correlation between the MG–LG differences in activation and MG–LG differences in fascicle behavior. The MG and LG are often considered as equivalent muscles but the neuromechanical differences between them suggest that they may have distinct functional roles during locomotion.
- Subjects :
- Physiology
[SDV]Life Sciences [q-bio]
Walking
Isometric exercise
Electromyography
Aquatic Science
Biology
Tendons
B-mode ultrasound
03 medical and health sciences
0302 clinical medicine
[SDV.MHEP.AHA]Life Sciences [q-bio]/Human health and pathology/Tissues and Organs [q-bio.TO]
medicine
Humans
Fascicle length
Treadmill
Muscle, Skeletal
Molecular Biology
Group level
Ecology, Evolution, Behavior and Systematics
medicine.diagnostic_test
Muscle activation
030229 sport sciences
Anatomy
Fascicle
Individual level
Biomechanical Phenomena
Muscle function
Insect Science
Animal Science and Zoology
Locomotion
030217 neurology & neurosurgery
Muscle Contraction
Lateral gastrocnemius
Subjects
Details
- ISSN :
- 14779145 and 00220949
- Volume :
- 224
- Database :
- OpenAIRE
- Journal :
- Journal of Experimental Biology
- Accession number :
- edsair.doi.dedup.....c9b3a58af54ecc404f2046f26106eb1f