Measurement of muscle fiber stiffness during stretch with two continuous different velocities in skeletal muscle fibers.
Ca2+ activated single glycerinated muscle fibers were stretched by 3% of its slack length Lo with moderate velocities ranging from 0.015 to 0.15Lo, and muscle fiber stiffness during and after stretch was measured by applying sinusoidal vibrations (peak-to-peak amplitude, 0.1% of Lo, 2kHz). During a single stretch, the fiber was first stretched by 1.5% with a velocity, and then it was further stretched by 1.5% with another velocity. It is suggested that, during stretch, a considerable fraction of cross-bridges slow down their cycling rate and increase their force-generating ability.
Kobayashi
Takakazu
T
Department of Electronic Engineering, Shibaura Institute of Technology, Tokyo, 135-8548 Japan. kobataka@sic.shibaura-it.ac.jp
Iwai
Masaaki
M
Phan
Kien Nguyen
KN
D000818:Animals; D002478:Cells, Cultured; D004548:Elasticity; D009068:Movement / Q000502:physiology*; D009119:Muscle Contraction / Q000502:physiology*; D018485:Muscle Fibers, Skeletal / Q000502:physiology*; D010812:Physical Stimulation / Q000379:methods; D016658:Psoas Muscles / Q000502:physiology*; D011817:Rabbits; D013314:Stress, Mechanical