Related Experiment Video
Updated: Oct 9, 2026

Method to Measure Tone of Axial and Proximal Muscle
Published on: December 14, 2011
Muscle contraction and relaxation described by tactile stiffness
1Department of Cardiothoracic Surgery, Faculty of Medicine, University of Tokyo, Tokyo, Japan.
Abstract:
We developed a tactile sensor system that measures the stiffness of objects (tactile stiffness) and used it to describe the time course of muscle contraction and relaxation. We examined fatigue resistance of the latissimus dorsi muscle (LDM), which is preconditioned for cardiomyoplasty. Time to peak, ripple of LDM, and time constant were calculated from the time course of LDM contraction and relaxation as described by tactile stiffness. We compared conditioned and unconditioned LDMs using these 3 parameters. The time course can be described by tactile stiffness. Tactile stiffness fell exponentially during LDM relaxation. In mean values, time to peak increased 230%, ripple decreased 20%, and time constants increased 424%. Significant differences were shown in 3 parameters between conditioned and unconditioned LDMs (p < 0.05). Our tactile sensor system can describe the time course of LDM contraction and relaxation. Examining the difference in time courses, we might detect the level of LDM preconditioning for cardiomyoplasty.
Related Concept Videos
Muscle Stimulation Frequency
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
Motor Unit Stimulation
The latent period of contraction marks the onset of excitation-contraction coupling, when the action potential propagates across the sarcolemma, preparing the muscle fibers for contraction. As the fibers enter the contraction phase, the...
Alterations in Muscle Tone lll
Smooth Muscle Contraction
The onset of contraction is triggered by an increase in calcium ions within the sarcoplasm, similar to the process in striated muscle. However, smooth muscles have a relatively smaller reservoir of the sarcoplasmic...
Relaxation of Skeletal Muscles
When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open.
Muscle Contraction

