Related Experiment Video

Updated: Jul 9, 2026

A Flexible Wearable Supernumerary Robotic Limb for Chronic Stroke Patients
03:55

A Flexible Wearable Supernumerary Robotic Limb for Chronic Stroke Patients

Published on: October 27, 2023

Length control of pneumatic artificial muscles inspired by intrafusal-extrafusal muscle interactions

Ko Sakamoto1, Yoichi Masuda1, Sei-Ichiro Takeda1

  • 1Department of Mechanical Engineering, The University of Osaka, Osaka, Japan.

Bioinspiration & Biomimetics
|July 7, 2026
PubMed

Keywords:
bio-inspired controlintrafusal-extrafusal interactionlength controlmechanical feedbackmuscle spindlepneumatic artificial musclessoft robotics

More Related Videos

Fabrication of Soft Pneumatic Network Actuators with Oblique Chambers07:09

Fabrication of Soft Pneumatic Network Actuators with Oblique Chambers

Published on: August 17, 2018

Procedures for Rat in situ Skeletal Muscle Contractile Properties09:49

Procedures for Rat in situ Skeletal Muscle Contractile Properties

Published on: October 15, 2011

Related Concept Videos

Smooth Muscle Contraction01:25

Smooth Muscle Contraction

Smooth muscle contraction is a complex process vital for various bodily functions, from maintaining blood vessel tension to facilitating the movement of food through the digestive tract. Unlike striated muscles, smooth muscle contraction begins more slowly and lasts longer.
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...
Motor Unit Stimulation01:20

Motor Unit Stimulation

When the neuron of a motor unit fires an action potential, it triggers a series of events, leading to a twitch contraction in the muscle fibers. The process of excitation-contraction coupling is crucial in relaying the action potential to the muscle fibers.
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...
Muscle Stimulation Frequency01:22

Muscle Stimulation Frequency

The contraction strength of muscles is regulated by motor neurons, which modulate the frequency of action potentials dispatched to the motor units based on the body's requirements. This process of varying the muscle stimulation frequency allows muscles to contract with a force that is precisely tailored to the needs of the moment, whether lifting a feather or a heavy box.
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
Fascicle Arrangement in Skeletal Muscles01:25

Fascicle Arrangement in Skeletal Muscles

Fascicles are bundles of muscle fibers in a skeletal muscle. Muscle fascicle arrangement is directly associated with the power and range of motion of various muscles. The configuration of these fascicles can vary, leading to different functional outcomes.
The four primary types of muscle based on fascicle arrangement are:
Excitation-Contraction Coupling in Skeletal Muscles01:20

Excitation-Contraction Coupling in Skeletal Muscles

Excitation-contraction coupling is a series of events that occur between generating an action potential and initiating a muscle contraction. It occurs at the triad, a structure found in skeletal muscle fibers that comprise a T-tubule and terminal cisternae of the sarcoplasmic reticulum on each side. These triads are visible in longitudinally sectioned muscle fibers. They are typically located at the A-I junction — the junction between the A and I bands of the sarcomere.
When an action potential...
Muscle Contraction01:10

Muscle Contraction

In skeletal muscles, acetylcholine is released by nerve terminals at the motor endplate—the point of synaptic communication between motor neurons and muscle fibers. The binding of acetylcholine to its receptors on the sarcolemma allows entry of sodium ions into the cell and triggers an action potential in the muscle cell. Thus, electrical signals from the brain are transmitted to the muscle. Subsequently, the enzyme acetylcholinesterase breaks down acetylcholine to prevent excessive muscle...