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Posts Tagged ‘muscle’

Scientists have designed boots that let you walk using 7% less energy


The exoskeleton is completely unpowered (wires are for sensors that measure muscle activity and exoskeleton torque). Image: Stephen Thrift

Scientists have built a light-weight wearable boot-like exoskeleton which reduces the energy needed for walking.

Researchers say the exoskeleton gives a 7% gain without chemical or electrical energy.

According to research published in the journal Nature, the energy saving is relatively modest but represents a considerable improvement on past designs.

Engineers have been trying to create machines since at least the 1890s to make walking easier but it is only recently that any attempt has met with success.

Steven Collins of the Department of Mechanical Engineering at Carnegie Mellon University and colleagues say the device acts in parallel with the user’s calf muscles, off-loading muscle force and reducing the energy consumed in contractions.

The device uses a mechanical clutch to hold a spring as it is stretched and relaxed by ankle movements when the foot is on the ground, helping to fulfil one function of the calf muscles and Achilles tendon.

People take about 10,000 steps a day or hundreds of millions of steps in a lifetime.

“While strong natural pressures have already shaped human locomotion, improvements in efficiency are still possible,” the study says. “Much remains to be learned about this seemingly simple behaviour.”

Watch the exoskeleton in action:

The above story is reprinted from materials provided by Business Insider.

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The Innervation of the Heart


An article on the innervation of the heart muscle.

A link to the article: The innervation of the Heart – click here

Initiation of the cardiac cycle is myogenic, originating in the sinuatrial node (SA). It is harmonizied in rate, force and output by autonomic nerves which operate on the nodal tissues and their prolongations, on coronary vessels and on the working atrial and ventricular musculature. All the cardiac branches of the N.vagus, X. cranial nerve, (parasympathetic) and all the sympathetic branches (except the cardiac branch of the superior cervical sympathetic ganglion) contain both afferent and efferent fibres; the cardiac branch of the superior cervical sympathetic ganglion is entirely efferent. Sympathetic fibres accelerate the heart and dilate the coronary arteries when stimulated, whereas parasympathetic (vagal) fibres slow the heart and cause constriction of coronary arteries.