why do our our arm and hands shake when exerting max effort?

Question

An example of that would be when we try to grip on something as hard as we can, our hands would shake.

In: 221

Answer 1

Human muscle fibers (like most animals) have a number of inhibitory reflexes that prevent them from operating at 100% power. This is because a maximally contracting muscle can easily injure itself or its tendons, opposing muscles, or nearby joints.

In addition, human exercise physiology is heavily optimized for endurance over peak power, so we likely have some inhibitory reflexes to lower energy use and increase endurance.

So when you are close to your limit on exercise, your muscles shake because your spine and/or brain are literally telling those muscles to stop working so hard.

Extreme emotional or physical events can sometimes overcome these inhibitory reflexes, causing phenomena like “hysterical strength” where a mother lifts a car off their child, a psychotic or intoxicated person performs extreme feats of strength/agility, or a person attacked by a wild animal kills it with their bare hands.

Answer 2

Human muscle fibers (like most animals) have a number of inhibitory reflexes that prevent them from operating at 100% power. This is because a maximally contracting muscle can easily injure itself or its tendons, opposing muscles, or nearby joints.

In addition, human exercise physiology is heavily optimized for endurance over peak power, so we likely have some inhibitory reflexes to lower energy use and increase endurance.

So when you are close to your limit on exercise, your muscles shake because your spine and/or brain are literally telling those muscles to stop working so hard.

Extreme emotional or physical events can sometimes overcome these inhibitory reflexes, causing phenomena like “hysterical strength” where a mother lifts a car off their child, a psychotic or intoxicated person performs extreme feats of strength/agility, or a person attacked by a wild animal kills it with their bare hands.