4 ms·

Human muscles are capable of much...(comparable to chimpanzees?). But there is some sort of a governor in place to ensure safety. In extreme circumstances, the

Human muscles are capable of much...(comparable to chimpanzees?). But there is some sort of a governor in place to ensure safety. In extreme circumstances, the governor can be "turned off" (adrenalin?) and we have cases of mothers lifting cars to save her child, etc.

ekianjo 13y ago
> lifting cars to save her child, etc. Lifting cars is often an exaggeration in terms of wording, the reality is usually lifting up one side of the car, which is very different in terms of weight.
rasz_pl 13y ago
no safety governor, just fine motor skills by addressing small specific muscle groups, hence unfortunate 'retard strength' myth (trading fine motor skills for blunt force)
- Evgeny 13y ago
  no safety governor, just fine motor skills by addressing small specific muscle groups I'm pretty sure the safeguard here is the Golgi tendon organ http://en.wikipedia.org/wiki/Golgi_tendon_organ http://en.wikipedia.org/wiki/Golgi_tendon_organ http://en.wikipedia.org/wiki/Golgi_tendon_reflex http://en.wikipedia.org/wiki/Golgi_tendon_reflex The Golgi tendon reflex operates as a protective feedback mechanism to control the tension of an active muscle by causing relaxation before the tendon tension becomes high enough to cause damage.
  - rasz_pl 13y ago
    Chimpanzee doesnt damage itself while having more strenght using same muscle mass as weaker human.
Symmetry 13y ago
Essentially. IIRC there are a couple of negative feedback loops, one local and one involving the brain, and they usually limit you to about a 1/3 duty cycle for each muscle fiber. There are certainly ways that ratio can be increased, just yelling can increase the maximum force you can consciously exert by about 15%. I have no idea what the maximum is, but I'd imagine that going much further than what you're normally limited to drastically increases your odds of tearing something during exertion. The reason chimpanzees can exert more force is anchoring, their muscles are anchored to the bone further form the joint so they have better mechanical advantage. A human has a much wider range of movement, though, and I believe we better maintain force under movement. So which a chimp might be able to lift themselves more easily, a human ends up being able to throw a rock or spear much further. EDIT: Also, ekianjo is right that lifting cars is an exaggeration.
- icegreentea 13y ago
  It's probably best not to compare human and chimp ROM, since that has less to do with muscle attachment sites, and isn't really that consistent, joint to joint. For example, a chimp shoulder has fabulous overhead ROM... as expected for a tree climber and swinger. The flip side of having crappier levers for force, is that we have better levers for precision.
jp555 13y ago
Muscle is not the only tissue involved with moving a weight around. Obviously you need a skeleton that can bear the load, and a heart & lungs fit enough to pump adequately oxygenated blood. But don't underestimate the large role a strength-adapted central nervous system plays.

ekianjo 13y ago

> lifting cars to save her child, etc. Lifting cars is often an exaggeration in terms of wording, the reality is usually lifting up one side of the car, which is very different in terms of weight.

rasz_pl 13y ago

no safety governor, just fine motor skills by addressing small specific muscle groups, hence unfortunate 'retard strength' myth (trading fine motor skills for blunt force)

Evgeny 13y ago
no safety governor, just fine motor skills by addressing small specific muscle groups I'm pretty sure the safeguard here is the Golgi tendon organ http://en.wikipedia.org/wiki/Golgi_tendon_organ http://en.wikipedia.org/wiki/Golgi_tendon_organ http://en.wikipedia.org/wiki/Golgi_tendon_reflex http://en.wikipedia.org/wiki/Golgi_tendon_reflex The Golgi tendon reflex operates as a protective feedback mechanism to control the tension of an active muscle by causing relaxation before the tendon tension becomes high enough to cause damage.
- rasz_pl 13y ago
  Chimpanzee doesnt damage itself while having more strenght using same muscle mass as weaker human.

Symmetry 13y ago

Essentially. IIRC there are a couple of negative feedback loops, one local and one involving the brain, and they usually limit you to about a 1/3 duty cycle for each muscle fiber. There are certainly ways that ratio can be increased, just yelling can increase the maximum force you can consciously exert by about 15%. I have no idea what the maximum is, but I'd imagine that going much further than what you're normally limited to drastically increases your odds of tearing something during exertion. The reason chimpanzees can exert more force is anchoring, their muscles are anchored to the bone further form the joint so they have better mechanical advantage. A human has a much wider range of movement, though, and I believe we better maintain force under movement. So which a chimp might be able to lift themselves more easily, a human ends up being able to throw a rock or spear much further. EDIT: Also, ekianjo is right that lifting cars is an exaggeration.

icegreentea 13y ago
It's probably best not to compare human and chimp ROM, since that has less to do with muscle attachment sites, and isn't really that consistent, joint to joint. For example, a chimp shoulder has fabulous overhead ROM... as expected for a tree climber and swinger. The flip side of having crappier levers for force, is that we have better levers for precision.

jp555 13y ago

Muscle is not the only tissue involved with moving a weight around. Obviously you need a skeleton that can bear the load, and a heart & lungs fit enough to pump adequately oxygenated blood. But don't underestimate the large role a strength-adapted central nervous system plays.