B Question about Gravity and my hands

[Einstein60]

When I stand and relax my hand without lifting it. It's very relaxed. Within few minutes, I feel my hands become heavy. Why is this so.

 

[.Scott]

Perhaps they feel heavier. This isn't a Physics question.

 

[Einstein60]

Perhaps they feel heavier. This isn't a Physics question.

I just wanted to know.

 

[berkeman]

When I stand and relax my hand without lifting it. It's very relaxed. Within few minutes, I feel my hands become heavy. Why is this so.

Do you mean when you lift your hands and hold them up for a while? Your muscles need to expend energy to hold a weight up, even though it is not moving (so from a purely Physics perspective you would think there is no F*d work being done).

Or do you mean something else?

 

[hmmm27]

Have you consulted with a medical doctor ?

 

[Baluncore]

When I stand and relax my hand without lifting it. It's very relaxed. Within few minutes, I feel my hands become heavy. Why is this so.

If you do not exercise the muscles in your arms, the valves in your veins, do not return blood to your core, so blood pools in your arms. Also, lymphatic fluid builds up.
https://en.wikipedia.org/wiki/Vein#Structure

 

[Einstein60]

Do you mean when you lift your hands and hold them up for a while? Your muscles need to expend energy to hold a weight up, even though it is not moving (so from a purely Physics perspective you would think there is no F*d work being done).

Or do you mean something else?

This is also part. But I meant when your hands are down relaxed without any force lifting it or moving it

 

[Einstein60]

It's not a a medical problem. It happens to everyone.

Have you consulted with a medical doctor ?

 

[PeroK]

There's a trick that we used to do as children (probably most of you know it). Stand in a doorway with your arms at your sides and push the backs of hands as hard as you can against the opposing sides of the doorway. After a few seconds, swivel round and your arms will automatically float up to shoulder height.

 

[berkeman]

It's not a a medical problem. It happens to everyone.

Not to me. You mean that if you stand for more than a few minutes, your hands go numb? What about when you sit? When you lie down?

 

[sysprog]

When I stand and relax my hand without lifting it. It's very relaxed. Within few minutes, I feel my hands become heavy. Why is this so.

I think that's it's probably at least partly because we constantly adjust values for what we perceive as the status quo.

To understand this, you could try a classic 3 water basins demonstration experiment: fill 3 basins, each big enough to accommodate your hands, one with hot water, one with cold water, and one with lukewarm water; place one hand in the hot water basin, and at the same time, one in the cold water basin, for about a minute, until they become acclimated to the temperature; then put both hands in the lukewarm water $-$ the cold water hand will feel the lukewarm water as hot, while the hot water hand will feel the lukewarm water as cold $-$ you can look at your hands and see that they're in the same water, but seeemingly sending you different messages about the temperature $-$ that's because of their each having immediately previously acclimated to a different temperature.

If you hold a soup can in each of your hands for a minute, then if you put the soup can down and idle your emplty hands at your sides, they will at first feel light, but if you wait for a few minutes like that, your hands may feel like light weights hanging from your your arms, and your arms may feel like weights hanging from your shoulders. For comparison purposes, you can hold hold your hands up, fisted or not, in a boxing pose for 30 seconds, and when you put them back to hanging at your sides, you'll feel relief from their weight.