Does standing tiptoes reduce the absortion of virabtions?

[paget]

Imagine someone stands in bus while it is driving. The road has usually several unsteady parts, where impacts on the bus occur. Those impacts result in minor movements and vibrations of the bus and of the passenger. Does it actually bring anything to sand tiptoes to reduce the absorbed impacts? The question is related to the effects on the brain.

 

[CWatters]

It's well known that human legs (including the feet) can act as springs. A lot of research has been done on this subject by people trying to make better artificial legs and feet. Google legs as springs..

https://www.google.co.uk/?gws_rd=ssl#q=human+legs+as+springs

It seem quite reasonable to assume that lifting your heels off the ground effectively allows your feet and tendons to act as springs. You then have a spring between the bus and the major part of your body mass. That may or may not reduce the vibration transmitted to your head (it depends on the frequency of the vibration. Perhaps look up resonance).

 

[paget]

i think the vertical vibrations were definatly reduced by lifting the heels. the horizontal vibrations rather not. But from the physical standpoint - the vibrations only occur on the shoe sole and the hand. how much of that is actually transferred to the head? I think hand and legs are quite flexible, so they would absorb most of the vibrations.

 

[Drakkith]

Low frequency vibrations, like bumps in the road, can easily be compensated for by standing on your toes or bending your knees. Higher frequency vibrations might propagate through your body, but they are hardly worth considering and pose no health risk. Consider that people can use a jackhammer for years or decades and the typical injuries are vibration related injuries to the hands, not to the brain, and these vibrations are far higher in both duration and amplitude than anything you experience riding a bus.

 

[sophiecentaur]

i think the vertical vibrations were definatly reduced by lifting the heels. the horizontal vibrations rather not. But from the physical standpoint - the vibrations only occur on the shoe sole and the hand. how much of that is actually transferred to the head? I think hand and legs are quite flexible, so they would absorb most of the vibrations.

Springs alone do not do a good job of cushioning. You also need friction to dissipate energy. Motor cars would leap off the road if it were not for the hydraulic dampers. Your muscles can provide an effective degree of 'active damping' when you stand up on a bus. This must be one reason why you tire after a short time on tip toes to make the ride more comfy.

 

[paget]

Low frequency vibrations, like bumps in the road, can easily be compensated for by standing on your toes or bending your knees. Higher frequency vibrations might propagate through your body, but they are hardly worth considering and pose no health risk. Consider that people can use a jackhammer for years or decades and the typical injuries are vibration related injuries to the hands, not to the brain, and these vibrations are far higher in both duration and amplitude than anything you experience riding a bus.

I did both, standing on tiptoes and bending the knees(at least a bit). You have to know, i didn't mention all here. I suffered mTBI 3 months ago. There was this rough bus ride on tuesday, which obviously had a negative effect on my injury(I feel much worse). I tried everything to absorb as less as possible of these shakes/vibrations. Obvously I did quite the best, if i look at your answer. The problem was maybe that the bus shaked constantly for a few seconds, because a certain part of the road was in such a bad condtion.

What are high frequency vibrations, can they be created in a bus ride?

Springs alone do not do a good job of cushioning. You also need friction to dissipate energy. Motor cars would leap off the road if it were not for the hydraulic dampers. Your muscles can provide an effective degree of 'active damping' when you stand up on a bus. This must be one reason why you tire after a short time on tip toes to make the ride more comfy.

Sophie, if i understand you right, you also think that the head was not much influenced by these vibrations?

The problem is I didn't see my head shaking and didn't feel it shaking. So the only way to figure this out is to regard the physical standpoint. Asking a doctor about this incident is completely useless(I tried it)

i found this very interesting article about excactly my question. it shows that standing on tiptoes eleminates the vertical vibrations very well, but not the horizontal vibrations(if i read it right). Subject 4 is the one standing on tiptoes.

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0CDkQFjAC&url=http://www.inacomm2013.ammindia.org/Papers/044-inacomm2013_submission_332.pdf&ei=IyzzVLbjA9H3aoL3gvAB&usg=AFQjCNFqc4AGphagaoNnTzEsTVjyZ3ruVQ

 

[Drakkith]

Locked temporarily.

 

[Drakkith]

Paget, I'm afraid that I'm going to have to close this thread. You have a brain injury and we cannot offer help due to liability. It's simply too risky since any advice given could potentially harm you or keep you from seeking medical help that would potentially help you. I would talk to your doctor if your bus ride causes you to feel worse than normal. There are potentially dozens of legitimate medical reasons why this could happen.