Mechanical Engineers Bio mechanics – brain teaser

So i'll post this brain teaser & it's open to really anybody who wants to give it a shot - I used it to tease 2 Engineers at work the other day.

What would a chair look like if our knees where on backwards ? lol

ABD

The same except our legs would be in the air ?
Or something in the shape or a U to support the legs ? ^^

Or maybe like a long chair because we wouldn't want to bend our legs if it's going to be more effort to support ?

Like a chair, if the question is as simple as stated.

If the question is actually more complex and you are asking what a seating device would look like in order to accomodate a body with opposing knee bend, then I would think it would look more like a legless pad. I'm envisioning most animals, where their equivalent to our ankle joint is what most people refer to as a knee. If nothing else about our physiology were to change, ie: we still sit on a butt at the rear of our body, our hip joints and feet joints all remain the same, then I don't see much other option but for us to assume a squat seating position. Even at that it would be difficult. The additional rearward leg movement/hip flex required to adapt to sitting on one's arse with backward knees is difficult geometry to picture. In fact, the more I think about it, the less I can see it.

But I really tend to overthink stuff like this, so I'll just go with my first guess. Like a chair.

DAMN YOU A.B.D, the mental picture is maddening..... I have too much shit to do to be thinking about this

Quote:

Originally posted by bustMall

DAMN YOU A.B.D, the mental picture is maddening..... I have too much shit to do to be thinking about this

You too just HAD to picture the thing, don't you ?

Yes. arrrrgh

A stump.

Why would it look any different? I mean, it doesn't matter which way your knees and hips bend, you can still sit.

well why not just sit in like a chaise lounge type chair? that way you dont have to bend your legs at all. even if your legs bent the wrong way at the knees, you could still sit with your legs extended (like laying down) out in front of you.

if you knees did bend at the wrong way, like SP says, you could still sit down... you'd just be looking at your feet

Would these "humans" be walking on all fours?

Quote:

Originally posted by pornversion

Would these "humans" be walking on all fours?

obviously they just walk backwards

Sorry but this problem should actually be handled by a structural engineer which is what I am. The chair is a structure where as the body is the mechanical side of the probmlem. If you were designing a body to fit a chair then you would need a mechanical engineer.

The question that needs to be answered is not about how the knees bend it is how the waist in jointed. If the waist is jointed in conjuction with the knees then the chair would look like a stool. The lower half of the body would sit the same way but the upper part of the body would be facing the direction of where the back of the chair would normally be.

If you girls are going to sit on your butts, the mechanics of getting to that seat are quite a bit more difficult than you are making it.

Quote:

Originally posted by jandmredclouds

Sorry but this problem should actually be handled by a structural engineer which is what I am. The chair is a structure where as the body is the mechanical side of the probmlem. If you were designing a body to fit a chair then you would need a mechanical engineer.

The question that needs to be answered is not about how the knees bend it is how the waist in jointed. If the waist is jointed in conjuction with the knees then the chair would look like a stool. The lower half of the body would sit the same way but the upper part of the body would be facing the direction of where the back of the chair would normally be.

Unless you are sitting on your pubic bone vs. normally sitting on your sacrum (for lack of better terms) I don't think this is correct?

Without re-orienting the butt and pube, I am not envisioning the ability to "sit" down with knees bending the opposite direction.

To make this simple, just try to imagine finding a way to sit on your pubic bone. Assuming normal average human physiology, I'm not seeing how it's possible?

Answer; Any body who mentioned lounge chair is correct. Class dismissed.. lol

Quote:

Originally posted by bustMall

...

Unless you are sitting on your pubic bone vs. normally sitting on your sacrum (for lack of better terms) I don't think this is correct?

Without re-orienting the butt and pube, I am not envisioning the ability to "sit" down with knees bending the opposite direction.

To make this simple, just try to imagine finding a way to sit on your pubic bone. Assuming normal average human physiology, I'm not seeing how it's possible?

If there were a proper counter balance then a person could sit on their pubic bone. The waist down being rotated 180 degrees would allow for this to happen.

If only the knees were jointed in reverse then to be the most efficient we would have evolved in to walking on all 4 limbs.

yup - but that wasn't the question..lol

Even with the lounge/chaise/whatever, as I see it, you would still need to lie on your face to effectively get down and get up. Once on the lounge, you could roll over, but that's the only option I can envision without any other physiological changes.

Fun exercise Dog.

yvw

If the knee bent backswards, how would they sit?? I mean the actual movement of sitting...
How would they get down to the chaise?