# The Mechanics of the Body (Specifically, masses and torques)

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I'm not sure that this belongs in the Math and Physics forum. I'm looking for typical Masses of human body parts, specifically things like a foot, upper leg, lower leg, etc. Also, I'm interested in how much torque each of the various joints of the human body (again, the major ones, knee, ankle, each degree of freedom for the upper leg joint etc) are typically capable of exerting. Are there any resources that anyone knows on this (published or online)? I've tried searching. Maybe I'm using the wrong keywords but I keep getting directed to BMI charts etc.

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I suppose you could roughly calculate the mass of specific body parts. Find the volume and mass of a typical human, and from that you can get a "flesh" density number. Then use the volumes of the individual parts you want to get the mass. It should be close anyways, there arnt alot of human parts that arnt made up of some fraction of bone/muscle/fat so I wouldnt think the density would vary *that* much from part to part.

The other option involves a group of girl scouts on a hiking trip, and a chainsaw, but I wont go into that one.

As for the second question, what do you mean by "torque the joints are capable of exerting"?
If it's a joint then it doesnt really exert any torque, it just provides a pivot to hold things together, while the muscle creates the torque via the bone-moment arm. If you mean "before they break" then I think it's more related to side loadings/shear forces than torque.
If you want this for the average strength of a person, you could probably figure it out using some basic trig and weights. Figure a average person can curl anywhere from 25-40lbs, and their arm is X length, you can come up with a torque figure from that for upper arms. Then work it through for different leg muscles, etc.

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An idea.

Go to a fitness studio and ask for average weights used for starters.

For each training equipment you can find a value, some ( not all ) equipment is specifically for a certain muscle.

This may help.

( Maybe you can also check the equipment manufacturers web site, but I don't have links handy. )

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These two links might be useful.

Grays Anatomy
Myology

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