Please Scroll Down to See Forums Below
napsgear
genezapharmateuticals
domestic-supply
puritysourcelabs
Research Chemical SciencesUGFREAKeudomestic
napsgeargenezapharmateuticals domestic-supplypuritysourcelabsResearch Chemical SciencesUGFREAKeudomestic

Physics/Kinesiology question just because I'm curious.

B

bottleneckblooz

Guest
I've always wondered this for some reason. Let's say you are doing bodyweight squats. Your quads are doing most of the work to lift the weight of your body, minus your shins of course. So if you had to calculate the exact amount of weight your quads are lifting, would you include the weight of the quadriceps muscle itself? Or would the weight of the muscle be canceled out because it is doing the work?
 
bottleneckblooz said:
I've always wondered this for some reason. Let's say you are doing bodyweight squats. Your quads are doing most of the work to lift the weight of your body, minus your shins of course. So if you had to calculate the exact amount of weight your quads are lifting, would you include the weight of the quadriceps muscle itself? Or would the weight of the muscle be canceled out because it is doing the work?

The bones, muscles, and connective tissue are part of the lever system doing the lifting, so no you can't include the weight of the muscle.

It would be analogous to including the weight of a floor jack to the what it's lifting.
 
You would include your upper body weight though.

and gloves.
 
It's going to be a gradational factor. You have to include all weight above the pivot point (ie knees) but as the lever changed in length the weight changes.

To simplifiy imagine putting a weight bar in a corner and picking it up. It is a lever and an object of mass so it requires force to pick it up. The bar can be seen as your femur and at it's most horizontal point the weight at the pivot is at a minimal and the weight at the end of the lever is at a maximum. As the lever goes up the weight shifts from one end to the other. So imagine you being on the end of the lever pulling a rope to raise the lever. Even though you are attached to the lever you still have to raise your own mass in a progressive lessening of force as the lever approaches vertical. In the vertical position all the weight is now on the pivot so no force is required to move the bar.

Cheers,
Scotsman
 
Top Bottom