Calculating Leverage & Force in Lower Leg Squat

[tomlib]

How can I calculate the leverage on the lower leg during a squat and the force that the thigh muscle must exert in order for the body to perform the squat. Can you help me?

 

[Lnewqban]

Please, see:
https://squatuniversity.com/2016/04/20/the-real-science-of-the-squat/

 

[A.T.]

How can I calculate the leverage on the lower leg during a squat and the force that the thigh muscle must exert in order for the body to perform the squat. Can you help me?

You have to look up the effective lever arm of the quadriceps at different knee flexion angles. It varies based on patella anatomy, but is roughly around 5 cm. The external torque can be computed from the ground reaction force, by inverse dynamics (if you care about the shank and foot mass), or just from the knee position.

 

[tomlib]

I would not count the torque, I would like to stick to the classic distribution of forces by vectors using trigonometry and crank calculation. Unfortunately, I don't have such an opportunity to understand everything. This movement seems unrealistic to me.

I saw how much work it can be to raise a sail for windsurfing.
When applying this model, the rope is actually in line with the boom, such a force is impossible.

 

[A.T.]

This movement seems unrealistic to me.

A simple squat?