how to restrict muscle movement in humanoid in unity

Hi,

How can I restrict muscle movement in humanoid avatar in unity? see screenshot for where I mean:

I want to be able to restrict upper and lower legs so that they cannot move sideways at all… so change the available movement/angle from say 90 degrees to only 10…

Any information would be most appreciated!

Cheers,
Kim

Kind of got this sorted but did not help my final game… in the avatar muscles settings, there are sliders for each body part, this slider has two “ends” to it, you can drag each end to the middle of the slider and then you do not see any muscle movement.