http://www.mysquatmechanics.com/First thing you should do: Move the slider that's on the right from Standing to Squatting.
The graph on the left shows a stick figure of someone squatting. Play around with the proportions to see how much your form is affected by proportions.
Additionally, the graph on the right is more complicated but shows interesting info that I hope people can make more sense of than me. Shows moment arm distances and such.
The summed moment may be our... sticking point? Well not necessarily (our summed moment may be largest at the point where, say, our knee moment is very high but we can be very quad dominant)