Understanding the concepts of overactive and underactive muscles (prep for CES exam)

I’m studying different exercise compensations and the associated underactive and overactive muscles that might be contributing to the problem… I really want to be able to think about the problem and apply it, not just memorize answers. Some just don’t make sense to me (even after looking at muscle insertions, origins, & actions). For example, the book states a knee moving inward on a single leg squat, overactive muscles = biceps fem(s.h.), lateral gastroc, and vastus lateralis. That doesn’t make sense to me given its actions. Can someone maybe help me find a different way to look at it so it makes better sense to me? Thx!