Any good animator should use primary references to inform their movement choices, even if that's simply observing movement first hand to get a rough idea. Analysing captured video reference is a step further to then stylise that movement into your own unique piece of animation.
Below are some suggestions for where you can find some good online sources for movement reference, as well as some of my own, but I'd always suggest to capture your own reference footage to study.
Additionally, lower down, I have included some fun secondary references to old and lesser known TV shows and movies that you may or may not have seen, but might provide some interesting research that might inspire you.
Line of Action
Draw This
New Masters Academy
Gesture Drawing Party
TV Shows and Movies you may not have seen
ANIME
CHINESE
AMERICAN
CANADIAN
EUROPEAN
multi-international
BRITISH
ARABIC
AUSTRALIAN