Mighty Kat, a fellow Oregon Olympic Weightlifter (and current state champion in her weight class), has an article up at Weightlifting Exchange entitled, “Six Tips for the Overhead Squat.”
The overhead squat is a pain in the ass, literally! But, it’s the first exercise that I tend to have people do in the gym. I give them a stick, do a demonstration, then have them try and “repeat after me”. I can learn a lot about where a person’s current level of fitness is by how well they are able to perform this exercise.
If they let the bar drift too far forward, or if their arms remain bent throughout, then I know they have shoulder flexibility issues. If they let their heels come up off the floor, then I know they have ankle and calf flexibility issues. Some times people will literally shake while performing an overhead squat. This can be from a number of causes, but foremost among them is a lack of stability strength and balance.