Careful Rouse. I'm on the verge of learning something, but I'm not quite sure what it is just yet. Me actually being able to learn something is scary.
I'm not trying to punch holes in your point. I'm trying to get you to punch them in mine by showing what I think are flaws (and it is very possible that I am wrong) in your arguement.
You ask about the plane of movement, specifically frontal and traverse (forwards and backward for me). As you squat down, the natural tendency is for you to fall forward with a lot of weight. You essentially have to tighten your core to keep this from occurring. I have found that you have to have a very strong core to squat without getting hurt, as you alluded to.
As for watching me squat, I guarantee you will find problems so no disrespect taken. Hell, my lamentation of my squat form can be found on this web site ( http://www.exrx.net/forum/viewtopic.php?t=5441
). My squat form has been tweaked no less than 4 times in the last 1.5 years, usually do to some micro-injuries, knee problems, hip problems, lower back tightening up, etc. Additionally, I have added several exercises to my regime to help me with my weaknesses. One of the things that has been helpful to me, especially with my lower back, is for me to go up in weight. If I feel that I am falling forward or my back starts tightening up, I go back down in weight and start hammering front squats (and recently picked up zercher squats). This strengthens my core to the point that when I go back up in weight I have no problems. Same thing with my hips. I have problems with those, drop the weight and hit box squats and one legged leg presses real hard.
Maybe that is a sidebar to my point, but I put a lot of effort in my core when I am squatting. I have to in order to prevent injuries.
And agreed, most people who come to the gym compensate. Most people have terrible form. Most guys sacrifice form for their ego.
I am a firm believer (and a lot of ifs are coming up) that if you squat correctly and if you are lifting heavy for you, then you are getting a hell of a core workout. Heck, I've even felt that I had done a 1000 sit ups after heavy benching.
I just can't picture, in my mind, how heavy lifting (especially squats) does not work the core sufficiently after looking at the videos and trying to understand what you are saying. Admittedly my knowledge base is at a lot lower level. I have nothing against specific arm or core work. In fact I do arm work quite often when I have an extra day, bored and don't want to go home after work. It isn't because I believe it is necessary, I just enjoy being in the gym.
To end my long winded answer to what plane of movement is loaded, in my mind I see and picture all planes (left, right, forward, backwards and all points in between) but especially forward and reverse. I'm sorry if you are getting frustrated with me. You probably feel like you are playing poker with a 5 year old. I would love to be convinced that if I do ABC of core work, then my squat numbers would go up. While you are at it, I beg for one thing that will make my bench numbers go up as well.