DougNZ wrote: [M]y central question: should the core be engaged early in the tipping and fitting phase by sinking the knees forward or should tori search for a contact point with his/her butt in the squat position?
I haven't been around for a while, so pardon my revival of this thread, but I think I can be of assistance to Doug
Generally speaking, there are two types of squats based on the "what moves first" analysis: hip-break and knee-break. If your hips move first (even just a little) before you bend your knees, it's called a hip-break squat. If your knees bend first, even if only slightly before the hips, it's a knee-break squat.
If you look at the following picture, I assume you're talking about something equivalent to fig 1) vs. fig 3)
In 1) we see an "Olympic squat", or what I above called a knee-break squat. This features a more upright torso, suitable for a front or overhead squat, and with transfer value to the Olympic lifts such as clean and snatch. The consequence of an upright torso is greater forwards displacement of the knees in order to achieve a valid depth.
In 3) we see the classic back squat usually performed by American powerlifters. This builds on a hip hinge (or "break") as the first part of movement.
(Note that it is of course possible to do a hip-break upright torso squat and vice versa, but this is very uncommon)
Here's a breakdown of muscles used in the two, courtesy of nsca.com:
- Emphasizing quadriceps size and strength, since the body position can remain more upright
- Suitable when working using lower loads and higher repetitions for more time under tension because the range of motion the knees and hips go through is great (if you have the ability to squat deep)
- Emphasizing the hips, hamstrings, and low back, since the torso stays more forward.
- Well suited for female lifters, since girls tend to already be more quadriceps dominant; focus should be on their lower body in order to train towards balancing their quadriceps strength with extra hip and hamstring work
- Does not require great ankle mobility
- Requires great shoulder mobility
Now, if the only thing required was simply to power an opponent directly upwards, there would be no discussion. It is a scientific fact that more forward knee travel has two important implications for powerlifting technique: 1) a longer range of motion and 2) more leverage is shifted to the knees instead of the hips. Thus, for more or less every normal lifter whose aim was to lift the most amount of weight, the recommendation would be a hip-break squat (complimented with a low barbell position).
However, in judo we are usually adding another vector to the equation. It is not simply a matter of lifting the opponent upwards. Furthermore, if one enters with a hip-break movement in mind, unless very skilled at kuzushi
I postulate that a lot of times one will end up with a) having to begin kake
from an angle where the arms and shoulders are working under suboptimal conditions, or b) having the opponent bend at the hip making him much more difficult to throw.
(Of course, I'm generalizing here, as there are a gajillion nuances to every technique)
Based on the above, it makes sense to recommend a knee-break squat at least for techniques such as seoi-nage
Last edited by cuivien on Mon Aug 25, 2014 5:56 am; edited 1 time in total (Reason for editing : adding a bit of information)