First, I personally am not a fan of partial ROM movements, especially when combined with very heavy weights. It works for some people, and that's fine for them, but I don't use them – but that's my opinion. It's a big world and everything works for someone, it's just not a tool that I like to use. So, I don't like 1/4 squats even though I know a lot of t&f coaches swear by them. Yes you can do a lot more weight, but I find that form breaks down during those 700 pound 1/4 squats and I've seen more back injuries from those than I care to think about.
I've actually found the same thing. I only do partial ROM squats about 1 cycle a year and they are always supplemented with deep squats in the same session. When I do use the partial ROM stuff, I prefer to do it more elastically and limit the load to no more than 120% of max full squat.
Second, I don't like situations with supermaximal amounts of weight either – so eccentric squats with 150% of your maximum squat. Again, we all have good intensions but form breaks down too badly.
As I said above, I've only approached that one time and I really didn't like it. As with the partial ROM stuff I typically stay in the realm 105-115% for supramaximal work. At these loads I haven't noticed any technical detioration for eccentric work however all of these techniques are things I reserve for athletes with at least 3 years of serious training. In fact, research evidence suggests this is actually the strength capacity for eccentric force production. That is, what we are calling maximal is really a reference to an athlete's concentric maximal strength….there eccentric maximal force capabilities are actually up to 25% higher. As a result, I think it's perfectly safe to use loads that are considerably (though reasonably) above the concentric maximal load. In fact, because of the differential between concentric and eccentric maximal strength capabilities (with eccentric being so much stronger) I would actually think that using 60-65% of concentric maximal load wouldn't be sufficient to provide an adequate stimuli.Using a load that is 60-75% of concentric max for eccentric lift work would actually be somewhere in the neighborhood of using a load that is about 50% of eccentric maximal load.
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