I think that this thread is getting a bit carried away in so far as the analysis. I think in general this branding of each person as quad dominant or hamstring dominant is a bit out of hand.
Here is a sprinter (albiet one of the most muscular of sprinters). He's not faster than you because of his superior posterior chain. He's not hamstring dominant nor quad dominant necessarily. Every part of his legs are stronger than yours and he's much more powerful and can run faster and jump much higher than most people. The goal is to get strong strong strong. Ideally you want to have a huge low-bar squat, huge high-bar squat, huge deadlift, huge front-squat, huge olympic lifts, be lean and train for jumping and running. In other words you are want to be a beast in the weight-room and hope it translates to the field/court/track whatever.
There are three big misconceptions about the low bar squat, besides that I don't have a problem with an athlete low-bar squatting. They are
a) That it more closely mimics the pull position and thus is a must for olympic lifters (rippetoe's claim - has been shot down by the every other olympic lifter).
b) The low-bar squat is better simply because (some) athletes can handle a larger load (again rippetoe, again makes little sense)
c) That sprinters are more hamstring dominant and therefore should low-bar squat. -> Yes, sprinting requires hamstring strength. However, the only time when ground contacts are long enough for weight room strength to carryover (the start of a race) the sprinter is using roughly equal parts hamstring/quad/glute. At top speed ground contacts are 0.1 seconds and the majority of the impulse is created by a stiff straight/almost straight leg making contact with the ground and the hamstings and glutes acting as a hip extensor momentarily to propel you forward. Unless you are really slow you don't deform and make enough ground contact to break at the hips and activate anywhere near the movement patterns that a low-bar squat provides. A reverse-hyper or even hamstring makes more sense in this case for specificity to sprinting than the LBS.
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Now the question that LBSS is really asking is specifically "is my time better spend Low-Bar squatting or high bar squatting as far as standing vertical jump is concerned". Remember, the goal is to be a beast at all of the above, and they are all related... so clearly both are good. If you are low-bar squatting and your vertical is going up and your getting faster and your becoming more of a beast... great. But which is better? I think the truth is nobody has definite proof. I'd love to see the results of a study where a bunch of fit, coordinated males with 25-30 inch vertical jumps are put on a diet of only vertical jumps olympic squats or vertical jumps and LBS for 1 year and the benefit of each squat is evaluated. In the absence of that study all we have is anecdotes. As I said before: I have seen many many more guys who have built up a huge low-bar squat despite showing little improvement to the olympic squat, deadlift, front squat, speed, or jumping ability than the other way around. In other words I have seen a lot of guys get big low-bar squats without becoming much of a beast at all. This isn't a knock especially against the low-bar squat... I have seen a lot of people with big deadlifts that can't run or jump or front squat at all. KF seems to agree with this observation. Now this article by Pendley seems to also suggest this, going so far as to say that his olympic squat brings up his low-bar squat but not that other way around. (in other words low-bar squats are superflous, kinda how I feel about deadlifts... [ another story]). Even Fred Hatfield is mentioned stating the claim that olympic squats have much more carryover in general.
So there you have it. At this point I think it's a bit unnecessary to analyze the biomechanics of why the olympic squat has been observed by so many people as having more carryover than the low bar squat. I have some of my own ideas as to why the olympic squat provides more carryover but they are really just broscience conjectures, that I don't think matter much to the argument. The bottom line seems to me that if your becoming more of a beast on a program centered around low-bar squats than by all means... continue. But if your low bar squat has gone up but your SVJ/other lifts are stagnant.... considering the observations of many other people and try incorporating some olympic squatting or front squatting into your program.
Finally, to answer Raptors old question of "What if I do a low-bar squat but I use leg-drive like a high-bar squat". Obviously the lack of carryover of the LBS relative to the olympic squat is not simply based on exactly where the bar is placed on your back. If your essentially doing an Olympic squat with funny bar placement... sure carryover is probably more similar to a that of an olympic squat. But if your coming so close to olympic squatting.... why not just olympic squat?