We used to do all sorts of things, like dynamic stretching and loading while stretched. I especially remember various drills for hurdles and jav. It's important to remember to do them for both upper and lower body, even if applied to only running and not throws.
In particular, I remember seemingly endless lunges, forward and backward, and really high box steps, using a large barbell with as much weight as you can take.
Also we had this special machine that was custom-made, that would work your hams and glutes while you were standing--there are commercial equivalents now in some gyms that I have seen, but they don't enable the same ROM, unfortunately.
Also dips with tons of weight, all the way down, to really stretch the chest. Stuff like that.
The stuff did wonders for the jav guys, who were always trying to increase their dynamic range, and the vaulters in particular.
It needs supervision, though, and a careful build-up, to avoid injury. The point is not necessarily to USE the entirety of what you build, just to increase the available envelope.
Yes, yes, I know that sprinting is basically defined by force application to the ground, and that power development at extreme joint angles does not seem to be directly applicable. But although perhaps not a maximum at extreme joint angle, force production does begin at that angle, and foot speed upon hitting the ground is dependent in large part upon the magnitude and time of force generation throughout the leg swing.
That gives better foot speed--and at top speed in a 100m, that is what you need. Force application to the ground, if I remember correctly, is not as great a factor at top speed, because inertia plays a large role, and the only "extra" force that must be supplied is that sufficient to overcome drag from basically the air resistance--which, at 25mph+, is not insignificant.
That is why you hear of 100m guys trying to not slow down in the latter half of a race. The required energy system starts to crap out, force production throughout the leg swing lessens, and foot speed slows, and the runner slows. Trying to conserve some energy earlier in the race can be a good strategy. Trying to increase the time available for the foot to reach top speed is another strategy that is used.
For some (only for some) 100m sprinters, developing more force at extreme joint angles can be beneficial, or even absolutely necessary to achieving a longer stride. I think that Collins is one of those sprinters.