Hi onspeed…
just maybe something to add if you liked in terms of your sprinters doing maximal quad training and having the MRI’s taken etc… the narrowing of the intervebral foramen where the spinal nerves exit to form all the lumbar and sacral plexus, and then down to the appropriate musculature can also be narrowed slightly by inflammation around facet joints that then over spills into those gaps.. esp when put under so much pressure from maximal squating and other bigs weight movements..
with this in mind you could always try and ensure that the sprinters ice their backs 3-4 times per day for the 2 days after the heavy lifting.. doesnt have to be all at once… but something like 15 min on 15 min off ratio.. whether do it progressively through the day or in evenings or mornings all at once…. even though they have no back pain or anything, I tell me athletes and patients how they can have tooth decay but no tooth ache.. doesnt mean you dont have the decay.. you may find that this helps recovery and also get that decrease incidence more to the 100%…
hope this helps
Luke