I think the solution here is obvious…a battle to the Death between Greg and I, all on the internet with name calling and incendiary statements. That or a pie-eating contest. Ok, Greg would win both of those so I guess we will just have to “talk it out”. In all seriousness, Greg’s response pretty well covers it. We are really looking at an integrated approach here.
Let me use an example: We had a power lifter working with us who was very strong but had so many soft tissue problems it was stunning. The guy absolutely could not do an OL style back squat, full range of movement push-ups or even lunge! Hanging fully extended from a bar to do pull-ups caused searing pain in his shoulders so all he would do was half range of movement pull-ups. Now this guy was VERY strong in the ROM he had but he as an extreme injury risk if you took him slightly out of his highly limited functional zone. This guy needed incremental increases in his ROM under reasonable load (some situations that meant a 45lb bar) but he also needed specific flexibility training, soft tissue work from an Active Release Practitioner to break up adhesions and scar tissue…and more patience than he could ultimately muster.
Now, as to your second question of when do you need flexibility training to get clients into a safe, biomechanically sound squat…if they can not do it, they need additional work! Tight hamstrings, hip flexors and calves are the major players here and I can guarantee you that if they do not have this natural ROM they do not have healthy posterior chain activation. We will be looking deeply at these issues pertaining to pre/re-hab in future Performance Menu issues as well as other media.