http://upload.wikimedia.org/wikipedia...n_Sequence.JPG
Mike Austin frame 8
http://perfectgolfswingreview.net/FofH-Hogan.jpg Ben Hogan
http://progolferdigest.com/wp-content...lesteros-4.jpg Seve Ballesteros
http://forums.iseekgolf.com/images/up...006c5c52fe.jpg Moe Norman
all of these great golfers had Reverse C. You definatly saw it a lot more in older golfers than more recent golfers. The reverse C appearance happens because the head is left back and the weight/hips shift forward and your trailing leg is kinda not important and completly passive as it dangles there and completing the bottom portion of the C, your back really isn't bent that far like a C, its just leaning back. Look at hammer throwers, they are leaning back like 45* when they release their hammer but they don't fall because that hammer pulls them up, if they hung their leg back there is would create a C look as well. There reason for that is that older goflers (ones using the hickory shafts) needed to use centrifigul force to hit the ball. Now since we have graphite and steel we can load the shaft up alot more and use compression to send the ball. If you tried to compress only back in hickory days golf would be and even more expensive sport than it already was. James Braid is one of the well know centrifigal method users and he recoreded a hit 398 using hickory and a gutta percha. If you could find any pictures of Ted Ray or Harry Vardon or James braid please let me know as they are very hard to come about.
If you see it worked, then why don't you see it as much today? I can't say for sure, but if you want to hear my guess... Have you ever heard of the saying "throwing the baby out with the bathwater)? I think that when people saw the swing they tried to imitate it based on visual only. It is one swing that is very hard to try to math visualy as it has many illusions to it. I think that when people attempted to match this swing visualy and without proper instruction or thought they ended up messing their backs up big time. So people said, this is bad for your back, we need to think of a new method to hit instead of trying to fix thier swing and threw away that method. Now the popular swing methods will cause problems to your knees and people are again trying to change the swing. I think that is why clements has a good method as it illudes to the centrifigal use though it is not 100% like it.
If you look at fram 8 This is a dynamic postion from a baseball pitcher which cannot be attained while static and cannot be held for very long either. Mike Austin hit his record 515 yard drive at age 64 which did have tailwinds and maybe got a good bounce and some don't belive it whatever. The man had a top swing speed of 155mph (compared to Tigers 125ish) and a cruising speed of 130ish. He hit the ball well over 300 into his 70's including averagein 308yds at age 74 in 12 differnt long drive competiions and he was just as accurate as he was long. and i know of a few 65+ people that can drive 300+ using this method.
http://cache.kotaku.com/assets/resour...ngpitching.jpg
If a baseball pitcher is pitching correctly he usually throws our his shoulder as the most common injury and the ball is pulling his arm out of his socket and that painfull looking picture of the all of that stress on the elbow is very very rare to be the site of an injury. As in golf if done correctly the centrifigul method very very rarely involves back pain though it looks very painfull it is not a static nor held postion.
now a reverse C is good when used correctly. not shifting your wieght through and keeping it on the back foot will cause more of a "h" i think, the back will be strait and the front leg out and that is jsut logical absurdity. if you wanted to hit a guy really hard, you wouldn't move backwards as you puched him, you would negate all of that forward force and you would have no balance ect. I don't know where the school of though came from that advocates weight moving backwards in the DS.
This was actually shorter than my 1st one but i kind of lost my train of thought.
So in summary, The reverse C looks a a lot worse than it is, and it is not not held for very long and it in itself is not bad for your back. It is the twisting torque, that whole "x factor" BS that is terrible for your back. And yes a reverse pivot is bad and if you think about it makes no sense from a physics standpoint nor a biomechanical one.