Originally Posted by benchmark00
If you're worried about ****s getting back injuries, a bigger problem you should be on the look out is the angle of the bowler's back foot when it lands, especially if you're coaching younger kids who are wanting to bowl fast (easier to get them early).
Get the kid to bowl a few balls and watch his back foot closely each time. If the back foot lands and is parallel to the crease, he's a side on bowler. If his back foot naturally points down the pitch, he's front on. Back problems happen when the bowler is neither of those things and instead his foot is pointed 'diagonally' or sort've towards backward square leg to a right hander.
If you have a kid like that, then you need to change his action or he'll get bulk back problems. If you're unsure which way he should go (front on or side on) get him to sit down on the ground with his legs together and out stretched, then get him to bowl a ball. If it's easier for him to bowl towards his legs, he's front on, if he finds it more natural to bowl at a 90 degree angle to his legs, he's side on.
In terms of what a collapsed back leg looks like in a fast bowler, look at Shaun Tait.
Thanks for the help, the sitting down and bowling test sounds pretty good, can't say I've heard of it before. I'm coaching kids at U/12 level, and they all want to bowl fast, so I want to make sure none of them end up with back issues later on.