So how much rotation actually is required? Well it is more than Freestyle which is about 30 degrees from horizontal. Backstroke is about 40 degrees from the horizontal and it can be up to 40 degrees, it doesn’t necessarily have to be exactly 40 degrees. The idea is that you want to have swimmers with a straight line from their shoulder to their elbow and that’s what’s depicted in this picture over here. All of these are slightly different angles, some of them are actually more acute than the 40 degrees, but you can see from shoulder to elbow, there’s a straight line on that front and under the surface of the water which means that they have enough rotation. They have a straight line and the hands are under the surface of the water, so they’re able to push water back. Once again if they were to take and just stay flat that hand would be under the surface of the water and they wouldn’t be able to get back there, without pinching the back of their shoulder which you can kind of vaguely see up in this frame is yeah, this guy’s not straight down in that straight nice diagonal this elbow is kind of a bit further back, there’s a big pinch here, same here with this one. There’s a big pinch in the back of his shoulder, due to the fact that he just isn’t rotated enough. He’s putting more stress on his joint. The last thing is that the less rotation you have, the more stress you’re going to put on your shoulder joints, and obviously shoulders are very sensitive and we need them for swimming. If your shoulder is a little sore or your shoulder hurts that really can affect your practice schedule your meet schedule, and overall just your swimming performance.