I blew out my back last year running and I'm still working through it. None of this stuff should hurt your back, but we've had a couple of guys who described the same kinds of problems - mainly because of trying to pull too hard with the back when turning. It may help to concentrate on releasing the musculature and letting the turn come out naturally (you may also find that you can actually turn further that way).

FWIW...

Best,

Chris