Originally Posted by maxpotapov
Yes it apparently does, otherwise why everybody on tour now migrates to natural gut hybrids (last time I checked)
Rafa, Berdych, Isner, Querrey, Verdasco, Almagro, Ferrer, Tipseravic, and others all use poly. I use poly, at various tensions, I'm not a pro, I don't have perfect technique and I've never had arm injuries. Saying that poly will give you an arm injury is just as much of a sweeping generalization as saying it won't. It all depends on the person.