First of all, I want to start off by saying that: if you have good strokes, you're not going to get tennis elbows or other forearm related issues. Now, why am I posting this? Recently, I started experimenting with polyesters as a full bed and as a hybrid in the mains. I usually play exclusive with gut/poly hybrids and I recently ran out of gut, so I thought I'd experiment with having polyesters in the mains and see what all the "spin and control" raves are about. Here are some background information: TW reissue Wilson Pro Staff 6.0 85, MSV Co-Focus 1.18 Gut/poly strung at 55/51 Full bed strung at 48/46 Poly/syn gut strung at 51/48 Trend is: I lowered my tension with having polys in the mains. I think I know why there are so many accounts of polys and arm problems. It comes down to the lack of power coming from these polys. Because of this lack of power, you need to hit harder. And of course, generating more power will stress your muscle groups more. Hence, the arm injuries. Now again, if you have good mechanics, there should be minimum stress to your forearm. But let's be honest, at our level, a lot of us DON'T have good mechanics, but essentially all of us are using polys, some are using them well beyond its actual playability, and that's where the injuries come in. Because of the lack of power, one is forced to hit harder which causes the forearm muscle groups to fatigue faster. We all know tennis elbows are chronic injuries, and chronic injuries are caused by fatigued muscle groups stressed beyond their capacity. I'll sum it up with the following: Low power -> harder swings -> faster muscle fatigue -> repeated stress to fatigued muscle groups -> chronic injuries All of which are exaggerated if you have bad mechanics. Feel free to chime in. I am not in anyway bashing polyesters, I think they have a place in tennis (obviously, since I cross them with my gut). But I think the onus on the players themselves. 1) Observe and adjust your fitness - does your elbow have the stamina to withstand the added shock that is transmitted by polyesters? If not, either stop using them or work on your forearm muscle groups. 2) Observe your strokes - Do you ACTUALLY hit with spin? Or do you hit flat like a pancake? Which a lot of novice players actually do despite claiming they're using "western"ish grips. If you're not hitting with spin, you're not benefiting from polys but taking all the abuse. 3) Finally, observe your mechanics - I don't care what strings or equipment you use. If your technique and mechanic is bad, your arm will explode. Natural gut or not. Those are my thoughts on polyesters, I will not continue to have polys in the mains anymore. I don't care for the lack of feel, nor do I care for the lack of power, and dead polys are a b**** to play with.