When using a full bed of poly, you have to hit hard enough to make the string give at impact. The more a string gives, the more it does two things. One, it absorbs the impact, making it easier on the arm. The other thing is that the more a string gives, the more energy it will return to the ball (think trampoline).
The main reasons people choose a poly in the first place is control and durability. Poly strings will, for most people, last longer (won't break), but will, over time, lose tension. Once the string has lost enough tension, the performance will decrease, making them even harder to generate power and spin.
For some, the control aspect is about not hitting the ball long. Many players don't hit the ball long as often with poly strings but sacrifice power and depth to do so. When the power goes down, you have to swing harder, which adds to the potential of arm trouble.
So, you've been using poly but it is hurting your arm. Now what?
There are several options.
1. Try a hybrid of poly and a softer string. This will add performance without sacrificing much durability. For most, polys on the mains and the softer string in the crosses will ease the arm issues while still giving a stiffer feel (for those who like that feel).
2. A "synthetic gut" string is a middle ground string that doesn't last like the polys but offers less spring than the softer multifilament strings.
3. For those with real arm issues, a multifilament string will offer more power and shock absorption. Both things will stress off the arm and give a more comfortable feel. You will also find less of a need to have to "kill the ball", by letting the strings do some of the work and stress from your arm.
4. For those who feel they need a poly, there are some newer, slightly softer poly strings. While not as easy on the arm as the other options, it will be an improvement over most poly strings.
If you are feeling the impact of every shot in your arm, stop by our Dale Mabry store and we can give you some options to have you playing more comfortable, and hopefully, better tennis.