Polyester strings have wrecked more elbows than anyone admits

The string that made modern spin possible is also the stiffest thing most club players have ever put in a frame.

Ask a coach why your elbow hurts and you'll get a lecture about your backhand. Late contact, arming the ball, wrist collapsing on the follow-through. Sometimes that's the answer. Very often the answer is the fifty grams of plastic strung across your racket at a tension you copied from somebody who hits the ball twice as hard as you do.

Polyester changed tennis. It's a stiff, low-powered, high-friction string that lets the mains slide and snap back, which is where a big chunk of modern topspin comes from. If you're generating serious racket-head speed it's brilliant, because the string bed's lack of power stops the ball sailing long and you can swing as fast as you like. That's the trade. You give up comfort and free power in exchange for control at high speed.

Now consider the weekend player. Slower swing, flatter contact, and the same string at fifty-four pounds because that's what the shop strings everything at. The string bed doesn't deform much, so the frame and the arm absorb what the strings should have absorbed. Every off-centre ball sends a shock straight up the forearm. And polyester goes dead within about ten to fifteen hours of play, well before it breaks, which means most people are playing on a string that has quietly become even stiffer than the day it went in.

That last part is the bit nobody knows. Players change strings when they snap. If you don't break strings, you may be playing on a plank for six months.

The practical fixes are dull and effective. Drop tension. Genuinely drop it, five or six pounds, not two, and accept that the ball will fly a bit until you adjust. Try a hybrid with a soft multifilament in the crosses, which keeps a lot of the spin behaviour and removes a surprising amount of the harshness. If you're not breaking strings, cut them out on a schedule anyway. And if none of that helps, look at grip size before you look at technique, because a grip that's too small makes you squeeze, and squeezing transmits everything.

Pros restring constantly and adjust by a pound or two for humidity and altitude, and the copying of that behaviour by amateurs is mostly harmless theatre. The part worth copying is the frequency, not the tension. Fresh string at a sane tension will do more for your arm than any amount of video analysis of your takeback.