used to hit with an former ATP player and had my rackets at 67 lbs kevlar mains and gosen syn crosses. I'm pretty strong with a 1hb and super loose arm, never muscling the ball on serves or groudies etc. Work got in the way and after years of not playing I ordered the head LM MP cause it was cheap and strung it with 60lbs luxilon. Now my arm is starting to hurt a little and I've heard the luxilon loosens up fast but so far it still feels really tight. Now I've strung my rackets as high as 70lbs and mechanics aren't my problem. I'm wondering if a lot of people are having arm problems with luxilons? Because IMO I would be one of the last people I would think who would have arm problems. I'm wondering if it's the dense 18x20 pattern or the luxilon or both?