Recently, whenever I straightened my arm while holding my racket pointing forward and hold on to this position for a while, I'm experiencing much pain on my elbow. This has never happened to me before. I can still ignore the pain and carry on playing but I'm afraid it may become worst. I've been playing tennis for more than a decade and been using PSC 6.1. What could have caused this pain? Is it tennis elbow? Any kind advise would be much appreciated. Thanks.