I just got back from my first match in 13 years. Something I noticed was that the inside of my forearm, near the elbow got tingly after the first set and proceeded to get almost numb. To clarify the location, if you face your palms upward it is locate in the muscle on the right side of the forearm. I seems that my service motion is causing it because I don't feel it, except the weakness in the entire arm itself, during groundies. I was definitely bombing my serves today, but it also seemed effortless. I wasn't struggling at all and my arm and grip were loose and comfortable during the entire motion. Has anyone ever heard of anything like this? It doesn't affect anything went away an hour after my match (the same as the 3 other times this has happened). The only time it gets tingly is during the serve. Anyone have any idea what this could be?