Forget about using RA numbers to tell you if a racquet is arm-friendly. The Volkl V1 Classic has an RA of 69 and yet is the most arm-friendly frame still on the market. It even felt softer than the newer Organix series with lower RA numbers from Volkl. OTOH, I've hears some reports of racquets with RA numbers way down in the 50s that are brutal on the arm.
If think that I'm blowing smoke up your shorts, demo the Volkl V1 Classic racquet from TW. While stiff racqets tend to produce more frame shock, it does not tell the whole story. In the end it is not the stiffness that will determine if the frame will be harsh on your arm -- it is how well the frame shock is dampened or how well it is prevented from reaching your arm.
Last edited by SystemicAnomaly; 10-04-2012 at 11:31 AM.