The best racquets for playability and for being arm-friendly tend to share the same characteristics, such as being heavier with a head light balance and are very flexible. After a lot of research I have found
(Dunlop Biometric 100)which has a 59 RDC flex rating, weighs 11.8 oz and has a -7HL balance
(Prince EX03 Tour)which has a 54 RDC flex rating, weighs 11.4 oz and has a -6HL balance
(Babolat Pure Storm) which has a 58 RDC flex rating, weighs 11.9 oz and has a -10HL balance
a few other great choices would be:
HEAD-Youtek-IG-Prestige-MP which has a 63 RDC flex rating, weighs 11.9 oz and has a -6HL balance
Wilson Prostaff Six One BLX which has a 63 RDC flex rating, weighs 11.6 oz and has a -7HL balance