With the Phoenix Suns clinging to their playoff lives in the Western Conference, star point guard Steve Nash insists his back feels "the best it's felt in a decade." Nash, who turned 38 in February, also told ESPN.com in a phone interview before Tuesday night's game in Sacramento he intends to "sign for three more years this summer" and play beyond his 40th birthday when he either inks a new deal to stay with the Suns or finds a new team via free agency.