Getting Old or What?

Yesterday, H woke up in the morning and complained about his back. Apparently, he pulled a muscle in his sleep. It seemed pretty bad. He can hardly nod his head. I wonder....is the mattress the cause of the problem, or is it plain OLD AGE? Or both? Our mattress is as old as our marriage. I wonder if I should change it to a new memory foam mattress. I heard that it has pressure-relieving capabilities. Think that would help H?