ask your MD for a physical therapy referral, then ask the physical therapist how best to position your body when sewing, they can come up with some amazing ideas! also make sure that you are taking rest breaks, not sitting for too long, try to sit straight to the machine and not lean over to see what you are doing, make sure you have plenty of light. take your pain medication about a half hour before a sewing session. Hope some of these help, arthritis is a (rhymes with witch), and I have it in both knees