My dad is 74 years old and has rheumatoid arthritis. My mother told me that he is having trouble standing/walking because his legs are so weak. He was using the walking trail close to their home but was having problems with his legs giving out and he would fall. She wanted to get him a treadmill or a stationary bike. I'm not sure what to suggest since he has never really "exercised" that I know of. He isn't sedentary - just not into fitness.