Seated low impact movements, coordinated with breath, to increase flexibility and strength, circulation, coordination, help to reduce risk of falls with improved posture and balance, to increase confidence and self-esteem, and have some laughs.
Pick out a good chair. The best chair will have a straight back and will be stable. Please, no wheels! Leave the rolling chairs in the office. You'll want something with a comfortable cushion, but not a deep armchair you'll disappear into. A sturdy kitchen chair is a good choice!
It is required that in any advance starting any movement practice, you must have a discussion with your doctor. You must honor all medical guidance in any movement session, including level of exertion, range of motion, and length of practice.