Gran, this is for you!
Here, I show some basic shoulder, elbow, and wrist/finger movements to help move blood through your body to warm you up and improve mobility. There are some moves that will help your brain get co-ordinated too!
Position yourself carefully with ankles under knees. Sit towards the middle or edge of your chair.
Move slowly. Nothing should hurt. Do less than me if you need. Breathe naturally. Relax your face. Be calm. Enjoy moving.
At the end just close your eyes and see if you can feel that your shoulders are warmer, your upper back is warmer, maybe even your finger tips are warmer.