Updated: Apr 9, 2020
Here is a Gentle Seated Stretch for you to try out. While I am sitting on a weight bench, I would recommend that you sit on a sturdy chair with a back and possibly arms for support. You want to warmup if you are not just finishing your exercise...a few minutes (3-5 min) of walking around your home with a few arm swings will be enough to prepare you for your stretches. Alternately, you can always warm up from a seated position with some marches, leg slides and some upper body movement like arm circles etc.
Have a look.....Let me know how it feels to you.....and feel free to post questions you might have for me. https://www.youtube.com/watch?v=uEygpj72ZSI&feature=youtu.be&fbclid=IwAR3Y2xzj6RCf3CrxwUEbahw-UnbRuJnO6V-BCNAz4PO6W2gy7B7GPYr7qfM