Perform his simple stretching routine daily to stay fit and mobile for longer.
If it is not comfortable for you to be on the floor, check out this video instead: https://youtu.be/zrtZsqETvyI
If some of those stretches feel too hard to you, good news: you just identified the ones that you need to work on the most!
Stretching is a personal practice that requires some knowledge of anatomy. Tight glutes or hamstring can cause back pain if not identified on time. Worse, some long-time untreated joint unbalances can cause permanent impairment like disk bulge or bad posture.
Please talk to your PT or physio if you need help. Or contact me on Facebook through my group "fit and fun life"