Imagine trying to cook your dinner while balanced on one foot, do you think you will be able to reach up or down to get the plates that you need without wobbling or falling over?
It's much easier if you have both feet on the floor.
Now, I'm not suggesting that you cook your meals laying down.
What I'm saying is that it is much easier to do things when you are more stable and balanced.
Laying down on the floor gives much more stability to your whole body than if you were standing. Therefore, you are going to be able to do more with your body.
It might seem silly but getting up from the floor is an important skill to have.
Being able to do it in a variety of ways and taking your joints through new and novel movement patterns will help you to regain mobility, strength and freedom to move.
Starting on the floor provides your body with a stable platform to perform a greater deal of movement than it would if you were standing.
Try this series of movements as I describe in the video