My aunt is an oncologist in South Africa. She became ill several years ago. She was so ill she had to have a chair lift fitted and my uncle once commented that if she were an animal we'd be merciful and put her out of her misery. Luckily he didn't because she made a full recovery in only two years!
She worked with a physio in SA. She started by making herself walk one metre a day. She maintained this and then when stable increased it. She did this until she could walk up her own hallway. But the thing that she thinks made the biggest difference was the water therapy. This was what the physio really helped her with. She started by spending 1 min in a warm pool three times a week. When she had maintained that for a month with out getting worse she upped it by a minute. Sometimes she maintained that time for a month, sometimes she maintained it for a week depending on what she and her physio felt was right. She says that when she started this it made the biggest difference. She would walk in the water until she got to being able to stay in the water for 15 minutes. Then she started to swim alternate visits. In this way she has made a full recovery. She is the fastest recovery the physio knows of but she has seen a few other people fully recover using this approach.
I think the water does two things. If you are experiencing Orthostatic Intolerance where your blood is pooling in your feet and the lower part of the body - and some doctors think 80% of us will experience it with all its other symptoms - the pressure, the weight of the water is helping to close the blood vessels down etc and push the blood up into the rest of the body. Secondly, I think that because the brain, the nervous system, etc is in freefall the sensation of the water on the skin, combined with the pressure confuses the brain. It means the skin is sending different signals to the brain about what it is sensing, distracting it from sending messages like tingle, thrum, adrenalin release, heart rate speed etc. I will blog again about my experiences of water therapy. I am finding it very helpful.