Sometimes when I get up in the night my body feels full of tremors, not much body control – anyone know why?
FIBH
I can barely control my body…It is a horrible feeling…
Often my knee’s bend on their own and my insides feel awful and full of tremors…all involentary?
It usually happens if I wake and get right up…happens in the night or after a nap…

Maybe you are still basically asleep…do you have any history of sleep-walking??
Occasionally, when we have not rested much in a day and we sleep, this can happen if we get up too abruptly. Try getting up slowly when you wake up, maybe lay there for a minute or 2 before sitting up or standing.
it may be symptoms of neuron disease .you have to consult with neurologist.
Sounds like your body is still in ‘sleep paralysis’ when you wake up. To prevent us from flailing around in our sleep when we have dreams, part of the natural sleep process is that the brain temporarily parlyzes the body. If a person wakes up while this is happening, it can take a few seconds for the brain to ‘unparalyze’ the body muscles and they may twitch or spasm. It feels scary, but it is totally normal.
If you are worried about it, or if the tremors seem too severe to you, definitely ask a doctor about it.
Sounds like either a sleep disorder of sorts, or some kind of neurological disorder. Please see a doctor; it could be something quite serious.
See a neurologist. This can be a symptom of Parkinson’s or other neurological disease.