What kind of physical therapy or recovery is needed for someone coming out of a coma of a few months' duration?
Heads up: this answer may not be what you want it to be. I’m sorry about that.
In my experience, most writers look to coma as sort of an ultimate plot device, a way to remove a character from the world of interaction. They try to turn characters on and off like lightswitches, which simply isn’t the case in the real world.
Let me tell you, friend, if your character has been in a coma for months they are permanently brain damaged. Healthy brains might take short breaks; anything from a few seconds to a minute or so (fainting) to a few hours (sleeping), but brains that cannot be conscious for months at a time are damaged brains. Your character may have speech impairments, severe cognitive deficits, the inability to remember basic skills like brushing their teeth and using the bathroom. They may have damage to areas of the brain that control speech, or language, or motor function. They may have severe personality changes due to damage in the frontal lobes.
This is a brain that has just barely survived some terrible tragedy. Your character won’t just wake up like a lightswitch one day. It will be slow, and take weeks. They’ll have to relearn almost everything again, but this time with an older, less plastic brain that might have serious wiring problems.
As for the physical rehab, as you asked… That’s going to
depend a lot on the patient. How much they can move, how their fine motor
skills are. Depending on what caused their coma, walking may be possible, or it
may not. Being still for so long causes issues. Expect them to likely have
diaper rash, potential bedsores. They might or might not actually lose weight,
because their feeding will be very careful—no munching on Big Macs in the neuro
ICU!—but the muscles will atrophy significantly from lack of use. Physical
therapy will be done to start getting strength back, very slowly. They’ll start
off with very short distances on a walker (if they’re able), then further and
further, typically with a nurse or a PT. Eventually they’ll be able to walk 20
feet, then 50, then 100, and more.All of this is also going to be modified based around what their brain is capable of, and whatever injuries their body took when they got into the coma in the first place.
I am not a physical therapist, so beyond that I’m not really sure. I’ve heard a lot of good things about working in warm baths with patients, because the water helps with buoyancy and increases resistance a little bit while people are walking, but I don’t know what the inclusion/exclusion criteria are, how much/how often it might be done, etc.
I realize all this is probably not what you were hoping for as a writer. I don’t mean to make this all sound crazy bleak, but the outcome for patients with prolonged coma IS bleak. I hope you, and other writers, have the courage to convey it that way.