Well, when I ruptured the disc in my back, I had to stop practicing; then, after my back surgery, I had to learn how to practice a completely different way.Before the surgery, I would curl up on my bed or the couch, and plunk away and call that 'practicing'. Well, boy howdy, how the world has changed.
Now, I have to sit use a wooden straightback chair, sit on the edge of it, making sure my back is straight, use my guitar strap and a classical guitar footrest. I've had to learn how to hold my guitar all over again, how to place my right elbow behind the front of the guitar, how to let my left arm relax and not tense up, thus letting my fingers use their natural weight on the strings. I hold my right hand differently now, too -- more in a 'cup' position than before.
Basically, it's been starting completely over. Before I would just play some songs -- now, I have to really work on chord changes, arpeggios, fingerpicking, etc. I've had to change the way I play -- probably for the better (hahaha). After three months, I've worked up from just holding the guitar and posing my fingers over the strings, to about an hour and a half a day.
All the best, Áine