The main danger is doing stuff you are not supposed to, like bending the hip at more than the allowed angle, which might possibly loosen up the prothesis. Worst case scenario: had a patient faint, and do some serious damage to the hip when she fell.
But as long as you are doing EXACTLY what the doctor and physio says to do, you should be okay. You (or whoever the patient is) should be asking them this question. They are the ones that know the situation the best. Please seek their advice.
Its true. I am there myself right now (at the age of 21 yes). Had a serious hip operation about 2 months ago. I will say it is very difficult to stay still and do as the doctor says but yes you can do to much. It is very easy to damage what has just been repaired by doing even just a little more than the doc has allowed you to do.
It really doesnt take much.
Pushing too hard after any surgery can have negative consequences. Especially after THR. Post -operative rehab instructions are given for a very good reason. It doesn't take much to 'pop' a new prosthesis. That's the reason for use of 'Charnley' pillow while in bed PO, and why pt is not to bend/flex etc too soon.
I recall a patient (a chiropractor if memory serves) who had an honest to goodness charnley total hip. You'd think she would have some modicum of anatomy etc. Anyway she climbed a ladder hanging curtains in her new office. Guess what happens when you lift that side up to the next rung. Yep outta place.
Another patient of the same doctor got drunk and climbed under the kitchen sink for some reason or other and yes outta place. That one had to be in traction for about 6 weeks because of all the tissue trauma. Then had the total redone. That was one angry doctor.
All the abduction pillows in the world won't protect a patient from stupid.
Have you had a replacement and are asking?
Did you get physical therapy after your surgery? PTs and OTs will drill into your head the do's and dont's ( 3 big ones.......bending more than 90 degrees at the hip, pointing toe internally/rotating hip internally/crossing legs)
Try and gain your quad strength back and your hip abductors and flexors as the typical hip protocol exercises teach. Use your walker/crutches as long as you need to until you feel safe. Don't sit in low or soft chairs/sofas.
Not exactly sure when you ask about doing too much......if you could be more specific that would be great!