I have a client with early onset osteoarthritis and has had several operations – (wrists, neck, foot). She now has degeneration in her right hip but does not want surgery any time soon. Would use of the foam roller on all of the areas around the hip be beneficial and advised in your opinion (if client can stand it?)
as a MELT instructor, I use soft foam rollers on all my clients and I teach classes with participants that have probably conditions like the one you describe. It is okay and indeed very beneficial.
Having said that, I would suggest that you acquaint yourself with the MELT technique. The soft roller and the length technique are very different from the white or black hard rollers that are still commonly used,