A friend's parents stopped talking to him and shamed him because he applied for a handicap parking permit (doctor recommended). He can't walk much more than 100 feet without agonizing pain. He's 28. The father's words were something like "how will you feel when you are taking away that parking spot from an elderly person who really needs it?"
I hope it gets better.
For what it's worth, pass on my support to him- if only for selfish reasons; I see myself becoming like him in the near future.
I was about 225 lbs and had experienced (mild) arthritis in my knees, starting in my late-20s. Around age 32 I resolved to finally get in shape, the arthritis was, at this point, mild-to-moderate, still in the knees (now in the hands). Losing the weight and regular exercise (in my case running, which I'd been doing as part of soccer on the field, but not for distance until this point) greatly improved my arthritis symptoms. The evenings after a run, my knees felt fantastic. Weeks where I skipped, the symptoms returned (no worse than before, just back to "normal").
Once the weight was lost, however, the symptoms almost completely went away. This is very much a YMMV situation, but it's something to consider.
Exercising the full range-of-motion of the joint + weight loss can help a lot, even if it is just delaying the inevitable. I'll happily accept 5-20 years of improved mobility even if I end up immobilized by this like a good chunk of my ancestors.
The exercise needn't be running. Cycling, elliptical, and rowing machines are low-impact cardio and let you exercise your knees range-of-motion pretty effectively. Bodyweight exercises like squats and lunges and similar, done regularly, will also improve the muscles around the knee, which can help.
Again, for some forms of arthritis this won't help or won't help as much, but for others (like me) it can be a life changer. The path I was on, I'd be unable to run or play soccer at this point (80% confidence in that statement, would've sought medical treatment by this point if I'd stayed on that path).
your friend's dad is just ashamed, and that's his way of lashing out. he's a mental midget.
and besides, when has anyone seen every disabled parking space taken up? places like hospitals have a huge amount of disabled spots so this barely ever happens.