My knees suffered very bad 2 years back, reaching for something on the floor was a mission.
Get your friend on the cleansing salad (liver) and spa treatment, and tell him this:
I was just 39 years onld when this happened (I was down with chronic fatigue back then) I felt symptoms similar to my grandma who is turning 94 this year. I had to come to realise that these illness we associate to old age are due to poor liver functions that allow for parasite to survive in our body.