Interesting question Chris.
Are we talking osteoarthritis or rheumatoid arthritis. Whatever the case, the ACSM has established guidelines for exercise programming for individuals with diagnosed arthritis.
I am a firm believer that if fitness professionals are going to train individuals with diagnosed disease:
1. The fitness professionals must learn to think about fitness programming with the objective of improving health.
2. One must understand the pathophysiology of the disease.
2. One must understand the osteo/arthrokinematics of joint affected by the disease.
3. One must understand how the disease affects overall function. Osteo/rheumatoid arthritis affected connective tissue.
4. One must know current exercise testing guidelines for the individuals living with arthritis.
Lastly, with all disease, one must take into consideration whether the individuals condition is controlled or not.
Best to you.