What’s the main cause of osteoarthritis

Primary osteoarthritis is mostly related to aging. With aging, the water content of the cartilage increases and the protein makeup of cartilage degenerates. Repetitive use of the joints over the years causes damage to the cartilage that leads to joint pain and swelling.

answer; i believe the correct answer is ( mediation);

which ever one is showing doing the same exercise in time intervals such as 30 seconds or a minute several times.