Riding a motorcycle without a knee brace in the summer is not usually associated with arthritis. Riding a motorcycle without a knee brace does not have much effect on the joints if the weather is hot. Rheumatoid arthritis is mainly caused by streptococcal infection, and osteoarthritis is caused by degeneration and proliferation of joints. Cold induces the symptoms of arthritis to worsen. If you have arthritis, synovial hyperplasia and hypertrophy, the cold stimulation will cause the synovial secretion of the joints to increase the fluid, the joints of the local circulation is not good to cause pain aggravation. Therefore, riding a motorcycle in the summer without wearing knee pads if there is no pain in the joints, usually has no effect, if there is joint pain need to go to the hospital in time to find out the cause, pay attention to the knee joints to keep warm.