Other Risk Factors for Osteoarthritis
Research has shown that people with weak quadriceps (thigh muscles) are at an increased risk of developing knee osteoarthritis. This may be due to the fact that the quadriceps act as shock absorbers for the knees. The stronger the thigh muscles, the more shock and stress they are able to keep off the knees. This is why strengthening these muscles decreases the chances of developing osteoarthritis.
Certain Medical Conditions
Certain medical conditions can cause damage to the cartilage or create a deformity, which increases stress on the joints. Some examples of these conditions include:
People who suffer knee and hip injuries to the joint are at an increased risk of developing osteoarthritis. The earlier in one's life the injury occurred, the greater this risk appears to be.
Repetitive Stress on Joints
People in certain occupations -- such as landscaping or jobs that involve operating machinery or doing a lot of typing -- appear to be at an increased risk of osteoarthritis. This increased risk is thought to be due to microscopic damage that can occur with repetitive actions. Athletes also appear to be at an increased risk, but not all athletes have the same risk. It appears that runners have no increased risk, while soccer players, football players, and baseball pitchers are at increased risk.
One interesting study illustrates this point particularly well. The study showed that using chopsticks contributes to osteoarthritis in the hand. Chopstick use puts stress on certain joints, specifically, joints of the thumb and second and third fingers. In this study, osteoarthritis was more common in several of the joints in the three fingers of the chopstick hand than in the hand not holding chopsticks.
It is important that people who do repetitive tasks learn how to modify their movements in order to decrease the repetitive stress.