What knee exercises are best for osteoarthritis?With knee osteoarthritis, several exercises can help strengthen the muscles around the knee joint, improve stability and reduce pain. Here are some effective exercises you can do at home. What is osteoarthritis of the knee? Osteoarthritis in the knee is a condition in which the cartilage in the knee joint gradually becomes thinner. Cartilage acts as a protective layer that allows the bones in the joint to move smoothly and absorb shock. In osteoarthritis, this cartilage becomes thinner or disappears completely, causing the bones to rub against each other. This leads to stiffness, pain and restricted movement. Osteoarthritis often results from wear and tear, but factors such as overuse, injury or heredity can also play a role.