Effect of knee pain on joint loading in patients with osteoarthritis.

Treatment of patients with osteoarthritis is often directed at relieving pain and restoring function. Pain, however, may serve as a protective mechanism in that patients may decrease their levels of activity or alter the manner in which they perform activities in response to pain. Pain reduction may result in increased loads on the joints during dynamic activities, which may result in more rapid disease progression. Therefore, treatment methods that relieve pain but result in a loss of the protective mechanisms associated with pain may not be beneficial in the long term. This mechanism of decreased pain associated with an overuse of the degenerated joint has been referred to as an "analgesic arthropathy." This article discusses common treatments or interventions used for patients with knee osteoarthritis and their potential effects on pain levels and loads at the knee joint during walking. Understanding the relationship between treatment methods, pain, and the knee joint loads during walking is important because walking is the most frequently performed activity, and the cyclic loads at the knee joint during walking are high.