What condition is indicated by needing medial longitudinal arch support in foot orthotics, specifically in the context of knee osteoarthritis?

The condition indicated by needing medial longitudinal arch support in foot orthotics, particularly in the context of knee osteoarthritis, is pes planus valgus. When a patient has pes planus, or flatfoot deformity, the medial arch collapses, potentially leading to altered biomechanics and increased stress on the knee joint. This can exacerbate conditions such as knee osteoarthritis by affecting the alignment and load distribution across the knee.

Arch support from foot orthotics can help stabilize the foot, improve alignment, and distribute forces more evenly, thereby reducing stress on the knee. This is particularly important in knee osteoarthritis, where joint protection and improved mechanical function are key goals of treatment. By addressing the foot mechanics, medial longitudinal arch support can therefore play a crucial role in alleviating some of the symptoms associated with knee osteoarthritis related to foot deformities like pes planus valgus.

Other conditions, such as rheumatoid arthritis, osteoporosis, and chondromalacia patella, may involve joint pain and mobility issues, but they do not specifically necessitate medial arch support as a direct treatment for knee osteoarthritis as pes planus does.