The goal of many noninvasive devices for knee osteoarthritis (OA) is to alter joint biomechanics and thereby limit regional exposure to damaging and provocative mechanical stresses. Optimal prescription of most noninvasive devices first requires the specification of which mechanical stresses should be reduced, and in which knee region. This article introduces several types of devices currently used in the treatment of knee OA. Each section begins with a short presentation of the device's biomechanical effects and considers evidence of clinical efficacy. Where possible, the authors conclude each section by offering their subjective insights and clinical impressions.