Insoles and Footwear in the Management of Knee Osteoarthritis

This chapter will review relevant research surrounding the use of insoles and footwear for knee osteoarthritis (OA). In particular, concepts relevant to the clinical application of these treatment techniques will be discussed. This chapter will examine the effects of common insole and footwear types on knee load, OA symptoms and disease progression. Increased joint loading increases the risk of OA progression, but is amenable to change. Given the prevalence of medial compartment OA, insoles and footwear largely aim to reduce the knee adduction moment, an indicator of medial compartment load. Lateral wedged insoles can reduce this moment but do not appear, at present, to slow disease progression. Whilst non- and quasi-experimental studies report favourable effects of lateral wedges on symptoms, most clinical trials have not been confirmatory. Medial wedged insoles show promise in relieving symptoms of lateral compartment disease. Walking in shoes increases joint load compared to barefeet. Shoes with a flat or low heel and that are flexible rather than stabilising in nature may be optimal for patients with knee OA, however effects of off-the-shelf shoes on OA symptoms are unknown. Promising shoe modifications currently under development include shoes that promote foot mobility and those with variable-stiffness or laterally wedged soles. In summary, insoles and footwear offer great potential as simple, inexpensive treatment strategies for knee OA. Further research is needed to evaluate their efficacy, particularly regarding their effects on knee symptoms and structural disease progression, and to determine which patient subgroups are most responsive.

Keywords: Osteoarthritis, insoles, footwear.