Purpose of review: This review highlights recent research findings, including their clinical application, for insoles and footwear in knee osteoarthritis. In particular, it examines their effect on knee load, osteoarthritis symptoms and disease progression.
Recent findings: Increased joint loading increases the risk of osteoarthritis progression, but is amenable to change. Given the prevalence of medial compartment osteoarthritis, 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 to slow disease progression. Although nonexperimental and quasiexperimental studies report favourable effects of lateral wedges on symptoms, 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 with walking in barefeet. Shoes with a flat or low heel and that are flexible rather than stabilizing may be optimal; however, effects of off-the-shelf shoes on osteoarthritis symptoms are unknown. Promising shoe modifications include shoes that promote foot mobility and those with variable stiffness or laterally wedged soles.
Summary: Insoles and footwear offer great potential, as simple, inexpensive-treatment strategies for knee osteoarthritis. Further research is needed to evaluate efficacy and to determine which patient subgroups are most responsive.