The review, published in The Cochrane Library, found custom foot orthoses -- insoles molded to a cast of the foot -- can relieve pain within three months in adults with rheumatoid arthritis, as well as in children with juvenile idiopathic arthritis, an early form of the disease. Adults with painful highly-arched feet or painfully prominent big toe joints also benefited from treatment with orthoses over three- and six-month periods, respectively.

The researchers examined results of 11 trials that together involved 1,332 people. They found the custom orthoses were safe interventions, but said more research is required to develop an understanding of their effectiveness.

"Custom foot orthoses can be an effective treatment for a variety of conditions, but there are still many causes of foot pain for which the benefit of this treatment is unclear," study lead researcher Fiona Hawke of the Central Coast campus of the University of Newcastle, Australia, said in a statement. "There is also a lack of data on the long-term effects of treating with orthoses."