Some experts recommend flat, flexible shoes for people with knee osteoarthritis, whereas others say stable, supportive shoes are better. Now a randomized trial has found that the latter — a stiff and stable shoe with good cushioning — is better than a supple and bendable one.

Osteoarthritis is the most common joint disorder in the United States. According to one recent estimate, 14 million Americans suffer from the pain and stiffness of knee arthritis.

Australian researchers randomly assigned 164 men and women, average age 65, to wear either a flexible or stiff shoe for at least six hours a day for six months. Footwear in the flat-shoe category included the Merrell Bare Access, the Vivobarefoot Primus Lite, the Vivobarefoot Mata Canvas, the Lacoste Marice and the Converse Dainty Low. In the stable-supportive group, shoes included the ASICS Kayano, the Merrell Jungle Moc, the Rockport Edge Hill, the Nike Air Max 90 Ultra and the New Balance 624.

Before and after the study, the researchers administered questionnaires and scales measuring pain, function and comfort. The report is in Annals of Internal Medicine.

The researchers found that 58% of those wearing stable shoes achieved a clinically significant reduction in pain, compared with 40% wearing the flexible shoes. On assessments of function, 11% more stable-shoe wearers reported improvements.