Dr. Najia Shakoor, a rheumatologist at Rush University Medical Center in Chicago, said the finding is important because loading on the knee joints is a key factor in the development of osteoarthritis -- the most common form of arthritis.
"Traditionally, footwear has been engineered to provide maximum support and comfort for the foot, with little attention paid to the biomechanical effects on the rest of the leg," Shakoor said in a statement. "But the shoes we wear have a substantial impact on the load on the knee joints, particularly when we walk."
Shakoor and colleagues analyzed the gait of 31 patients with symptoms of osteoarthritis while they walked barefoot and with four popular shoe types: Dansko clogs, often worn by healthcare professionals; Brooks Addiction stability shoes; Puma H-Street shoes, a flat athletic shoe with flexible soles and flip-flops.
The study, published in the journal Arthritis Care & Research, found that for the clogs and stability shoes, the loads on the knee joints were up to 15 percent greater than with the flat walking shoes, flip-flops or barefoot walking.