Rush University Medical CenterOsteoarthritis is said to be a collection of diseases and mechanical irregularities concerning degradation of joints, counting articular cartilage and the subchondral bone subsequent to it. A study from Rush University Medical Center has discovered that flip-flops and sneakers with elastic soles are said to be easier on the knees as compared to clogs or even special walking shoes.

Study authors examined the gait of roughly 31 patients with symptoms of osteoarthritis in the Rush Motion Analysis Lab while they walked barefoot and with four well-known shoe kinds. One of them is Dansko clogs, which are frequently worn by healthcare professionals who have to be on their feet almost the entire day. The second one is Brooks Addiction stability shoes which are believed to be prescribed for foot comfort and stability. The next one is Puma H-Street shoes which are flat athletic shoes with flexible soles. The last one is flip-flops.

“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. But the shoes we wear have a substantial impact on the load on the knee joints, particularly when we walk. Our study demonstrated that flat, flexible footwear significantly reduces the load on the knee joints compared with supportive, stable shoes with less flexible soles,” commented, Dr. Najia Shakoor, a rheumatologist at Rush and the primary author of the study.

The burden on the knee joints seemed to vary considerably depending on the footwear. When it comes to the clogs and stability shoes, the load on the knee joints were up to 15 percent more as compared to the flat walking shoes, flip-flops or barefoot walking. Knee loading was believed to be roughly the same whether the participant wore flips-flops or walked barefoot.

Shakoor mentioned, “Currently, knee braces and wedged orthotic shoe inserts are used to relieve the load on the knee joints of patients with osteoarthritis, but everyday footwear is also a factor to consider. The results in our study demonstrate that the reduction in load achieved with different footwear, from 11 to 15 percent, is certainly comparable to reduction in load with braces and shoe inserts.”

As per Shakoor, numerous facets of footwear could disturb the joint loading.

Shakoor remarked, “Heel height is one factor, and may explain why the stability shoes and clogs in our study, both of which had higher heels, produced greater knee loads. Stiffness is also a factor. We’ve shown in earlier studies that barefoot walking is associated with lower knee loads than walking with conventional footwear. It may be that the flexible movement of the bare foot is mechanically advantageous. The natural flex of the foot when it contacts the ground probably attenuates the impact on the joint, compared to the artificial ‘stomping’ movement created by a stiff-soled shoe.”

In the current study, Shakoor mentioned that flip-flops and the walking shoe are flat, elastic and lightweight and appeared to imitate the mechanics while walking bare feet.

Shakoor mentioned, “Clogs and stability shoes, conventionally believed to provide appropriate cushioning and support, actually increased the loading on the knee joints, as opposed to shoes with less ‘support,’ flatter heels and more flexibility.”

Shakoor warned that nevertheless knee loading may not be the only consideration in any clinical recommendations based on her study. The expert also mentioned that when it comes to elderly and infirm people, flip-flops could contribute to falls because of their loose-fitting design. Factors like these need to be taken into account.

The study was published in the Journal Arthritis Care & Research.