Flip flops Creaky joints seem to come with old age, just like grey hair and the need to hold the newspaper at arm’s length to read it. But for the one in five UK adults who suffer with arthritis, the effect goes far beyond just stiffness.
Arthritis, the most common long-term condition in the UK, can have devastating effects, including constant pain and disability. At this level of severity arthritis needs medical intervention. However, there are self-help measures that can help, such as losing weight and keeping moving.
A new study, published online in the journal Arthritis Care & Research, has come up with interesting findings. Dr Najia Shakoor, a rheumatologist at Rush University Medical Centre, and colleagues have found that what we wear on our feet can ease the load on our knees.
"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," said Dr Shakoor, lead author of the study. "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."
Dr Shakoor and her team studied 31 patients with arthritis symptoms. They analysed their gait when they walked barefoot, and with four different types of shoes on. The shoes were:
- a brand of clogs often worn by healthcare professionals who have to stand for long periods
- a brand of shoes prescribed for stability
- a popular brand of athletic shoes with flexible soles
- flip-flops
The study discovered that the loads on the participants' knee joints were different, depending on the shoes. Wearing flat, flexible walking shoes, flip-flops or no shoes at all meant the loads on the knee joint were up to 15 percent less than when wearing the clogs and stability shoes.
Heel height and the stiffness of the sole both appear to play a part. The stability shoes and the clogs used in the study both had higher heels than the other options. And in past studies walking barefoot has been linked to less loading on the knees.
"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 stiff-soled shoe," says Dr Shakoor.
"There's a growing body of evidence that shoes do increase the loads on the knee," says Dr Anthony Redmond, Arthritis Research UK senior lecturer in rheumatology at the University of Leeds.
"There are risks associated with barefoot walking, and if you have diabetes, and reduced ability to feel injury, going barefoot is an absolute no-no. The advice to people with knee problems would be to wear shoes that are as flexible as possible, However there’s always a trade-off between protection, which is why most people wear shoes, the function that the shoes allow, and looks."
If you’re still hankering after those high heels that look so elegant, Dr Redmond has a final word of warning. "There’s very good evidence that high heels are bad for your knees."
First published 25 March, 2010