Inspired by her high-heel wearing sister, Danielle Barkema, a kinesiology master's student at Iowa State University, expanded on previous research to examine the long-term effects of the shoes on knees. We spoke last week.
It's common knowledge that wearing high heels can be tough on the body. What did you find that expanded on what we already know about the effects of wearing high heels?
We looked at the changes that occurred in high-heeled walking in the lower-extremity joints -- the hip, knees and ankles -- and if these changes have adverse effects on the body. We focused on the knee and problems that may arise later in life in the knee. There have been previous high-heeled walking studies that have shown there are forces across the knee joint, specifically greater loading or compression on the inner portion of the knee. That was several years ago and looked at barefoot versus a short heel. This loading is important because over time it's shown to lead to greater joint degeneration and it can lead to the development of osteoarthritis. We were trying to see if a systematic manipulation of heel height -- a flat, a mid-heel about two inches and a high-heel about three and a half inches -- had a systematic increase in loading. That's what occurred. It was easier to classify that relationship. Not only does wearing high heels put you at greater risk for osteoarthritis later in life, but the higher the heel [means] an even greater risk.
How did you go about your study?
I had 15 women participate. They came into our biomechanics lab and we just had them walk over and over through our data collection area. They did this in each heel height. We have [motion-capture] cameras surrounding the area in which they walk. We put reflective markers on various parts of their bodies and these cameras record reflection, picking up information on the location of these markers. That characterizes the motion of their bodies. We also have them walk over a platform embedded in the floor. It measures the forces acting on the body. We use that information in conjunction with the motion information [to derive] numbers used to determine information, like joint positions and forces and loading.
Those numbers show you the way the body was affected by shoes?
Yes. Obviously we can't directly measure in the knee without some invasive measures. This is protocol. It's been around a long time. We're using the forces and the position of the body to get estimates. We're using external measurements, which are equal and opposite to what's going on inside the body.
If you're doing the study over a short period of time, how can you deduce the long-term effects of wearing high heels?
It is difficult to say. A lot of people ask [whether there is] a certain amount of time before you see problems. With knee osteoarthritis, it usually develops later in life. I can't tell you if you wear them this much you'll get it or you won't. It seems to be that based on the loading that's taking place, the more you wear them and the higher the heels, you are putting yourself at greater risk.
Is it best to wear flats?
Just based on this measure, the flats were the lowest loading on the knee. But you can argue it. There is some information about flat shoes not providing enough support for your foot. You can't really say it's absolutely the best to wear, but based on this measure it seems like higher heels are worse for that part of you knee joint.
Talk about what inspired you to do this work.
I have a twin sister. She moved out to Chicago right after graduating and got a job as a retail manager in a department store. She was on her feet pretty much all day everyday and she and her co-workers were wearing high heels. She noticed that a lot of the older women had various problems. They were complaining of foot, knee, hip problems. One had to get a hip replacement. She thought it was interesting because they'd been wearing high heels all day everyday for a period of years. She mentioned it to me and I thought it was an interesting project to look at.
Are you wearing high heels less often now that you've done this research?
I'm not telling everybody to go throw out their high heels and never wear them again. They are fun to wear and I do wear them. What I do, and what I tell my friends, is to try to limit them as much as possible.
Image, top: High heels / Courtesy of Thomas Steiner
Image, bottom: Danielle Barkema