A Scientific Look at High Heels
http://well.blogs.nytimes.com/2012/01/25/scientists-look-at-the-dangers-of-high-heels/
PROCEED WITH CAUTION! INFO DENSE POST AHEAD!
Can you think of a better way to start the week than with a discussion of high heels? We all like high heels… Well, at least guys do (and we know quite a few women who do as well…some of you may be reading this post). NO, WE DO NOT LIKE TO WEAR THEM, but we can admire the way they make the calves look so great and the increased lumbar lordosis and accentuation of the greatest gait muscles ever created!
Were they based off “chopines” from the 15th century; an elevated shoe (7-30 inches high!) which kept the peoples feet literally “out of the muck” (they didn’t have modern plumbing back then) or are they older? Or was the heel invented out of necessity to keep horse riders literally “in the saddle” ? Chinese and Turkish history says maybe they were to keep women (particularly concubines) from escaping. For the intents of discussion, we will stick with this last premise, as it fits nicely with the findings of this article (based on the study published here)
Remember the neuromechanics posts on muscle spindles or golgi tendon organs (GTO’s) ? If not, click the links and check them out; suffice it to say that the take home message is: Spindles respond to length and GTO’s respond to tension.
We also remember that GTO;’s modulate the muscles function that they come from. In other words, they literally “turn off” the muscle they come from (it is a disynaptic, post synaptic pathway for you neuro geeks out there). In light of that, lets look at some quotes form the article:
“the scientists found that heel wearers moved with shorter, more forceful strides than the control group, their feet perpetually in a flexed, toes-pointed position. This movement pattern continued even when the women kicked off their heels and walked barefoot. ”
No surprises here. Go up on your toes and take a few strides (more difficult for guys, since the biggest heel we may have is about 12mm in our running shoes). Which muscles are engaging? See how difficult it is to take a full stride? Try to engage your glutes. Not so easy, eh? Now put your foot flat on the floor, extend your toes and NOW engage your glutes. Easier? Presyanptic loading of the motor neuron pool pays big dividends!
They go on to say: “As a result, the fibers in their calf muscles had shortened and they put much greater mechanical strain on their calf muscles than the control group did.”
Hmmm… shortened muscles put under greater tension. Sounds like a job for the golgi’s, and what do they do? Inhibit the muscle from contracting. No wonder is was harder.
“In the control group, the women who rarely wore heels, walking primarily involved stretching and stressing their tendons, especially the Achilles tendon. But in the heel wearers, the walking mostly engaged their muscles.”
Wow, here is evidence They changed their motor programming! Did you ever think that high heels could change the way our brain works? Maybe it’s a secret plot to take over the world….or maybe not…
The Gait Guys…Lovers of high heels as long as you don’t walk in them….
The physics of heeled shoes. (or, “Using Newton’s Laws to determine sole pressure.”)
Did you know that a 110 lb. woman wearing stiletto high heel shoes puts a lot more pressure on the ground than a 6,000lb elephant?
First lets begin with Newton’s laws of motion. They are three physical laws that form the basis for classical mechanics. They describe the relationship between the forces acting on a body and its motion due to those forces. They are summarized as follows:
- First law: The velocity of a body remains constant unless the body is acted upon by an external force. Meaning that a body stays at rest or in motion unless forced to do otherwise.
- Second law: The acceleration of a body is parallel and directly proportional to the net force F and inversely proportional to the mass m, i.e., F = ma.
- Third law: The mutual forces of action and reaction between two bodies are equal, opposite and collinear.
Now, we all know these laws well but here is something a little different today. Today we have lovely Dr. Deborah Berebichez the first Mexican woman at the Stanford University graduating with a doctorate in physics. Here she gives a simple dialogue of the application of these 3 laws to footwear.
In her PhD dissertation physicist Berebichez developed a new method for electromagnetic waves to focus with extreme accuracy in space and time. Berebichez is currently researching at the Courant Institute of Mathematical Sciences of New York University .
Our point ? This is a brilliant woman and so when she speaks about the physics of high heeled shoes, you should listen. 5 inches is the max ladies (oy vay !)
h(max)=Q (12 + (3s/8))
but remember, this the maximum height to stay stable and not risk falling over. It has nothing to do with the risk of pain and pathology to the body that will occur over time ! But that is another mathematical equation that might be best suited for our other favorite fellow-geek and mathemetician Garth Sunden @ Geek Logik who can figure out any formula for anything you wish to assess (for example, “What are my chances in scoring a date with a girl at a bar? click here).
Watch her video attached here to learn about Newton’s 3 laws and how they apply to shoes and heel height. It is great stuff ! It is important to note that even in the highest of women’s heeled shoes heel strike still occurs first (although it is softened as heel height increases……don’t bother asking us how we know this please), hence Berebichez’s point on heel pressure stands correct but somewhat muted. Heel strike does not however necessarily mean true impact. We encourage our patients to note the difference between heel impact and contact. Just because in normal walking gait (running can be different) the parameters dictate heel strike it does not have to be a long latent heavy impact period. Heel strike and impact should not be accentuated, heavy or prolonged. Many gait pathologies can occur when it is significant because the forces move up into the organism, for example increased knee extension or longer duration of the rear foot inversion phase and thus supination foot phase. Rather, begin to focus the thought more on heel contact (sort of a quick kiss as opposed to a long drawn out French-kiss necking session) and the subsequent and immediate soft gradual transition into the full foot loading phases. In otherwords, finesse the heel contact phase. Perhaps if runners had always looked at heel strike this way we would never have seen such a major intellectual epiphany towards midfoot and forefoot strike being the answer and heel strike being the black plague of all things gait/running related. So, at this moment, while it is still fresh in your mind, get up from your chair and walk and feel the difference between kissing the heel on the ground and a major heel-floor make-out session ! You may immediately note the woes of your ways. You may begin to make walking a more conscious finessed movement while in the process begin to note that walking should be soft and fluid, almost an art form or conscious zen-like meditative act where constant awareness is key.
For those new to gait talk and running, remember that walking gait does dictate this heel strike phase where as in proper running this phase is absent when unshod and most of the research is leaning towards this absence when shod as well (hence the minimialist shoe trend of today).
To put a cap on this talk, we would like to say that these are our kinda people ! Geeks rule ! (but then there are these kinds of people here (Las Vegas high heel shoe race, for those of you who don’t want to link elsewhere) that need to have their heads checked a little…… have they not hear Dr. B’s lecture on heels ?)
Shawn and Ivo…… The Gait Geeks, the guys you beat up in grade school, and now the kinds of geeks you gravitate to for intellectual stimulation. How ironic huh ? Who’s your daddy now !
Feet Suffer for High Heel Fashion→
/From the article,
“The big problem created by wearing high-heel shoes was abnormal weight distribution, she said. Instead of the foot bearing the weight of the body in the heel and the ball of the foot, all the weight fell on to the ball of the foot when wearing high heels, especially narrow, pointy-toed shoes. The increased pressure could make corns and callouses develop on the ball of the foot, increase the likelihood of developing ingrown toenails, bunions and hammertoes and contribute to neuroma, a painful thickening of the nerve between the toe bones. In some habitual heel wearers the calf and Achilles muscles could shorten into a tighter position leading to strain and an increased risk of tendonitis or tendon rupture when reverting to walking in a flat shoe or barefoot. Foot problems typically started to present for women in their 40s, with pain limiting their ability to function, she said. "Most foot conditions are chronic and develop over a period of time,” Professor Bower said. As we age our joints, ligaments and tendons loosen and the foot will lengthen slightly and incrementally because it is no longer toned. The fat pad under the heel and ball of the foot that cushions the foot from birth declines and the bones and joints become more prominent. The older foot, with less naturally occurring support and padding, was therefore at an increased risk of problems from wearing high heels, she said. “
It is all stuff most of us have heard already, but it is always nice to hear it again and pass it onto our patients and children.
High heels and women in them are great to look at, but just not meant to walk in for any extended period of time. The Gait Guys say, "Put them on your fireplace mantle where you can enjoy them daily, rather than on your foot.”
Ivo and Shawn, The Gait Guys