Nonergonomic! Athletic Footwear Unsafe due to Perceptual Illusions

Nonergonomic! Athletic Footwear Unsafe due to Perceptual Illusions
[人因工程 ]
(2003/04/29)

Athletic Footwear Unsafe due to Perceptual Illusions

Modern athletic footwear provides remarkable plantar comfort when walking, running, or jumping. However, when injurious plantar loads elicit negligible perceived plantar discomfort, a perceptual illusion is created whereby perceived impact is lower than actual impact, which results in inadequate impact-moderating behavior and consequent injury.

Wearers of expensive running shoes that are promoted as having additional features that protect (e.g., more cushioning, “pronation correction”) are injured significantly more frequently than runners employing inexpensive shoes (costing less that US $40)…

In addition, in barefoot populations running-related injuries are rare, which indicates that humans adapted to barefoot running run with lower impact than the unadapted group referred to above. This also suggests that the lower extremity is inherently durable and is made susceptible to injury by footwear use. Based on the above data, not withstanding unsupported claims by footwear manufacturers of improved protection with their products, it seems appropriate to consider expensive athletic footwear from major manufacturers (and perhaps less expensive shoes) as unsafe.

This is strengthened by reports indicating that, when habitually barefoot humans walk (and probably when they run), they have greater knee flexion, which has been shown to reduce shock.

Barefoot activity when practical (no need for thermal insulation; no risk of crush injuries; social acceptability) deserves consideration since plantar sensory mediated protective adaptations seem optimized for this condition. Although this may run counter to notions prevalent in economically advanced countries recounting dangers of barefoot activity and necessity of footwear even when barefoot activity is feasible, supporting data are lacking, and many have concluded that footwear design is guided by fashion rather than health considerations.

In summary, people who perform activities involving high impact while wearing footwear currently promoted as offering protection in this environment are at high risk for injury. Unlike the natural state (barefoot and natural surfaces), where impact is sensed and, through impact-moderating behavior, is maintained at a safe level, an inadequate understanding of the physiology of human impact control has resulted in footwear which makes chronic overloading inevitable by providing plantar comfort to the wearer even when enormous vertical impact is experienced.

Editor’s Comments:

Household fuses sometimes blow out as soon as they are installed. Sometimes one after another. When they do, frustrated homeowners may resort to the “penny in the fuse box” trick. They wedge an ordinary copper penny in the socket where the fuse normally goes. Presto! No more blown fuses, and the lights stay on indefinitely, or until the house burns down around you. As any fire marshall will tell you, you might as well drench yourself with gasoline and light a match. That’s how dangerous it is.

Providing an inordinate amount of “ergonomic” cushioning in footwear is the physiological equivalent of putting a penny in the fuse box. By masking the impact on one’s feet, knees, even spinal column, “ergonomic” cushioning negates natural impact-moderating behavior that would have maintained physical activity at a safe level. The result is injury to the wearer, induced by the very item that was supposed to protect against injury.

The underlying principle is simple, yet powerful: “Nature knows best.” To paraphrase a famous margarine commercial from many years ago, “It’s not wise to fool Mother Nature!”

— Bevin Chu

Explanation: Athletic Footwear and Chronic Overloading
Illustration(s): World Champion Barefoot Runner Zola Budd-Pieterse of South Africa
Author(s): Steven E. Robbins and Gerard J. Gouw
Affiliation: “Athletic footwear: unsafe due to perceptual illusions,” Medicine and Science in Sports and Exercise, 23(2), 1991, pp. 217-224.
Source: http://www.barefooters.org/medicine/med_sci_sports_exer-23.2.html
Publication Date: December 27, 1996
Original Language: English
Editor: Bevin Chu, Registered Architect

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Nonergonomic! Athletic Footwear and Chronic Overloading

Nonergonomic! Athletic Footwear and Chronic Overloading
[人因工程 ]
(2003/04/28)

Athletic Footwear and Chronic Overloading

Some authors have concluded that chronic overloading with locomotion is inevitable in modern man because of inherent lower extremity fragility. Accordingly, footwear, such as running shoes, which attempt to attenuate shock waves through interposition of yielding layers between the plantar surface and ground, are presumed essential for safe running, and are also promoted for use during walking. However, this supposition seems inconsistent with reports indicating that habitually unshod humans are not subject to chronic overloading during running. By taking this into account, the lower extremity must be inherently durable, and chronic overloading must be a consequence of wearing footwear, and probably due to increased shock with their use.

It has been observed that locomotion in barefoot-adapted subjects (normally unshod, or customarily shod after allowing several weeks of barefoot adaptation) differs from customarily shod subjects in that those barefoot adapted ‘grasp’ with their digits when they walk…

Obviously, the ideal solution to the running related injury problem in shod populations lies in barefoot locomotion, since protective adaptations seems to be optimized for this state. Normally shod people would have to allow sufficient time for adaptation of the plantar skin and intrinsic foot musculature (perhaps 6 weeks), and run barefoot frequently, perhaps daily, to sustain this adaptation. However, once adapted, the foot is extremely durable.

See Illustration: Abebe Bikila, Marathon Winner, 1960 Rome Olympics. At the Tokyo Olympics in 1964, Bikila became the first person to repeat an olympic marathon victory. Bikila set another world record at 2:12:11 and became the first marathoner to finish the race under 2:13.

The lower extremity is inherently durable, and, when unencumbered by footwear, it can endure running without signs of chronic overloading, because a vigilant system restrains shock. The use of modern athletic footwear, in addition to being inferior to older footwear in moderating shock during running, renders the lower extremity susceptible to injury because of design flaws introduced by the preoccupation with optimization of plantar comfort.

The obvious solution to the problem of chronic overloading in shod runners is to promote barefoot running.

Editor’s Comments:

The authors’ solution to preventing injuries artificially induced by “ergonomic” footwear is to get rid of footwear altogether. Their solution is admittedly radical. But just because it is radical doesn’t mean it’s wrong. Radical is not a synonym for “crackpot”.

Needless to say, industrial designers in the employ of footwear manufacturers are never going to go along with the authors’ suggestion, regardless of whether it is scientifically validated. Even industrial designers not beholden to footwear manufacturers, and willing to “think outside the box” may find it difficult to accept the authors’ solution.

But these are hardly the only alternatives. One need not endorse the authors’ radical solution to acknowledge the persuasiveness of their analysis. I myself am unwilling to go about barefoot in most urban settings. I prefer to hold out for some workable compromise, one which allows my feet to move naturally while protecting them from broken glass, rusty nails, even hookworm parasites in pet droppings. Note that I have deliberately avoided raising the highly subjective issue of bare feet and social convention, as that complicates the issue even further.

Coming up with a workable, real world solution that satisfies a multitude of conflicting design considerations is easier said than done. But to continue down the tired, discredited path toward “ergonomic shoe design” is flagrant self-deception. It is akin to searching for your lost key under the street lamp when you know you dropped it in the dark alley, merely because it is easier to see in the bright light.

— Bevin Chu

Explanation: Athletic Footwear and Chronic Overloading
Illustration(s): Abebe Bikila, Marathon Winner, 1960 Rome Olympics
Author(s): Steven E. Robbins, Gerard J. Gouw, and Adel M. Hanna
Affiliation: “Athletic Footwear and Chronic Overloading,” Sports Medicine, 9(2), 1990, pp. 76-85.
Source: http://www.barefooters.org/medicine/sports_med-9.2.html
Publication Date: December 27, 1996
Original Language: English
Editor: Bevin Chu, Registered Architect

Nonergonomic! The Mechanics of the Bare Foot

Nonergonomic! The Mechanics of the Bare Foot
[人因工程 ]
(2003/04/24)

Running-Related Injury Prevention through Innate Impact-Moderating Behavior

These data provide insight into how, when barefoot, the plantar surface resists perforation yet provides protection to local bony structures. These data further support the notion that plantar sensory feedback plays a central role in safe and effective locomotion.

A relation has been reported between barefoot activity and raising of the main longitudinal arch, presumably by increased intrinsic foot muscle tone. The subjects with the greatest reduction in arch span performed barefoot activity outdoors. This suggests that surface irregularities causing local deformations on the plantar surface contributed to intrinsic foot muscular activation.

When compared to locomotion with existing footwear, these mechanics of the bare foot may offer improved balance during locomotion. This is compatible with the preference of many gymnasts and dancers for being barefoot to wearing footwear. (emphasis added)

Editor’s Comments:

Could it be that “ergonomic” shoe design has taken a disastrous turn somewhere along the way? Could it be that instead of piling on the padding willy-nilly, “ergonomic” shoe designers should be doing the exact opposite? Could it be that they should be thinning down and paring away the conventional shoe until it comes as close as possible to the bare human foot, while providing protection from the elements?

Ergonomic athletic shoes, we are solemnly assured, provide “improved balance and added stability for the human foot.”

Really?

If so, why don’t Olympic Gold Medal gymnast Kui Yuanyuan and her competitors wear “ergonomic” footwear while competing on the balance beam? Anything that offers a winning edge is going to find its way into an aspiring Olympian’s kit of tools after all. So why do these fiercely competitive young athletes whose careers are made or broken by their sense of balance compete in bare feet? Do they know something the “ergonomic” shoe designers don’t?

— Bevin Chu

Explanation: Running-Related Injury Prevention through Innate Impact-Moderating Behavior
Illustration(s): Olympic Gold Medal Gymnast Kui Yuanyuan
Author(s): Steven E. Robbins, Gerard J. Gouw, and Adel M. Hanna
Affiliation: “Running-related injury prevention through innate impact-moderating behavior,” Medicine and Science in Sports and Exercise, 21(2), 1987, pp. 130-139.
Source: http://www.barefooters.org/medicine/med_sci_sports_exer-21.2.html
Publication Date: December 27, 1996
Original Language: English
Editor: Bevin Chu, Registered Architect

Nonergonomic! Bu Xie, Espadrilles, Aqua Socks

Nonergonomic! Bu Xie, Espadrilles, Aqua Socks
[人因工程 ]
(2003/04/23)



Overload Protection: Avoidance Response to Heavy Plantar Surface Loading

The paradoxical low incidence of similar injuries reported in barefoot populations implies that modern footwear may produce injuries that normally would not be present without their use.

Sensory-induced behavior associated with the physical interaction of the plantar surface with the ground (in the unshod), or the footwear and underlying surface (in the shod), is considered unimportant to the traditional thesis. This omission is astonishing because logically, the plantar surface, being a highly sensible layer, would produce significant sensations in either state, and it is common knowledge that noxious plantar skin sensation can easily induce avoidance behavior

Many years have passed since the first of a series of reports consistently indicated that there is no correlation between the amount of shoe cushioning and impact absorption of footwear during locomotion. (emphasis added) Similarly, epidemiological studies over the same period have provided no evidence of a trend of enhanced protection with modern athletic footwear. (emphasis added) Rather than being dismissed as glaringly incomplete and inadequate, these concepts are still being promoted by biomechanists, physicians, and manufacturers of footwear as an effective solution to the injury problem in high impact environments.

There can also be other explanations of this current situation. Investors may have become too preoccupied with sophisticated hardware rather than their principal task of performing experiments which test hypotheses. Further, as much of this research is “in-house” (performed by footwear company staff or as direct contracts from footwear manufacturers), intellectual freedom may be compromised, resulting in a reluctance on the part of investors to draw conclusions that may undermine current product lines promoted by their employers or patrons.

Whatever the cause, there has been little effort directed at explaining reported data and searching for alternative explanations. Rather, invalid models have led to footwear that do not protect and in fact may be injurious.

Editor’s Comments:

Novice medical students are taught a fundamental precept: “First, do no harm!” Industrial design professionals involved in “ergonomic design,” while not doctors, should internalize this wisdom from the medical profession. Industrial designers have an ethical obligation to take a hard look at real world empirical evidence before slapping “ergonomically-designed” labels on products they are responsible for.

Shoe manufacturers need not fear such studies as dire threats to the shoe industry. After all, it is possible to arrive at entirely different practical conclusions from the same theoretical data. What the exact solution is, I’m not sure. Perhaps the answer is some sort of thin-soled, lightweight new shoe prototype which does not depart too radically from “socially acceptable” conventional footwear in appearance, but which avoids its ergnomic defects.

Curiously enough, prototypes meeting these criteria might well resemble traditional Chinese cloth shoes or traditional European “espadrilles,” only executed in more durable space-age materials, slightly modified for assembly line production. Modern day “Aqua Socks” or “Reef Walkers” come remarkably close to what I have in mind. See illustration(s): Traditional Chinese Shoes, Traditional European Espadrilles, and Aqua Socks/Reef Walkers.

— Bevin Chu

Explanation: Overload Protection: Avoidance Response to Heavy Plantar Surface Loading
Illustration(s): Traditional Chinese Bu Xie. Traditional Mediterranean Espadrilles. Aqua Socks/Reef Walkers
Author(s): Steven E. Robbins, Adel M. Hanna, and Gerard J. Gouw
Affiliation: “Overload Protection: Avoidance Response to Heavy Plantar Surface Loading,” Medicine and Science in Sports and Exercise, 20(1), 1988, pp. 85-92.
Source: http://www.barefooters.org/medicine/med_sci_sports_exer-20.1.html
Publication Date: December 27, 1996
Original Language: English
Editor: Bevin Chu, Registered Architect

Nonergonomic! The Anatomy of the Human Foot

Nonergonomic! The Anatomy of the Human Foot
[人因工程 ]
(2003/04/22)




Running-Related Injury Prevention through Barefoot Adaptations

A number of reports indicate an extremely low running-related injury frequency in barefoot populations in contrast to reports about shod populations.

Despite the modern engineered running shoe, a sports medicine clinic reported a large series of running-related injury referrals with an average weekly mileage at the time of injury of 19 miles for women and 27 miles for men. Practitioners of sports medicine have observed injuries in runners using every shoe model available. The above reports can hardly be considered an endorsement of the modern running shoe as a protective device.

The opinion that the lower extremities are inherently fragile goes against the authors’ understanding of the concept of natural selection.

The reports that the authors have received indicate a low frequency of plantar fasciitis in barefoot populations.

A paradox in presented of lower extremity fragility associated with the wearing of protective footwear and relative resistance to injury in the barefoot or unprotected state. To explain this paradox, the authors hypothesized that there exist adaptations associated with barefoot activity that provide impact absorption and protection against running-related injuries. An adaptation involving foot arch deflection on loading is hypothesized to be an important adaptation providing impact absorption. In contrast, it is hypothesized that the known rigidity of the shod foot may explain the reported high injury frequency in North American runners.

The modern running shoe and footwear in general have successfully diminished sensory feedback without diminishing the injury inducing impact, a dangerous situation. (emphasis added)

The arch support, which is present in all running footwear, would interfere with the downward deflection of the medial arch on loading. Furthermore, the use of orthodics, or other structures that are fitted to the mold of the soft tissues of the foot, could cause similar difficulty. Such designs occur when an engineer looks at the foot as an inflexible lever which is delicate and thus requires packaging. Various myths persist about foot behavior due to poor understanding of its biology.

The solution to the problem of running-related injuries could be as simple as promoting barefoot activity. [ ! ] (emphasis added)

Editor’s Comments:

One need not endorse Robbins and Hanna’s solutions to acknowledge the correctness of their observations.

“The opinion that the lower extremities are inherently fragile goes against the authors’ understanding of the concept of natural selection… an engineer looks at the foot as an inflexible lever which is delicate and thus requires packaging.”

The mental model of the human body cherished by many ergonomic experts is fundamentally flawed. As practitioners of Holistic Medicine, especially Traditional Chinese Medicine have known for millennia, the human body is a dynamic organic process, not a static mechanical device. Armed with a defective “mechanistic” understanding of the human body, such ergonomic “experts” not only have not solved ergonomic problems, they have unwittingly created them.

Mother Nature has been involved in engineering a hell of a lot longer than modern man. Before Homo Sapiens (“Man of Wisdom”) presumes to “improve” upon Nature, he should first make sure he understands it.

— Bevin Chu

Explanation: Running-Related Injury Prevention through Barefoot Adaptations
Illustration(s): Plantar Fasciitis
Author(s): Steven E. Robbins and Adel M. Hanna
Affiliation: “Running-related injury prevention through barefoot adaptations,” Medicine and Science in Sports and Exercise, 19(2), 1987, pp. 148-156.
Source: http://www.barefooters.org/medicine/med_sci_sports_exer-19.2.html
Publication Date: December 27, 1996
Original Language: English
Editor: Bevin Chu, Registered Architect

Nonergonomic! Footbinding Circa 2003

Nonergonomic! Footbinding Circa 2003
[人因工程 ]
(2003/04/22)

Radiographic Evaluation of Hallux Valgus







Introduction

Hallux valgus is a common foot disorder of several etiologies, which can lead to significant foot pain and deformity. Little has been published in the radiographic literature about the pre- and postoperative radiographic findings of this very common and very treatable cause of foot pain.

Definition

The term hallux valgus denotes deviation of the great toe toward the fibular border of the foot. Hallux valgus is not synonymous with bunion, which is derived from the same root as “bun” or “bunch”, and means an area of swelling. In connection with the foot, bunion usually refers to the prominent medial portion of the first metatarsal head and especially to the bursa or a bursa plus osteophyte over it, when this exists. A bursa and/or osteophyte may or may not accompany hallux valgus.

Pathogenesis

The etiology of hallux valgus is somewhat controversial. Some cases are congenital, perhaps secondary to a sloping surface of the first tarsometatarsal joint. When this joint is hypermobile, with or without the normal angle, it is often referred to as an “atavistic” tarsometatarsal joint. Other cases are almost certainly due to environmental factors, such as poorly fitting footwear. The fashionable shoes worn by many women are more constraining than the shoes worn by men and are felt by many authors to be the etiologic factor in most cases of hallux valgus. This would help to explain the 10:1 ratio of females to males seen with this disorder. (emphasis added)

Editor’s Comments:

The ancient Chinese practice of footbinding was responsible for untold suffering endured by women in Chinese society. Thankfully that chapter in history is over.

Or is it?

What is the modern practice of forcing womens’ feet into pointy-toed shoes with 3″ heels, except a “kinder, gentler” form of footbinding? Long term wearing of pointy-toed high-heeled shoes permanently deforms womens’ feet, even crippling their wearers, just as surely as footbinding once did. Any difference is merely one of degrees, not intended visual effect.

We moderns are not nearly as enlightened or progressive as we like to imagine. Knowledgeable historians are well aware of this embarrassing reality. Footbinding was merely a more extreme version of the same foot fetishism that dictates womens’ shoe designs in 2003. Now, as then, many women acquiesce. Knowing they will be devalued in sexual attractiveness if they fail to “toe the line,” many modern women chose excruxiating physical deformity rather than be caught dead with “sensible shoes” on their feet.

Women who can’t bring themselves to give up high heels may want to opt for open-toed sandals instead of pointy-toed pumps. (See Illustration: Designer Sandals) The worst harm to womens’ feet is apparently inflicted by the enclosed toe portion of high-heeled shoes. (See Illustration: Designer Pumps) Sandals at least allow their toes to stretch out somewhat, making the best of an ergonomically unhealthy circumstance.

— Bevin Chu

Explanation: Radiographic Evaluation of Hallux Valgus
Illustration(s): Designer Shoes. 25 year old Female Normal Feet No Shoes. Same Patient in Shoes with 3 inch Heels. No High Heels! Designer Sandals. Designer Pumps
Author(s): Michael L. Richardson, M.D., Sigvard T. Hansen, M.D., Ray F. Kilcoyne, M.D.
Affiliation: Departments of Radiology and Orthopaedic Surgery, University of Washington
Source: http://www.rad.washington.edu/anatomy/halluxvalgus.html
Publication Date: October 11, 2001
Original Language: English
Editor: Bevin Chu, Registered Architect

Nonergonomic! Is Ergonomic Footwear Truly Ergonomic?

Nonergonomic! Is Ergonomic Footwear Truly Ergonomic?
[人因工程 ]
(2003/04/21)


Survey in China and India of Feet That Have Never Worn Shoes

The low incidence of dermatomycotic infection here noted might be attributed to the fact that most foot fungi require dark, warm and damp interdigital spaces for growth such as that provided by shoes and stockings on a foot that has no free outlet for its perspiration. In addition, these bare feet get the beneficial fungicidal effects of the sun’s ultra-violet rays.

No instances among the barefoot feet were found of: Onychrocryptosis, Hyperidrosis, Bromidrosis, Hallux Valgus, Hallux Varus, Bursitis at the first or fifth metatarso-phalangeal articulations.

Almost everyone surveyed showed a marked spacing between the first and second toes such as that found on young babies. The great toe was either pointing straight ahead or slightly abducted to provide a greater weight-bearing base or, possibly, to compensate for a shortened first metatarsal segment.

One hundred and eighteen of those interviewed were rickshaw coolies. Because these men spend very long hours each day on cobblestone or other hard roads pulling their passengers at a run it was of particular interest to survey them. If anything, their feet were more perfect than the others. All of them, however, gave a history of much pain and swelling of the foot and ankle during the first few days of work as a rickshaw puller. But after either a rest of two days or a week’s more work on their feet, the pain and swelling passed away and never returned again. There is no occupation more strenuous for the feet than trotting a rickshaw on hard pavement for many hours each day yet these men do it without pain or pathology. These figures prove that restrictive footgear, particularly ill-fitting footgear, cause most of the ailments of the human foot.

Baby shoes cause great harm to growing, formative feet. The so-called “sentimental” value of baby’s shoes might well be dispensed with.

People who have never worn shoes acquire very few foot defects, most of which are painless and non-debilitating. The range of their foot motions are remarkably great, allowing for full foot activity. Shoes are not necessary for healthy feet and are the cause of most foot troubles. Children should not be encouraged to walk prematurely and should not wear any footwear until absolutely necessary. Footgear is the greatest enemy of the human foot.

Editor’s Comments:

Design at its conscientious best demands a willingness to jettison everything one “knows” and start over with a clean slate. Shulman’s implication that modern man should do away with footwear altogether is admittedly, pretty radical. One need not agree with Shulman’s prescription to recognize that his research casts serious doubt on the alleged necessity of “ergonomic footwear.”

I for one am not willing to go without some kind of footwear in the modern urban environment. Even leaving aside the risk of cuts from rusty nails or broken glass, one hardly wants to put up with dirty feet!

Certain occupations will of course continue to require conventional footwear. In addition to hard hats, construction workers will need to keep wearing steel-toed construction boots to protect themselves from work-related accidents. But off the job blue or white collar workers and professional or amateur athletes need not be constrained by such job-specific considerations.

The challenge for industrial designers is to explore bold new shoe designs that accomodate both the natural characteristics of the human foot and the harsh requirements of Life in the Big City. What the final product will look like is anybody’s guess. Perhaps some sort of high-tech, thin-soled, light-weight, breathable designs will eventually replace the traditional dress and casual shoes we wear in 2003.

We would be naive in the extreme however if we assumed that functional considerations were the primary determinant in shoe styling trends. Consumer footwear purchases are overwhelmingly the result of emotional preferences having nothing whatsoever to do with ergonomic considerations. As anyone familiar with ultra-trendy, pointy-toed, women’s heels knows, the ancient practice of foot-binding never vanished, it merely assumed less extreme forms.

“So there is always this clash between form and function in every design. Look at women’s shoes: purely for the sake of style, women will wear shoes that are expensive and painful.”
— Frank Nuovo, Vice-President in Charge of Design, Nokia

— Bevin Chu

Explanation: Survey in China and India of Feet That Have Never Worn Shoes
Illustration(s): “Ergonomic Athletic Shoes”
Author: Samuel B. Shulman
Affiliation: “Survey in China and India of Feet That Have Never Worn Shoes,” The Journal of the National Association of Chiropodists, 49, 1949, pp. 26-30.
Source: http://sportsmedicine.about.com/gi/dynamic/offsite.htm?site=http%3A%2F%2Fwww.barefooters.org%2Fmedicine%2F
Publication Date: December 27, 1996
Original Language: English
Editor: Bevin Chu, Registered Architect