Today’s post is a very nice follow up to the one earlier in the week entitled “Materials: do soft soles improve running shoes?”……which also commented on client perceptions of the footwear. We hope the shoe and R&D companies are paying close attention to the work were are making available here.
Perceiving is believing
What you think matters! Perception of shoe cushioning seems congruent with what you believe. If you THINK the cushioned shoe will be softer, you will probably perceive it as so, even though there may be little to no change in ground reaction forces. Most studies show cushioned shoes actually INCREASE impact forces.
McCAW, STEVEN T.; HEIL, MARK E.; HAMILL, JOSEPH: The effect of comments about shoe construction on impact forces during walking
Medicine & Science in Sports & Exercise: July 2000 - Volume 32 - Issue 7 - pp 1258-1264
conclusions as quoted in their article:
“Footwear designers incorporate a variety of midsole materials and mechanical systems to cushion shock while controlling rearfoot motion. To market shoes, advertising copy and the claims of salespeople often extol the benefits of the materials and design incorporated in a shoe. This marketing strategy is common, as evident from a perusal of a fitness magazine, in spite of a paucity of unbiased biomechanical testing of the validity of many of these claims, and a lack of understanding of how such claims may influence the gait behavior of a purchaser of a pair of shoes.”
It is vital to understand their next research finding from this study,
“The results indicated the impact ground reaction force varied as a function of the advertising message. When subjects were informed that a particular surface provided additional cushioning, impact ground reaction force data were higher (121% of body weight) than when subjects were provided with a warning message (110% of body weight). The results were interpreted as suggestive of subjects moderating impact in accordance with the expected cushioning of the material. That is, subjects were less inclined to use a landing strategy that would reduce impact force if they had been told that cushioning would be provided by the surface material. The study raises the question of how subjects would respond if the cushioning characteristics of a shoe, rather than a landing surface, were altered, because a shoe represents a more personalized aspect of the foot/ground interface.”
From their study they referenced Robbins and Waked:
“Robbins and Waked (15) demonstrated that subjects may be deceived into accepting higher forces during landing if provided with misleading information regarding the energy absorbing characteristics of the landing. Because of research suggesting a possible cause of lower impact peaks in harder shoes to be an intrinsic avoidance mechanism (1), it may be theorized based on expectancy theory that influencing someone to believe that one shoe can absorb more energy than another may result in different ground reaction force values. Contrary and sometimes confusing findings in the literature emphasize the need for further study in the area of perception and energy absorption. The purpose of this study was, therefore, to determine the effect of investigator comments regarding shoe construction on the ground reaction force measured during walking.”
This is an excellent article that seems to suggest that there is far more to it than the engeneering that goes into the shoe. That marketing and consumer assumptions are a part of how a shoe is used and works.
Very interesting ! We hightly recommend you purchase this article here…..