Accessible Summary:

Purpose: Bernard Marti published a epidemiological report in which he related running injury frequency with shoe model and manufacturer. After correcting for variables of age, gender, running mileage and previous injury, the most prominent finding was a relation between injury frequency and shoe cost - the more expensive shoes accounting for 123% greater injury frequency than the cheapest ones. The purpose of this experiment was to explain Marti's data. What made this relation intriguing was that both expensive and cheap shoes are made with almost identical sole materials, therefore their performance in terms of impact should be identical.  The one difference between expensive and cheap shoes is how they are advertised - expensive shoes are advertised deceptively as possessing features that enhance protection, with no data to support any protective advantage. The running shoe is marketed mainly as a protective device with expensive ones have additional protective features than cheap ones. Novel footwear technology is usually found on more expensive models.

Synopsis: This experimental tests the influence of deceptive advertising suggesting protection on eliciting a false sense of security and dangerous behavior.   Impact was measured when subjects stepped off of a low platform on to a rigid support surface covered the identical support surface encased by a fabric of different colors so as to look different. Prior to each conditional subjects were given a written message stating that the material they were landing on came from either cheap, expensive, or new high technology products. Impact varied significantly as a function of advertising message.  Advertising message stating cheapest resulted in significantly less impact than the other conditions. Expensive and new technology messages resulted in significantly higher impact.  Trends increased with repeated footfalls.  The advertising message caused a false sense of security with expensive and new technology products and cautious behavior with those advertised as cheap.

Significance: This was the first report to provide data indicating that advertising of protective devices protective devices can strongly influence user behavior.  In the case of athletic footwear, falsely and deceptively advertising expensive models as offering greater protection though advanced features appears to be the cause of the 123% greater injury frequency experienced by users of expensive models.  This raises the need for honest advertising of protective devices.