Individual project | Fall 2022 | #Footwear #Sports&Fitness #BrandExtension
In the United States alone, 60 million people participated in running, jogging, and trail running in 2017¹. The sport of long distance running continues to grow at a global level as well, with race participation increasing by 57% from 2008 to 2018². While there are countless reasons for why someone might choose to run, the number one reason reported for people’s choice to run is to stay healthy.³ However, a 2007 systematic review found a 20 to 80% incidence of lower extremity injury in long distance runners, the average incidence rate across all of the studies being 50%.⁴ This data was greatly supported by the findings of my own survey, with 82.9% of respondents reporting dealing with or having dealt with running related injuries.
In a 2011 marathon with over 2000 participants, 93.7% were classified by researchers as rearfoot strikers.⁵ A 2013 study found that “forefoot strikers demonstrated lower patellofemoral stress compared to heel strikers.”⁶ A 2012 study found that “running with [midfoot strikes] barefoot or minimally shod produced the least strain in the tibia throughout the running cycle when compared to heel striking even in a technologically advanced shoe.”⁷ A 2013 study reported that “runners with forefoot strikes had a significant reduction in the loading rate, which is considered an important factor for running injuries.”⁸
“Compared to running in shoes without a drop, running in shoes with drops > 5 mm increases the peak patellofemoral joint stress significantly,” a 2022 study reported.⁹ A 2021 study found that “running in shoes with a 10-mm drop was associated with a higher rate of knee joint injuries… compared with running in shoes without a drop.”¹⁰ This is because the “cushioning (along with an elevated heel) enables runners to land with a dorsiflexed ankle by limiting the discomfort associated with heel contact.”¹¹
For reference, the wildly popular adidas Ultraboost running shoe has a 10 mm drop. While this specific shoe has a higher drop than average, runblogger.com’s database of the 240 models carried in 2015 by runningwarehouse.com calculated the average drop to be 6.72 mm.¹²
Using the zero-drop Altra Escalante 2 as the minimalist shoe placeholder, I prototyped dozens of tactile feedback patterns on interchangeable insoles. The tactile feedback patterns were located under the heel in order to alert the wearer of their own heel striking, so that they may adjust their form until they encounter no more feedback from the shoe. The final prototype involved a plastic bar perpendicularly spanning the heel of the shoe, approximately a quarter inch in height.
Test participant one running in their own standard running shoes.
Test participant one running in the tactile feedback prototype.
A majority of the test participants responded positively to the prototype and objectively improved their foot striking pattern. While not all of them eliminated heel striking immediately upon wearing the prototype, 80% of test participants either adopted a midfoot or forefoot strike or decreased their foot strike angle when heel striking.
1. Statista Research Department, "Running & Jogging - Statistics & Facts," Statista, (November 16, 2020), https://www.statista.com/topics/1743/running-and-jogging/#dossierKeyfigures
2. Jens Jakob Andersen, "The State of Running 2019," International Institute for Race Medicine, (July 16, 2019), https://racemedicine.org/the-state-of-running-2019/
3. Sina Horsthemke, “Running Boom Despite Corona: The Trends 2021,” ISPO, (February 2, 2021), https://www.ispo.com/en/markets/running-boom-despite-corona-trends-2021
4. R.N. van Gent et al., "Incidence and determinants of lower extremity running injuries in long distance runners: a systematic review," British Journal of Sports Medicine 41, no. 8 (August 2007): 469-480, https://doi.org/10.1136%2Fbjsm.2006.033548
5. Mark E. Kasmer et al., “Foot-Strike Pattern and Performance in a Marathon,” International Journal of Sports Physiology and Performance 8, no. 3 (May 2013): 286-292, https://doi.org/10.1123/ijspp.8.3.286
6. Juha-Pekka Kulmala et al., "EFFECTS OF STRIKING STRATEGY ON LOWER EXTREMITY LOADING DURING RUNNING," British Journal of Sports Medicine 47, no. 10 (April 2013), https://bjsm.bmj.com/content/47/10/e3.41
7. A. Sheikh-Warak, "Comparing Strains in the Tibia induced by different Running Styles: Shod heel striking, minimally shod midfoot striking and barefoot," (June 2012): 1-6, https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.467.4655&rep=rep1&type=pdf
8. Yo Shih, Kuan-Lun Lin, Tzyy-Yuang Shiang, “Is the foot striking pattern more important than barefoot or shod conditions in running?” Gait and Posture 38, no. 3 (July 2013): 490-494, https://doi.org/10.1016/j.gaitpost.2013.01.030
9. Masen Zhang et al., "The effect of heel-to-toe drop of running shoes on patellofemoral joint stress during running," Gait and Posture 93, (March 2022): 230-234, https://doi.org/10.1016/j.gaitpost.2022.02.008
10. Masen Zhang et al., "Biomechanical Analysis of Running in Shoes with Different Heel-to-Toe Drops," Applied Sciences 11, no. 24 (December 20, 2021), https://doi.org/10.3390/app112412144
11. Jason Bonacci et al., “Running in a minimalist and lightweight shoe is not the same as running barefoot: a biomechanical study,” British Journal of Sports Medicine 47, no. 6 (January 2013): 387-392, http://dx.doi.org/10.1136/bjsports-2012-091837
12. Runblogger, “Choosing a Running Shoe – Sort By Price, Weight, Stack Height, Heel-Forefoot Drop,” Runblogger.com, (June 10, 2015), https://runblogger.com/choosing-a-running-shoe-drop-weight-price
