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ASICS ARTICLE
Athletic Footware: A synergy of Performance
Dr. Chris Bishop PhD Director of Biomechanics, The Biomechanics Lab A lot of people don't give footwear enough credit.
and knowledge 30 years ago compared to now.
Not only is footwear a powerful manipulator of human movement, but it can also have a drastic effect on human performance. So what goes into the design of a shoe that can have such an effect? A lot of hard work, innovative thinking, creative design and calculated execution. As a result of this hard work and innovative thinking, World Athletics has now established rules in footwear design limiting the number of carbon fibre plates as well as the stack height of the midsole. On one hand we can thank NIKE and the controversy around AlphaFLY, yet every company was doing something similar. They were exploring the ability of footwear to influence performance. But this was right at the top end of runners. The elite of the elite. What about our recreational runners? Is there a way we can help them improve performance too? We know from the science that there are three ways in which footwear can influence human performance (through a surrogate measure of running economy): 1.
Shoe mass
2.
Longitudinal bending stiffness
3.
Cushioning
Maximizing all three creates what is known as a 'Synergy of Performance." So let's explore these factors. Firstly - is light mass all the rage? We know light shoes influence performance. This was originally proposed by Ned Frederick back in the 1980s, with the finding of increasing shoe mass by 100g had a negative effect on running economy in the order of magnitude of 1%. Roger Kram and his lab have validated this finding (see Franz et al. 2012), which makes Ned's experimental findings even more impressive given the lack of equipment
Figure extracted from Franz et al. (2012) But is there a point (of explicit mass) by which just putting a shoe on will result in improvements in running economy? A colleague of mine (Dr Joel Fuller who is now at Macquarie Uni) wrote a great review that identified a US size 9 shoe that weighed < 220g would instantaneously result in an improvement in running economy. Yet there was one comment from Kram’s keynote at the Recent FBG symposium in Canada that really resonated with me… “The design of competition shoes for road racing on paved surfaces should not overemphasize weight minimization at the expense of cushioning… (Tung et al. 2014)
So is light weight really better…In pursuit of light weight, what do we compromise? Durability? Energy return? I'm not sure I'm willing to sacrifice both… So moving on…is a stiff forefoot a good idea? We know from the early work out of Calgary by Roy
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