As the athletics events at the 2024 Olympic and Paralympic Games get underway, Niama Knapp looks at advances in shoe technology and the “super shoes” powering the athletes on track in Paris.
One-hundredth of a second, or a single centimetre, can be the difference between winning an Olympic gold medal and a silver medal.
With so much at stake and such fine margins of victory, sporting goods companies compete to develop products that help elite athletes gain a competitive advantage.
Innovation in running shoes has intensified in recent years, but what is behind the rise in “super shoes” and what are the IP considerations for product developers?
Super shoes
Nike introduced the Vaporfly 4% in 2017, claiming (and since proving) a 4% increase in running economy (a measure of running efficiency) due to its curved carbon plate, and 31mm-thick super soft and superlight foam.
There’s definitely something to super shoe claims to better running efficiency. Since their advent, almost every long-distance road-running world record has been broken in men’s and women’s competitions.
Advances in shoe technology have been so significant that, in 2020, World Athletics amended its rules regarding competition shoes for elite athletes to state that: the shoe must have been available for purchase on the open retail market for at least four months; the sole thickness must not exceed 40 mm; and the shoe must not contain more than one rigid embedded plate or blade of any material – a decision which might be considered surprising, considering World Athletics’ previous stance on running shoe technology. They not only banned the use of PUMA’s 1960s “brush spikes”, they also disqualified any official record set when wearing them.
Features – carbon fibre plate and midsole foam
The use of carbon fibre in running shoes is not new. As far back as 1989, Brooks introduced “propulsion technology”, featuring a propulsion plate composed of multiple layers of carbon filament fibres.
Perhaps of more interest was Nike’s use of high-energy-return Pebax®, a trademarked and patented variation of polyether block amide (PEBA), moulded to form a foam midsole. PEBA, a block copolymer consisting of soft polyether and rigid polyamide blocks, is a thermoplastic elastomer. Its wide and variable range of durability and flexibility is achieved through different block ratios. This variability in combination with PEBA being lightweight enables multiple uses in sport shoe technology, from uppers to outsole and midsole components.
Conventionally, running shoe midsoles are made of ethylene vinyl acetate (EVA), which provides cushioning and a spring back of, at most, 65% of the energy released into them. In contrast, Pebax® returns 87%. This is due to a more lightweight foam moulded into to a thicker midsole, which, in turn, correlates to a higher energy return: hence, World Athletics’ restriction on sole thickness.
It’s the combination of the carbon fibre plate and superlight foam that makes a true super shoe – thick midsoles alone would make for extremely unstable shoes. This problem is solved with a stabilising curved carbon-fibre plate. However, this is only one of the plate’s benefits – it also protects from eccentric loading (meaning less muscle damage, longer training times and quicker recovery) and repositions the centre of pressure to reduce joint work. These benefits are exemplified by athletes such as Sifan Hassan, who will attempt to run three events (the 5,000m, 10,000m and the Marathon) at the Paris Olympics – a feat never before attempted.
Role of Intellectual property in super shoe development
Running shoes can be protected by various types of IP – patents for the technology, designs for the shape and look and trademarks for the brand name and logo.
For example, Pebax® foam is trademarked (registration number 1254164 (US), 009973991 (EU), UK00913783022 (UK)) by the French chemical company Arkema. More recently, staying in trend with the surge in interest in renewable materials, Arkema has patented a block copolymer (such as PEBA) derived from renewable materials and a method for making said block copolymer (see EP2342262A2). Similarly, Nike owns a number of patents directed at a combination of the above PEBA technology with carbon plates (see US20170095034B2, US20190373982B2 and US20180184757B2).
The Vaporfly is a true testament to the power of IP. As top athletes broke or rejected sponsorship deals for the opportunity to switch to performance-enhancing super shoes, and World Athletics modified their rules to restrict competition shoe wear, competition between sporting goods companies to develop and patent their own versions of super shoe technology skyrocketed. Hoka was first to catch up in 2019 with HOKA ONE ONE® technology, featuring a carbon fibre plate and EVA. Other brands, such as ASICS, Saucony, Brooks, Adidas and New Balance followed suit with half- or full-length curved carbon fibre plates combined with PEBA, EVA, TPU (thermoplastic polyurethane) or OBC (olefin block copolymers) foams, or combinations thereof.
We can expect the Paris Olympics to showcase a variety of super shoes, and potentially the next super shoe technology – LightSprayTM technology. A single-step process designed by On which sprays a lightweight and high-performance upper around the shoe in just three minutes. Not only is this technology lightweight, but it is also said to reduce waste during the shoe manufacturing process.
Traditionally, innovation in running shoes, compared to other sports technologies, has moved at a slower rate. However, the super-shoe breakthrough has already, and will no doubt further, encourage innovation that will additionally push the boundaries of performance, and with this comes increasing importance for companies to protect their products through the various routes IP has to offer.
