The Enko running shoes were first publicized in late 2014. They are a unique spring loaded footwear that was developed over 12 years by Christian Freschi. They are based in Villepinte, Île-de-France, France. The first batch of footwear was launched by a crowd funding project at Indiegogo early in 2015.
This shoe has mechanical spring loaded parts that are integrated into the sole. This design provides the shoe with additional cushioning and energy release. This is claimed to increase comfort and performance. The springs are interchangeable and are determined based on the weight of the runner. Calculations provided by the company suggest that the gains provided by the shock absorbers in terms of mechanical energy is between 6% and 14% depending on the speed of the runner. The details of these calculations are provided in this document.
The design of the Enko running shoes are underpinned with a patent:
The invention relates to a shoe including a shoe portion and a sole, the sole including two main portions that are pivotably connected together and being characterized in that the second front portion, secured to the shoe portion of the forepart, extends to the rear of a first swivel pin in a lever arm portion, projects to the rear within the same plane as that of the front portion, and is kinetically secured to the latter. The rear end of said arm has a second swivel pin with the end of at least one resilient module, the other end of which is pivotably connected around a third swivel pin secured to the rear end of the rear portion of the sole.
Video of runner using the shoe:
- does posterior protrusion of 'spring' increase risk for anterior compartment syndrome due to the lever arm to the ankle joint?
- not clear if in compliance with the IAAF rules