A study describing the characteristics of two commercially available running-specific prosthetic feet concluded that the specific responsive features of the blades could guide sprint athletes’ choice of prostheses. The study was published online August 1 in Prosthetics and Orthotics International.
The researchers tested four stiffness categories of Össur’s Cheetah® Xtend™ and Cheetah Xtreme™ at seven alignment setups and three drop masses (28, 38, and 48kg), using an experimental setup to avoid the external interference of athlete performance variations. Results for peak ground reaction force, contact time, flight time, reactive strength index, and maximal compression were determined during controlled dropping of the prostheses onto a force platform with the different masses attached to the experimental setup.
No statistically significant differences were found between the different setups of the running-specific prostheses, however, statistically significant differences were found between the two models for all outcome variables:
- Peak ground reaction force: Xtend > Xtreme
- Contact time: Xtreme > Xtend
- Flight time: Xtreme > Xtend
- Reactive strength index: Xtend > Xtreme
- Maximal compression: Xtreme > Xtend
According to the researchers, the findings suggest that the Xtreme stores more elastic energy than the Xtend, which will lead to a greater performance response among sprint athletes.
Editor’s note: The study authors do not appear to have a conflict of interest.