Characterisation of the responsive properties of two running-specific prosthetic models

Prosthet Orthot Int. 2017 Apr;41(2):141-148. doi: 10.1177/0309364616660249. Epub 2016 Aug 6.

Abstract

Background: The need for information regarding running-specific prosthetic properties has previously been voiced. Such information is necessary to assist in athletes' prostheses selection.

Objectives: This study aimed to describe the characteristics of two commercially available running-specific prostheses.

Study design: The running-specific prostheses were tested (in an experimental setup) without the external interference of athlete performance variations.

Methods: Four stiffness categories of each running-specific prosthetic model (Xtend and Xtreme) were tested at seven alignment setups and three drop masses (28, 38 and 48 kg). Results for peak ground reaction force (GRFpeak), contact time ( tc), flight time ( tf), reactive strength index (RSI) and maximal compression (Δ L) were determined during controlled dropping of running-specific prostheses onto a force platform with different masses attached to the experimental setup.

Results: No statistically significant differences were found between the different setups of the running-specific prostheses. Statistically significant differences were found between the two models for all outcome variables (GRFpeak, Xtend > Xtreme; tc, Xtreme > Xtend; tf, Xtreme > Xtend; RSI, Xtend > Xtreme; Δ L, Xtreme > Xtend; p < 0.05).

Conclusion: These findings suggest that the Xtreme stores more elastic energy than the Xtend, leading to a greater performance response. The specific responsive features of blades could guide sprint athletes in their choice of running-specific prostheses. Clinical relevance Insights into the running-specific prosthesis (RSP) properties and an understanding of its responsive characteristics have implications for athletes' prosthetic choice. Physiologically and metabolically, a short sprint event (i.e. 100 m) places different demands on the athlete than a long sprint event (i.e. 400 m), and the RSP should match these performance demands.

Keywords: Biomechanics; mechanical characteristics; prosthetic design; prosthetic feet; prosthetics; running-specific prosthetics; testing of prosthetic and orthotic components.

MeSH terms

  • Amputation / rehabilitation
  • Artificial Limbs*
  • Biomechanical Phenomena
  • Humans
  • Leg
  • Models, Anatomic
  • Prosthesis Design / methods*
  • Prosthesis Fitting / methods*
  • Running / physiology*
  • Sensitivity and Specificity
  • Stress, Mechanical*
  • Weight-Bearing