title: Characterisation of the responsive properties of two running-specific prosthetic models.
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.
  
  
  OBJECTIVE
  This study aimed to describe the characteristics of two commercially available running-specific prostheses.
  
  
  METHODS
  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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: 1 Stellenbosch University, Stellenbosch, South Africa.
authors.forename: Lara
authors.initials: L
authors.lastname: Grobler
authors.affiliation: 1 Stellenbosch University, Stellenbosch, South Africa.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Ferreira
authors.affiliation: 2 Katholieke Universiteit Leuven, Leuven, Belgium.
authors.forename: Benedicte
authors.initials: B
authors.lastname: Vanwanseele
authors.affiliation: 1 Stellenbosch University, Stellenbosch, South Africa.
authors.forename: Elmarie E
authors.initials: EE
authors.lastname: Terblanche
mesh_terms: D000671:Amputation, Surgical / Q000534:rehabilitation; D001186:Artificial Limbs; D001696:Biomechanical Phenomena; D006801:Humans; D007866:Leg; D008953:Models, Anatomic; D011474:Prosthesis Design / Q000379:methods*; D017755:Prosthesis Fitting / Q000379:methods*; D012420:Running / Q000502:physiology*; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D016474:Weight-Bearing
keywords: Biomechanics; mechanical characteristics; prosthetic design; prosthetic feet; prosthetics; running-specific prosthetics; testing of prosthetic and orthotic components