title: Effects of physical exertion on trans-tibial prosthesis users' ability to accommodate alignment perturbations.
abstract: BACKGROUND
  It has long been reported that a range of prosthesis alignments is acceptable in trans-tibial prosthetics. This range was shown to be smaller when walking on uneven surfaces. It has also been argued that findings on gait with prostheses that were obtained under laboratory conditions are limited in their applicability to real-life environments.
  
  
  OBJECTIVE
  This study investigated the hypothesis that efforts to compensate for suboptimal alignments by active users of trans-tibial prostheses become less effective when levels of physical exertion increase.
  
  
  METHODS
  A 2 × 2 repeated-measures analysis of variance was conducted to compare the effects of physical exertion and subtle alignment perturbations on gait with trans-tibial prostheses.
  
  
  METHODS
  The gait of eight subjects with trans-tibial amputation was analyzed when walking with two different prosthesis alignments and two different physical exertion levels. The main and interaction effects were statistically evaluated.
  
  
  RESULTS
  Bilateral step length symmetry and measures of step variability within the same leg were found to be affected by the intervention. There was no significant effect on index variables that combined kinematic or kinetic measures.
  
  
  CONCLUSIONS
  Findings showed that persons with trans-tibial prostheses responded heterogeneously to the interventions. For most variables, the research hypothesis could not be confirmed.
  
  
  CONCLUSIONS
  Findings support the practice of allotting several sessions to the alignment of trans-tibial prostheses, as users' gait responds differently to perturbations when external factors (e.g. exertion) change. Furthermore, the found inhomogeneity in the population of persons with trans-tibial amputation supports the use of technical gait assessment methods in clinical practice.
authors.affiliation: University of Pittsburgh, Pittsburgh, PA, USA gfiedler@pitt.edu.
authors.forename: Goeran
authors.initials: G
authors.lastname: Fiedler
authors.affiliation: University of Wisconsin-Milwaukee, Milwaukee, WI, USA.
authors.forename: Brooke A
authors.initials: BA
authors.lastname: Slavens
authors.affiliation: University of Wisconsin-Milwaukee, Milwaukee, WI, USA.
authors.forename: Kristian M
authors.initials: KM
authors.lastname: O'Connor
authors.affiliation: University of Wisconsin-Milwaukee, Milwaukee, WI, USA.
authors.forename: Roger O
authors.initials: RO
authors.lastname: Smith
authors.affiliation: University of Washington, Seattle, WA, USA.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Hafner
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000671:Amputation, Surgical / Q000379:methods / Q000534:rehabilitation*; D000674:Amputees / Q000534:rehabilitation*; D000886:Anthropometry; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D005082:Physical Exertion / Q000502:physiology*; D011379:Prognosis; D011474:Prosthesis Design; D017755:Prosthesis Fitting / Q000009:adverse effects / Q000379:methods*; D016059:Range of Motion, Articular / Q000502:physiology; D018570:Risk Assessment; D012494:Sampling Studies; D013977:Tibia / Q000601:surgery; D016138:Walking / Q000502:physiology*; D016474:Weight-Bearing
keywords: Gait; gait analysis; prosthetics; rehabilitation; rehabilitation of prostheses users