Adaptation and prosthesis effects on stride-to-stride fluctuations in amputee gait

Shane R. Wurdeman, Sara A Myers, Adam L. Jacobsen, Nicholas Stergiou

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

Twenty-four individuals with transtibial amputation were recruited to a randomized, crossover design study to examine stride-to-stride fluctuations of lower limb joint flexion/extension time series using the largest Lyapunov exponent (λ). Each individual wore a "more appropriate" and a "less appropriate" prosthesis design based on the subject's previous functional classification for a three week adaptation period. Results showed decreased λ for the sound ankle compared to the prosthetic ankle (F 1,23 = 13.897, p = 0.001) and a decreased λ for the "more appropriate" prosthesis (F 1,23 = 4.849, p = 0.038). There was also a significant effect for the time point in the adaptation period (F 2,46 = 3.164, p = 0.050). Through the adaptation period, a freezing and subsequent freeing of dynamic degrees of freedom was seen as the λ at the ankle decreased at the midpoint of the adaptation period compared to the initial prosthesis fitting (p = 0.032), but then increased at the end compared to the midpoint (p = 0.042). No differences were seen between the initial fitting and the end of the adaptation for λ (p = 0.577). It is concluded that the λ may be a feasible clinical tool for measuring prosthesis functionality and adaptation to a new prosthesis is a process through which the motor control develops mastery of redundant degrees of freedom present in the system.

Original languageEnglish (US)
Article numbere100125
JournalPloS one
Volume9
Issue number6
DOIs
StatePublished - Jun 23 2014

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Amputees
prostheses
gait
Gait
Ankle
Prostheses and Implants
Cross-Over Studies
Prosthesis Fitting
Prosthesis Design
Amputation
Freezing
Lower Extremity
Joints
amputation
Degrees of freedom (mechanics)
Prosthetics
limbs (animal)
Time series
time series analysis
freezing

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)

Cite this

Adaptation and prosthesis effects on stride-to-stride fluctuations in amputee gait. / Wurdeman, Shane R.; Myers, Sara A; Jacobsen, Adam L.; Stergiou, Nicholas.

In: PloS one, Vol. 9, No. 6, e100125, 23.06.2014.

Research output: Contribution to journalArticle

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