title: Lower extremity kinematics during walking and elliptical training in individuals with and without traumatic brain injury.
abstract: OBJECTIVE
  Elliptical training may be an option for practicing walking-like activity for individuals with traumatic brain injuries (TBI). Understanding similarities and differences between participants with TBI and neurologically healthy individuals during elliptical trainer use and walking may help guide clinical applications incorporating elliptical trainers.
  
  
  METHODS
  Ten participants with TBI and a comparison group of 10 neurologically healthy participants underwent 2 familiarization sessions and 1 data collection session. Kinematic data were collected as participants walked on a treadmill or on an elliptical trainer. Gait-related measures, including coefficient of multiple correlations (a measure of similarity between ensemble joint movement profiles; coefficient of multiple correlations [CMCs]), critical event joint angles, variability of peak critical event joint angles (standard deviations [SDs]) of peak critical event joint angles, and maximum Lyapunov exponents (a measure of the organization of the variability [LyEs]) were compared between groups and conditions.
  
  
  RESULTS
  Coefficient of multiple correlations values comparing the similarity in ensemble motion profiles between the TBI and comparison participants exceeded 0.85 for the hip, knee, and ankle joints. The only critical event joint angle that differed significantly between participants with TBI and comparison participants was the ankle during terminal stance. Variability was higher for the TBI group (6 of 11 comparisons significant) compared with comparison participants. Hip and knee joint movement patterns of both participants with TBI and comparison participants on the elliptical trainer were similar to walking (CMCs ≥ 0.87). Variability was higher during elliptical trainer usage compared with walking (5 of 11 comparisons significant). Hip LyEs were higher during treadmill walking. Ankle LyEs were greater during elliptical trainer usage.
  
  
  CONCLUSIONS
  Movement patterns of participants with TBI were similar to, but more variable than, those of comparison participants while using both the treadmill and the elliptical trainer. If incorporation of complex movements similar to walking is a goal of rehabilitation, elliptical training is a reasonable alternative to treadmill-based training.Video Abstract available (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A65) for more insights from the authors.
authors.affiliation: Movement and Neurosciences Center, Institute for Rehabilitation Science and Engineering, Madonna Rehabilitation Hospital, Lincoln, Nebraska (T.W.B, J.M.B, A.P.T.); and Nebraska Biomechanics Core Facility, University of Nebraska Omaha (T.W.B, N.S.).
authors.forename: Thad
authors.initials: T
authors.lastname: Buster
authors.forename: Judith
authors.initials: J
authors.lastname: Burnfield
authors.forename: Adam P
authors.initials: AP
authors.lastname: Taylor
authors.forename: Nicholas
authors.initials: N
authors.lastname: Stergiou
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology; D001930:Brain Injuries / Q000503:physiopathology / Q000534:rehabilitation*; D005080:Exercise Test; D005081:Exercise Therapy; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D035002:Lower Extremity / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D016138:Walking / Q000502:physiology*