title: Linear variability of gait according to socioeconomic status in elderly.
abstract: OBJECTIVE
  To evaluate the linear variability of comfortable gait according to socioeconomic status in community-dwelling elderly.
  
  
  METHODS
  For this cross-sectional observational study 63 self- functioning elderly were categorized according to the socioeconomic level on medium-low (n= 33, age 69.0 ± 5.0 years) and medium-high (n= 30, age 71.0 ± 6.0 years). Each participant was asked to perform comfortable gait speed for 3 min on an 40 meters elliptical circuit, recording in video five strides which were transformed into frames, determining the minimum foot clearance, maximum foot clearance and stride length. The intra-group linear variability was calculated by the coefficient of variation in percent.
  
  
  RESULTS
  The trajectory parameters variability is not different according to socioeconomic status with a 30% (range= 15-55%) for the minimum foot clearance and 6% (range= 3-8%) in maximum foot clearance. Meanwhile, the stride length consistently was more variable in the medium-low socioeconomic status for the overall sample (p= 0.004), female (p= 0.041) and male gender (p= 0.007), with values near 4% ​​(range = 2.5-5.0%) in the medium-low and 2% (range = 1.5-3.5%) in the medium-high.
  
  
  CONCLUSIONS
  The intra-group linear variability is consistently higher and within reference parameters for stride length during comfortable gait for elderly belonging to medium-low socioeconomic status. This might be indicative of greater complexity and consequent motor adaptability.
authors.affiliation: Departamento de Kinesiología, Facultad de Ciencias de la Salud, Universidad Católica del Maule, Talca, Chile.
authors.forename: Paul
authors.initials: P
authors.lastname: Medina González
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D057187:Independent Living; D008297:Male; D012737:Sex Factors; D012923:Social Class; D000072797:Walking Speed
keywords: Gait; aging; allostasis; biomechanical phenomena; socioeconomic factors