The reliability and validity of measures of gait variability in community-dwelling older adults.

OBJECTIVE To examine the test-retest reliability and concurrent validity of variability of gait characteristics. DESIGN Cross-sectional study. SETTING Research laboratory. PARTICIPANTS Older adults (N=558) from the Cardiovascular Health Study. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Gait characteristics were measured using a 4-m computerized walkway. SD determined from the steps recorded were used as the measures of variability. Intraclass correlation coefficients (ICC) were calculated to examine test-retest reliability of a 4-m walk and two 4-m walks. To establish concurrent validity, the measures of gait variability were compared across levels of health, functional status, and physical activity using independent t tests and analysis of variances. RESULTS Gait variability measures from the two 4-m walks demonstrated greater test-retest reliability than those from the single 4-m walk (ICC=.22-.48 and ICC=.40-.63, respectively). Greater step length and stance time variability were associated with poorer health, functional status and physical activity (P<.05). CONCLUSIONS Gait variability calculated from a limited number of steps has fair to good test-retest reliability and concurrent validity. Reliability of gait variability calculated from a greater number of steps should be assessed to determine if the consistency can be improved.

[1]  U. Nayak,et al.  The effect of age on variability in gait. , 1984, Journal of gerontology.

[2]  Jeffrey M. Hausdorff,et al.  Gait variability and fall risk in community-living older adults: a 1-year prospective study. , 2001, Archives of physical medicine and rehabilitation.

[3]  Brian Caulfield,et al.  Increasing the number of gait trial recordings maximises intra-rater reliability of the CODA motion analysis system. , 2007, Gait & posture.

[4]  J. M. Rothstein.  Measurement in physical therapy , 1985 .

[5]  Richard W. Bohannon.  Comfortable and maximum walking speed of adults aged 20-79 years: reference values and determinants. , 1997, Age and ageing.

[6]  L. Fried,et al.  Recruitment of adults 65 years and older as participants in the Cardiovascular Health Study. , 1993, Annals of epidemiology.

[7]  C. J. V. van Uden,et al.  Test-retest reliability of temporal and spatial gait characteristics measured with an instrumented walkway system (GAITRite®) , 2004, BMC musculoskeletal disorders.

[8]  S. Studenski,et al.  Too much or too little step width variability is associated with a fall history in older persons who walk at or near normal gait speed , 2005, Journal of NeuroEngineering and Rehabilitation.

[9]  W. Satariano,et al.  Reliability of physical performance and self-reported functional measures in an older population. , 1998, The journals of gerontology. Series A, Biological sciences and medical sciences.

[10]  Subashan Perera,et al.  Gait variability and the risk of incident mobility disability in community-dwelling older adults. , 2007, The journals of gerontology. Series A, Biological sciences and medical sciences.

[11]  P. A. Hageman,et al.  Comparison of gait of young women and elderly women. , 1986, Physical therapy.

[12]  Jeffrey M. Hausdorff,et al.  Etiology and modification of gait instability in older adults: a randomized controlled trial of exercise. , 2001, Journal of applied physiology.

[13]  Bernard R. Rosner,et al.  Fundamentals of Biostatistics. , 1992 .

[14]  O. Edholm,et al.  Studies of gait and mobility in the elderly. , 1981, Age and ageing.

[15]  M. Batavia,et al.  The validity and reliability of the GAITRite system's measurements: A preliminary evaluation. , 2001, Archives of physical medicine and rehabilitation.

[16]  R. Kronmal,et al.  The Cardiovascular Health Study: design and rationale. , 1991, Annals of epidemiology.

[17]  T. M. Owings,et al.  Step width variability, but not step length variability or step time variability, discriminates gait of healthy young and older adults during treadmill locomotion. , 2004, Journal of biomechanics.

[18]  Mb Lerner-Frankiel.  Functional community ambulation : what are your criteria? , 1990 .

[19]  M. G. Kovar,et al.  The Supplement on Aging to the 1984 National Health Interview Survey. , 1987, Vital and health statistics. Ser. 1, Programs and collection procedures.

[20]  B. E. Maki,et al.  Gait Changes in Older Adults: Predictors of Falls or Indicators of Fear? , 1997, Journal of the American Geriatrics Society.

[21]  T. M. Owings,et al.  Measuring step kinematic variability on an instrumented treadmill: how many steps are enough? , 2003, Journal of biomechanics.

[22]  M Peyrot,et al.  Causal analysis: theory and application. , 1996, Journal of pediatric psychology.

[23]  Jeffrey M. Hausdorff,et al.  Increased gait unsteadiness in community-dwelling elderly fallers. , 1997, Archives of physical medicine and rehabilitation.

[24]  A M Jette,et al.  Are performance-based measures sufficiently reliable for use in multicenter trials? Musculoskeletal Impairment (MSI) Study Group. , 1999, The journals of gerontology. Series A, Biological sciences and medical sciences.

[25]  J. Donelan,et al.  Mechanical and metabolic requirements for active lateral stabilization in human walking. , 2004, Journal of biomechanics.