title: Tests of stepping as indicators of mobility, balance, and fall risk in balance-impaired older adults.
abstract: OBJECTIVE
  To determine the relationships between two tests of stepping ability (the maximal step length (MSL) and rapid step test (RST)) and standard tests of standing balance, gait, mobility, and functional impairment in a group of at-risk older adults.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  University-based laboratory.
  
  
  METHODS
  One hundred sixty-seven mildly balance-impaired older adults recruited for a balance-training and fall-reduction program (mean age 78, range 65-90).
  
  
  METHODS
  Measures of stepping maximally (MSL, the ability to maximally step out and return to the initial position) and rapidly (RST, the time taken to step out and return in multiple directions as fast as possible); standard measures of balance, gait, and mobility including timed tandem stance (TS), tandem walk (TW, both timing and errors), timed unipedal stance (US), timed up and go (TUG), performance oriented mobility assessment (POMA), and 6-minute walk (SMW); measures of leg strength (peak knee and ankle torque and power at slow and fast speeds); self-report measures of frequent falls (>2 per 12 months), disability (Established Population for Epidemiologic Studies of the Elderly (EPESE) physical function), and confidence to avoid falls (Activity-specific Balance Confidence (ABC) Scale). Spearman and Pearson correlation, intraclass correlation coefficient, logistic regression, and linear regression were used for data analysis.
  
  
  RESULTS
  MSL consistently predicted a number of self-report and performance measures at least as well as other standard balance measures. MSL correlations with EPESE physical function, ABC, TUG, and POMA scores; SMW; and peak maximum knee and ankle torque and power were at least as high as those correlations seen with TS, TW, or US. MSL score was associated with the risk of being a frequent faller. In addition, the six MSL directions were highly correlated (up to 0.96), and any one of the leg directions yielded similar relationships with functional measures and a history of falls. Relationships between RST and these measures were relatively modest.
  
  
  CONCLUSIONS
  MSL is as good a predictor of mobility performance, frequent falls, self-reported function, and balance confidence as standard stance tests such as US. MSL simplified to one direction may be a useful clinical indicator of mobility, balance, and fall risk in older adults.
authors.affiliation: Mobility Research Center, Division of Geriatric Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA.
authors.forename: Be-long
authors.initials: BL
authors.lastname: Cho
authors.forename: Diane
authors.initials: D
authors.lastname: Scarpace
authors.forename: Neil B
authors.initials: NB
authors.lastname: Alexander
mesh_terms: D000058:Accidental Falls / Q000706:statistics & numerical data; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D016330:Frail Elderly; D005684:Gait / Q000502:physiology; D015577:Geriatric Assessment; D006801:Humans; D007866:Leg / Q000502:physiology; D008124:Locomotion / Q000502:physiology; D016015:Logistic Models; D008297:Male; D009135:Muscular Diseases / Q000503:physiopathology*; D004856:Postural Balance / Q000502:physiology*; D011237:Predictive Value of Tests; D012307:Risk Factors; D018709:Statistics, Nonparametric; D013997:Time Factors; D019415:Torque; D016138:Walking / Q000502:physiology*