Four-Meter Gait Speed: Normative Values and Reliability Determined for Adults Participating in the NIH Toolbox Study.

OBJECTIVES: To establish reference values and determine test-retest reliability for usual and maximal 4-meter gait speed. DESIGN: Cross-sectional observational study. SETTING: Offices in 10 geographically dispersed cities in the United States. PARTICIPANTS: Men and women (N=1320), aged 18 to 85 years, enrolled in the National Institutes of Health Toolbox norming study. INTERVENTION: Not applicable. MAIN OUTCOME MEASURES: Specifically used were data from men and women who were timed over 4 meters (after a static start) while walking at their usual and maximum speeds. Norms for usual and maximum gait speed were derived using data from 1320 participants. Test-retest reliability for 164 participants was described using paired t tests, intraclass correlation coefficients (ICCs), and minimal detectable changes (MDCs). RESULTS: Mean usual speed was 1.12 meters per second, whereas mean maximum speed was 1.61 meters per second. As a general linear model showed 4-meter gait speed to differ significantly according to gait condition (speed), sex, and age group; estimates of normal were calculated accordingly. The usual speed of 80- to 85-year-old women was lowest at 0.95 meters per second; the maximum speed of 18- to 29-year-old men was highest at 1.85 meters per second. Test-retest measures did not differ significantly, but the ICCs were only fair and the MDCs were high. CONCLUSIONS: Normative reference values provided herein may be helpful in interpreting measurements of 4-meter gait speed obtained from adult men and women. The limited reliability of the gait speed measurements, however, limits their usefulness in making judgments regarding change.