The impact of testing protocol on recorded gait speed.

BACKGROUND: Gait speed predicts disability, cognitive decline, hospitalization, nursing home admission and mortality. Although gait speed is often measured in clinical practice and research, testing protocols vary widely and their impact on recorded gait speed has yet to be explored.

OBJECTIVES: Our purpose is to describe and compare gait speeds obtained from different testing protocols in the same individuals.

DESIGN: Cross-sectional.

SETTING: University research setting. Participants Subjects were 104 community-dwelling older adults who could ambulate household distances independently (mean age = 77.2 ± 6.1).

MEASUREMENTS: Gait speed was recorded over 4m using the protocols: (1) standing start, usual pace over ground, (2) walking start, usual pace over ground with an optokinetic device, (3) walking start, usual pace over ground with a stop watch (4) walking start, usual pace on a computerized walkway, and (5) walking start, fast pace on a computerized walkway. A linear mixed model and pairwise comparisons was used to compare gait speeds within individuals across different protocols.

RESULTS: Mean ± SD gait speed for each condition was: standing start, usual pace over ground 0.97 ± 0.23 m/s; walking start, usual pace over ground 1.14 ± 0.2 5m/s; walking start, usual pace on walkway 1.01 ± 0.26 m/s; and walking start, fast pace on walkway 1.31 ± 0.34 m/s. On average, the determined gait speed was 0.17 m/s faster during the walking compared to the standing start (p < .001), 0.07 m/s slower on the computerized walkway compared to over ground (p < .001), and 0.25 m/s faster during the fast pace compared to the usual pace walk (p < .001).

CONCLUSION: Starting protocol (standing vs. walking), testing surface (over ground vs. computerized walkway), and walking pace (usual vs. fast) impact recorded gait speed in older adults. Care should be taken when comparing gait speeds from studies with different testing protocols.