Abstract

Background: The time taken to complete the 400 m Walk Test has been shown to be significantly correlated with mortality rate and overall health. However, the test may be difficult to administer using a standardized course length, and it is known that changing the course length influences the total time to complete the test. GO_PT, a mobile phone application, allows for assessment of steady-state cadence, steadystate gait speed, and turn duration during a 400 m Walk Test, but it is presently unknown whether those outcomes are influenced by course length. It was hypothesized that steady-state gait characteristics and average turn duration would be unaffected by course length.

Methods: Twenty-one apparently healthy adults were recruited for this study (eight females: 43 to 79 years, and 13 males: 40 to 85 years). The testing took place on an indoor track with a hard surface made out of synthetic rubber. The subjects completed a 400 m Walk Test three times on a linear course with approximately 10 minutes of rest in between each trial. The three lengths used for the trials were 16, 20, and 25 m. Steady-state cadence, steady-state gait speed, turn duration, and total time were assessed using the GO_PT mobile phone application. Repeated measures ANOVA was used to test for a main effect of the three course lengths on 400 m Walk Test outcomes.

Results: Steady-state cadence was shown to be unaffected by course length (132.3 +/- 12.4, 132.9 +/- 13.0, and 132.6 +/- 13.1 steps/min for the 16, 20, and 25 m courses, respectively). Course length did not significantly influence steady-state gait speed either (1.65 +/- 0.26, 1.67 +/- 0.27, and 1.67 +/- 0.26 m/s for the 16, 20, and 25 m courses, respectively). However, turn duration did significantly decrease with increasing course length (4.3 +/- 0.9, 4.2 +/- 0.9, and 4.1 +/- 0.8 s for the 16, 20, and 25 m courses, respectively). As expected, the total time of completion significantly decreased with increasing course length (281.7 +/- 51.6, 272.1 +/- 53.6, and 265.3 +/- 50.5 s for the 16, 20, and 25 m courses, respectively).

Conclusions: Course length was shown to be inversely related to 400 m Walk Test completion time. On the other hand, course lengths between 16 and 25 m appear to have no important effect on steady-state gait cadence, steady-state gait speed, or turn duration. Except for total time, a technician may use the 16, 20, and 25 m course lengths interchangeably when utilizing the GO_PT app.

Keywords: Six Minute Walk Test, gait speed, cadence, turn duration