The validity and reliability of the GAITRite system's measurements: A preliminary evaluation

Objective: To compare the concurrent validity and reliability of the GAITRite(TM) computerized gait analysis system with validated paper-and-pencil and video-based methods. Design: Within-groups, repeated-measures design. Setting: Research laboratory in a physical therapy education program. Participant: One healthy woman, age 27 years. Interventions: A subject walked across the walkway of the GAITRite system at various walking rates and degrees of step symmetry for 2 of the 3 analyses. Paper placed over the walkway enabled concurrent paper-and-pencil analysis. The subject was concurrently videotaped from the side. For the other analysis, a stride simulator with known step and stride lengths was applied to the walkway to simulate 2 steps and 1 stride. Main Outcome Measures: Cadence, walking speed, right and left step and stride lengths, and right and left step times. Results: Excellent paper-and-pencil and GAITRite correlations (intraclass correlation coefficient [ICC] > 95) for spatial measures and excellent video-based and GAITRite correlations (ICC > 93) for temporal measures were found. GAITRite measures of step lengths and times were reliable in both walkway center and left-of-center measurements. Conclusions: Based on this data, GAITRite is a valid and reliable tool for measuring selected spatial and temporal parameters of gait.