Validity of the Optogait photoelectric system for the assessment of spatiotemporal gait parameters

The purpose of this study was to evaluate the discriminant and concurrent (criterion-related) validity of a recently introduced floor-based photocell system (Optogait, Microgate, Bolzano, Italy) with a validated electronic walkway for the assessment of spatiotemporal gait parameters. Fifteen patients (mean age±standard deviation: 65±7 years) with total knee arthroplasty and 15 healthy matched control subjects were asked to walk at different velocities while gait variables were recorded simultaneously by the two instruments. The Optogait and the criterion instrument detected the same differences in walking parameters between patients and controls. Intraclass correlation coefficients ranged between 0.933 (swing time) and 0.999 (cycle time, cadence and walking speed). Cycle time and stance time were significantly longer, while swing time, step length, cadence and walking speed were significantly lower for Optogait (p<0.001) compared to the criterion instrument. The Optogait system demonstrated high discriminant and concurrent validity with an electronic walkway for the assessment of spatiotemporal gait parameters in orthopedic patients and healthy controls. However, the two measuring instruments cannot be used interchangeably for quantitative gait analysis, and further validation of floor-based photocell technology is warranted.