Validity and reliability of an internet-based temporal gait assessment tool with healthy adults: a pilot study

To assess in healthy adults the validity and the inter- and intrarater reliability of the Internet-based Shaw Gait Assessment (SGA).

Concurrent test-retest reliability and validity study with participants, 4 raters, and the Elite motion analysis system (used as the criterion standard).

Motion analysis laboratory in a university physical therapy department.

Convenience sample of 16 healthy men and women (age range, 28-53y).

Each subject performed 2 consecutive walks "at a comfortable pace" on a 6-m walkway. A video camera from the Elite motion analysis system filmed reflective markers, which were attached to subjects' shoes, and the reflective markers provided the criterion standard. Four raters simultaneously recorded each walk by using laptop computers and the SGA.

Paired t test (5% level) for average differences between each test and retest for raters and the Elite; Pearson correlations, limits of agreement, and coefficients of variation (CVs) for validity of the tool; intraclass correlation coefficients (ICCs) for inter- and intrarater reliability.

Pearson product moment correlation coefficients between each of the raters and the Elite ranged from .92 to .95 for speed, from .85 to .97 for cadence, from .87 to .92 for step length, from .61 to .84 for left advance limb time, and from .68 to .83 for right advance limb time. Pooled CVs for all variables were below 8% for all raters and the Elite. Pooled ICCs for intrarater reliability were .89 for speed, .99 for cadence, .84 for step length, .76 for left limb advance time, and .84 for right limb advance time. Interrater ICCs were .89 for speed, .82 for cadence, .76 for step length, .66 for left limb advance time, and .81 for right limb advance time.

The SGA is a valid and reliable tool for several key temporal measures of gait in a healthy adult population.