B. Cuffia, MS, PT, MossRehab Hospital, Philadelphia, PA

C. Palmer, PTA, MossRehab Hospital, Philadelphia, PA

S. Pierce, MS, PT, MossRehab Hospital, Philadelphia, PA

S. Schaumburg, MS, PT, MossRehab Hospital, Philadelphia, PA

R. Wellmon, MS, PT, NCS, MossRehab Hospital, Philadelphia, PA

Purpose: The purpose of this investigation was to examine interrater, intrarater, and test-retest reliability and concurrent validity of the Gait Grid Gait Mat (GG) for assessing selected temporal and spatial gait parameters in healthy subjects.

Subjects: Thirty-six healthy subjects (19 males and 17 females, mean age = 35.4 + 9.9 years, range = 20.8-59.2 years) were recruited through convenience sampling as particpants for this study.

Methods: Data was collected using the GG, which is a black naugahyde mat measuring 7.62 m by 0.762 m, and the Gait Mat II (GM II) which is a computerized gait analysis system. The GG is demarcated with consecutively spaced lines separated by a distance of 4 cm. Five raters were used to collect data from the GG using a traditional inked footprint method and the procedure recommended by the grid's manufacturer. Data were also collected by superimposing the GG over the GM II.

Analysis: The GG and GM II were used to collect footfall data to calculate mean step length, mean stride length, and mean gait velocity. These variables were examined to assess interrater reliability, intrarater reliability, test retest reliability, and concurrent validity using interdass correlation coefficients (ICC).

Results: ICC for the GG were as follows; interrater reliability = .99, intrarater reliability = .95-.97, test-retest reliability = .90-.97, and concurrent validity = .90-.98. ICC using the inked footprint method and the GG were as follows: interrater reliability = .99, intrarater reliability = .93-.97, and test-retest reliability = .92-.96.

Conclusion: The GG was found to have high interrater, intrarater, and test-retest reliability. When examining concurrent validity, the GG produced highly reliable results using the procedure outlined by the manufacturer.

Relevance: The GG appears to offer clinicians a reliable and valid low cost means for assessing selected ambulation characteristics. The GG, when compared to the traditional inked footprint method and a computerized gait assessment system, was able to generate reliable results. The GG requires less time to collect footfall data as compared to the inked footprint method. Further research is necessary examining the reliability of the GG for individuals with pathology.