Responsiveness of 2 procedures for measurement of temporal and spatial gait parameters in older adults.

OBJECTIVE: To determine the responsiveness of the GAITRite system and a stopwatch-footfall count technique for measurement of walking speed, cadence, and stride length during comfortable and fast-paced walking. DESIGN: Criterion standard. SETTING: Research laboratory in a physical therapy education program. PARTICIPANTS: Twenty-four healthy volunteers (13 men, 11 women; mean age 74.5 years) without lower extremity injury or history of falls. INTERVENTIONS: Participants walked across a GAITRite mat with embedded pressure sensors at their self-selected comfortable and fast walking speeds. Simultaneously, an examiner, using a stopwatch, recorded the elapsed time necessary to cross the mat and counted the number of complete footfalls. MAIN OUTCOME MEASURE(S): Walking speed, cadence, and stride length were compared between the GAITRite system and the stopwatch-footfall count technique for both comfortable and fast walking speeds. Responsiveness values for each procedure were described by the 95% minimal detectable change (MDC). RESULTS: During comfortable self-paced walking, MDC values for the stopwatch-footfall count technique ranged from 10% to 65% greater than those obtained for the GAITRite system. During fast self-paced walking MDC values for the stopwatch-footfall count technique ranged from 26% to 65% larger than those measured by the GAITRite system for the temporal and spatial gait performance parameters. CONCLUSIONS: When measured by the GAITRite system, the 95% MDC values for temporal and spatial gait parameters of older community-dwelling adults were more responsive to change than those obtained by the stopwatch-footfall technique. Clinicians should recognize that self-selected walking speed, cadence, and stride length when obtained by an instrumented walkway must be equal to or exceed 12.6 cm/s, 8.4 steps/min, or 7 cm, respectively, for the change to be considered real change and not from measurement error.

Number of strides required for reliable measurements of pace, rhythm and variability parameters of gait during normal and dual task walking in older individuals.

The reliability with which spatiotemporal gait parameters are measured has neither been well-established for variability parameters nor during dual task walking. The purpose of this study was to examine test-retest reliability of three gait parameters representing pace, rhythm and variability in healthy older persons during normal and dual task walking and to determine the number of strides necessary to measure the parameters reliably. Twenty-four healthy adults aged 65 or older participated in the study. Subjects walked during normal and dual task (backward spelling) walking conditions at self-selected speeds and then repeated the tests. Velocity, cadence and variability in stride velocity were measured with GAITRite instrumentation. Intraclass correlation coefficients (ICCs) were calculated and the numbers of strides required to meet desired magnitudes of reliability were estimated with the Spearman-Brown prophecy formula. ICCs for velocity and cadence were high (>0.841) during normal and dual task walking, indicating strong test-retest reliability. Test-retest reliability for variability in stride velocity was moderate (ICC=0.656) in normal walking and poor (ICC=0.226) in dual task walking. While data collected from fewer than 10 to 20 strides may reliably measure velocity and cadence in either normal or dual task walking, measuring variability in stride velocity reliably may require that data be collected from hundreds of strides, particularly in dual task walking.