Concurrent related validity of the GAITRite® walkway system for quantification of the spatial and temporal parameters of gait
Introduction
Measurements of the spatial and temporal parameters of footstep patterns are frequently obtained to identify gait deviations, make diagnoses, determine appropriate therapy and monitor patient progress. Although visual observation is the most common method for assessing gait disorders, it has poor inter-rater and retest reliability [1], [2], [3] as well as poor criterion validity against kinematic analysis [4]. Timed measures of gait using a stopwatch have moderate to high reliability [5], [6], [7] yet limit data collection to mean values for gait speed, stride length and cadence. Measurement of footstep patterns using chalk [8], [9] and ink-pad methods [10], [11], [12] has the advantage of yielding data on step length and step width, yet is time consuming and cumbersome.
Clinicians have recently used commercially available gait measurement tools to quantify the spatial and temporal parameters of the footstep pattern [13], [14], [15]. Most commonly used is the Clinical Stride Analyser® (CSA). The CSA® consists of footswitches placed inside the shoes and attached to a portable data logger worn at the subject's waist. Studies on elderly adults [16] and people with movement disorders arising from stroke [13], [17], Parkinson's Disease (PD), [14], [18], [19], [20], [21], [22] and Huntington's Disease [23] have established high retest reliability, inter-rater reliability and predictive validity. For example, Morris et al. [20] examined the repeatability of CSA® measures of speed, cadence, stride length and percentage of the gait cycle in double limb support (DS% GC) in 15 subjects with PD and 15 matched control subjects. Repeatability was high for measures taken 30 min apart with intraclass correlation coefficient (ICC) values ranging from 0.92 to 0.99. Hill and colleagues [17] quantified the retest reliability of spatiotemporal parameters measured with the CSA® in 22 subjects with stroke. Data collected for two walking trials measured 5 min apart were highly consistent (ICC (2,1) 0.92–0.96). These and other studies [13], [14], [18] indicate that the CSA® can be used as a tool against which to judge the reliability and criterion related validity of other measurement tools.
There are two components of criterion related validity; (i) concurrent validity and (ii) predictive validity. Concurrent validity is established when simultaneous measurements are made by the tool to be validated and the criterion [24]. Predictive validity refers to the ability of the target test to predict the outcome of the criterion test [24]. The aim of this study is to examine the concurrent validity of the GAITRite® with the CSA® for the measurement of footstep patterns in adults. The GAITRite® system is a portable ‘carpet’ walkway that has pressure sensors embedded within its length. Subjects walk over the carpet without the encumbrance of wires or markers and data can be quickly and easily obtained for each step within the entire gait trial. Variables that can be quantified include walking speed, cadence, step length, single and double limb support duration and stride width for individual steps and the step sequence.
A single case report by McDonough et al. [25] explored the concurrent validity of GAITRite® measures of footstep parameters against chalked footsteps markings on the floor. Temporal parameters were validated against a hand-held stopwatch. For the spatial parameters, high ICC's were obtained for right and left step length (ICC (2,1)=0.97, 0.99, respectively) despite the potential for measurement error inherent in the process of using chalk to mark steps. Poor to moderate correlations were obtained between the GAITRite® and stopwatch measures of temporal parameters such as cadence (ICC (2,1)=0.31) and right step time (ICC (2,1)=0.67). A possible source of error from the hand-held stopwatch arises from subjective judgements of the timing of gait cycle events, as well as errors introduced by delays in stopwatch activation.
In a similar study, Selby-Silverstein and Besser [9] compared GAITRite® data with powdered footstep patterns obtained from 22 strides. Although ICC values of 0.99 were reported for step and stride length, the mean absolute error was 0.51 cm for step length and 0.67 cm for stride length. This level of error probably arises from error inherent in attempting to measure from chalk imprints. In the same study Selby-Silverstein et al. correlated outputs from the GAITRite® with the Parotec® system, an insole pressure measurement tool. Two adults with diabetes mellitus were instructed to take different sized steps, yielding moderate correlations between the two systems for the measurement of step and stride time (ICC (2,1)=0.83, 0.77, respectively). The lower than expected correlations may have arisen because of the difference in the temporal resolution of the GAITRite® and the pressure insole system. The differences between the systems in switch and closing time may have reduced the strength of the correlations.
Cutlip et al. [26] recently correlated GAITRite® footstep measures with those obtained on the Peak Performance Technologies Motus 3.1®, a video based movement analysis system. Ten healthy adults were tested simultaneously on both systems at preferred, fast and slow speeds. Step duration and stance and swing duration were strongly correlated (r=0.97, 0.98, 0.94, respectively). The correlation for step length was also high at r=0.93, despite the potential for parallax error due to using only a single camera positioned parallel to the walkway [26]. Whereas the Peak® system calculated spatiotemporal data from a single stride, the GAITRite® calculated data over the entire length of a 4.8 m electronic walkway. The intra-subject variability in the subject footstep patterns over these distances might have reduced the strength of correlation between a single stride and the mean value of several strides. In the presence of intra-subject variability the true variability between the measurement devices cannot be calculated.
The concurrent validity of the spatial and temporal measures of gait obtained by the GAITRite® remain inconclusive because the sample sizes in previous studies have been small (one to ten subjects) and the criterion measures, such as chalked footsteps, have not always been appropriate. The aim of this study is to further evaluate the concurrent validity of the GAITRite® in a large adult sample using the CSA® as the criterion measure. The CSA® was chosen as a criterion measure, because it has been widely used for the measurement of spatiotemporal parameters of gait. It was hypothesised that data would demonstrate validity of the GAITRite® in the measurement of spatiotemporal parameters with a clinically acceptable level of measurement error.
Section snippets
Subjects
Twenty-five adult subjects participated in the investigation. Subjects were from a sample of convenience, recruited from associates, staff and students at La Trobe University, Australia. The study inclusion criteria included the ability to walk 100 m independently without gait aids or an orthosis. Subjects were excluded if they reported a neurological or orthopaedic condition that affected their gait. Subjects with known cardiac or respiratory disease or uncorrected visual impairment were also
Results
The mean and S.D. values for each of the gait variables over the three speed conditions are summarised in Table 1. The mean preferred gait speed (1.46 m/s, S.D. 0.17), cadence (114.9 steps per min, S.D. 6.5) and stride length (1.53 m, S.D. 0.15) fell within the range for values reported in the literature for a healthy adult sample [30], [31].
Discussion
In concordance with previous findings, [9], [25] GAITRite® measures of speed, cadence and stride length demonstrated good concurrent validity. The level of agreement between the CSA® and the GAITRite® was high at preferred, slow and fast walking speeds. The validity of the GAITRite® measures of speed, cadence and stride length were not affected by walking speed. The findings in the present investigation contrast with those of Cutlip et al. [26] who reported an increase in step length and stride
Conclusion
This investigation supports the use of GAITRite® as a valid and reliable measurement of selected spatial and temporal parameters in normal adult gait. The GAITRite® has the additional benefit of being quick and simple to use and would be attractive to clinicians required to obtain accurate gait data with minimal set up or data analysis time. Additional research is necessary to determine the validity in the measurement of spatiotemporal gait in adults and children with gait pathologies.
References (34)
- et al.
Systematic and random error in repeated measurement of temporal and distance parameters of gait after stroke
Arch. Phys. Med. Rehabil.
(1997) - et al.
Retest reliability of the temporal and distance characteristics of hemiplegic gait using a footswitch system
Arch. Phys. Med. Rehabil.
(1994) - et al.
Goal-directed secondary motor tasks: their effects on gait in subjects with Parkinson disease
Arch. Phys. Med. Rehabil.
(2000) - et al.
Gait consistency over a 7-day interval in people with Parkinson's disease
Arch. Phys. Med. Rehabil.
(1999) - et al.
The validity and reliability of the GAITRite system's measurements: a preliminary evaluation
Arch. Phys. Med. Rehabil.
(2001) - et al.
Evaluation of an instrumented walkway for measurement of the kinematic parameters of gait
Gait Posture
(2000) - et al.
Interrater reliability of videotaped observational gait-analysis assessments
Phys. Ther.
(1991) - et al.
Reliability among physical therapists in diagnosis and treatment of gait deviations in hemiplegics
Percept. Mot. Skills
(1973) - et al.
Reliability of observational kinematic gait analysis
Phys. Ther.
(1985) - et al.
In defence of gait analysis. Observation and measurement in gait assessment
J. Bone Joint Surg. Br.
(1985)
Measurement of temporal aspects of gait obtained with a multimemory stopwatch
J. Orthop. Sports Phys. Ther.
Reliability of measurements obtained with the timed ‘Up & Go’ test in people with Parkinson disease
Phys. Ther.
Use of a multimemory stopwatch to measure the temporal gait parameters
J. Orthop. Sports Phys. Ther.
The concurrent validity of the Functional Ambulation Profile and the GAITRite® system
Phys. Ther.
Accuracy of the GAITRite® system for measuring temporal-spatial parameters of gait
Phys. Ther.
Measurement of step length and step width: a comparison of videotape and direct measurements
Physiotherapy Canada
Balance performance and step width in noninstitutionalized, elderly, female fallers and nonfallers
Phys. Ther.
Cited by (591)
Cognitive function influences cognitive-motor interference during dual task walking in multiple sclerosis
2024, Multiple Sclerosis and Related DisordersVitamin D Supplementation and Muscle Power, Strength and Physical Performance in Older Adults: A Randomized Controlled Trial
2023, American Journal of Clinical NutritionFoot pressure-based analysis of gait while using a smartphone
2023, Gait and PosturePathological Gait Analysis With an Open-Source Cloud-Enabled Platform Empowered by Semi-Supervised Learning-PathoOpenGait
2024, IEEE Journal of Biomedical and Health Informatics