The Reliability and Validity of Measures of Gait Variability in Community-Dwelling Older Adults

Brach JS, Perera S, Studenski S, Newman AB. The reliability and validity of measures of gait variability in community-dwelling older adults.

Objective

To examine the test-retest reliability and concurrent validity of variability of gait characteristics.

Design

Cross-sectional study.

Setting

Research laboratory.

Participants

Older adults (N=558) from the Cardiovascular Health Study.

Interventions

Not applicable.

Main Outcome Measures

Gait characteristics were measured using a 4-m computerized walkway. SD determined from the steps recorded were used as the measures of variability. Intraclass correlation coefficients (ICC) were calculated to examine test-retest reliability of a 4-m walk and two 4-m walks. To establish concurrent validity, the measures of gait variability were compared across levels of health, functional status, and physical activity using independent t tests and analysis of variances.

Results

Gait variability measures from the two 4-m walks demonstrated greater test-retest reliability than those from the single 4-m walk (ICC=.22–.48 and ICC=.40–.63, respectively). Greater step length and stance time variability were associated with poorer health, functional status and physical activity (P<.05).

Conclusions

Gait variability calculated from a limited number of steps has fair to good test-retest reliability and concurrent validity. Reliability of gait variability calculated from a greater number of steps should be assessed to determine if the consistency can be improved.     

Reliability and validity of the dynamic gait index in persons with chronic stroke

Jonsdottir J, Cattaneo D. Reliability and validity of the Dynamic Gait Index in persons with chronic stroke.

Objective

To establish the test-retest and interrater reliability as well as the concurrent construct validity of the Dynamic Gait Index (DGI) as a measure for dynamic balance in people with chronic stroke.

Design

Cohort study.

Setting

Day hospital and ambulatory care at a rehabilitation center.

Participants

A consecutive sample of 25 participants, at least 3 months poststroke and able to walk at least 10m with or without a walking aid, participated in the study. Two independent raters rated performances on the DGI.

Interventions

Not applicable.

Main Outcome Measures

The DGI was administered in 2 testing sessions 3 days apart. In the second session, the participants were rated by 2 raters. Intraclass correlation coefficients (ICCs), model 2,1, and the Bland and Altman method were used to analyze total scores and item scores. Concurrent construct validity was tested by correlating results to the Berg Balance Scale, the timed walking test, the Timed Up & Go test, and the Activities-specific Balance Confidence Scale.

Results

ICCs for test-retest and interrater reliability of total scores were good (.96, .96, respectively) whereas reliability for single item scores was moderate to good (range, .55−.93). The hypotheses for concurrent construct validity were confirmed with all measures (range, .68−.83).

Conclusions

The DGI showed high reliability and showed evidence of concurrent validity with other balance and mobility scales. It is a useful clinical tool for evaluating dynamic balance in ambulatory people with chronic stroke.     

Reliability and Validity of the Functional Gait Assessment: A Systematic Review

Aims: The purpose of this systematic review is to assemble the available literature related to the psychometric properties (reliability and validity) of the Functional Gait Assessment (FGA) for patient populations that have been studied using the FGA. Methods: Studies of a cohort design were examined for reliability or criterion validity of the FGA from four electronic databases using a systematic review process. Results: Eight studies met the inclusion criteria. The FGA has a high inter-rater reliability across the patient populations studied and has high concurrent validity in patients with Parkinson disease, stroke, and community dwelling older adults. Conclusions: Findings suggest that the FGA is a useful clinical tool for the reported patient populations. Consideration should be given to the quality and limited number of studies included in this systematic review. Further research to enhance the accuracy of these findings is needed, including clearly defining a cut-off score for fall risk.     

Basic Psychometric Properties of the Transfer Assessment Instrument (Version 3.0)

Objectives

To refine the Transfer Assessment Instrument (TAI 2.0), develop a training program for the TAI, and analyze the basic psychometric properties of the TAI 3.0, including reliability, standard error of measurement (SEM), minimal detectable change (MDC), and construct validity.

Design

Repeated measures.

Setting

A winter sports clinic for disabled veterans.

Participants

Wheelchair users (N=41) who perform sitting-pivot or standing-pivot transfers.

Intervention

Not applicable.

Main Outcome Measures

TAI version 3.0, intraclass correlation coefficients, SEMs, and MDCs for reliable measurement of raters' responses. Spearman correlation coefficient, 1-way analysis of variance, and independent t tests to evaluate construct validity.

Results

TAI 3.0 had acceptable to high levels of reliability (range, .74–.88). The SEMs for part 1, part 2, and final scores ranged from .45 to .75. The MDC was 1.5 points on the 10-point scale for the final score. There were weak correlations (ρ range, −.13 to .25; P>.11) between TAI final scores and subjects' characteristics (eg, sex, body mass index, age, type of disability, length of wheelchair use, grip and elbow strength, sitting balance).

Conclusions

With comprehensive training, the refined TAI 3.0 yields high reliability among raters of different clinical backgrounds and experience. TAI 3.0 was unbiased toward certain physical characteristics that may influence transfer. TAI fills a void in the field by providing a quantitative measurement of transfers and a tool that can be used to detect problems and guide transfer training.     

Reliability of the Dynamic Gait Index in individuals with multiple sclerosis

McConvey J, Bennett SE. Reliability of the Dynamic Gait Index in individuals with multiple sclerosis.

Objectives

To determine if the Dynamic Gait Index (DGI) is a reliable tool for assessing balance in people with multiple sclerosis (MS) and to determine the validity of the DGI by using the 6.1-m timed walk.

Design

Instrument reliability test: physical therapists viewed a videotape of 10 subjects with MS performing the DGI and scored their gait by using DGI criteria. Two weeks after the first session, therapists’ viewed the videotape again and scored subjects’ gait to establish interrater reliability.

Setting

Hospital-based outpatient rehabilitation clinic.

Participants

Eleven physical therapists and 10 people with MS.

Interventions

Not applicable.

Main outcome measures

Total DGI scores and each of the 8 DGI items were compared between and within raters (physical therapists). Time to walk 6.1m was compared with the total DGI score to examine concurrent validity.

Results

Interrater reliability for total DGI scores was .983, with each of the 8 items ranging from .910 to .976 (intraclass correlation coefficient, P<.05). Intrarater reliability for total DGI scores ranged between .760 and .986 (Pearson bivariate analysis, P<.05). An inverse relationship of −.801 (Pearson bivariate analysis, P<.01) existed between the total DGI scores and the 6.1-m walk.

Conclusions

The DGI is a reliable functional assessment tool that correlated inversely with timed walk, showing its concurrent validity.     

Reliability of the dynamic gait index in people with vestibular disorders

OBJECTIVE: To examine the interrater reliability of the Dynamic Gait Index (DGI) when used with patients with vestibular disorders and with previously published instructions. DESIGN: Correlational study. SETTING: Outpatient physical therapy clinic. PARTICIPANTS: Subjects included 30 patients (age range, 27-88y) with vestibular disorders, who were referred for vestibular rehabilitation. INTERVENTIONS: Subjects' performance on the DGI was concurrently rated by 2 physical therapists experienced in vestibular rehabilitation to determine interrater reliability. MAIN OUTCOME MEASURES: Percentage agreement, kappa statistics, and the ratio of subject variability to total variability were calculated for individual DGI items. Kappa statistics for individual items were averaged to yield a composite kappa score of the DGI. Total DGI scores were evaluated for interrater reliability by using the Spearman rank-order correlation coefficient. RESULTS: Interrater reliability of individual DGI items varied from poor to excellent based on kappa values (kappa range,.35-1.00). Composite kappa values showed good overall interrater reliability (kappa=.64) of total DGI scores. The Spearman rho demonstrated excellent correlation (r=.95) between total DGI scores given concurrently by the 2 raters. CONCLUSION: DGI total scores, administered by using the published instructions, showed moderate interrater reliability with subjects with vestibular disorders. The DGI should be used with caution in this population at this time, because of the lack of strong reliability.     

星状伸展平衡测试评定脑卒中患者动态平衡的信度和效度

探讨星状伸展平衡测试(SEBT)对脑卒中患者动态平衡功能评定的价值。     

Reliability of the parallel walk test for the elderly

Lark SD, McCarthy PW, Rowe DA. Reliability of the parallel walk test for the elderly.

Objective

To determine interrater agreement and test-retest reliability of the parallel walk test (PWT), a simple method of measuring dynamic balance in the elderly during gait.

Design

Cohort study.

Setting

Outpatient clinic.

Participants

Elderly fallers (N=34; mean ± SD age, 81.3±5.4y) registered at a falls clinic participated in this study based on Mini-Mental State Examination and Barthel Index scores.

Interventions

Subjects were timed as they walked 6m between 2 parallel lines on the floor at 3 different widths (20, 30.5, 38cm) wearing their own footwear. They were scored for foot placement on (1 point) or outside the lines (2 points) by 2 separate raters. Fifteen subjects were retested 1 week later.

Main Outcome Measures

Footfall score and time to complete the PWT. Intraclass correlation coefficients (ICCs) and 95% limits of agreement were calculated for interrater and test-retest reliability.

Results

For widths of 20, 30.5, and 38cm, interrater reliability ICC range was .93 to .99 and test-retest ICC range was .63 to .90.

Conclusions

The PWT was implemented easily by 2 raters with a high degree of interrater reliability. Test-retest reliability was not as high, possibly because of the high susceptibility of variation from 1 week to the next for frail elderly subjects. The 20- and 30.5-cm widths are recommended for future use of the PWT.     

Examination of Sustained Gait Speed During Extended Walking in Individuals With Chronic Stroke

Objectives

To determine if individuals with chronic stroke were able to sustain their peak gait speed during the 6-minute walk test (6MWT), and to explore this sustainability across community ambulation potential subgroups.

Design

Prospective cross-sectional study.

Setting

University-based research laboratory, hospitals, and stroke support groups.

Participants

A sample of individuals with chronic stroke (N=48) completed a series of questionnaires and physical outcome measures, including gait mat assessment, during a single visit.

Interventions

Not applicable; 1-time cross-sectional data collection.

Main Outcome Measures

During the 6MWT, we measured peak gait speed and end gait speed to assess sustainability, along with beginning gait speed, total distance walked, and rating of perceived exertion. We also assessed maximum gait speed during the 10-meter walk test (10MWT). Finally, we examined these gait outcomes across the subgroups.

Results

During the 6MWT, peak gait speed declined from .89m/s (SD=.38) to an end speed of .82m/s (SD=.36), whereas perceived exertion increased from 7.7 (SD=2.6) to 11.8 (SD=3.6). This peak gait speed was slower than the 10MWT maximum speed of 1.06m/s (SD=.51), but faster than the 6MWT beginning speed of .81m/s (SD=.34). The unlimited community ambulator subgroup was the primary contributor to sustainability differences.

Conclusions

Predicting community ambulation potential based on the discrete gait speed from the 10MWT and endurance based on the average from the 6MWT might be incomplete if gait speed sustainability is not also assessed.     

Clinical tests for the evaluation of postural instability in patients with parkinson's disease

OBJECTIVE: To determine which test for postural instability in Parkinson's disease (PD) is reliable, valid, and easy to perform in a clinical setting. DESIGN: Cross-sectional reliability and validity study. SETTING: Academic center for movement disorders. PARTICIPANTS: Forty-two patients with PD and 15 controls. Based on the results of a structured interview, the patients were divided in PD-unstable (n=22) and PD-stable (n=20) groups. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Several variants of the retropulsion test with differences in execution and scoring. Responses were scored on 5 different rating scales (ratings of Nutt, Bloem, Pastor; the Unified Parkinson's Disease Rating Scale [UPDRS]; the Short Parkinson Evaluation Scale). These tests were compared with steady-stance positions. RESULTS: The interrater reliability was high for most ratings, with weighted kappa ranging from.63 for the UPDRS to.98 for both the Pastor rating and steady-stance positions. Most ratings distinguished between the groups. However, the Nutt rating had the highest overall predictive accuracy, with a sensitivity of.63 and a specificity of.88. CONCLUSIONS: The most valid test for postural stability in PD was an unexpected shoulder pull, executed once, with taking more than 2 steps backward considered abnormal. This retropulsion test is easy to use in a clinical setting.     

Validity of a Functional Dynamic Walking Test for the Elderly

Lark SD, Pasupuleti S. Validity of a functional dynamic walking test for the elderly.

Objective

To determine the validity of a safe, quick, and simple method of measuring dynamic balance in the elderly during gait called the parallel walk test.

Design

Control study.

Setting

Outpatient clinic, community.

Participants

Twenty-seven elderly fallers (age 82±6y) registered at a falls clinic and 34 elderly nonfallers (age 76±7y) were recruited to this study based on Mini Mental State Examination and Barthel Index scores.

Interventions

Subjects were timed as they walked 6m between 2 parallel lines on the floor at 3 different widths (20, 30.5, 38cm) in their own footwear. They were scored for foot placement on the line (1 point) or outside the lines (2 points). Participants also performed a timed 6-m tandem walk test, a 30-second tandem stance, and a 30-second parallel stance.

Main Outcome Measures

Scores and time to complete the parallel walk test and tandem walk test along with the time of standing for tandem and parallel stance. Validity coefficients were calculated for the sensitivity and specificity of the parallel walk test.

Results

All subjects completed the parallel walk test, but few attempted and completed the tandem walk test. The fallers had significantly greater scores at 20 and 30.5cm and took significantly longer to complete the 6m at all widths. The 20-cm width was most discriminatory. The parallel walk test showed a significant correlation with the tandem stance.

Conclusions

All subjects attempted and completed the parallel walk test but not the tandem walk test. The time to completion and scoring accurately measures dynamic balance during gait in elderly fallers. The parallel walk test could be a useful tool in the clinical setting for assessing balance in gait pre- and postintervention.     

Reliability and Responsiveness of the Activities of Daily Living Computerized Adaptive Testing System in Patients With Stroke

Objective

To examine the intrarater reliability, interrater reliability, and responsiveness of the Activities of Daily Living Computerized Adaptive Testing system (ADL CAT) in patients with stroke.

Design

One repeated-measures design (at an interval of 7d) was used to examine the intrarater reliability and interrater reliability of the ADL CAT. For the responsiveness study, participants were assessed with the ADL CAT at admission to the rehabilitation ward and at discharge from the hospital.

Setting

Eight rehabilitation units.

Participants

Three different (nonoverlapping) groups of patients (N=157) were recruited. Fifty-five and 42 outpatients with chronic stroke participated in the intrarater and interrater reliability studies, respectively; 60 inpatients who had recently had a stroke participated in the responsiveness study.

Interventions

Not applicable.

Main Outcome Measure

ADL CAT.

Results

The intraclass correlation coefficient values were .94 and .80 for the ADL CAT in the intrarater reliability and interrater reliability studies, respectively. The classical test theory–based minimal detectable change values were 6.5 and 9.5 for the ADL CAT in the intrarater reliability and interrater reliability studies, respectively. The Kazis' effect size and standardized response mean of the ADL CAT were moderate (.62–.73).

Conclusions

The ADL CAT has good intrarater reliability and interrater reliability in outpatients with chronic stroke, and sufficient responsiveness in inpatients with stroke undergoing inpatient rehabilitation. Further investigations on the responsiveness of the ADL CAT in outpatients are needed to obtain more evidence on the utility of the ADL CAT.     

工作能力支持量表(中文版)在就业年龄脑卒中患者中的信度和效度

目的 检验工作能力支持量表(WSS)在就业年龄脑卒中患者中的信度和效度。 方法采用翻译-回译方法将WSS译为中文。2018年12月至2019年3月,便利选取郑州市2所社区卫生服务中心下属社区的就业年龄脑卒中患者193例,由2名护士采用WSS中文版进行调查。进行项目分析、内容效度分析、探索性因子分析、内部一致性分析和评定者间信度分析。 结果 A部分内容效度为0.94,B部分为0.90;A部分16个条目,提取3个公因子,累积方差贡献率67.747%;B部分12个条目,提取3个公因子,累积方差贡献率56.056%;A和B部分Cronbach α系数为0.933和0.778,评定者间信度除条目B8、B10外,kappa系数均 > 0.6。 结论 WSS中文版信效度满意,可用于评估中青年脑卒中患者重返工作过程中的工作能力支持。     

Intratester Reliability and Validity of Concentric Measurements Using a New Hand-Held Dynamometer

Janssen JC, Le-Ngoc L. Intratester reliability and validity of concentric measurements using a new hand-held dynamometer.

Objective

To assess the reliability of a new hand-held dynamometer (HHD) to perform concentric measurements, and to determine the agreement between the HHD and the criterion standard isokinetic dynamometer.

Design

Elbow flexion concentric measurements were performed on a mechanical arm using the HHD and the isokinetic dynamometer.

Setting

Engineering laboratory and university strength-testing facility.

Participants

Three patient profiles, differing in range of motion (ROM) and strength, were simulated by a mechanical arm.

Interventions

Not applicable.

Main Outcome Measures

Peak torque and ROM obtained from concentric elbow flexion profiles.

Results

Intratester reliabilities, measured with the intraclass correlation coefficient (ICC_1,1), of the peak torque and start and end ROM are excellent for both the HHD (.99, .98, and .99, respectively) and the isokinetic dynamometer (.99 for all 3 variables). The angle of peak torque was rated fair to good in intrareliability for both devices, at .64 (HHD) and .69 (isokinetic dynamometer). Validity, measured within the limits of agreement (LOA) between the 2 devices, was clinically acceptable for peak torque and start ROM, although not for end ROM and angle of peak torque.

Conclusions

It is possible to use the new HHD to obtain dynamic measurements of joint motion. Intratester reliability of the HHD is excellent and is in clinical acceptable agreement with the isokinetic dynamometer for peak torque and start ROM. End ROM was, however, not in agreement because of a systematic error in the isokinetic dynamometer measurement for 1 of the 3 tested profiles. Intratester reliabilities of the angle of peak torque were fair to good for both the HHD and isokinetic dynamometer, but the LOA were not clinically acceptable. Stability of the arm and speed of measurement might be confounding factors in this study.     

Use of the Continuous Scale Physical Functional Performance Test in Stroke Survivors

Manns PJ, Tomczak CR, Jelani A, Cress ME, Haennel R. Use of the continuous scale physical functional performance test in stroke survivors.

Objective

To (1) determine the feasibility of the continuous scale physical functional performance 10-item test (CS-PFP10) for the measurement of physical function in stroke survivors, (2) characterize physical functional performance of stroke survivors and their matched controls, and (3) explore the associations among physical functional performance, ambulatory activity, and peak oxygen uptake (Vo₂peak).

Design

Case control.

Setting

University research setting.

Participants

Ten participants with stroke and 10 healthy controls matched for age, sex, and physical activity.

Interventions

Not applicable.

Main Outcome Measures

The CS-PFP10 test was used to measure functional ability. The test requires performance of 10 serial tasks that range from low to high difficulty. The step activity monitor was used to measure absolute ambulatory activity and was reported as the average number of steps a day over a 4-day period. Vo₂peak was determined using a metabolic cart and a recumbent cycle ergometer.

Results

Stroke survivors scored lower than healthy controls on all individual tasks, domains, and the total score on the CS-PFP10. Higher Vo₂peak was associated with higher total scores on the CS-PFP10 in both stroke survivors and controls. In stroke survivors, lower levels of impairment (as indicated by the Chedoke-McMaster stroke assessment) were associated with higher total CS-PFP10 scores.

Conclusions

The CS-PFP10 is a measure of physical performance that is feasible to use with ambulatory participants with stroke. Future investigations with people with stroke should explore the ability of the CS-PFP10 to provide meaningful information about change in CS-PFP10 subscales with interventions that target items on the subscales, such as balance or upper extremity strength.     

The development and validity of the Salford Gait Tool: an observation-based clinical gait assessment tool

OBJECTIVES: To develop the construct, content, and criterion validity of the Salford Gait Tool (SF-GT) and to evaluate agreement between gait observations using the SF-GT and kinematic gait data. DESIGN: Tool development and comparative evaluation. SETTING: University in the United Kingdom. PARTICIPANTS: For designing construct and content validity, convenience samples of 10 children with hemiplegic, diplegic, and quadriplegic cerebral palsy (CP) and 152 physical therapy students and 4 physical therapists were recruited. For developing criterion validity, kinematic gait data of 13 gait clusters containing 56 children with hemiplegic, diplegic, and quadriplegic CP and 11 neurologically intact children was used. For clinical evaluation, a convenience sample of 23 pediatric physical therapists participated. INTERVENTIONS: We developed a sagittal plane observational gait assessment tool through a series of design, test, and redesign iterations. The tool's grading system was calibrated using kinematic gait data of 13 gait clusters and was evaluated by comparing the agreement of gait observations using the SF-GT with kinematic gait data. MAIN OUTCOME MEASURES: Criterion standard kinematic gait data. RESULTS: There was 58% mean agreement based on grading categories and 80% mean agreement based on degree estimations evaluated with the least significant difference method. CONCLUSIONS: The new SF-GT has good concurrent criterion validity.     

Assessing Locomotion Ability in West African Stroke Patients: Validation of ABILOCO-Benin Scale

Objective

To calibrate and validate the Benin version of ABILOCO, a Rasch-built scale developed to assess locomotion ability in stroke patients.

Design

Prospective study and questionnaire development.

Setting

Rehabilitation centers.

Participants

Stroke patients (N=230; mean age ± SD, 51.1±11.6y; 64.3% men).

Intervention

Not applicable.

Main Outcome Measures

Participants completed a preliminary list of 36 items including the 13 items of ABILOCO. Items were scored as “impossible,” “difficult,” or “easy.” The mobility subdomain of FIM (FIM-mobility), the Functional Ambulation Classification (FAC), the 6-minute walk test (6MWT), and the 10-meter walk test (10MWT) were used to evaluate and elucidate the validity of the ABILOCO-Benin scale.

Results

Successive Rasch analyses led to the selection of 15 items that define a unidimensional, invariant, and linear measure of locomotion ability in stroke patients. This modified version of the ABILOCO scale, named ABILOCO-Benin, showed an excellent internal consistency, with a Person Separation Index of .93, and excellent test-retest reliability with high intraclass correlation coefficients of .95 (P<.001) for item difficulty and .93 (P<.001) for subject measures. It also presented good construct validity compared with FAC, FIM-mobility, 6MWT, and 10MWT (r≥.75, P<.001).

Conclusions

ABILOCO-Benin presents good psychometric properties. It allows valid, reliable, and objective measurements of locomotion ability in stroke patients.     

Predictive validity and responsiveness of the functional ambulation category in hemiparetic patients after stroke

OBJECTIVE: To determine the reliability, concurrent and predictive validity, and responsiveness of the Functional Ambulation Category (FAC) in hemiparetic patients after stroke. DESIGN: Prospective cohort. SETTING: An early rehabilitation center for patients with neurologic disorders. PARTICIPANTS: Fifty-five nonambulatory patients after first-ever stroke, with duration of illness between 30 and 60 days, were included. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: FAC, Rivermead Mobility Index (RMI), walking velocity, step length, and six-minute walking test (6MWT) were assessed at the beginning, after 2 and 4 weeks of rehabilitation, and again 6 months later. After 6 months, community ambulation was also assessed. Test-retest and interrater reliability, concurrent, discriminant, and predictive validity and responsiveness of the FAC were calculated. RESULTS: Based on video examinations, high test-retest reliability (Cohen kappa=.950) and interrater reliability (kappa=.905) were found. FAC scores at the beginning and after 2 weeks, 3 weeks, and 6 months correlated highly with the RMI (Spearman rho=.686, rho=.787, rho=.825, rho=.893, respectively), distance walked in the 6MWT (rho=.949, rho=.937, rho=.931, rho=.906, respectively), walking velocity (rho=.952, rho=.939, rho=.902, rho=.901, respectively), and step length (rho=.952, rho=.932, rho=.896, rho=.877, respectively) at the same time points (all P<.001). The RMI, walking velocity, step length, and distance walked in the 6MWT differed for each FAC category (P<.001). After 4 weeks of rehabilitation, an FAC score of 4 or higher predicted community ambulation at 6 months with 100% sensitivity and 78% specificity. FAC scores changed significantly between the first 2 and second 2 weeks (Wilcoxon z=8.7, z=7.9, respectively; both P<.001) of the inpatient rehabilitation program. CONCLUSIONS: The FAC has excellent reliability, good concurrent and predictive validity, and good responsiveness in patients with hemiparesis after stroke.