The Reliability of Spatiotemporal Gait Data for Young and Older Women During Continuous Overground Walking

Reliability of an Instrumented Pressure Walkway for Measuring Walking and Running Characteristics in Young, Athletic Individuals

Background

Spatiotemporal parameters of gait are useful for identifying pathological gait patterns and presence of impairments. Reliability of the pressure-sensitive ZenoTM Walkway has not been established in young, active individuals without impairments, and no studies to this point have included running.

Purpose

The purposes of this study were to 1) determine if up to two additional trials of walking and running on the ZenoTM Walkway are needed to produce consistent measurements of spatiotemporal variables, and 2) establish test-retest reliability and minimal detectable change (MDC) values for common spatiotemporal variables measured during walking and running.

Study Design

Cross-Sectional Laboratory Study.

Methods

Individuals (n=38) in this cross-sectional study walked and ran at self-selected comfortable speed on a pressure-sensitive ZenoTM Walkway. Twenty-one participants returned for follow-up testing between one and 14 days later. Intraclass correlation coefficients (ICCs) were used to assess reliability of spatiotemporal variable means using three, four, or five passes over the ZenoTM Walkway and to assess test-retest reliability of spatiotemporal variables across sessions.

Results

All variables showed excellent reliability (ICC > 0.995) for walking and running when measured using three, four, or five passes. Additionally, all variables demonstrated moderate to excellent test-retest reliability during walking (ICC: 0.732-0.982) and running (ICC: 0.679-0.985).

Conclusion

This study establishes a reliable measurement protocol of three one-way passes when using the ZenoTM Walkway for walking or running analysis. This is the first study to establish reliability of the ZenoTM Walkway during running and in young, active individuals without neuromusculoskeletal pathology.

Level of Evidence

3b.

The variability of dual-task walking parameters using in-shoe inertial sensors in nonconcussed individuals: A randomized within-subject repeated measures design

Background and Aims

There is a need for high utility and portability, and cost-effective technologies that are suitable for assessing dual-task gait after experiencing a concussion. Current technologies utilized such as 3D motion capture and force plates are too complex and expensive for most practitioners. The aim of this study was to quantify the variability of dual-task walking gait parameters using in-shoe inertial sensors in nonconcussed individuals.

Methods

This was a randomized within-subject repeated measures design conducted within a sports laboratory. Twenty healthy, uninjured, nonconcussed participants were recruited for this study. Gait variables of interest were measured across three 2-min continuous walking protocols (12 m, 30 m, 1 min out and back) while performing a cognitive task of counting backward in sevens from a randomly generated number between 300 and 500. Testing was completed over three occasions separated by 7 days, for a total of nine walking trials. Participants completed the testing protocols in a randomized, individual order. The primary outcome was to determine the variability of dual-task walking gait parameters using in-shoe inertial sensors in nonconcussed individuals across three protocols.

Results

Three to four participants were allocated to each randomized protocol order. Regarding the absolute consistency (coefficient of variation [CV]) between testing occasions, no gait measure was found to have variability above 6.5%. Relative consistency (intraclass correlation coefficient [ICC]) was acceptable (>0.70) in 95% of the variables of interest, with only three variables < 0.70. Similar variability was found across the three testing protocols.

Conclusion

In-shoe inertial sensors provide a viable option for monitoring gait parameters. This technology is also reliable across different testing distances, thus offering various testing options for practitioners. Further research needs to be conducted to examine the variability with concussed subjects.

Methodological Critique of Concussive and Non-Concussive Dual Task Walking Assessments: A Scoping Review

OBJECTIVE

To understand the methodological approaches taken by various research groups and determine the kinematic variables that could consistently and reliably differentiate between concussed and non-concussed individuals.

METHODS

MEDLINE via PubMed, CINAHL Complete via EBSCO, EBSCOhost, SPORTDiscus, and Scopus were searched from inception until 31 December 2021, using key terms related to concussion, mild traumatic brain injury, gait, cognition and dual task. Studies that reported spatiotemporal kinematic outcomes were included. Data were extracted using a customised spreadsheet, including detailed information on participant characteristics, assessment protocols, equipment used, and outcomes.

RESULTS

Twenty-three studies involving 1030 participants met the inclusion criteria. Ten outcome measures were reported across these articles. Some metrics such as gait velocity and stride length may be promising but are limited by the status of the current research; the majority of the reported variables were not sensitive enough across technologies to consistently differentiate between concussed and non-concussed individuals. Understanding variable sensitivity was made more difficult given the absence of any reporting of reliability of the protocols and variables in the respective studies.

CONCLUSION

Given the current status of the literature and the methodologies reviewed, there would seem little consensus on which gait parameters are best to determine return to play readiness after concussion. There is potential in this area for such technologies and protocols to be utilised as a tool for identifying and monitoring concussion; however, improving understanding of the variability and validity of technologies and protocols underpins the suggested directions of future research. Inertial measurement units appear to be the most promising technology in this aspect and should guide the focus of future research.

IMPACT

Results of this study may have an impact on what technology is chosen and may be utilised to assist with concussion diagnosis and return to play protocols.

Absolute Reliability of Gait Parameters Acquired With Markerless Motion Capture in Living Domains

Purpose: To examine the between-day absolute reliability of gait parameters acquired with Theia3D markerless motion capture for use in biomechanical and clinical settings. Methods: Twenty-one (7 M,14 F) participants aged between 18 and 73 years were recruited in community locations to perform two walking tasks: self-selected and fastest-comfortable walking speed. Participants walked along a designated walkway on two separate days.Joint angle kinematics for the hip, knee, and ankle, for all planes of motion, and spatiotemporal parameters were extracted to determine absolute reliability between-days. For kinematics, absolute reliability was examined using: full curve analysis [root mean square difference (RMSD)] and discrete point analysis at defined gait events using standard error of measurement (SEM). The absolute reliability of spatiotemporal parameters was also examined using SEM and SEM%. Results: Markerless motion capture produced low measurement error for kinematic full curve analysis with RMSDs ranging between 0.96° and 3.71° across all joints and planes for both walking tasks. Similarly, discrete point analysis within the gait cycle produced SEM values ranging between 0.91° and 3.25° for both sagittal and frontal plane angles of the hip, knee, and ankle. The highest measurement errors were observed in the transverse plane, with SEM >5° for ankle and knee range of motion. For the majority of spatiotemporal parameters, markerless motion capture produced low SEM values and SEM% below 10%. Conclusion: Markerless motion capture using Theia3D offers reliable gait analysis suitable for biomechanical and clinical use.

The reliability of gait parameters captured via instrumented walkways: a systematic review and meta-analysis

INTRODUCTION

Electronic pressure-sensitive walkways are commonly available solutions to quantitatively assess gait parameters for clinical and research purposes. Many studies have evaluated their measurement properties in different conditions with variable findings. In order to be informed about the current evidence of their reliability for optimal clinical and scientific decision making, this systematic review provided a quantitative synthesis of the test-retest reliability and minimal detectable change of the captured gait parameters across different test conditions (single and cognitive dual-task conditions) and population groups.

EVIDENCE ACQUISITION

A literature search was conducted in PubMed, Embase, and Scopus until November 2021 to identify articles that examined the test-retest reliability properties of the gait parameters captured by pressure-sensitive walkways (gait speed, cadence, stride length and time, double support time, base of support) in adult healthy individuals or patients. The methodological quality was rated using the Consensus-Based Standards for the Selection of Health Measurement Instruments Checklist. Data were meta-analyzed on intraclass correlation coefficient to examine the test-retest relative reliability. Quantitative synthesis was performed for absolute reliability, examined by the weighted average of minimal detectable change values.

EVIDENCE SYNTHESIS

A total of 44 studies were included in this systematic review. The methodological quality was adequate in half of the included studies. The main finding was that pressure-sensitive walkways are reliable tools for objective assessment of spatial and temporal gait parameters both in single-and cognitive dual-task conditions. Despite few exceptions, the review identified intraclass correlation coefficient higher than 0.75 and minimal detectable change lower than 30%, demonstrating satisfactory relative and absolute reliability in all examined populations (healthy adults, elderly, patients with cognitive impairment, spinocerebellar ataxia type 14, Huntington's disease, multiple sclerosis, Parkinson's disease, rheumatoid arthritis, spinal cord injury, stroke or vestibular dysfunction).

CONCLUSIONS

Current evidence suggested that, despite different populations and testing protocols used in the included studies, the test-retest reliability of the examined gait parameters was acceptable under single and cognitive dual-task conditions. Further high-quality studies with powered sample sizes are needed to examine the reliability findings of the currently understudied and unexplored pathologies and test conditions.

Reliability of IMU-Derived Temporal Gait Parameters in Neurological Diseases

Evaluating gait is part of every neurological movement disorder assessment. Generally, the physician assesses the patient based on their experience, but nowadays inertial measurement units (IMUs) are also often integrated in the assessment. Instrumented gait analysis has a longstanding tradition and temporal parameters are used to compare patient groups or trace disease progression over time. However, the day-to-day variability needs to be considered especially in specific patient cohorts. The aim of the study was to examine day-to-day variability of temporal gait parameters of two experimental conditions in a cohort of neurogeriatric patients using data extracted from a lower back-worn IMU. We recruited 49 participants (24 women (age: 78 years ± 6 years, BMI = 25.1 kg/m² and 25 men (age: 77 years ± 6 years, BMI = 26.5 kg/m²)) from the neurogeriatric ward. Two gait distances (4 m and 20 m) were performed during the first session and repeated the following day. To evaluate reliability, the Intraclass Correlation Coefficient (ICC2,k) and minimal detectable change (MDC) were calculated for the number of steps, step time, stride time, stance time, swing time, double limb support time, double limb support time variability, stride time variability and stride time asymmetry. The temporal gait parameters showed poor to moderate reliability with mean ICC and mean MDC95% values of 0.57 ± 0.18 and 52% ± 53%, respectively. Overall, only four out of the nine computed temporal gait parameters showed high relative reliability and good absolute reliability values. The reliability increased with walking distance. When only investigating steady-state walking during the 20 m walking condition, the relative and absolute reliability improved again. The most reliable parameters were swing time, stride time, step time and stance time. Study results demonstrate that reliability is an important factor to consider when working with IMU derived gait parameters in specific patient cohorts. This advocates for a careful parameter selection as not all parameters seem to be suitable when assessing gait in neurogeriatric patients.

Gait analysis with videogrammetry can differentiate healthy elderly, mild cognitive impairment, and Alzheimer's disease: A cross-sectional study

Gait parameters have been investigated as an additional tool for differential diagnosis in neurocognitive disorders, especially among healthy elderly (HE), those with mild cognitive impairment (MCI), and Alzheimer's disease (AD) patients. A videogrammetry system could be used as a low-cost and clinically practical equipment to capture and analyze gait in older adults. The aim of this study was to select the better gait parameter to differentiate these groups among different motor test conditions with videogrammetry analyses. Different motor conditions were used in three specific assessments: 10-meter walk test (10mWT), timed up and go test (TUGT), and treadmill walk test (TWT). These tasks were compared among HE (n=17), MCI (n=23), and AD (n=23) groups. One-way ANOVA, Kruskal-Wallis, and Bonferroni post-hoc tests were used to compare variables among groups. Then, an effect size (ES) and a linear regression analysis were calculated. The gait parameters showed significant differences among groups in all conditions, but not in TWT. Controlled by confounding variables, the gait velocity in 10mWT at usual speed, and TUGT in dual-task condition, predicts 39% and 53% of the difference among diagnoses, respectively. Finally, these results suggest that a low-cost and practical video analysis could be able to differentiate HE, those with MCI, and AD patients in clinical assessments.

Reliability, measurement error and minimum detectable change in mobility measures: a cohort study of community-dwelling adults aged 50 years and over in Ireland

OBJECTIVE

To estimate the effects of repeat assessments, rater and time of day on mobility measures and to estimate their variation between and within participants in a population-based sample of Irish adults aged ≥50 years.

DESIGN

Test-retest study in a population representative sample.

SETTING

Academic health assessment centre of The Irish Longitudinal Study on Ageing (TILDA).

PARTICIPANTS

128 community-dwelling adults from the Survey for Health, Ageing and Retirement in Europe (SHARE) Ireland study who agreed to take part in the SHARE-Ireland/TILDA collaboration.

INTERVENTIONS

Not applicable.

OUTCOME MEASURES

Participants performed timed up-and-go (TUG), repeated chair stands (RCS) and walking speed tests administered by one of two raters. Repeat assessments were conducted 1-4 months later. Participants were randomised with respect to a change in time (morning, afternoon) and whether the rater was changed between assessments. Within and between-participant variance for each measure was estimated using mixed-effects models. Intraclass correlation (ICC), SE of measurement and minimum detectable change (MDC) were reported.

RESULTS

Average performance did not vary between baseline and repeat assessments in any test, except RCS. The rater significantly affected performance on all tests except one, but time of day did not. Reliability varied from ICC=0.66 (RCS) to ICC=0.88 (usual gait speed). MDC was 2.08 s for TUG, 4.52 s for RCS and ranged from 19.49 to 34.73 cm/s for walking speed tests. There was no evidence for lower reliability of gait parameters with increasing time between assessments.

CONCLUSIONS

Reliability varied for each test when measurements are obtained over 1-4 months with most variation due to rater effects. Usual and motor dual task gait speed demonstrated highest reliability.

The validity of spatiotemporal gait analysis using dual laser range sensors: a cross-sectional study

Background

The spatiotemporal parameters were used for sophisticated gait analysis in widespread clinical use. Recently, a laser range sensor has been proposed as a new device for the spatiotemporal gait measurement. However, measurement using a single laser range sensor can only be used for short-range gait measurements because the device irradiates participants with lasers in a radial manner. For long-range gait measurement, the present study uses a modified method using dual laser range sensors installed at opposite ends of the walking path. The aim of present study was to investigate the concurrent validity of the proposed method for spatiotemporal gait measurement by comparison to a computer-based instrumented walkway system.

Methods

Ten healthy participants were enrolled in this study. Ten-meter walking tests at 100, 75, and 50% of the comfortable speed were conducted to determine the concurrent validity of the proposed method compared to instrumented walkway measurements. Frequency distributions of errors for foot-contact (FC) and foot-off (FO) estimated times between the two systems were also calculated to determine the adequacy of estimation of FC and FO from three perspectives: accuracy (smallness of mean error), precision (smallness of variability), and unambiguity (monomodality of histogram). Intra-class correlation coefficient (2,1) was used to determine the concurrent validity of spatiotemporal parameters between the two systems.

Result

The results indicate that the detection times for FC and FO estimated by the proposed method did not differ from those measured by the instrumented walkway reference system. In addition, histogram for FC and FO showed monomodality. Intra-class correlation coefficients of the spatiotemporal parameters (stance time: 0.74; double support time: 0.56; stride time: 0.89; stride length: 0.83; step length: 0.71; swing time: 0.23) were not high enough. The mean errors of all spatiotemporal parameters were small.

Conclusions

These results suggest that the proposed lacks sufficient concurrent validity for spatiotemporal gait measurement. Further improvement of this proposed system seems necessary.

Trial registration

UMIN000032710. Registered 24 May 2018. Retrospectively registered.

Intra-rater repeatability of gait parameters in healthy adults during self-paced treadmill-based virtual reality walking

Self-paced treadmill walking is becoming increasingly popular for the gait assessment and re-education, in both research and clinical settings. Its day-to-day repeatability is yet to be established. This study scrutinised the test-retest repeatability of key gait parameters, obtained from the Gait Real-time Analysis Interactive Lab (GRAIL) system. Twenty-three male able-bodied adults (age: 34.56 ± 5.12 years) completed two separate gait assessments on the GRAIL system, separated by 5 ± 3 days. Key gait kinematic, kinetic, and spatial-temporal parameters were analysed. The Intraclass-Correlation Coefficients (ICC), Standard Error Measurement (SEM), Minimum Detectable Change (MDC), and the 95% limits of agreements were calculated to evaluate the repeatability of these gait parameters. Day-to-day agreements were excellent (ICCs > 0.87) for spatial-temporal parameters with low MDC and SEM values, <0.153 and <0.055, respectively. The repeatability was higher for joint kinetic than kinematic parameters, as reflected in small values of SEM (<0.13 Nm/kg and <3.4°) and MDC (<0.335 Nm/kg and <9.44°). The obtained values of all parameters fell within the 95% limits of agreement. Our findings demonstrate the repeatability of the GRAIL system available in our laboratory. The SEM and MDC values can be used to assist researchers and clinicians to distinguish 'real' changes in gait performance over time.

Computerized Dual-Task Testing of Gait and Visuospatial Cognitive Functions; Test-Retest Reliability and Validity

The common occurrence of age decline in mobility and cognition does cause a decrease in the level of physical activity and an increased falls risk. Consequently, dual -task (DT) assessment that simultaneously addresses both mobility skills and cognitive functions are important because, continued difficulties and fall injuries will have a sizable impact in this population. The first objective of the present study was to assess test-retest reliability of a computerized DT treadmill walking protocol and concurrent outcome measures of gait and visuospatial executive function in a group of healthy older adults. Secondly, discriminative validity was evaluated by examining the effect of DT conditions (single task vs. dual-task) on; (a) spatiotemporal gait measures (average and coefficient of variation) and (b) visuomotor and visuospatial executive performance measures. Twenty-five community-dwelling individuals median age 65 (range 61-67) were recruited from a Fitness Facility. Participants performed a computerized visuomotor tracking task and a visuospatial executive game task in standing and while treadmill walking. Testing was conducted on two occasions, 1 week apart. Moderate to high test-retest reliability (ICC values of 0.65-0.88) were observed for spatiotemporal gait variables. No significant differences between the group means were observed between test periods in any gait variable. Moderate test-retest reliability (ICC values of 0.6-0.65) was observed for measures of visuomotor and visuospatial executive performance during treadmill walking. Significant DT effects were observed for both spatiotemporal gait variables and visuospatial executive performance measures. This study demonstrates the reliability and reproducibility of the computer-based assessment tool for dual task treadmill walking. The high to moderate ICC values and the lack of systematic errors in the measures indicate that this tool has the ability to repeatedly record reliable data from community-dwelling older adults. The present computerized dual-task protocols broaden the types of standardized visuomotor and visuospatial executive activities for use with DT treadmill walking that has previously been reported.

The test-retest reliability and minimal detectable change of spatial and temporal gait variability during usual over-ground walking for younger and older adults

Gait variability is a marker of gait performance and future mobility status in older adults. Reliability of gait variability has been examined mainly in community dwelling older adults who are likely to fluctuate over time. The purpose of this study was to compare test-retest reliability and determine minimal detectable change (MDC) of spatial and temporal gait variability in younger and older adults. Forty younger (mean age=26.6 ± 6.0 years) and 46 older adults (mean age=78.1 ± 6.2 years) were included in the study. Gait characteristics were measured twice, approximately 1 week apart, using a computerized walkway (GaitMat II). Participants completed 4 passes on the GaitMat II at their self-selected walking speed. Test-retest reliability was calculated using Intra-class correlation coefficients (ICCs(2,1)), 95% limits of agreement (95% LoA) in conjunction with Bland-Altman plots, relative limits of agreement (LoA%) and standard error of measurement (SEM). The MDC at 90% and 95% level were also calculated. ICCs of gait variability ranged 0.26-0.65 in younger and 0.28-0.74 in older adults. The LoA% and SEM were consistently higher (i.e. less reliable) for all gait variables in older compared to younger adults except SEM for step width. The MDC was consistently larger for all gait variables in older compared to younger adults except step width. ICCs were of limited utility due to restricted ranges in younger adults. Based on absolute reliability measures and MDC, younger had greater test-retest reliability and smaller MDC of spatial and temporal gait variability compared to older adults.

Reproducibility of gait parameters at different surface inclinations and speeds using an instrumented treadmill system

Instrumented treadmill systems allow the practical assessment of gait parameters under several walking conditions. Aim of this study was to evaluate the reproducibility of gait parameters at different surface inclinations and walking speeds using an instrumented treadmill system in healthy individuals. A total of 20 subjects (10 women) with a mean age of 31 years were evaluated with an instrumented treadmill system (FDM-T, Zebris Medical GmbH) during two identical test sessions. Spatial (step length, step width, foot rotation), temporal (cadence, single-limb support, step time) and ground reaction force (heel force, toe force, time to heel force, time to toe force) gait parameters were assessed at three treadmill inclinations (level, uphill, downhill) and five speeds (2, 3, 4, 5, 6 km/h). Between-day reproducibility was evaluated with smallest detectable changes for agreement and intraclass correlation coefficients for reliability. Low agreement and reliability were observed for (i) step length, cadence and step time during slow (2 and 3 km/h) and uphill walking and (ii) time to heel force and time to toe force under the majority of walking conditions. The instrumented treadmill system used in this study provided reproducible measurements for the majority of the evaluated spatial, temporal and ground reaction force gait parameters in healthy individuals. The assessment of time to heel/toe force should be however avoided, and particular care should be taken for some spatial (step length) and temporal (cadence and step time) parameters while walking uphill and/or at slow speeds.

Ground reaction forces are more sensitive gait measures than temporal parameters in rodents following rotator cuff injury

Gait analysis is a quantitative, non-invasive technique that can be used to investigate functional changes in animal models of musculoskeletal disease. Changes in ground reaction forces following injury have been observed that coincide with differences in tissue mechanical and histological properties during healing. However, measurement of these kinetic gait parameters can be laborious compared to the simpler and less time-consuming analysis of temporal gait parameters alone. We compared the sensitivity of temporal and kinetic gait parameters in detecting functional changes following rotator cuff injury in rats. Although these parameters were strongly correlated, temporal measures were unable to detect greater than 50% of the functional gait differences between injured and uninjured animals identified simultaneously by ground reaction forces. Regression analysis was used to predict ground reaction forces from temporal parameters. This model improved the ability of temporal parameters to identify known functional changes, but only when these differences were large in magnitude (i.e., between injured vs. uninjured animals, but not between different post-operative treatments). The results of this study suggest that ground reaction forces are more sensitive measures of limb/joint function than temporal parameters following rotator cuff injury in rats. Therefore, although gait analysis systems without force plates are typically efficient and easy to use, they may be most appropriate for use when major functional changes are expected.

The Impact of a Portable Metabolic Measurement Device on Gait Characteristics of Older Adults With Mobility Limitations

BACKGROUND AND PURPOSE

Increased carriage loads have been found to alter gait biomechanics in young healthy adults and military personnel; however, less is known regarding the influence of added carriage load on the gait characteristics of older adults-especially those with mobility limitations. The purpose of this study was to examine spatial and temporal gait characteristics during instrumented and noninstrumented overground walking in a sample of older adults with slow gait.

METHODS

Forty older adults with slow gait completed 2 bouts of walking (instrumented and noninstrumented) over a computerized walkway during 1 clinic visit. Mean spatial-temporal characteristics, gait variability, and gait speed over 8 passes were recorded. Paired t tests and intraclass correlation coefficients were used to quantify differences.

RESULTS AND DISCUSSION

Nine of the 10 gait variables did not differ statistically between instrumented and noninstrumented gait (P < .05). Intraclass correlation coefficients (ICCs) for mean gait characteristics were excellent (range ICC = 0.94-0.98; 95% confidence interval = 0.89-0.99), and for gait variability ranged from fair to excellent (range ICC = 0.56-0.79; 95% confidence interval = 0.28-0.89). Our study was able to demonstrate no significant impact of instrumentation on gait characteristics in a sample of older adults with slow gait.

CONCLUSION

Our findings begin to fill in the gaps in the literature regarding the impact of added carriage loads on more vulnerable populations and lend support for the use of similar weighted metabolic devices as a component of gait assessment in older adults with confidence that the additional carriage-load will not significantly impact concurrent measures of gait.

Instrumenting gait with an accelerometer: a system and algorithm examination

Gait is an important clinical assessment tool since changes in gait may reflect changes in general health. Measurement of gait is a complex process which has been restricted to the laboratory until relatively recently. The application of an inexpensive body worn sensor with appropriate gait algorithms (BWM) is an attractive alternative and offers the potential to assess gait in any setting. In this study we investigated the use of a low-cost BWM, compared to laboratory reference using a robust testing protocol in both younger and older adults. We observed that the BWM is a valid tool for estimating total step count and mean spatio-temporal gait characteristics however agreement for variability and asymmetry results was poor. We conducted a detailed investigation to explain the poor agreement between systems and determined it was due to inherent differences between the systems rather than inability of the sensor to measure the gait characteristics. The results highlight caution in the choice of reference system for validation studies. The BWM used in this study has the potential to gather longitudinal (real-world) spatio-temporal gait data that could be readily used in large lifestyle-based intervention studies, but further refinement of the algorithm(s) is required.

Influence of a walking aid on temporal and spatial parameters of gait in healthy adults

OBJECTIVE

To determine the effect of using a walking aid on temporal and spatial parameters of gait when used for balance versus support on the dominant and nondominant hand side.

DESIGN

Repeated measures observational study design.

SETTING

University gymnasium.

PARTICIPANTS

Twenty-seven healthy male and female adults of mean ± standard deviation age 44.74 ± 10.00 years.

METHODS

Five walking conditions (C) were completed by all participants on the GAITRite pressure mat. Normal walking (C1), walking with a cane in the dominant hand (C2) and nondominant hand (C3) as if using for balance, walking with a cane in the dominant hand (C4) and nondominant hand (C5) while allowing approximately 10% of the body weight through the cane.

MAIN OUTCOME MEASUREMENTS

Temporal measurements (swing time, stance time, single limb support time, double limb support time) as percentage of a gait cycle and the base of support for the left and the right foot for all 5 walking conditions.

RESULTS

A significant difference (P < .001) was observed between C1, C2, and C3 in percentage swing time and percentage stance time of the ipsilateral side, and in percentage single limb support time of the contralateral side. The double limb support time was significantly different (P ≤ .04) for both ipsilateral and contralateral sides. Comparisons among C1, C4, and C5 demonstrated significance (P < .001) for all variables. Post hoc analysis showed significance between C1 and C4, and C1 and C5 for all variables except percentage stance time of the ipsilateral side and percentage single limb support of the contralateral side.

CONCLUSIONS

In healthy adults, use of a cane for balance modifies swing and stance parameters of the ipsilateral side and does not affect the base of support formed by the feet. When used for support, the cane alters the swing and stance parameters, and also the base of support formed by the feet.

Associations of self-report measures with gait, range of motion and proprioception in patients with lumbar spinal stenosis

INTRODUCTION

Spinal stenosis is defined as neurogenic claudication due to narrowing of the spinal canal lumen diameter. As the disease progresses, ambulation and gait may be impaired. Self-report measures are routinely used in the clinical setting to capture data related to lumbar pain symptoms, function and perceived disability. The associations between self-report measures and objective measures of physical function in patients with lumbar spinal stenosis are not well characterized. The purpose of this study was to determine the correlation between self-reported assessments of function with objective biomechanical measures of function.

METHODS

25 subjects were enrolled in this study. Subjects completed self-report questionnaires and biomechanical assessments of gait analysis, lumbar 3D ROM and lumbar proprioception. Correlations were determined between self-report measures and biomechanical data.

RESULTS

The Oswestry Disability Index (ODI) was strongly correlated with stride length and gait velocity and weakly correlated with base of support. ODI was also weakly correlated with left lateral bending proprioception but not right lateral bending. The SF12 was not significantly correlated with any of the biomechanical measurements. Pain scores were weakly correlated with velocity, and base of support, and had no correlation any of the other biomechanical measures.

DISCUSSION

There is a strong correlation between gait parameters and functional disability as measured with the ODI. Quantified gait analysis can be a useful tool to evaluate patients with lumbar spinal stenosis and to assess the outcomes of treatments on this group of patients.

Reliability of spatiotemporal and kinetic gait parameters determined by a new instrumented treadmill system

Background

Despite the emerging use of treadmills integrated with pressure platforms as outcome tools in both clinical and research settings, published evidence regarding the measurement properties of these new systems is limited. This study evaluated the within– and between–day repeatability of spatial, temporal and vertical ground reaction force parameters measured by a treadmill system instrumented with a capacitance–based pressure platform.

Methods

Thirty three healthy adults (mean age, 21.5 ± 2.8 years; height, 168.4 ± 9.9 cm; and mass, 67.8 ± 18.6 kg), walked barefoot on a treadmill system (FDM–THM–S, Zebris Medical GmbH) on three separate occasions. For each testing session, participants set their preferred pace but were blinded to treadmill speed. Spatial (foot rotation, step width, stride and step length), temporal (stride and step times, duration of stance, swing and single and double support) and peak vertical ground reaction force variables were collected over a 30–second capture period, equating to an average of 52 ± 5 steps of steady–state walking. Testing was repeated one week following the initial trial and again, for a third time, 20 minutes later. Repeated measures ANOVAs within a generalized linear modelling framework were used to assess between–session differences in gait parameters. Agreement between gait parameters measured within the same day (session 2 and 3) and between days (session 1 and 2; 1 and 3) were evaluated using the 95% repeatability coefficient.

Results

There were statistically significant differences in the majority (14/16) of temporal, spatial and kinetic gait parameters over the three test sessions (P < .01). The minimum change that could be detected with 95% confidence ranged between 3% and 17% for temporal parameters, 14% and 33% for spatial parameters, and 4% and 20% for kinetic parameters between days. Within–day repeatability was similar to that observed between days. Temporal and kinetic gait parameters were typically more consistent than spatial parameters. The 95% repeatability coefficient for vertical force peaks ranged between ± 53 and ± 63 N.

Conclusions

The limits of agreement in spatial parameters and ground reaction forces for the treadmill system encompass previously reported changes with neuromuscular pathology and footwear interventions. These findings provide clinicians and researchers with an indication of the repeatability and sensitivity of the Zebris treadmill system to detect changes in common spatiotemporal gait parameters and vertical ground reaction forces.

Effects of a progressive aquatic resistance exercise program on the biochemical composition and morphology of cartilage in women with mild knee osteoarthritis: protocol for a randomised controlled trial

BACKGROUND

Symptoms associated with osteoarthritis of the knee result in decreased function, loss of working capacity and extensive social and medical costs. There is a need to investigate and develop effective interventions to minimise the impact of and even prevent the progression of osteoarthritis. Aquatic exercise has been shown to be effective at reducing the impact of osteoarthritis. The purpose of this article is to describe the rationale, design and intervention of a study investigating the effect of an aquatic resistance exercise intervention on cartilage in postmenopausal women with mild knee osteoarthritis.

METHODS

A minimum of 80 volunteers who meet the inclusion criteria will be recruited from the local population through newspaper advertisements. Following initial assessment volunteers will be randomised into two groups. The intervention group will participate in a progressive aquatic resistance exercise program of 1-hour duration 3 times a week for four months. The control group will be asked to maintain normal care during this period. Primary outcome measure for this study is the biochemical composition of knee cartilage measured using quantitative magnetic resonance imaging; T2 relaxation time and delayed gadolinium-enhanced magnetic resonance imaging techniques. In addition, knee cartilage morphology as regional cartilage thickness will be studied. Secondary outcomes include measures of body composition and bone traits using dual energy x-ray absorptiometry and peripheral quantitative computed tomography, pain, function using questionnaires and physical performance tests and quality of life. Measurements will be performed at baseline, after the 4-month intervention period and at one year follow up.

DISCUSSION

This randomised controlled trial will investigate the effect a progressive aquatic resistance exercise program has on the biochemical composition of cartilage in post-menopausal women with mild knee osteoarthritis. This is the first study to investigate what impact aquatic exercise has on human articular cartilage. In addition it will investigate the effect aquatic exercise has on physical function, pain, bone and body composition and quality of life. The results of this study will help optimise the prescription of aquatic exercise to persons with mild knee osteoarthritis.

TRIAL REGISTRATION

ISRCTN65346593.

Independent domains of gait in older adults and associated motor and nonmotor attributes: validation of a factor analysis approach

BACKGROUND

Gait is an important predictor of survival in older adults. Gait characteristics help to identify markers of incipient pathology, inform diagnostic algorithms and disease progression, and measure efficacy of interventions. However, there is no clear framework to guide selection of gait characteristics. This study developed and validated a model of gait in older adults based on a strong theoretical paradigm.

METHODS

One hundred and eighty-nine older adults with a mean (SD) age of 69.5 (7.6) years were assessed for 16 spatiotemporal gait variables using a 7-m instrumented walkway (GAITRite) while walking for 2 minutes. Principal components analysis and factor analysis "varimax" procedure were used to derive a model that was validated using a multimethod approach: replication of previous work; association of gait domains with motor, cognitive, and behavioral attributes; and discriminatory properties of gait domains using age as a criterion.

RESULTS

Five factors emerged from the principal components analysis: pace (22.5%), rhythm (19.3%), variability (15.1%), asymmetry (14.5%), and postural control (8.0%), explaining 79.5% of gait variance in total. Age, executive function, power of attention, balance self-efficacy, and physical fatigue were independently and selectively associated with 4 gait domains, explaining up to 40.1% of total variance. Median age discriminated pace, variability, and postural control domains.

CONCLUSIONS

This study supports a 5-factor model of gait in older adults with domains that preferentially select for motor, cognitive, and behavioral attributes. Future research is required to validate the model. If successful, it will facilitate hypothesis-driven research to explain underlying gait mechanisms, identify contributory features to gait disturbance, and examine the effect of intervention.

Efficacy of a whole-body vibration intervention to effect exercise tolerance and functional performance of the lower limbs of people with chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a respiratory condition characterised by dyspnoea, excessive sputum production, chronic cough, bronchitis and emphysema. Functionally, exercise tolerance is poor for people with COPD and is linked to difficulty in performing daily tasks. More specifically, exercise difficulties are due partly to dyspnoea and lower limb skeletal muscle dysfunction. The benefit of exercise that does not exacerbate the disease while improving exercise tolerance is salient. Whole-body vibration (WBV) is a mode of physical activity known to improve muscular function of the lower limbs, yet efficacy has not been investigated for a WBV intervention conducted in a home-based setting for people with COPD.

METHODS/DESIGN

This clinically registered trial is a non-randomised placebo cross-over intervention based in the home of each participant (ACTRN12612000508875). Participants diagnosed with COPD will complete a six-week WBV intervention and then after a two-week washout period, will complete a six-week placebo training intervention. Participants will complete sessions twice a week. The duration of the trial is 14 weeks. Community-dwelling older adults with COPD will provide informed voluntary consent to participate. Outcome measures will include immediate, acute, and long-term responses to exercise.

DISCUSSION

Quantifying responses to WBV among people with COPD will allow discussion of efficacy of WBV as a mode of physical activity. The skill required by the participant to perform physical activity with WBV is not demanding and may enhance habitual sustainability. The results of this trial could be used to support further research in both clinical and community settings.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ANZCTR12612000508875).

Reliability of gait parameters during treadmill walking in community-dwelling healthy seniors

The present study aimed at assessing the between- and within-day-variability of temporal and spatial gait characteristics during treadmill walking in community-dwelling seniors. In 20 active, healthy seniors (10 women, 10 men, age: 64.8 (SD 3.2) years, height: 1.70 (0.10) m, weight: 69.7 (10.9) kg, physical activity: 11 (6) h week(-1)) gait characteristics were assessed on three days in weekly intervals (between-day variability). Either on days two or three, testing was repeated 30 min after the initial trial (within-day variability). We determined routine spatio-temporal gait parameters as well as gait variability during 400 steps at a normal walking speed (5.0 (0.4) km h(-1)) on a one-dimensional ground reaction force measuring treadmill. No significant mean differences occurred in any parameter for between- and within-day comparisons. Between-day ICC were high (ICC≥0.86) for most parameters except for temporal (ICC=0.44) and spatial (ICC=0.22) gait variability. Coefficients of variation (CoV) were also high in the latter parameters (CoV=30.2-36.1%), whereas all other variables showed clearly lower values (CoV<7%). CoV were still lower between days 2 and 3 (CoV<5%). Compared to between-day comparisons, within-day variability was comparable in spatio-temporal gait parameters (CoV<5%, ICC≥0.97) and lower in gait variability parameters (CoV<18%, ICC≥0.72-0.74). In conclusion, most gait parameters were highly reliable during treadmill walking. Changes of less than 10% can be detected with sufficient confidence. Gait variability parameters were less reliable and, thus, should be carefully interpreted.

What to measure when determining orthotic needs in children with Down syndrome: a pilot study

PURPOSE

To compare the effects of off-the-shelf foot orthoses and supramalleolar orthoses on the gait of children with Down syndrome (DS), and establish criteria for determining orthoses prescription for a child with DS.

METHODS

We assessed the gait of 6 children (aged 4-7 years) with DS using the GAITRite system, and obtained height, weight, leg length, hypermobility, calcaneal eversion, navicular drop, and tibial torsion measurements.

RESULTS

Supramalleolar orthoses lead to a longer cycle time than foot orthoses (P = .05) and barefoot walking (P = .03) and a lower cadence than barefoot walking (P = .04). Significant strong correlations with gait parameters were obtained for height, leg length, and hypermobility. Biomechanical measurements showed no significant correlations with gait parameters.

CONCLUSIONS

The role of physical examination data, including anthropometric and biomechanical measurements in the prescription of orthoses requires further investigation.

Measurement error and minimum detectable change in 4-meter gait speed in older adults

BACKGROUND AND AIMS

Gait speed is a commonly-used assessment and outcomes measure in geriatric clinical and research settings. Although relative reliability of usual gait speed has been well studied in community- dwelling older adults, less emphasis has been placed on a measure of absolute reliability (the standard error of measurement [SEM]), and on an associated clinically relevant index of real change in gait speed, minimum detectable change (MDC). The purpose of this study was to quantify measurement error and MDC for usual gait speed over 4 meters in community-dwelling older adults ambulating at intermediate and fast speeds.

METHODS

Community-dwelling older adults ambulating at intermediate gait speed (IGS), (n=15, mean age 74.2 yrs) and fast gait speed (FGS), (n=15, mean age 72.1) were included in this study. Participants performed two trials of gait speed over a distance of 4 meters. SEM and MDC at the 95% confidence level (MDC95) were computed for the IGS and FGS groups.

RESULTS

Mean gait speed was 85.4 cm/s (IGS) and 129.9 cm/s (FGS). Measurement error (<5% of mean gait speed) and minimum detectable change (<13% of mean gait speed) were low in both groups. MDC95 was computed as 10.8 cm/s and 14.4 cm/s for the IGS and FGS groups, respectively.

CONCLUSIONS

To be considered real change beyond the bounds of measurement error, change in 4-meter gait speed should exceed 10.8 cm/s (for intermediate speed ambulators) or 14.4 cm/s (for fast speed ambulators). Low measurement error in assessing 4-meter gait speed in community-dwelling older adults suggests that gait speed assessed over short distances has excellent reproducibility across trials. Low minimum change values suggest that 4-meter gait speed may be responsive and sensitive to change.

Stride dynamics, gait variability and prospective falls risk in active community dwelling older women

BACKGROUND

Measures of walking instability such as stride dynamics and gait variability have been shown to identify future fallers in older adult populations with gait limitations or mobility disorders. This study investigated whether measures of walking instability can predict future fallers (over a prospective 12 month period) in a group of healthy and active older women.

METHODS

Ninety-seven healthy active women aged between 55 and 90 years walked for 7 min around a continuous walking circuit. Gait data recorded by a GAITRite(®) walkway and foot-mounted accelerometers were used to calculate measures of stride dynamics and gait variability. The participant's physical function and balance were assessed. Fall incidence was monitored over the following 12 months.

RESULTS

Inter-limb differences (p≤0.04) in stride dynamics were found for fallers (one or more falls) aged over 70 years, and multiple fallers (two or more falls) aged over 55 years, but not in non-fallers or a combined group of single and non-fallers. No group differences were found in the measures of physical function, balance or gait, including variability. Additionally, no gait variable predicted falls.

CONCLUSIONS

Reduced coordination of inter-limb dynamics was found in active healthy older fallers and multiple fallers despite no difference in other measures of intrinsic falls risk. Evaluating inter-limb dynamics may be a clinically sensitive technique to detect early gait instability and falls risk in high functioning older adults, prior to change in other measures of physical function, balance and gait.