The untapped potential of physical activity monitoring for quality assurance of field-based walking tests in clinical respiratory trials.

Field-based walking tests are well-established outcome measures in clinical research trials and in the evaluation of routine clinical services, including pulmonary rehabilitation. Despite widespread use, there has been little attention to, or reporting of, the quality assurance of these tests. Physical activity monitoring has become increasingly popular and data from activity monitors could be used for quality assurance of field-based walking tests. We provide examples in this article of data-driven insights possible with this approach, using data from waist-worn accelerometry, for the incremental shuttle walking test (ISWT), endurance shuttle walk test (ESWT) and six-minute walk test (6MWT). Given the multitude of devices to measure physical activity and the range metrics to describe physical activity, we also comment on some of the technical considerations to using activity monitors for walking test quality assurance. Data-driven approaches to quality assurance are already commonplace for other outcome measures in clinical respiratory trials, but little is known about this approach for field-based walking tests. The application of physical activity monitoring may be extended to other field-based exercise tests and additional rehabilitation services. This may be more challenging for self-paced walking tests such as the 6MWT. Future work should apply this approach to research trials and service evaluations to explore the impact of field-based walking test quality on performance (e.g. distance on the ISWT or time achieved for the ESWT), responsiveness to interventions (e.g. pulmonary rehabilitation) and effectiveness of training procedures (e.g. remote training for multi-site trials).

Deriving personalised physical activity intensity thresholds by merging accelerometry with field-based walking tests: Implications for pulmonary rehabilitation.

During pulmonary rehabilitation (PR), patients receive individually tailored walking exercise training. The personalised nature of exercise prescription is a fundamental component of PR. Despite this, the measurement of physical activity (PA) has been limited to a 'one size fits all' approach and can be challenging to translate into clinically meaningful or real-world units, such as cadence. This discrepancy may partly explain the inconsistent evidence for the impact of PR on PA. It may also provide an opportunity to standardise PA assessment in the context of chronic respiratory disease (CRD) and PR, where field-based walking tests are routine measures. This technical note provides an example of how to develop personalised PA intensity thresholds, calibrated against an individual's performance on the Incremental Shuttle Walking Test (ISWT; maximal) and Endurance Shuttle Walk Test (ESWT; sub-maximal). These are externally paced tests, with each level (speed) of the tests denoting a specific speed (intensity); ranging 1.8 km/h (ISWT Level 1) to 8.5 km/h (ISWT Level 12). From the ESWT, it becomes possible to evaluate adherence to each individual's walking exercise prescription. Future research should explore this approach and its responsiveness to PR. It may be possible to extend this methodology with the inclusion of physiological parameters (e.g., heart rate, calorimetry, and oxygen consumption) to derive relative intensity markers (e.g. moderate-to-vigorous), accounting for individual differences in exercise capacity, under the same paradigm as PR exercise prescription.

Repeated assessment of key clinical walking measures can induce confounding practice effects.

Accurate functional outcome measures are critical for both clinical trials and routine patient assessments. Many functional outcomes improve with test repetition, a phenomenon that can confound the findings of longitudinal assessments. In this viewpoint, we tackle the poorly considered issue of practice effects in prevailing clinical walking tests based on current literature, while also presenting the original data from our own work, in which we investigated practice effects in the timed 25-foot walk (T25FW), timed-up and go (TUG), and 2-minute walk test (2MWT). In these tests, performed on 3 consecutive days in 10 patients with multiple sclerosis and 40 healthy controls, we observed significant practice effects in several established walking outcomes, including a 9.0% improvement in patients' TUG performance (p = 0.0146). Pre-training in these walking tests prior to baseline measurement may mitigate practice effects, thereby improving the accuracy and value of their repeated use in research and clinical settings.

[The Expanded Disability Status Scale scoring in patients with multiple sclerosis]. / Az Expanded Disability Status Scale használata és a motoros képességek vizsgálata sclerosis multiplexes betegekben.

Gait disturbance is a major symptom in patients with multiple sclerosis. The Expanded Disability Status Scale (EDSS) was first used in clinical trials of multiple sclerosis for the assessment of disability, however it has become more and more widely used in clinical practice as well. Nowadays its use is essential in application of the new diagnostic criteria, the new clinical form classification and in monitoring the efficacy of therapies. EDSS is based on a standardised neurological examination, but focuses on those symptoms that are frequent in multiple sclerosis. Based on the examination it assesses seven functional systems: visual, brainstem, pyramidal, cerebellar, sensory, bowel-bladder and cerebral functions. EDSS scores can be determined based on the scores given in the functional systems and on testing the walking distance. In newer versions the "Ambulation score" has been added. This chapter clarifies the scores based on the maximal walking distance and the need for a walking aid to walk this distance. The Neurostatus/EDSS training method improves the reproducibility of the standardised neurological examination that forms the basis of the EDSS scoring. Of the tests assessing walking, the Timed-25 Foot Walk Test and the self-administered 12-Item Multiple Sclerosis Walking Scale are suitable for routine evaluation of walking performance. An increase of more than 20% in the Timed-25 Foot Walk may be considered a significant change in gait.

Comparison of bioenergetics of walking during a multistage incremental shuttle walk test and a 6-min walk test in active older adults.

The goal of the present research was to compare the bioenergetics variability of walking, during the 6-min walk test (6-MWT) and a multistage incremental shuttle walk test (MISWT) in an active older population. Twenty-two healthy physically active older adults with a group mean age of 70.4 ± 5.8 years completed the 6-MWT and the MISWT. Heart rate (HR), walking speed and walking [Formula: see text]O2 were measured throughout each test with a portable metabolic cart. Strong correlations were found for the [Formula: see text]O2 peak and the walking speed (r = 0.91 and r = 0.89 respectively for 6-MWT and MISWT). Differences in [Formula: see text]O2 peak values were analysed with a paired Student's t test. Repeated measures ANOVA were conducted to detect differences between tests. The Bland and Altman plot indicates that the average difference between both tests was 2.5 ml kg-1 min-1. MISWT [Formula: see text]O2 peak means were significantly greater than the 6-MWT [Formula: see text]O2 peak mean values (21.6 ± 5.3 vs. 18.9 ± 4.5 ml kg-1 min-1) which indicate bioenergetics differences between the two walking tests. Thus, the MISWT and 6-MWT elicited different walking [Formula: see text]O2 peak and HR suggesting that the MISWT field test challenge the participants to a higher level of cardiovascular and respiratory stress. The walking [Formula: see text]O2 peak recorded for the MISWT was significantly greater than the 6-MWT. Consequently, both tests seem to measure different facets of the aerobic capacity. MISWT seems to be a better indicator of maximal aerobic power whereas the 6-MWT provides more relevant information regarding aerobic endurance in aging population.

Test-retest reliability, construct validity and determinants of 6-minute walk test performance in adult patients with asthma.

INTRODUCTION AND OBJECTIVES: Current knowledge regarding the measurement properties of the 6-minute walk test (6MWT) in patients with asthma is limited. Therefore, the aim of this study was to assess the test-retest reliability, measurement error and construct validity of the 6MWT and identify determinants of 6-minute walk distance (6MWD) in patients with asthma. PATIENTS AND METHODS: 201 asthma patients referred for pre-pulmonary rehabilitation assessment, were retrospectively analyzed (age 61±12 years, 42% male, FEV1 78±27% predicted). Patients performed two 6MWTs on subsequent days using a 30 m straight walking course. Other measurements included resting dyspnea, maximal exercise capacity, body composition, pulmonary function, pulmonary and quadriceps muscle strength and symptoms of anxiety and depression. Measurement error (absolute reliability) was tested using standard error of measurement (SEM), minimal detectable change at 95% confidence interval (MDC95%) and Bland and Altman 95% limits of agreement, whereas test-retest reliability (relative reliability) and construct validity were assessed using the intra-class correlation coefficient (ICC2,1) and correlations, respectively. RESULTS: The 6MWD showed excellent test-retest reliability (ICC2,1: 0.91). The mean change in 6MWD after the second 6MWT was 18m (95%CI 11-24m), with 73% of the patients walking further in the second test. The SEM and MDC95% for the 6MWT were 35 m and 98 m, respectively. The best 6MWD correlated strongly with peak oxygen uptake during CPET and resting dyspnea (r = 0.61-0.64) and had no-to-moderate correlations with body composition, pulmonary function, respiratory and quadriceps muscle strength and symptoms of anxiety and depression (r = 0.02-0.45). Multiple linear regression was able to identify maximal workload, BMI, rollator use, maximal expiratory pressure, FEV1 and DLCO as independent determinants of the best 6MWD (R2 = 0.58). CONCLUSIONS: The 6MWT was considered to be reliable and valid in patients with asthma, which strengthens its clinical utility. However, the majority of patients demonstrated a considerable learning effect in the second 6MWT, providing a strong rationale for performing two 6MWTs.

Assessment of exercise capacity using field walking tests in patients after the Fontan procedure: A case-control study.

BACKGROUND: Despite the frequent use of the 6-minute walk test (6MWT), exercise capacity has not been assessed with the incremental shuttle walk test (ISWT) in patients who have undergone the Fontan procedure. It is unclear whether these tests cause clinically relevant cardiorespiratory responses in these patients. OBJECTIVES: We aimed to assess cardiorespiratory responses to the 6MWT and ISWT in Fontan patients, compare the responses with those in the controls, and examine the agreement between the two field tests. METHODS: Submaximal exercise capacity was assessed using the 6MWT, maximal exercise capacity using the ISWT, quadriceps isometric muscle strength with a hand dynamometer, and body composition using a bioelectrical impedance device. RESULTS: Twenty-one Fontan patients (16.42±6.63 years, 5F/16M) and 21 controls (16.57±4.30 years, 7F/14M) were included. While body composition was similar between the groups (p>0.05), quadriceps isometric muscle strength and 6MWT and ISWT distance were lower in the Fontan patients than in the controls (p<0.05). In both the 6MWT and ISWT, pre- and post-test heart rate (HR), oxygen saturation (SpO2), dyspnea, and leg fatigue differed significantly between the Fontan patients and the controls (p<0.05). In addition, the ISWT resulted in a more significant change in HR, SpO2, and leg fatigue than the 6MWT in the Fontan patients (p<0.05). Bland-Altman plots for the 6MWT vs. the ISWT indicated agreement between the two tests. CONCLUSION: There were remarkable changes in HR, SpO2, dyspnea, and leg fatigue in both tests. With similar safety to the 6MWT but with more caution applied for adverse events, the ISWT can also be performed as a field test to evaluate exercise capacity and identify more pronounced exercise-induced responses (especially oxygen desaturation) in Fontan patients.

The prognostic value of fixed time and self-paced walking tests in patients diagnosed with idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a specific form of chronic fibrosing interstitial pneumonia that has an unknown etiology. The natural history of the disease is characterized by a progressive decline in pulmonary function and overall health and well-being. The median survival time is between 2-3 years; however, the disease course is variable and unpredictable. The twelve-minute walking test (12MWT) and six-minute walking test (6MWT) are two fixed time tests that are commonly used in clinical practice. Our short and clinically oriented narrative review attempted to summarize current evidence supporting the use of fixed time, self-paced walking tests in predicting the outcome of patients diagnosed with IPF. A number of studies have justified that the 6MWT is a simple, cost-effective, well documented, fixed time, and self-paced walking test which is a valid and reliable measure of disease status and can also be used as a prognostic tool in patients with IPF. However, there is a need for dedicated and validated reference equations for this population of patients. It is also necessary to fill the knowledge gap about the role of the 12MWT. We hypothesize that it would be useful in evaluating patients that are in the early stages of the disease.

Mobility Skills With Exoskeletal-Assisted Walking in Persons With SCI: Results From a Three Center Randomized Clinical Trial.

Background: Clinical exoskeletal-assisted walking (EAW) programs for individuals with spinal cord injury (SCI) have been established, but many unknown variables remain. These include addressing staffing needs, determining the number of sessions needed to achieve a successful walking velocity milestone for ambulation, distinguishing potential achievement goals according to level of injury, and deciding the number of sessions participants need to perform in order to meet the Food and Drug Administration (FDA) criteria for personal use prescription in the home and community. The primary aim of this study was to determine the number of sessions necessary to achieve adequate EAW skills and velocity milestones, and the percentage of participants able to achieve these skills by 12 sessions and to determine the skill progression over the course of 36 sessions. Methods: A randomized clinical trial (RCT) was conducted across three sites, in persons with chronic (≥6 months) non-ambulatory SCI. Eligible participants were randomized (within site) to either the EAW arm first (Group 1), three times per week for 36 sessions, striving to be completed in 12 weeks or the usual activity arm (UA) first (Group 2), followed by a crossover to the other arm for both groups. The 10-meter walk test seconds (s) (10MWT), 6-min walk test meters (m) (6MWT), and the Timed-Up-and-Go (s) (TUG) were performed at 12, 24, and 36 sessions. To test walking performance in the exoskeletal devices, nominal velocities and distance milestones were chosen prior to study initiation, and were used for the 10MWT (≤ 40s), 6MWT (≥80m), and TUG (≤ 90s). All walking tests were performed with the exoskeletons. Results: A total of 50 participants completed 36 sessions of EAW training. At 12 sessions, 31 (62%), 35 (70%), and 36 (72%) participants achieved the 10MWT, 6MWT, and TUG milestones, respectively. By 36 sessions, 40 (80%), 41 (82%), and 42 (84%) achieved the 10MWT, 6MWT, and TUG criteria, respectively. Conclusions: It is feasible to train chronic non-ambulatory individuals with SCI in performance of EAW sufficiently to achieve reasonable mobility skill outcome milestones.

The 100-meter timed test: Normative data in healthy males and comparative pilot outcome data for use in Duchenne muscular dystrophy clinical trials.

Timed walking tests are often used to measure function in boys with Duchenne muscular dystrophy (DMD). Our objective was to evaluate the 100 meter timed test (100m), a fixed distance test of maximal performance, for use in DMD. To this end, we sought to establish normative 100m performance in healthy controls, compare DMD performance to controls, and evaluate the reliability of 100m. Seventy-two boys with DMD (18 steroid-naïve, 54 on steroids) and 599 controls (4-14 years) completed the 100m as speedily as possible on a 25-meter track. Repeat testing was completed between 1 and 42 days later and again at 1 year in a subgroup of 96 control boys. Additionally 35 DMD boys were followed longitudinally (5-19 months). Descriptive statistics are presented by age and cohort. There was a significant difference in performance between groups (p < 0.01). Age and body mass index (BMI) significantly influenced 100m (p < 0.0001) in the control cohort. Test-retest reliability was excellent for both cohorts (ICC > 0.90, p < 0.001). Normative data can be used to determine percent-predicted 100m times to quantify the severity of running impairment in children with a motor deficit. Performance of 100m follows the natural history established by other outcome measures in DMD.

Convergent validity of the Timed Up and Go Test and Ten-metre Timed Walk Test in pregnant women with pelvic girdle pain.

Pregnant women with pelvic girdle pain (PGP) often experience functional difficulties, in particular walking difficulties. Currently, however, there is a lack of validated performance-orientated outcome measures available for use in this population. The Timed Up and Go (TUG) test and Ten-metre Timed Walk Test (10 mTWT) are two short-distance walking tests that have demonstrated reliability in pregnant women with PGP, but as yet have no established validity. The aim of the present study was to evaluate the convergent validity of the TUG and 10 mTWT by comparing performances on these two walking tests with scores achieved on the Active Straight Leg Raise (ASLR) test and the Pelvic Girdle Questionnaire (PGQ). Eighteen pregnant women with PGP aged 31.4 years (SD = 2.7) and 28.9 weeks pregnant (SD = 7.3) were included. Spearman rank correlation coefficient (rs) was used to determine convergent validity. Strong correlations were found between the TUG and ASLR (rs = 0.73, p = 0.001), and the 10 mTWT and ASLR (rs = -0.65, p = 0.003). Relationships between the TUG and PGQ were moderate (rs = 0.41 to 0.52) and between the 10 mTWT and PGQ low to moderate (rs = -0.25 to -0.56). The strong relationships between the walking tests and the ASLR may suggest these tests all assess the same construct. The weaker relationships found between the walking tests and the PGQ may be related to the self-report and multiple functional activities nature of the questionnaire. This study found both the TUG and 10 mTWT to be valid weight-bearing physical performance measures, although more research is warranted due to the small study sample.

THE EFFECT OF TRANSFEMORAL INTERFACE DESIGN ON GAIT SPEED AND RISK OF FALLS.

Falls and diminished walking capacity are impairments common in persons with transfemoral amputation (TFA). Reducing falls and optimizing walking capacity through such means as achieving a more normal gait speed and community ambulation should be considered when formulating the prosthetic prescription. Because walking capacity and balance confidence are compromised with TFA, these outcomes should be considered when evaluating interfaces for transfemoral prosthetic users. The purpose of this study was to compare the effect of TFA interface design on walking capacity and balance confidence A retrospective cohort design was utilized involving unilateral TFA patients who used ischial ramus containment (IRC) and High-Fidelity (HiFi) interfaces (independent variables). Dependent variables included the Activity-specific Balance Scale (ABC) and the two-minute walk test (2MWT). Complete records were available for 13 patients (n = 13). The age range was 26 to 58 years. Three patients functioned at the K4 activity level, whereas all others functioned at the K3 level. Mean ABC scores were significantly different (p ≤ 0.05) at 77.2 (±16.8; 35.6 to 96.9) for IRC and 90.7 (±5.7; 77.5 to 98.7) for HiFi. The mean distance walked on the 2MWT was 91.8 m (±22.0, 58.3 to 124.7) for IRC compared to 110.4 m (±28.7; 64.7 to 171.1) for the HiFi socket (p ≤ 0.05). Alternative transfemoral interface design, such as the HiFi socket, can improve walking capacity and balance confidence in higher-functioning TFA patients.

Robot-assisted gait training might be beneficial for more severely affected children with cerebral palsy.

PURPOSE: Robot-assisted gait training (RAGT) can complement conventional therapies in children with cerebral palsy. We investigated changes in walking-related outcomes between children with different Gross Motor Function Classification System (GMFCS) levels and the dose-response relationship. METHODS: Data from 67 children (3.9-19.9 years) with GMFCS levels II-IV were evaluated retrospectively. Every child received RAGT with the Lokomat complementing a multidisciplinary rehabilitation program. Changes in various walking-related outcomes were assessed. RESULTS: Walking-related outcomes did not improve differently between GMFCS level groups. Significant within-group improvements were mainly observed in children with GMFCS level IV. A dose-response relationship was present for children with GMFCS levels III and IV. CONCLUSIONS: Our results indicated that, although children with a GMFCS level IV walked less during an average Lokomat session, they experienced significant improvements in walking-related outcomes. Further, training dose correlated with changes in walking-related outcomes. However, between-group differences in changes in walking-related outcomes were not significant.

Reliability of the Timed Up and Go test and Ten-Metre Timed Walk Test in Pregnant Women with Pelvic Girdle Pain.

BACKGROUND AND PURPOSE: There is a lack of functional objective tests available to measure functional status in women with pelvic girdle pain (PGP). The purpose of this study was to establish test-retest and intertester reliability of the Timed Up and Go (TUG) test and Ten-metre Timed Walk Test (10mTWT) in pregnant women with PGP. METHODS: A convenience sample of women was recruited over a 4-month period and tested on two occasions, 1 week apart to determine test-retest reliability. Intertester reliability was established between two assessors at the first testing session. Subjects were instructed to undertake the TUG and 10mTWT at maximum speed. One practise trial and two timed trials for each walking test was undertaken on Day 1 and one practise trial and one timed trial on Day 2. RESULTS: Seventeen women with PGP aged 31.1 years (SD [standard deviation] = 2.3) and 28.7 weeks pregnant (SD = 7.4) completed gait testing. Test-retest reliability using the intraclass correlation coefficient (ICC) was excellent for the TUG (0.88) and good for the 10mTWT (0.74). Intertester reliability was determined in the first 13 participants with excellent ICC values being found for both walking tests (TUG: 0.95; 10mTWT: 0.94). CONCLUSION: This study demonstrated that the TUG and 10mTWT undertaken at fast pace are reliable, objective functional tests in pregnant women with PGP. While both tests are suitable for use in the clinical and research settings, we would recommend the TUG given the findings of higher test-retest reliability and as this test requires less space and time to set up and score. Future studies in a larger sample size are warranted to confirm the results of this study.

Comparison of two walk tests in determining the claudication distance in patients suffering from peripheral arterial occlusive disease.

BACKGROUND: The purpose of this study was to compare the six-minute walk test (6MWT) and the incremental shuttle walk test (ISWT) in terms of the initial onset of pain (IOP), maximal claudicating pain (MCP), maximum walking distance (MWD), initial ankle brachial index (IABI), post ankle brachial index (PABI), and difference in ankle brachial index (DFABI), as well as to correlate changes in IOP and MWD, MCP and MWD, IABI and MWD, PABI and MWD, and DFABI and MWD in the 6MWT and ISWT. MATERIALS AND METHODS: Participants (n = 19, 17 men and 2 women) were randomly allocated to the 6MWT or ISWT and crossed over to the other test after 24 hours. The baseline ankle brachial index (ABI) measurements were taken using the Doppler, following which the participants performed the tests. Post-test MWD, IOP, MCP, and ABI were measured. The paired t test was used pre- and post the walk test and the Pearson correlation was used to find any relationship between the desired variables. RESULTS: The paired t test at 95% confidence interval for IABI and PABI (P > 0.05) was insignificant for the 6MWT and ISWT. The Pearson correlation of MWD with IOP showed a fair correlation, and the correlation of MWD to MCP showed a strong correlation in ISWT. CONCLUSION: ISWT can be of vital importance as a tool to assess the functional status of patients suffering from Peripheral Arterial Occlusive Disease (PAOD) in both the clinical and research areas, and reflects a better assessment of the functional limitation when walking with PAOD as compared to the 6MWT.

Can overestimation of walking ability increase the risk of falls in people in the subacute stage after stroke on their return home?

PURPOSE: Falls are common in patients who have had a stroke who return home after neurorehabilitation. Some studies have found that walking speed inversely correlates with the risk of falls. SCOPE: This study examined whether comparison between comfortable self-selected walking speed and maximum maintainable speed is informative with regard to the risk of falls in patients with stroke. METHODS: A prospective cohort study was performed with 75 ambulant stroke patients. At discharge, the Barthel Index score and performance at the 10-m and 6-min walking tests were assessed. Number of falls was recorded by telephone interview every two months for one year. Regression analysis was performed to identify factors that were related to the risk of falls. RESULTS: Using forward multiple linear regression, only the ratio between walking speeds on the 6-min and 10-m tests was linked to the number of falls in the year after discharge (R=-0.451, p<0.001, OR=0.046). Patients who chose a walking speed for short distances that was not maintainable long term fell more frequently. CONCLUSIONS: A discrepancy between short and long-term walking speed can help in identifying subjects in the subacute stage after stroke with an increased risk of suffering a fall.

Reference equation for the 2-minute walk test in adults and the elderly.

BACKGROUND: The 2-min walk test (2MWT) has been used in several health conditions, but the interpretation of its results is limited due to a lack of reference values. The aim of this study was to establish a reference equation to predict the distance walked (DW) in the 2MWT for healthy adults and the elderly and to test its reproducibility. METHODS: We evaluated 390 healthy subjects (195 male), 18-89 y old, with normal spirometry and no history of previous chronic diseases. Two 2MWTs were performed on the same day, 30 min apart. To test the reliability of the prediction equation, 70 subjects (35 male) were prospectively included in the study. RESULTS: Men walked farther than women (221 [202-240] vs 199 [164-222] m, respectively; P < .0001). Significant correlations were observed between DW and age (r = -0.50), weight (r = 0.23), height (r = 0.40), and gender (r = 0.35) (P < .001 for all). Age and gender persisted in the model to predict DW (R(2) = 0.51). There was no difference between the DW by the subjects (197 [182-216] m) and that estimated by the prediction equation (197 [179-222] m) (P = .68). CONCLUSIONS: We established a prediction equation that may be used as a reference to interpret performance on the 2MWT of adults and the elderly with different health conditions.