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.
Evidence-based recommendations on the clinical use of cardiopulmonary exercise testing (CPET) in lung and heart disease are presented, with reference to the assessment of exercise intolerance, ...prognostic assessment and the evaluation of therapeutic interventions (e.g. drugs, supplemental oxygen, exercise training). A commonly used grading system for recommendations in evidence-based guidelines was applied, with the grade of recommendation ranging from A, the highest, to D, the lowest. For symptom-limited incremental exercise, CPET indices, such as peak O(2) uptake (V'O(2)), V'O(2) at lactate threshold, the slope of the ventilation-CO(2) output relationship and the presence of arterial O(2) desaturation, have all been shown to have power in prognostic evaluation. In addition, for assessment of interventions, the tolerable duration of symptom-limited high-intensity constant-load exercise often provides greater sensitivity to discriminate change than the classical incremental test. Field-testing paradigms (e.g. timed and shuttle walking tests) also prove valuable. In turn, these considerations allow the resolution of practical questions that often confront the clinician, such as: 1) "When should an evaluation of exercise intolerance be sought?"; 2) "Which particular form of test should be asked for?"; and 3) "What cluster of variables should be selected when evaluating prognosis for a particular disease or the effect of a particular intervention?"
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.
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.
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).
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.
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.
•Six minute walk test (6MWT) and incremental shuttle walk test (ISWT) caused remarkable changes in heart rate, oxygen saturation, dyspnea, and leg fatigue in patients after the Fontan procedure ...compared to healthy subjects.•ISWT lead to the more pronounced exercise-induced responses, especially in oxygen desaturation.•With similar safety to the 6MWT, the ISWT can also be performed as a field test to evaluate exercise capacity and as an outcome measure in some clinical settings in patients with Fontan procedure.
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.
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.
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.
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.
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 Obstacles Test and Curb Test have been used to measure gait speed and functional balance in adults. Recently, they have been modified for use in children but the normative values have not been ...established. This requires correlating the sex, age, height, weight, and BMI% of children with the test results and developing prediction equations. In this cross-sectional study, the Obstacles Test and Curb Test were administered to a convenience sample of 240 typically developing children aged 6-11 years. The factors associated with the time to complete each test were studied and prediction equations were established. The completion times were 5.27 ± 0.81 s for the Obstacles Test and 2.82 ± 0.45 s for the Curb Test. The Obstacles Test showed a fair negative relationship with height (Pearson's r = -0.41, P < 0.001), age ( r = -0.35, P < 0.001), and weight ( r = -0.32, P < 0.05). The Curb Test also had fair negative correlations with height ( r = -0.42, P < 0.001), age ( r = -0.39, P < 0.001), and weight ( r = -0.31, P < 0.001). Both tests showed poor correlations with the sex eta ( η ) = 0.15 and 0.12, respectively. Nonetheless, age and sex emerged as the main predictors of both test scores, accounting for 14% and 17% of the total variance in the Obstacles Test and Curb Test times, respectively. Normative values and prediction equations for both tests in typically developing children may be used for individual comparisons and in clinical research for the evaluation of interventions targeting disabled children.
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.
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.
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.
It is feasible to train chronic non-ambulatory individuals with SCI in performance of EAW sufficiently to achieve reasonable mobility skill outcome milestones.
Walking tests can provide an indicator of balance and fragility of people. They measure the gait speed and compare it to reference values related to various pathologies. We propose a radar sensor ...system that allows the evaluation of the gait speed in these tests in an automatic manner. The proposed approach consists of three phases; a first phase where the system automatically distinguishes the three sections of the test, namely walk #1, turn, and walk #2. Then, a second phase where the obtained signal is processed to evaluate the gait speed of the person. This is done through time-frequency analysis of the radar signal. In order to deal with the non-stationary nature of the radar signals, we consider the short-time Fourier transfer in our time-frequency analysis. The third phase consists in segmenting each walk into three segments, namely an acceleration zone, a measured-gait zone, and a deceleration zone. We provide a segmentation of the walking in order to automatically distinguish these zones. The proposed approach is validated using a Vicon motion-capture system, with a mean RMSE equal to 0.076 m/s. As compared to traditional techniques, our proposed system is automatic and does not require acceleration and deceleration zones.
The Obstacles and Curb tests are timed walking assessments that have emerged from the Spinal Cord Injury Functional Ambulation Profile and have been modified for children; however, their psychometric ...properties have not been adequately investigated. The aim of this research was to examine the psychometric properties of the Obstacles and Curb tests for children with cerebral palsy (CP). This cross-sectional study included 68 children aged 6-12 years; there were 34 children with CP and 34 age- and sex-matched typically developing children. Validity was examined by correlation with the 10-m Walk Test (10-MWT), Modified Time Up and Go test (mTUG), and Pediatric Balance Scale (PBS). Differences in the Obstacle and Curb test scores were calculated between children with CP and typically developing children and within different Gross Motor Function Classification System (GMFCS) levels. Children with CP completed the tests twice within a 30-min interval in the same session. The tests showed significant strong to very strong correlations with the 10-MWT, mTUG, and PBS. The within-session reliability was excellent, typically developing children were significantly faster than children with CP with high sensitivity and specificity, and the time differed significantly within the GMFCS level. Thus, the Obstacles and Curb tests can be considered valid, reliable, and sensitive walking tests for ambulatory children with CP.
Context: The field walking tests like 6MWT and ISWT are commonly used indicators of functional capacity in patients with cardiopulmonary diseases. This study was designed to assess the correlation of ...six minute walk distance (6MWD) and incremental shuttle walk distance (ISWD) with the severity of airflow obstruction (FEV1%) in patients with chronic obstructive pulmonary disease. Aims: Comparison of correlation of six minute walk test and Incremental shuttle walk test with the severity of airflow obstruction in COPD patients.Settings and Design: Hospital-based prospective cross-sectional study in a tertiary care centre. Methods and Material: One hundred and twelve (112) spirometrically confirmed COPD patients underwent 6MWT and ISWT. The diagnosis of COPD and its severity was assessed by the GOLD criteria. 6MWT and ISWT were done on the same patient with a gap of 5-6 hours and the distance walked (6MWD and ISWD) was correlated with the severity of COPD (FEV1). Statistical Analysis Used: One way ANOVA to compare mean distance walked in 6MWT and ISWT with different grades of COPD. Pearson Correlation was done to correlate packyears of smoking and age with 6MWD and ISWD. Results: The mean distance walked in the 6MWT and ISWT was estimated and compared across the four categories of GOLD grading. There was no statistically significant difference between the study subjects of corresponding GOLD grades based on the distance walked in 6MWT and in ISWT. However, a linear correlation was depicted between ISWD and post-bronchodilator FEV1. A model of linear regression showed that ISWD was an independent contributor to post-bronchodilator FEV1 in our study. Conclusions: Incremental shuttle walk test, an externally paced near to standard test with its incremental nature, can be used as an appropriate surrogate for FEV1 in determining the severity of airflow obstruction in COPD patients.
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