Four hundred meters walking test in the evaluation of heart failure patients.

PubMed

Zdrenghea, D; Beudean, Maria; Pop, Dana; Zdrenghea, V

2010-01-01

The best evaluation of the severity and prognosis of heart failure patients is obtained by the maximal exercise stress testing, but for the very large number of HF patients and for evaluation of their daily effort capacity submaximal stress testing, mainly 6 minutes walking test are used. The limit of 6mWT is that during it the patients are not motivated to walk and also, the periphery, so important for heart failure patients, is not equally involved. To compare a new fixed walking test-400m walking test with 6MWT and maximal exercise testing. There were investigated 20 patients with dilated cardiomyopathy (DCM). The patients were included in the study after the relief of the congestive syndrome. Each patient was submitted in three consecutive days to a maximal symptom-limited exercise stress test on cycloergometer, a six minutes walking test, a 400 meters walking test. The last one consisted of walking on a corridor 40 meters long, at a speed chosen by the patient himself. The results were expressed in seconds representing the necessary time to cover the established 400 meters of distance. During cycloergometer exercise stress test the calculated mean peak VO2 was 15.2 +/- 1.4 mlO2/kg/min (4.32 METs). The mean distance walked during 6MWT was 350 +/- 34m and the mean time needed to walk 400m (400mWT) was 300 +/- 27 seconds. The correlation between peak VO2 and distance walked during 6MWT was -0.40, a similar but negative value (r = -0.42) being registered between peak VO2 and time registered during 400mWT. Only weak correlation was registered between LVEF and all the three tests. In turn the correlation between distance registered during 6MWT and time registered during 400mWT was excellent: r = -0.60. 400mWT is a useful tool for the evaluation of submaximal effort capacity of CHF patients. Its value to evaluate exercise capacity is similar with that of the 6 MWT, but 400mWT can assure a better evaluation of peripheral involvement.

Foot placement relies on state estimation during visually guided walking.

PubMed

Maeda, Rodrigo S; O'Connor, Shawn M; Donelan, J Maxwell; Marigold, Daniel S

2017-02-01

As we walk, we must accurately place our feet to stabilize our motion and to navigate our environment. We must also achieve this accuracy despite imperfect sensory feedback and unexpected disturbances. In this study we tested whether the nervous system uses state estimation to beneficially combine sensory feedback with forward model predictions to compensate for these challenges. Specifically, subjects wore prism lenses during a visually guided walking task, and we used trial-by-trial variation in prism lenses to add uncertainty to visual feedback and induce a reweighting of this input. To expose altered weighting, we added a consistent prism shift that required subjects to adapt their estimate of the visuomotor mapping relationship between a perceived target location and the motor command necessary to step to that position. With added prism noise, subjects responded to the consistent prism shift with smaller initial foot placement error but took longer to adapt, compatible with our mathematical model of the walking task that leverages state estimation to compensate for noise. Much like when we perform voluntary and discrete movements with our arms, it appears our nervous systems uses state estimation during walking to accurately reach our foot to the ground. Accurate foot placement is essential for safe walking. We used computational models and human walking experiments to test how our nervous system achieves this accuracy. We find that our control of foot placement beneficially combines sensory feedback with internal forward model predictions to accurately estimate the body's state. Our results match recent computational neuroscience findings for reaching movements, suggesting that state estimation is a general mechanism of human motor control. Copyright © 2017 the American Physiological Society.

Alternatives to the six-minute walk test in pulmonary arterial hypertension.

PubMed

Mainguy, Vincent; Malenfant, Simon; Neyron, Anne-Sophie; Saey, Didier; Maltais, François; Bonnet, Sébastien; Provencher, Steeve

2014-01-01

The physiological response during the endurance shuttle walk test (ESWT), the cycle endurance test (CET) and the incremental shuttle walk test (ISWT) remains unknown in PAH. We tested the hypothesis that endurance tests induce a near-maximal physiological demand comparable to incremental tests. We also hypothesized that differences in respiratory response during exercise would be related to the characteristics of the exercise tests. Within two weeks, twenty-one PAH patients (mean age: 54(15) years; mean pulmonary arterial pressure: 42(12) mmHg) completed two cycling exercise tests (incremental cardiopulmonary cycling exercise test (CPET) and CET) and three field tests (ISWT, ESWT and six-minute walk test (6MWT)). Physiological parameters were continuously monitored using the same portable telemetric device. Peak oxygen consumption (VO(2peak)) was similar amongst the five exercise tests (p = 0.90 by ANOVA). Walking distance correlated markedly with the VO(2peak) reached during field tests, especially when weight was taken into account. At 100% exercise, most physiological parameters were similar between incremental and endurance tests. However, the trends overtime differed. In the incremental tests, slopes for these parameters rose steadily over the entire duration of the tests, whereas in the endurance tests, slopes rose sharply from baseline to 25% of maximum exercise at which point they appeared far less steep until test end. Moreover, cycling exercise tests induced higher respiratory exchange ratio, ventilatory demand and enhanced leg fatigue measured subjectively and objectively. Endurance tests induce a maximal physiological demand in PAH. Differences in peak respiratory response during exercise are related to the modality (cycling vs. walking) rather than the progression (endurance vs. incremental) of the exercise tests.

Alternatives to the Six-Minute Walk Test in Pulmonary Arterial Hypertension

PubMed Central

Mainguy, Vincent; Malenfant, Simon; Neyron, Anne-Sophie; Saey, Didier; Maltais, François; Bonnet, Sébastien; Provencher, Steeve

2014-01-01

Introduction The physiological response during the endurance shuttle walk test (ESWT), the cycle endurance test (CET) and the incremental shuttle walk test (ISWT) remains unknown in PAH. We tested the hypothesis that endurance tests induce a near-maximal physiological demand comparable to incremental tests. We also hypothesized that differences in respiratory response during exercise would be related to the characteristics of the exercise tests. Methods Within two weeks, twenty-one PAH patients (mean age: 54(15) years; mean pulmonary arterial pressure: 42(12) mmHg) completed two cycling exercise tests (incremental cardiopulmonary cycling exercise test (CPET) and CET) and three field tests (ISWT, ESWT and six-minute walk test (6MWT)). Physiological parameters were continuously monitored using the same portable telemetric device. Results Peak oxygen consumption (VO2peak) was similar amongst the five exercise tests (p = 0.90 by ANOVA). Walking distance correlated markedly with the VO2peak reached during field tests, especially when weight was taken into account. At 100% exercise, most physiological parameters were similar between incremental and endurance tests. However, the trends overtime differed. In the incremental tests, slopes for these parameters rose steadily over the entire duration of the tests, whereas in the endurance tests, slopes rose sharply from baseline to 25% of maximum exercise at which point they appeared far less steep until test end. Moreover, cycling exercise tests induced higher respiratory exchange ratio, ventilatory demand and enhanced leg fatigue measured subjectively and objectively. Conclusion Endurance tests induce a maximal physiological demand in PAH. Differences in peak respiratory response during exercise are related to the modality (cycling vs. walking) rather than the progression (endurance vs. incremental) of the exercise tests. PMID:25111294

Estimating exercise capacity from walking tests in elderly individuals with stable coronary artery disease.

PubMed

Mandic, Sandra; Walker, Robert; Stevens, Emily; Nye, Edwin R; Body, Dianne; Barclay, Leanne; Williams, Michael J A

2013-01-01

Compared with symptom-limited cardiopulmonary exercise test (CPET), timed walking tests are cheaper, well-tolerated and simpler alternative for assessing exercise capacity in coronary artery disease (CAD) patients. We developed multivariate models for predicting peak oxygen consumption (VO2peak) from 6-minute walk test (6MWT) distance and peak shuttle walk speed for elderly stable CAD patients. Fifty-eight CAD patients (72 SD 6 years, 66% men) completed: (1) CPET with expired gas analysis on a cycle ergometer, (2) incremental 10-meter shuttle walk test, (3) two 6MWTs, (4) anthropometric assessment and (5) 30-second chair stands. Linear regression models were developed for estimating VO2peak from 6MWT distance and peak shuttle walk speed as well as demographic, anthropometric and functional variables. Measured VO2peak was significantly related to 6MWT distance (r = 0.719, p < 0.001) and peak shuttle walk speed (r = 0.717, p < 0.001). The addition of demographic (age, gender), anthropometric (height, weight, body mass index, body composition) and functional characteristics (30-second chair stands) increased the accuracy of predicting VO2peak from both 6MWT distance and peak shuttle walk speed (from 51% to 73% of VO2peak variance explained). Addition of demographic, anthropometric and functional characteristics improves the accuracy of VO2peak estimate based on walking tests in elderly individuals with stable CAD. Implications for Rehabilitation Timed walking tests are cheaper, well-tolerated and simpler alternative for assessing exercise capacity in cardiac patients. Walking tests could be used to assess individual's functional capacity and response to therapeutic interventions when symptom-limited cardiopulmonary exercise testing is not practical or not necessary for clinical reasons. Addition of demographic, anthropometric and functional characteristics improves the accuracy of peak oxygen consumption estimate based on 6-minute walk test distance

Calf Muscle Oxygen Saturation During Six-Minute Walk Test And Its Relationship With Walking Impairment In Symptomatic Peripheral Artery Disease.

PubMed

Andrade-Lima, Aluísio; Cucato, Gabriel G; Domingues, Wagner J R; Germano-Soares, Antônio H; Cavalcante, Bruno R; Correia, Marilia A; Saes, Glauco F; Wolosker, Nelson; Gardner, Andrew W; Zerati, Antônio E; Ritti-Dias, Raphael M

2018-05-21

Impaired microcirculation is associated with poor walking capacity in symptomatic peripheral artery disease (PAD) patients during treadmill test, however, this test does not simulate the efforts of daily walking of these patients. Thus, the aim of the study was to describe the microcirculation responses during six-minute walk test (6MWT) and to analyze the relationship between microcirculation indicators and walking impairment in symptomatic PAD patients. Thirty-four patients were included (mean age = 67.6 ± 11.2). The clinical characteristics were collected and they performed a 6MWT in which initial claudication distance (ICD) and total walking distance (TWD) were recorded. During and after the 6MWT, calf muscle oxygen saturation (StO 2 ) parameters were monitored continuously to measure microcirculation behavior. The association between calf muscle StO 2 parameters and walking impairment was analyzed by Pearson or Spearman correlations. Walking impairment was not associated with any StO 2 parameters during exercise. In contrast, after 6MWT, recovery time of StO 2 (r = -0.472, P = .008) and recovery time to maximal StO 2 (r= -0.402, P = .019) were negatively correlated with ICD. Furthermore, the distance walked under claudication symptoms (ΔTWD - ICD) was positively correlated with recovery time to maximal StO 2 (r = 0.347, P = .048). In symptomatic PAD patients, shorter ICD values during a 6MWT are associated with a delayed recovery in calf muscle StO 2 after exercise. Calf muscle StO 2 parameters decrease subtly during 6MWT, suggesting that the degree of ischemia in the calf muscle during ground walking, simulating efforts of the daily walking, is relatively low. Copyright © 2018 Elsevier Inc. All rights reserved.

Shuttle walking test and 6-minute walking test induce a similar cardiorespiratory performance in patients recovering from an acute exacerbation of chronic obstructive pulmonary disease.

PubMed

Vagaggini, B; Taccola, M; Severino, S; Marcello, M; Antonelli, S; Brogi, S; De Simone, C; Giardina, A; Paggiaro, P L

2003-01-01

The incremental shuttle walking test (SWT) has recently been proposed as a more valid and reproducible alternative to the conventional 6-min walking test (6MWT) in the evaluation of exercise tolerance in patients with chronic obstructive pulmonary disease (COPD). To compare the cardiorespiratory performance obtained during two sessions of SWT with that obtained during two sessions of 6MWT. We examined 18 patients (forced expiratory volume in 1 s: 48 +/- 14%) recovering from an acute exacerbation of COPD that had required hospitalization. In the same afternoon, each patient performed two SWT and two 6MWT, with an interval of at least 30 min between each test; the sequence of the tests was randomized. Mean walking distance was greater in the second SWT test than in the first SWT. The changes from baseline in systolic blood pressure, heart rate, respiratory rate, oxygen saturation and dyspnea Borg index at the end of the test were similar between the two 6MWT and the two SWT. There was a highly significant correlation between walking distances measured during SWT and during 6MWT (rho: 0.85, p < 0.0005). Neither SWT nor 6MWT correlated with functional data of COPD. SWT, though being considered to be closer to a submaximal exercise test than 6MWT, does not induce a greater cardiorespiratory performance than 6MWT in patients recovering from acute exacerbation of COPD. Copyright 2003 S. Karger AG, Basel

Comparing Types of Financial Incentives to Promote Walking: An Experimental Test.

PubMed

Burns, Rachel J; Rothman, Alexander J

2018-04-19

Offering people financial incentives to increase their physical activity is an increasingly prevalent intervention strategy. However, little is known about the relative effectiveness of different types of incentives. This study tested whether incentives based on specified reinforcement types and schedules differentially affected the likelihood of meeting a walking goal and explored if observed behavioural changes may have been attributable to the perceived value of the incentive. A 2 (reinforcement type: cash reward, deposit contract) × 2 (schedule: fixed, variable) between-subjects experiment with a hanging control condition was conducted over 8 weeks (n = 153). Although walking was greater in the incentive conditions relative to the control condition, walking did not differ across incentive conditions. Exploratory analyses indicated that the perceived value of the incentive was associated with the likelihood of meeting the walking goal, but was not affected by reinforcement type or schedule. The reinforcement type and schedule manipulations tested in this study did not differentially affect walking. Given that walking behaviour was associated with perceived value, designing incentive strategies that optimise the perceived value of the incentive may be a promising avenue for future research. © 2018 The International Association of Applied Psychology.

A Biomechanical Investigation of Selected Lumbopelvic Hip Tests: Implications for the Examination of Walking.

PubMed

Bailey, Robert Walter; Richards, Jim; Selfe, James

2016-01-01

The purpose of this study was to compare lumbopelvic hip ranges of motion during the Trendelenburg, Single Leg Squat, and Corkscrew Tests to walking and to describe the 3-dimensional lumbopelvic hip motion during the tests. This may help clinicians to select appropriate tests when examining gait. An optoelectronic movement analysis tracking system was used to assess the lumbopelvic hip region of 14 healthy participants while performing Trendelenburg, Single Leg Squat, and Corkscrew Tests and walking. The lumbopelvic hip 3-dimensional ranges of movement for the clinical tests were compared with walking using a repeated-measures analysis of variance with pairwise comparisons. No significant differences were found between the pelvic obliquity during the Trendelenburg Test and walking (Trendelenburg Test: L, 11.3° ± 4.8°, R, 10.8° ± 5.0° vs walk: L, 8.3° ± 4.8°, R 8.3° ± 5.1°, L, P = .143, R, P = .068). Significant differences were found between the hip sagittal plane range of movement during the Single Leg Squat and walking (Single Leg Squat: L, 44.2° ±13.7°, R, 41.7° ±10.9° vs walk: 38.6° ±7.0°, R 37.8° ±5.1°, P < .05), the hip coronal plane range of movement (Single Leg Squat: L, 9.1° ±5.8°, R, 9.0° ± 4.6° vs walk: L, 9.4° ± 2.3°, R 9.5° ± 2.0°, P < .05), and the hip coronal plane range of movement during the Corkscrew Test and walking (Corkscrew: L, 5.7° ±3.3°, R, 5.7° ±3.2° vs walk: L, 9.4° ± 2.3°, R 9.5° ± 2.0°, P < .05). The results of the present study showed that, in young asymptomatic participants with no known lumbopelvic hip pathology, the pelvic obliquity during the Trendelenburg Test and walking is similar. During the Single Leg Squat, the hip moved more in the sagittal plane and less in the coronal plane when compared with walking. There was more movement in the hip transverse plane movement during the Corkscrew Test than during walking. These results suggest that for the Trendelenburg Test to be

Short-distance walking speed tests in people with Parkinson disease: reliability, responsiveness, and validity.

PubMed

Combs, Stephanie A; Diehl, M Dyer; Filip, Jacqueline; Long, Erin

2014-02-01

The aims of this study were to determine test-retest reliability and responsiveness of short-distance walking speed tests for persons with Parkinson disease (PD). Discriminant and convergent validity of walking speed tests were also examined. Eighty-eight participants with PD (mean age, 66 years) with mild to moderate severity (stages 1-4 on the Hoehn and Yahr Scale) were tested on medications. Measures of activity included the comfortable and fast 10-m walk tests (CWT, FWT), 6-min walk test (6MWT), mini balance evaluations systems test (mini-BEST Test), fear of falling (FoF), and the Activity-Specific Balance Confidence Scale (ABC). The mobility subsection of the PD quality of life-39 (PDQ39-M) served as a participation-based measure. Test-retest reliability was high for both walking speed measures (CWT, ICC(2,1) = 0.98; FWT, ICC(2,1) = 0.99). Minimal detectable change (MDC(95)) for the CWT and FWT was 0.09 m/s and 0.13 m/s respectively. Participants at Hoehn & Yahr levels 3/4 demonstrated significantly slower walking speed with the CWT and FWT than participants at Hoehn & Yahr levels 1 and 2 (P < .01). The CWT and FWT were both significantly (P ≤ .002) correlated with all activity and participation-based measures. Short-distance walking speed tests are clinically useful measures for persons with PD. The CWT and FWT are highly reliable and responsive to change in persons with PD. Short distance walking speed can be used to discriminate differences in gait function between persons with mild and moderate PD severity. The CWT and FWT had moderate to strong associations with other activity and participation based measures demonstrating convergent validity. Copyright © 2013 Elsevier B.V. All rights reserved.

Screening for physical inactivity among adults: the value of distance walked in the six-minute walk test. A cross-sectional diagnostic study.

PubMed

Sperandio, Evandro Fornias; Arantes, Rodolfo Leite; da Silva, Rodrigo Pereira; Matheus, Agatha Caveda; Lauria, Vinícius Tonon; Bianchim, Mayara Silveira; Romiti, Marcello; Gagliardi, Antônio Ricardo de Toledo; Dourado, Victor Zuniga

2016-01-01

Accelerometry provides objective measurement of physical activity levels, but is unfeasible in clinical practice. Thus, we aimed to identify physical fitness tests capable of predicting physical inactivity among adults. Diagnostic test study developed at a university laboratory and a diagnostic clinic. 188 asymptomatic subjects underwent assessment of physical activity levels through accelerometry, ergospirometry on treadmill, body composition from bioelectrical impedance, isokinetic muscle function, postural balance on a force platform and six-minute walk test. We conducted descriptive analysis and multiple logistic regression including age, sex, oxygen uptake, body fat, center of pressure, quadriceps peak torque, distance covered in six-minute walk test and steps/day in the model, as predictors of physical inactivity. We also determined sensitivity (S), specificity (Sp) and area under the curve of the main predictors by means of receiver operating characteristic curves. The prevalence of physical inactivity was 14%. The mean number of steps/day (≤ 5357) was the best predictor of physical inactivity (S = 99%; Sp = 82%). The best physical fitness test was a distance in the six-minute walk test and ≤ 96% of predicted values (S = 70%; Sp = 80%). Body fat > 25% was also significant (S = 83%; Sp = 51%). After logistic regression, steps/day and distance in the six-minute walk test remained predictors of physical inactivity. The six-minute walk test should be included in epidemiological studies as a simple and cheap tool for screening for physical inactivity.

Comparing peak and submaximal cardiorespiratory responses during field walking tests with incremental cycle ergometry in COPD.

PubMed

Hill, Kylie; Dolmage, Thomas E; Woon, Lynda; Coutts, Debbie; Goldstein, Roger; Brooks, Dina

2012-02-01

Field and laboratory-based tests are used to measure exercise capacity in people with COPD. A comparison of the cardiorespiratory responses to field tests, referenced to a laboratory test, is needed to appreciate the relative physiological demands. We sought to compare peak and submaximal cardiorespiratory responses to the 6-min walk test, incremental shuttle walk test and endurance shuttle walk test with a ramp cycle ergometer test (CET) in patients with COPD. Twenty-four participants (FEV(1) 50 ± 14%; 66.5 ± 7.7 years; 15 men) completed four sessions, separated by ≥24 h. During an individual session, participants completed either two 6-min walk tests, incremental shuttle walk tests, endurance shuttle walk tests using standardized protocols, or a single CET, wearing a portable gas analysis unit (Cosmed K4b(2)) which included measures of heart rate and arterial oxygen saturation (SpO(2)). Between tests, no difference was observed in the peak rate of oxygen uptake (F(3,69) = 1.2; P = 0.31), end-test heart rate (F(2,50) = 0.6; P = 0.58) or tidal volume (F(3,69) = 1.5; P = 0.21). Compared with all walking tests, the CET elicited a higher peak rate of carbon dioxide output (1173 ± 350 mL/min; F(3,62) = 4.8; P = 0.006), minute ventilation (48 ± 17 L/min; F(3,69) = 10.2; P < 0.001) and a higher end-test SpO(2) (95 ± 4%; F(3,63) = 24.9; P < 0.001). In patients with moderate COPD, field walking tests elicited a similar peak rate of oxygen uptake and heart rate as a CET, demonstrating that both self- and externally paced walking tests progress to high intensities. © 2011 The Authors. Respirology © 2011 Asian Pacific Society of Respirology.

Comparison of walking performance over the first 2 minutes and the full 6 minutes of the Six-Minute Walk Test

PubMed Central

2014-01-01

Background Although the Six-Minute Walk Test (6MWT), as recommended by the American Thoracic Society, is widely used as a measure of functional endurance, it may not be applicable in some settings and populations. We sought to examine, therefore, performance over the first 2 minutes and the full 6 minutes of the 6MWT. Specifically, we investigated completion rates, distances walked, test-retest reliability, and the relationship between distances walked over the first 2 and the full 6 minutes of the 6MWT. Methods Community-dwelling children and adults age 3–85 years (n = 337) were asked to walk back and forth on a 15.24 meter (50 ft) course as far as possible without running over a 6 minute period. Test completion and the distance covered by the participants at 2 and 6 minutes were documented. The reliability of distances covered at 2 and 6 minutes was determined by retesting a subsample of 54 participants 6 to 10 days later. The relationship between distances covered at 2 and 6 minutes was determined for the 330 participants completing the 6MWT. Results All 337 participants completed at least 2 minutes of walking, but 7 children less than 5 years of age ceased walking before 6 minutes had elapsed. For the remaining 330 participants the mean distance walked was 186 meters at 2 minutes and 543 meters at 6 minutes. The distances covered at 2 and 6 minutes were reliable between sessions (intraclass correlation coefficients = 0.888 and 0.917, respectively). The distances covered over 2 and 6 minutes were highly correlated (r = 0.968). Conclusions The completion rate, values obtained, test-retest reliability, and relationship of the distances walked in 2 and 6 minutes support documentation of 2 minute distance during the 6MWT. The findings also provide support for use of a Two-Minute Walk Test as the endurance component in the Motor Battery of the NIH Toolbox. PMID:24767634

Decreased Variability of the 6-Minute Walk Test by Heart Rate Correction in Patients with Neuromuscular Disease

PubMed Central

Prahm, Kira P.; Witting, Nanna; Vissing, John

2014-01-01

Objective The 6-minute walk test is widely used to assess functional status in neurological disorders. However, the test is subject to great inter-test variability due to fluctuating motivation, fatigue and learning effects. We investigated whether inter-test variability of the 6MWT can be reduced by heart rate correction. Methods Sixteen patients with neuromuscular diseases, including Facioscapulohumeral muscular dystrophy, Limb-girdle muscular dystrophy, Charcot-Marie-Tooths, Dystrophia Myotonica and Congenital Myopathy and 12 healthy subjects were studied. Patients were excluded if they had cardiac arrhythmias, if they received drug treatment for hypertension or any other medical conditions that could interfere with the interpretation of the heart rate and walking capability. All completed three 6-minute walk tests on three different test-days. Heart rate was measured continuously. Results Successive standard 6-minute walk tests showed considerable learning effects between Tests 1 and 2 (4.9%; P = 0.026), and Tests 2 and 3 (4.5%; P = 0.020) in patients. The same was seen in controls between Tests 1 and 2 (8.1%; P = 0.039)). Heart rate correction abolished this learning effect. Conclusion A modified 6-minute walk test, by correcting walking distance with average heart rate during walking, decreases the variability among repeated 6-minute walk tests, and should be considered as an alternative outcome measure to the standard 6-minute walk test in future clinical follow-up and treatment trials. PMID:25479403

Sacubitril/Valsartan: Effect on Walking Test and Physical Capability.

PubMed

Sgorbini, Luca; Rossetti, Antonella; Galati, Alfonso

The 6-min walk test (6MWT) is a simple and inexpensive exercise test to evaluate physical functional capacity that is widely used in heart failure (HF) patients. With the 6MWT, a distance <350 m is associated with increased mortality in patients with HF, and change in walking distance >50 m is considered clinically relevant. To our knowledge, information on improvement in physical functional capacity with sacubitril/valsartan, as assessed by the 6MWT, is still scant. In our daily practice, we apply this test to all patients whenever possible; therefore, we report here the findings observed in a small series of 5 patients with HF with reduced ejection fraction after a 1-month treatment with sacubitril/valsartan at full dose. The mean distance walked on the 6MWT at baseline was 129 m (±64 SD), and this value increased to 436 m (±156) after 1 month of therapy with sacubitril/valsartan 97/103 mg b.i.d. The mean difference from baseline was 305 m (±110). According to these preliminary findings, in clinical practice, a 1-month therapy of sacubitril/valsartan optimized at a 97/103-mg b.i.d. dose appears to be associated with a relevant improvement in the 6MWT. © 2017 S. Karger AG, Basel.

The six-minute walk test is an excellent predictor of functional ambulation after total knee arthroplasty

PubMed Central

2013-01-01

Background The Six-minute walk (6MW) and Timed-Up-and-Go (TUG) are short walk tests commonly used to evaluate functional recovery after total knee arthroplasty (TKA). However, little is known about walking capacity of TKA recipients over extended periods typical of everyday living and whether these short walk tests actually predict longer, more functional distances. Further, short walk tests only correlate moderately with patient-reported outcomes. The overarching aims of this study were to compare the performance of TKA recipients in an extended walk test to healthy age-matched controls and to determine the utility of this extended walk test as a research tool to evaluate longer term functional mobility in TKA recipients. Methods The mobility of 32 TKA recipients one year post-surgery and 43 healthy age-matched controls were assessed using the TUG, 6MW and 30-minute walk (30MW) tests. The latter test was repeated one week later. Self-reported function was measured using the WOMAC Index and a physical activity questionnaire. Results 30MW distance was significantly shorter amongst TKA recipients (mean 2108 m [95% CI 1837 to 2381 m]; Controls 3086 m [2981 to 3191 m], P < 0.001). Test-retest repeatability was high (ICC = 0.97, TKA; 0.96, Controls). Amongst TKA recipients, the 30MW distance correlated strongly with the shorter tests (6MW, r = 0.97, P < 0.001; TUG, r = −0.82, P < 0.001). Multiple regression modeling found 6MW distance to be the only significant predictor (P < 0.001) of 30MW distance, explaining 96% of the variability. The TUG test models were moderate predictors of WOMAC function (55%) and physical activity (36%) and were stronger predictors than 6MW and 30 MW tests. Conclusions Though TKA recipients are able to walk for 30 minutes one year post-surgery, their performance falls significantly short of age-matched norms. The 30MW test is strongly predicted by 6MW test performance, thus providing strong construct validity for the use of the 6MW test in

Could the two-minute step test be an alternative to the six-minute walk test for patients with systolic heart failure?

PubMed

Węgrzynowska-Teodorczyk, Kinga; Mozdzanowska, Dagmara; Josiak, Krystian; Siennicka, Agnieszka; Nowakowska, Katarzyna; Banasiak, Waldemar; Jankowska, Ewa A; Ponikowski, Piotr; Woźniewski, Marek

2016-08-01

The consequence of exercise intolerance for patients with heart failure is the difficulty climbing stairs. The two-minute step test is a test that reflects the activity of climbing stairs. The aim of the study design is to evaluate the applicability of the two-minute step test in an assessment of exercise tolerance in patients with heart failure and the association between the six-minute walk test and the two-minute step test. Participants in this study were 168 men with systolic heart failure (New York Heart Association (NYHA) class I-IV). In the study we used the two-minute step test, the six-minute walk test, the cardiopulmonary exercise test and isometric dynamometer armchair. Patients who performed more steps during the two-minute step test covered a longer distance during the six-minute walk test (r = 0.45). The quadriceps strength was correlated with the two-minute step test and the six-minute walk test (r = 0.61 and r = 0.48). The greater number of steps performed during the two-minute step test was associated with higher values of peak oxygen consumption (r = 0.33), ventilatory response to exercise slope (r = -0.17) and longer time of exercise during the cardiopulmonary exercise test (r = 0.34). Fatigue and leg fatigue were greater after the two-minute step test than the six-minute walk test whereas dyspnoea and blood pressure responses were similar. The two-minute step test is well tolerated by patients with heart failure and may thus be considered as an alternative for the six-minute walk test. © The European Society of Cardiology 2016.

Thirty-Second Walk Test: Expansion of Normative Data.

PubMed

Lieberstein, Michael; Weingarten, Goldie; Vialu, Carlo; Itzkowitz, Adina; Doyle, Maura; Covino, Frank; Kaplan, Sandra L

2018-01-01

To collect 30-second walk test (30sWT) normative data on a large, diverse sample of school children developing typically, ages 5 to 13 years, and describe the influences of gender, body mass index, and path shape on distance walked. Five physical therapists administered the 30sWT on 1223 children developing typically (boys = 517, girls = 706) from 20 urban schools. Average distances (standard deviation) ranged from 139.1 (20.3) to 163.0 (18.6) ft; children aged 10 years walked the farthest and those aged 5 years the shortest. Distance steadily increased from ages 5 to 10 years, steadily decreased from ages 11 to 13 years; children aged 8, 9, and 10 years had statistical but not functionally meaningful gender differences. Body mass index and path shape had no meaningful effects. Distance and velocities are similar to prior studies. This study updated 30sWT normative values with a large, ethnically diverse, urban sample developing typically. Norms may be useful as part of a comprehensive examination.

Titrating Oxygen Requirements During Exercise: Evaluation of a Standardized Single Walk Test Protocol.

PubMed

Giovacchini, Coral X; Mathews, Anne M; Lawlor, Brian R; MacIntyre, Neil R

2018-04-01

Oxygen supplementation for exercise-induced hypoxemia is a common clinical practice that improves exercise tolerance. However, we know of no standardized exercise oxygen titration protocol using a single walk test. We report our experience with a protocol developed in our laboratory. Our protocol is based on the 6-min walk test (6MWT). Pulse oximetry readings (oxygen saturation [Spo 2 ]) are monitored, and supplemental oxygen is added in 2 L/min increments to keep Spo 2 > 88%. This continues for at least 6 min of walking with the Spo 2 remaining > 88% for at least 3 min. The records of consecutive patients over 4 months undergoing this procedure were reviewed for test performance, oxygen titration results, and adverse events. Two hundred twenty-two patients were tested; only two prematurely terminated the protocol because of intractable dyspnea. One hundred fifty-six patients (38%) required oxygen supplementation, with the first titration most commonly occurring between 1 and 2 min of walking. Nine of the patients had the first titration after 5 min of walking. The average test duration was 7 min (maximum, 15 min). The average number of titrations was 2.2 (maximum six). Sixteen patients could not maintain Spo 2 > 88% for 3 min despite administration of 15 L/min of supplemental oxygen (maximal dose). Our protocol was easily performed as a modification of a standard 6MWT with no serious adverse events. Because it is based on a widely accepted measurement of functional capabilities, and because it determined a stable final oxygen dose for ≥ 3 min of walking in most patients, we believe this protocol can be easily adapted for clinical use. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Prevalence of Walking-Related Motor Fatigue in Persons With Multiple Sclerosis: Decline in Walking Distance Induced by the 6-Minute Walk Test.

PubMed

Leone, Carmela; Severijns, Deborah; Doležalová, Vendula; Baert, Ilse; Dalgas, Ulrik; Romberg, Anders; Bethoux, Francois; Gebara, Benoit; Santoyo Medina, Carmen; Maamâgi, Heigo; Rasova, Kamila; Maertens de Noordhout, Benoît; Knuts, Kathy; Skjerbaek, Anders; Jensen, Ellen; Wagner, Joanne M; Feys, Peter

2016-05-01

To investigate the individual occurrence of walking-related motor fatigue in persons with multiple sclerosis (PwMS), according to disability level and disease phenotype.Study design This was a cross-sectional, multinational study.Participants They were 208 PwMS from 11 centers with Expanded Disability Status Scale (EDSS) scores up to 6.5. The percentage change in distance walked (distance walked index, DWI) was calculated between minute 6 and 1 (DWI(6-1)) of the 6-Minute Walk Test (6MWT). Its magnitude was used to classify participants into 4 subgroups: (1) DWI(6-1)[≥5%], (2) DWI(6-1)[5%; -5%], (3) DWI(6-1)[-5%; > -15%], and (4) DWI(6-1)[≤-15%]. The latter group was labeled as having walking-related motor fatigue. PwMS were stratified into 5 subgroups based on the EDSS (0-2.5, 3-4, 4.5-5.5, 6, 6.5) and 3 subgroups based on MS phenotype (relapsing remitting [RR], primary progressive [PP], and secondary progressive [SP]). The DWI6-1was ≥5% in 16 PwMS (7.7%), between 5% and -5% in 70 PwMS (33.6%), between -5% and -15% in 58 PwMS (24%), and ≤-15% in 64 PwMS (30.8%). The prevalence of walking-related motor fatigue (DWI(6-1)[≤-15%]) was significantly higher among the progressive phenotype (PP = 50% and SP = 39%; RR = 15.6%) and PwMS with higher disability level (EDSS 4.5-5.5 = 48.3%, 6 = 46.3% and 6.5 = 51.5%, compared with EDSS 0-2.5 = 7.8% and 3-4 = 16.7%;P< .05). Stepwise multiple regression analysis indicated that EDSS, but not MS phenotype, explained a significant part of the variance in DWI(6-1)(R(2)= 0.086;P< .001). More than one-third of PwMS showed walking-related motor fatigue during the 6MWT, with its prevalence greatest in more disabled persons (up to 51%) and in those with progressive MS phenotype (up to 50%). Identification of walking-related motor fatigue may lead to better-tailored interventions. © The Author(s) 2015.

Why the null matters: statistical tests, random walks and evolution.

PubMed

Sheets, H D; Mitchell, C E

2001-01-01

A number of statistical tests have been developed to determine what type of dynamics underlie observed changes in morphology in evolutionary time series, based on the pattern of change within the time series. The theory of the 'scaled maximum', the 'log-rate-interval' (LRI) method, and the Hurst exponent all operate on the same principle of comparing the maximum change, or rate of change, in the observed dataset to the maximum change expected of a random walk. Less change in a dataset than expected of a random walk has been interpreted as indicating stabilizing selection, while more change implies directional selection. The 'runs test' in contrast, operates on the sequencing of steps, rather than on excursion. Applications of these tests to computer generated, simulated time series of known dynamical form and various levels of additive noise indicate that there is a fundamental asymmetry in the rate of type II errors of the tests based on excursion: they are all highly sensitive to noise in models of directional selection that result in a linear trend within a time series, but are largely noise immune in the case of a simple model of stabilizing selection. Additionally, the LRI method has a lower sensitivity than originally claimed, due to the large range of LRI rates produced by random walks. Examination of the published results of these tests show that they have seldom produced a conclusion that an observed evolutionary time series was due to directional selection, a result which needs closer examination in light of the asymmetric response of these tests.

Reference Values for the Six-Minute Walk Test in Healthy Children and Adolescents: a Systematic Review.

PubMed

Cacau, Lucas de Assis Pereira; de Santana-Filho, Valter Joviniano; Maynard, Luana G; Gomes, Mansueto; Fernandes, Marcelo; Carvalho, Vitor Oliveira

2016-01-01

The aim of the study is to compare the available reference values and the six-minute walk test equations in healthy children/adolescents. Our systematic review was planned and performed in accordance with the PRISMA guidelines. We included all studies that established reference values for the six-minute walk test in healthy children/adolescents. To perform this review, a research was performed in PubMed, EMBASE (via SCOPUS) and Cochrane (LILACS), Bibliographic Index Spanish in Health Sciences, Organization Collection Pan-American Health Organization, Publications of the World Health Organization and Scientific Electronic Library Online (SciELO) via Virtual Health Library until June 2015 without language restriction. The initial research identified 276 abstracts. Twelve studies met the inclusion criteria and were fully reviewed and approved by both reviewers. None of the selected studies presented sample size calculation. Most of the studies recruited children and adolescents from school. Six studies reported the use of random samples. Most studies used a corridor of 30 meters. All studies followed the American Thoracic Society guidelines to perform the six-minute walk test. The walked distance ranged 159 meters among the studies. Of the 12 included studies, 7 (58%) reported descriptive data and 6 (50%) established reference equation for the walked distance in the six-minute walk test. The reference value for the six-minute walk test in children and adolescents ranged substantially from studies in different countries. A reference equation was not provided in all studies, but the ones available took into account well established variables in the context of exercise performance, such as height, heart rate, age and weight. Countries that did not established reference values for the six-minute walk test should be encouraged to do because it would help their clinicians and researchers have a more precise interpretation of the test.

Reference Values for the Six-Minute Walk Test in Healthy Children and Adolescents: a Systematic Review

PubMed Central

Cacau, Lucas de Assis Pereira; de Santana-Filho, Valter Joviniano; Maynard, Luana G.; Gomes Neto, Mansueto; Fernandes, Marcelo; Carvalho, Vitor Oliveira

2016-01-01

Objective The aim of the study is to compare the available reference values and the six-minute walk test equations in healthy children/adolescents. Our systematic review was planned and performed in accordance with the PRISMA guidelines. We included all studies that established reference values for the six-minute walk test in healthy children/adolescents. Methods To perform this review, a research was performed in PubMed, EMBASE (via SCOPUS) and Cochrane (LILACS), Bibliographic Index Spanish in Health Sciences, Organization Collection Pan-American Health Organization, Publications of the World Health Organization and Scientific Electronic Library Online (SciELO) via Virtual Health Library until June 2015 without language restriction. Results The initial research identified 276 abstracts. Twelve studies met the inclusion criteria and were fully reviewed and approved by both reviewers. None of the selected studies presented sample size calculation. Most of the studies recruited children and adolescents from school. Six studies reported the use of random samples. Most studies used a corridor of 30 meters. All studies followed the American Thoracic Society guidelines to perform the six-minute walk test. The walked distance ranged 159 meters among the studies. Of the 12 included studies, 7 (58%) reported descriptive data and 6 (50%) established reference equation for the walked distance in the six-minute walk test. Conclusion The reference value for the six-minute walk test in children and adolescents ranged substantially from studies in different countries. A reference equation was not provided in all studies, but the ones available took into account well established variables in the context of exercise performance, such as height, heart rate, age and weight. Countries that did not established reference values for the six-minute walk test should be encouraged to do because it would help their clinicians and researchers have a more precise interpretation of the test

Nordic walking versus walking without poles for rehabilitation with cardiovascular disease: Randomized controlled trial.

PubMed

Girold, Sébastien; Rousseau, Jérome; Le Gal, Magalie; Coudeyre, Emmanuel; Le Henaff, Jacqueline

2017-07-01

With Nordic walking, or walking with poles, one can travel a greater distance and at a higher rate than with walking without poles, but whether the activity is beneficial for patients with cardiovascular disease is unknown. This randomized controlled trial was undertaken to determine whether Nordic walking was more effective than walking without poles on walk distance to support rehabilitation training for patients with acute coronary syndrome (ACS) and peripheral arterial occlusive disease (PAOD). Patients were recruited in a private specialized rehabilitation centre for cardiovascular diseases. The entire protocol, including patient recruitment, took place over 2 months, from September to October 2013. We divided patients into 2 groups: Nordic Walking Group (NWG, n=21) and Walking Group without poles (WG, n=21). All patients followed the same program over 4 weeks, except for the walk performed with or without poles. The main outcome was walk distance on the 6-min walk test. Secondary outcomes were maximum heart rate during exercise and walk distance and power output on a treadmill stress test. We included 42 patients (35 men; mean age 57.2±11 years and BMI 26.5±4.5kg/m 2 ). At the end of the training period, both groups showed improved walk distance on the 6-min walk test and treatment stress test as well as power on the treadmill stress test (P<0.05). The NWG showed significantly greater walk distance than the WG (P<0.05). Both ACS and PAOD groups showed improvement, but improvement was significant for only PAOD patients. After a 4-week training period, Nordic walking training appeared more efficient than training without poles for increasing walk distance on the 6-min walk test for patients with ACS and PAOD. Copyright © 2017. Published by Elsevier Masson SAS.

Reliability and feasibility of the six minute walk test in subjects with myotonic dystrophy.

PubMed

Kierkegaard, Marie; Tollbäck, Anna

2007-12-01

The objective was to describe test-retest reliability and feasibility of the six minute walk test in adult subjects with myotonic dystrophy type 1. Twelve subjects (28-68 years, mean 44) performed three six minute walk tests on two occasions, one week apart. Relative reliability was high (ICC(2.1)=0.99) and absolute reliability values were low (standard error of measurement 12 m, repeatability 33 m). Feasibility was investigated in a sample of 64 subjects (19-70 years, mean 43). Fifty-two subjects were able to perform two tests on the same day. Subjects with severe proximal weakness had difficulties performing repeated tests. A practice trial followed by a second test on the same day can be recommended for most subjects, and the best test should be used for evaluations. In conclusion, even though the study sample was small, the present study indicates that the six minute walk test is reliable and feasible in subjects with myotonic dystrophy type 1.

Usefulness of a 50-meter round walking test for fall prediction in the elderly requiring long-term care

PubMed Central

Hachiya, Mizuki; Murata, Shin; Otao, Hiroshi; Ihara, Takehiko; Mizota, Katsuhiko; Asami, Toyoko

2015-01-01

[Purpose] This study aimed to verify the usefulness of a 50-m round walking test developed as an assessment method for walking ability in the elderly. [Subjects] The subjects were 166 elderly requiring long-term care individuals (mean age, 80.5 years). [Methods] In order to evaluate the factors that had affected falls in the subjects in the previous year, we performed the 50-m round walking test, functional reach test, one-leg standing test, and 5-m walking test and measured grip strength and quadriceps strength. [Results] The 50-m round walking test was selected as a variable indicating fall risk based on the results of multiple logistic regression analysis. The cutoff value of the 50-m round walking test for determining fall risk was 0.66 m/sec. The area under the receiver operating characteristic curve was 0.64. The sensitivity of the cutoff value was 65.7%, the specificity was 63.6%, the positive predictive value was 55.0%, the negative predictive value was 73.3%, and the accuracy was 64.5%. [Conclusion] These results suggest that the 50-m round walking test is a potentially useful parameter for the determination of fall risk in the elderly requiring long-term care. PMID:26834327

Usefulness of a 50-meter round walking test for fall prediction in the elderly requiring long-term care.

PubMed

Hachiya, Mizuki; Murata, Shin; Otao, Hiroshi; Ihara, Takehiko; Mizota, Katsuhiko; Asami, Toyoko

2015-12-01

[Purpose] This study aimed to verify the usefulness of a 50-m round walking test developed as an assessment method for walking ability in the elderly. [Subjects] The subjects were 166 elderly requiring long-term care individuals (mean age, 80.5 years). [Methods] In order to evaluate the factors that had affected falls in the subjects in the previous year, we performed the 50-m round walking test, functional reach test, one-leg standing test, and 5-m walking test and measured grip strength and quadriceps strength. [Results] The 50-m round walking test was selected as a variable indicating fall risk based on the results of multiple logistic regression analysis. The cutoff value of the 50-m round walking test for determining fall risk was 0.66 m/sec. The area under the receiver operating characteristic curve was 0.64. The sensitivity of the cutoff value was 65.7%, the specificity was 63.6%, the positive predictive value was 55.0%, the negative predictive value was 73.3%, and the accuracy was 64.5%. [Conclusion] These results suggest that the 50-m round walking test is a potentially useful parameter for the determination of fall risk in the elderly requiring long-term care.

Development of 1-Mile Walk Tests to Estimate Aerobic Fitness in Children

ERIC Educational Resources Information Center

Sung, Hoyong; Collier, David N.; DuBose, Katrina D.; Kemble, C. David; Mahar, Matthew T.

2018-01-01

To examine the reliability and validity of 1-mile walk tests for estimation of aerobic fitness (VO[subscript 2max]) in 10- to 13-year-old children and to cross-validate previously published equations. Participants (n = 61) walked 1-mile on two different days. Self-reported physical activity, demographic variables, and aerobic fitness were used in…

Are the average gait speeds during the 10meter and 6minute walk tests redundant in Parkinson disease?

PubMed

Duncan, Ryan P; Combs-Miller, Stephanie A; McNeely, Marie E; Leddy, Abigail L; Cavanaugh, James T; Dibble, Leland E; Ellis, Terry D; Ford, Matthew P; Foreman, K Bo; Earhart, Gammon M

2017-02-01

We investigated the relationships between average gait speed collected with the 10Meter Walk Test (Comfortable and Fast) and 6Minute Walk Test (6MWT) in 346 people with Parkinson disease (PD) and how the relationships change with increasing disease severity. Pearson correlation and linear regression analyses determined relationships between 10Meter Walk Test and 6MWT gait speed values for the entire sample and for sub-samples stratified by Hoehn & Yahr (H&Y) stage I (n=53), II (n=141), III (n=135) and IV (n=17). We hypothesized that redundant tests would be highly and significantly correlated (i.e. r>0.70, p<0.05) and would have a linear regression model slope of 1 and intercept of 0. For the entire sample, 6MWT gait speed was significantly (p<0.001) related to the Comfortable 10 Meter Walk Test (r=0.75) and Fast 10Meter Walk Test (r=0.79) gait speed, with 56% and 62% of the variance in 6MWT gait speed explained, respectively. The regression model of 6MWT gait speed predicted by Comfortable 10 Meter Walk gait speed produced slope and intercept values near 1 and 0, respectively, especially for participants in H&Y stages II-IV. In contrast, slope and intercept values were further from 1 and 0, respectively, for the Fast 10Meter Walk Test. Comfortable 10 Meter Walk Test and 6MWT gait speeds appeared to be redundant in people with moderate to severe PD, suggesting the Comfortable 10 Meter Walk Test can be used to estimate 6MWT distance in this population. Copyright © 2016 Elsevier B.V. All rights reserved.

Are the Average Gait Speeds During the 10 Meter and 6 Minute Walk Tests Redundant in Parkinson Disease?

PubMed Central

Duncan, Ryan P.; Combs-Miller, Stephanie A.; McNeely, Marie E.; Leddy, Abigail L.; Cavanaugh, James T.; Dibble, Leland E.; Ellis, Terry D.; Ford, Matthew P.; Foreman, K. Bo; Earhart, Gammon M.

2016-01-01

We investigated the relationships between average gait speed collected with the 10 Meter Walk Test (Comfortable and Fast) and 6 Minute Walk Test (6MWT) in 346 people with Parkinson disease (PD) and how the relationships change with increasing disease severity. Pearson correlation and linear regression analyses determined relationships between 10 Meter Walk Test and 6MWT gait speed values for the entire sample and for sub-samples stratified by Hoehn & Yahr (H&Y) stage I (n=53), II (n=141), III (n=135) and IV (n=17). We hypothesized that redundant tests would be highly and significantly correlated (i.e. r > 0.70, p < 0.05) and would have a linear regression model slope of 1 and intercept of 0. For the entire sample, 6MWT gait speed was significantly (p<0.001) related to the Comfortable 10 Meter Walk Test (r=0.75) and Fast 10 Meter Walk Test (r=0.79) gait speed, with 56% and 62% of the variance in 6MWT gait speed explained, respectively. The regression model of 6MWT gait speed predicted by Comfortable 10 Meter Walk gait speed produced slope and intercept values near 1 and 0, respectively, especially for participants in H&Y stages II–IV. In contrast, slope and intercept values were further from 1 and 0, respectively, for the Fast 10 Meter Walk Test. Comfortable 10 Meter Walk Test and 6MWT gait speeds appeared to be redundant in people with moderate to severe PD, suggesting the Comfortable 10 Meter Walk Test can be used to estimate 6MWT distance in this population. PMID:27915221

Repeat six-minute walk tests in patients with chronic heart failure: are they clinically necessary?

PubMed

Adsett, Julie; Mullins, Robert; Hwang, Rita; Hogden, Amy; Gibson, Ellen; Houlihan, Kylie; Tuppin, Michael; Korczyk, Dariusz; Mallitt, Kylie-Ann; Mudge, Alison

2011-08-01

Owing to a reported learning effect in patients with chronic cardiopulmonary disease, performance of at least two six-minute walk tests (6MWT) are recommended as standard practice. Patients with chronic heart failure (CHF) are typically elderly and frail and it is unknown whether current guidelines are practical in a clinical setting. The aim of this study was to determine whether repeat performance of 6MWTs in patients with CHF is related to between-test interval or baseline performance. This was a multisite observational study enrolling participants entering into heart failure rehabilitation programmes. Participants performed two 6MWTs with randomly allocated inter-test intervals between 15 and 90 minutes. Distance walked in the second test was compared with the first test using a paired t test. Eighty-eight participants (45 females, age 65 ± 14 years) with stable CHF were enrolled. Mean distance walked increased from 301 metres in test 1 to 313 metres in test 2 (p < 0.001). No significant change was recorded between test 1 and test 2 for those whose baseline distance was <300 metres. The interval between tests had no significant effect on the distance walked. The change in 6MWT distance was significantly associated with better baseline performance but not with the interval between tests.

Is the 6-minute walk test a reliable substitute for peak oxygen uptake in patients with dilated cardiomyopathy?

PubMed

Zugck, C; Krüger, C; Dürr, S; Gerber, S H; Haunstetter, A; Hornig, K; Kübler, W; Haass, M

2000-04-01

The 6-min walk test may serve as a more simple clinical tool to assess functional capacity in congestive heart failure than determination of peak oxygen uptake by cardiopulmonary exercise testing. The purpose of the study was to prospectively examine whether the distance ambulated during a 6-min walk test (i) correlates with peak oxygen uptake, (ii) allows peak oxygen uptake to be predicted, and (iii) provides prognostic information similar to peak oxygen uptake in patients with dilated cardiomyopathy and left ventricular ejection fraction < or = 35%. In 113 patients (age: 54+/-12 years, NYHA: 2.2+/-0.8) with dilated cardiomyopathy (left ventricular ejection fraction 19+/-7%) a 6-min walk test and cardiopulmonary exercise testing were performed. The 6-min walk test and peak oxygen uptake were closely correlated at the initial visit (r=0.68, n=113), as well as after 263+/-114 (r=0.71, n=28) and 381+/-170 days (r=0.74, n=14). During serial exercise testing the 6-min walk test allowed peak oxygen uptake to be reliably predicted (r=0.76 between calculated and real peak oxygen uptake). After 528+/-234 days, 42 patients were hospitalized due to worsening heart failure and/or died from cardiovascular causes. Compared to clinically stable patients, these 42 patients walked a shorter distance (423+/-104 vs 501+/-95 m, P<0.001) and had a lower peak oxygen uptake (12.7+/-4.0 vs 17.4 + 5.6 ml x min(-1) x kg(-1), P<0.001). By univariate analysis the 6-min walk test outperformed other prognostic parameters such as left ventricular ejection fraction, cardiac index and plasma norepinephrine concentration and conferred a prognostic power similar to peak oxygen uptake. This predictive value could be further improved in a multivariate model, by combining the 6-min walk test with independent variables, such as left ventricular ejection fraction or cardiac index. The 6-min walk test correlated with peak oxygen uptake when tested serially over the course of the disease. Although both

Changes in cardiopulmonary function in normal adults after the Rockport 1 mile walking test: a preliminary study.

PubMed

Kim, Kyoung; Lee, Hye-Young; Lee, Do-Youn; Nam, Chan-Woo

2015-08-01

[Purpose] The purpose of this study was to investigate the changes of cardiopulmonary function in normal adults after the Rockport 1 mile walking test. [Subjects and Methods] University students (13 males and 27 females) participated in this study. Before and after the Rockport 1 mile walking test, pulmonary function, respiratory pressure, and maximal oxygen uptake were measured. [Results] Significant improvements in forced vital capacity and maximal inspiratory pressure were observed after the Rockport 1 mile walking test in males, and significant improvements in forced vital capacity, forced expiratory volume at 1 s, maximal inspiratory pressure, and maximal expiratory pressure were observed after the Rockport 1 mile walking test in females. However, the maximal oxygen uptake was not significantly different. [Conclusion] Our findings indicate that the Rockport 1 mile walking test changes cardiopulmonary function in males and females, and that it may improve cardiopulmonary function in middle-aged and older adults and provide basic data on cardiopulmonary endurance.

Changes in cardiopulmonary function in normal adults after the Rockport 1 mile walking test: a preliminary study

PubMed Central

Kim, Kyoung; Lee, Hye-Young; Lee, Do-Youn; Nam, Chan-Woo

2015-01-01

[Purpose] The purpose of this study was to investigate the changes of cardiopulmonary function in normal adults after the Rockport 1 mile walking test. [Subjects and Methods] University students (13 males and 27 females) participated in this study. Before and after the Rockport 1 mile walking test, pulmonary function, respiratory pressure, and maximal oxygen uptake were measured. [Results] Significant improvements in forced vital capacity and maximal inspiratory pressure were observed after the Rockport 1 mile walking test in males, and significant improvements in forced vital capacity, forced expiratory volume at 1 s, maximal inspiratory pressure, and maximal expiratory pressure were observed after the Rockport 1 mile walking test in females. However, the maximal oxygen uptake was not significantly different. [Conclusion] Our findings indicate that the Rockport 1 mile walking test changes cardiopulmonary function in males and females, and that it may improve cardiopulmonary function in middle-aged and older adults and provide basic data on cardiopulmonary endurance. PMID:26356048

Effect of course length and corridor width on the 2-minute walk test performance in geriatric patients.

PubMed

Lindemann, Ulrich; Beck, Luisa; Becker, Clemens

2017-02-01

To evaluate the effect of course length and corridor width on 2-minute walk test results in older adults. Cross-sectional and experimental study with different test conditions. Geriatric rehabilitation clinic. A total of 21 patients (median age 81 years). Patients walked two minutes on a 20 m and 40 m course with a 2 m or 1 m corridor width and on a continuous course without any turning in a corridor of 2 m width, five walks in total. The distance traveled within the 2 minutes was recorded. Compared with the 20 m course length, median walking distances measured by the 2-minute walk test in a walk way 2 m broad were better on the continuous corridor without any turn (136.9 m vs. 129.3 m, p = 0.002) and on the 40 m course (131.8 m vs. 129.3 m, p = 0.003). Walking distance on a 20 m course length was longer in a corridor of 2 m width compared with the 1 m corridor width (129.3 m vs. 119.2 m, p = 0.005). The walking distance was not affected by corridor width on the 40 m course length. Performance of elderly patients on the 2-minute walk test is influenced by the width of the corridor and the length of the course used.

Within-day variability on short and long walking tests in persons with multiple sclerosis.

PubMed

Feys, Peter; Bibby, Bo; Romberg, Anders; Santoyo, Carme; Gebara, Benoit; de Noordhout, Benoit Maertens; Knuts, Kathy; Bethoux, Francois; Skjerbæk, Anders; Jensen, Ellen; Baert, Ilse; Vaney, Claude; de Groot, Vincent; Dalgas, Ulrik

2014-03-15

To compare within-day variability of short (10 m walking test at usual and fastest speed; 10MWT) and long (2 and 6-minute walking test; 2MWT/6MWT) tests in persons with multiple sclerosis. Observational study. MS rehabilitation and research centers in Europe and US within RIMS (European network for best practice and research in MS rehabilitation). Ambulatory persons with MS (Expanded Disability Status Scale 0-6.5). Subjects of different centers performed walking tests at 3 time points during a single day. 10MWT, 2MWT and 6MWT at fastest speed and 10MWT at usual speed. Ninety-five percent limits of agreement were computed using a random effects model with individual pwMS as random effect. Following this model, retest scores are with 95% certainty within these limits of baseline scores. In 102 subjects, within-day variability was constant in absolute units for the 10MWT, 2MWT and 6MWT at fastest speed (+/-0.26, 0.16 and 0.15m/s respectively, corresponding to +/-19.2m and +/-54 m for the 2MWT and 6MWT) independent on the severity of ambulatory dysfunction. This implies a greater relative variability with increasing disability level, often above 20% depending on the applied test. The relative within-day variability of the 10MWT at usual speed was +/-31% independent of ambulatory function. Absolute values of within-day variability on walking tests at fastest speed were independent of disability level and greater with short compared to long walking tests. Relative within-day variability remained overall constant when measured at usual speed. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

Using built environment characteristics to predict walking for exercise

PubMed Central

Lovasi, Gina S; Moudon, Anne V; Pearson, Amber L; Hurvitz, Philip M; Larson, Eric B; Siscovick, David S; Berke, Ethan M; Lumley, Thomas; Psaty, Bruce M

2008-01-01

Background Environments conducive to walking may help people avoid sedentary lifestyles and associated diseases. Recent studies developed walkability models combining several built environment characteristics to optimally predict walking. Developing and testing such models with the same data could lead to overestimating one's ability to predict walking in an independent sample of the population. More accurate estimates of model fit can be obtained by splitting a single study population into training and validation sets (holdout approach) or through developing and evaluating models in different populations. We used these two approaches to test whether built environment characteristics near the home predict walking for exercise. Study participants lived in western Washington State and were adult members of a health maintenance organization. The physical activity data used in this study were collected by telephone interview and were selected for their relevance to cardiovascular disease. In order to limit confounding by prior health conditions, the sample was restricted to participants in good self-reported health and without a documented history of cardiovascular disease. Results For 1,608 participants meeting the inclusion criteria, the mean age was 64 years, 90 percent were white, 37 percent had a college degree, and 62 percent of participants reported that they walked for exercise. Single built environment characteristics, such as residential density or connectivity, did not significantly predict walking for exercise. Regression models using multiple built environment characteristics to predict walking were not successful at predicting walking for exercise in an independent population sample. In the validation set, none of the logistic models had a C-statistic confidence interval excluding the null value of 0.5, and none of the linear models explained more than one percent of the variance in time spent walking for exercise. We did not detect significant

OXYGEN UPTAKE BEFORE AND AFTER THE ONSET OF CLAUDICATION DURING A 6-MINUTE WALK TEST

PubMed Central

Gardner, Andrew W.; Ritti-Dias, Raphael M.; Stoner, Julie A.; Montgomery, Polly S.; Khurana, Aman; Blevins, Steve M.

2011-01-01

Purposes To compare oxygen uptake before and after the onset of claudication in subjects with peripheral artery disease (PAD) during a 6-minute walk test, and to identify predictors of the change in oxygen uptake following the onset of claudication pain Methods Fifty subjects with PAD were studied, in which 33 experienced claudication (Pain Group) during a 6-minute walk test, and 17 were pain-free during this test (Pain-Free Group). Oxygen uptake and ambulatory cadence were primary outcomes obtained during the 6-minute walk test. Results The Pain Group experienced onset of claudication pain at 179 ± 45 meters (mean ± standard deviation) and continued to walk to achieve a 6-minute walk distance of 393 ± 74 meters, which was similar (p = 0.74) to the Pain-Free Group (401 ± 76 meters). Oxygen uptake increased (p < 0.0001) after the onset of pain in the Pain Group, and this change was greater (p = 0.025) than the increase in oxygen uptake from the second to fifth minute of walking in the Pain-Free Group. Furthermore, ambulatory cadence decreased after the onset of pain in the Pain Group (p = 0.0003). The change in oxygen uptake was associated with metabolic syndrome (p = 0.0023), 6-minute walk distance (p = 0.0037), age, (p = 0.0041), and the oxygen uptake during the second minute of the test (p = 0.012). Conclusion Claudication increases oxygen uptake of self-paced, over-ground ambulation despite a decrease in cadence. The pain-mediated increase in oxygen uptake was blunted in subjects with metabolic syndrome, suggesting that they have an impaired ability to increase oxygen uptake during ambulation. The clinical significance is that claudication increases metabolic cost of ambulation, thereby increasing the relative intensity of exercise and reducing the tolerance to sustain ambulation. PMID:21890308

Clinical correlation between the 6-min walk test andcardiopulmonary exercise testing in patients with pulmonary arterial hypertension.

PubMed

Acar, Serap; Savcı, Sema; Kardibak, Didem; Özcan Kahraman, Buse; Akdeniz, Bahri; Özpelit, Ebru; Sevinç, Can

2016-12-20

The aims of the present study were to assess the relationship between the distance walked during the 6-min walk test (6MWT) and exercise capacity as determined by cardiopulmonary exercise testing (CPET) in patients with pulmonary arterial hypertension (PAH) and to investigate the prognostic value of the 6MWT in comparison to clinical parameters of CPET and echocardiography findings. Thirty PAH patients participated in the study. Subject characteristics and New York Heart Association (NYHA) classifications were recorded. All subjects completed the 6MWT and CPET. Relationships among the variables were analyzed by the Pearson correlation test. Correlation coefficients between 6MWT distance and other variables were determined by linear regression analysis. Distance walked in the 6MWT was significantly correlated with the following exercise parameters: peak oxygen consumption, work load, and metabolic equivalents. Additionally, cardiac index was correlated with peak oxygen consumption and metabolic equivalents. We also showed that cardiac index and age were two significant determinants for exercise performance, accounting for 35.4% of the variance in the 6MWT. The 6MWT provides information that may be a better index for the patient's NYHA functional class determination than maximal exercise testing.

Two 6-minute Walk Tests Are Required During Hospitalisation for Acute Exacerbation of COPD.

PubMed

Osadnik, Christian R; Borges, Rodrigo C; McDonald, Christine F; Carvalho, Celso R F; Holland, Anne E

2016-06-01

The 6-minute walk test (6MWT) is recommended to be performed twice to accurately assess exercise performance in stable chronic obstructive pulmonary disease (COPD) due to the presence of a learning effect. It is unknown whether a learning effect exists when the 6MWT is performed during hospitalisation for acute exacerbation of COPD (AECOPD). This study investigated whether repeat 6MWTs are necessary when conducted in inpatients with AECOPD. Pooled analysis was undertaken of data from two studies (Australia and Brazil) involving 46 participants (25 males, mean age 67.2 years, FEV1 43% predicted) admitted with AECOPD. Two 6MWTs, separated by ≥20 minutes, were performed on the day of discharge. Six-minute walk distance (6MWD; primary outcome), perceived dyspnoea (Borg scale), heart rate and oxyhaemoglobin saturation were recorded. 6MWD data from tests one (T1) and two (T2) were analysed via visual inspection of Bland-Altman plots. Factors associated with test improvement or decline were explored. Mean 6MWD difference between T1 and T2 was 6.2 m, however limits of agreement were wide (-92.2 m to 104.5 m). 32 (70%) participants improved (by any distance) from T1 to T2 by a mean (± standard deviation) of 32 m ± 28 m. Of these, 14 (30%) improved by a distance > 30 m. Fourteen (30%) participants recorded poorer 6MWD at T2 by a mean of 52 m ± 36 m. No factors were able to identify participants who improved or declined upon repeat testing. When performed in patients admitted to hospital with AECOPD, the 6MWT needs to be conducted twice in order to better estimate 6MWD.

Reproducibility of the Self-Controlled Six-Minute Walking Test in Heart Failure Patients

PubMed Central

Guimarães, Guilherme Veiga; Carvalho, Vitor Oliveira; Bocchi, Edimar Alcides

2008-01-01

INTRODUCTION The six-minute walk test (6WT) has been proposed to be a submaximal test, but could actually demand a high level of exercise intensity from the patient, expressed by a respiratory quotient >1.0, following the guideline recommendations. Standardizing the 6WT using the Borg scale was proposed to make sure that all patients undergo a submaximal walking test. PURPOSE To test the reproducibility of the six-minute treadmill cardiopulmonary walk test (6CWT) using the Borg scale and to make sure that all patients undergo a submaximal test. METHODS Twenty-three male heart failure patients (50±9 years) were included; these patients had both ischemic (5) and non-ischemic (18) heart failure with a left ventricle ejection fraction of 23±7%, were diagnosed as functional class NYHA II-III and were undergoing optimized drug therapy. Patients were guided to walk at a pace between “relatively easy and slightly tiring” (11 and 13 on Borg scale). The 6CWT using the Borg scale was performed two times on a treadmill with zero inclination and patient control of speed with an interval of 24 hours. During the sixth minute, we analyzed ventilation (VE, L/min), respiratory quotient, Oxygen consumption (VO2, ml/kg/min), VE/VCO2 slope, heart rate (HR, bpm), systolic blood pressure (SBP, mmHg), diastolic (DBP, mmHg) blood pressure and distance. RESULTS The intraclass correlation coefficients at the sixth minute were: HR (ri=0.96, p<0.0001), VE (ri=0.84, p<0.0001), SBP (ri=0.72, p=0.001), distance (ri=0.88, p<0.0001), VO2 (ri=0.92, p<0.0001), SlopeVE/VCO2 (ri=0.86, p<0.0001) and RQ<1 (ri=0.6, p=0.004). CONCLUSION Using the 6CWT with the Borg scale was reproducible, and it seems to be an appropriate method to evaluate the functional capacity of heart failure patients while making sure that they undergo a submaximal walking test. PMID:18438574

Reproducibility of the self-controlled six-minute walking test in heart failure patients.

PubMed

Guimarães, Guilherme Veiga; Carvalho, Vitor Oliveira; Bocchi, Edimar Alcides

2008-04-01

The six-minute walk test (6WT) has been proposed to be a submaximal test, but could actually demand a high level of exercise intensity from the patient, expressed by a respiratory quotient >1.0, following the guideline recommendations. Standardizing the 6WT using the Borg scale was proposed to make sure that all patients undergo a submaximal walking test. To test the reproducibility of the six-minute treadmill cardiopulmonary walk test (6CWT) using the Borg scale and to make sure that all patients undergo a submaximal test. Twenty-three male heart failure patients (50+/-9 years) were included; these patients had both ischemic (5) and non-ischemic (18) heart failure with a left ventricle ejection fraction of 23+/-7%, were diagnosed as functional class NYHA II-III and were undergoing optimized drug therapy. Patients were guided to walk at a pace between "relatively easy and slightly tiring" (11 and 13 on Borg scale). The 6CWT using the Borg scale was performed two times on a treadmill with zero inclination and patient control of speed with an interval of 24 hours. During the sixth minute, we analyzed ventilation (VE, L/min), respiratory quotient, Oxygen consumption (VO2, ml/kg/min), VE/VCO2 slope, heart rate (HR, bpm), systolic blood pressure (SBP, mmHg), diastolic (DBP, mmHg) blood pressure and distance. The intraclass correlation coefficients at the sixth minute were: HR (r i=0.96, p<0.0001), VE (r i=0.84, p<0.0001), SBP (r i=0.72, p=0.001), distance (r i=0.88, p<0.0001), VO2 (r i=0.92, p<0.0001), SlopeVE/VCO2 (r i=0.86, p<0.0001) and RQ<1 (r i=0.6, p=0.004). Using the 6CWT with the Borg scale was reproducible, and it seems to be an appropriate method to evaluate the functional capacity of heart failure patients while making sure that they undergo a submaximal walking test.

Fixed-distance walk tests at comfortable and fast speed: Potential tools for the functional assessment of coronary patients?

PubMed

Morard, Marie-Doriane; Besson, Delphine; Laroche, Davy; Naaïm, Alexandre; Gremeaux, Vincent; Casillas, Jean-Marie

2017-01-01

There is ambiguity concerning the walk tests available for functional assessment of coronary patients, particularly for the walking speed. This study explores the psychometric properties of two walking tests, based on fixed-distance tests, at comfortable and fast velocity, in stabilized patients at the end of a cardiac rehabilitation program. At a three-day interval 58 coronary patients (mean age of 64.85±6.03 years, 50 men) performed three walk tests, the first two at a comfortable speed in a random order (6-minute walk test - 6MWT - and 400-metre comfortable walk test - 400mCWT) and the third at a brisk speed (200-metre fast walk test - 200mFWT). A modified Bruce treadmill test was associated at the end of the second phase. Monitored main parameters were: heart rate, walking velocity, VO 2 . Tolerance to the 3 tests was satisfactory. The reliability of the main parameters was good (intraclass correlation coefficient>0.8). The VO 2 concerning 6MWT and 400mCWT were not significantly different (P=0.33) and were lower to the first ventilatory threshold determined by the stress test (P<0.001): 16.2±3.0 vs. 16.5±2.6 vs. 20.7±5.1mL·min -1 ·kg -1 respectively. The VO 2 of the 200mFWT (20.2±3.7) was not different from the first ventilatory threshold. 400mCWT and 200mFWT are feasible, well-tolerated and reliable. They explore two levels of effort intensity (lower and not different to the first ventilatory threshold respectively). 400mCWT is a possible alternative to 6MWT. Associated with 200mFWT it should allow a better measurement of physical capacities and better customization of exercise training. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Submaximal Exercise Testing Treadmill and Floor Walking.

DTIC Science & Technology

1978-05-01

Amputations," Archives of Physical Medicine and Rehabilitation, 56:67-71, 1975. 36. van der Walt, W. H., and Wyndham, C. H,, "An Equation for...C. H., van Renaburg, A. J., Rogr, G. G., Greyson, J. S.. and van der Walt, V. H., "Walk or Jog for Health: I, The Energy Cost of Walking or Running at...G., Greyson, J. S., and van der Walt, V. H., "Walk or Jog for Health: II, Iatimating the Maximi Aerobic Capacity for Exercise,* South &frIca Kedical

Clinical tests of ankle plantarflexor strength do not predict ankle power generation during walking.

PubMed

Kahn, Michelle; Williams, Gavin

2015-02-01

The aim of this study was to investigate the relationship between a clinical test of ankle plantarflexor strength and ankle power generation (APG) at push-off during walking. This is a prospective cross-sectional study of 102 patients with traumatic brain injury. Handheld dynamometry was used to measure ankle plantarflexor strength. Three-dimensional gait analysis was performed to quantify ankle power generation at push-off during walking. Ankle plantarflexor strength was only moderately correlated with ankle power generation at push-off (r = 0.43, P < 0.001; 95% confidence interval, 0.26-0.58). There was also a moderate correlation between ankle plantarflexor strength and self-selected walking velocity (r = 0.32, P = 0.002; 95% confidence interval, 0.13-0.48). Handheld dynamometry measures of ankle plantarflexor strength are only moderately correlated with ankle power generation during walking. This clinical test of ankle plantarflexor strength is a poor predictor of calf muscle function during gait in people with traumatic brain injury.

Physiological response to the 6-minute walk test in chronic heart failure patients versus healthy control subjects.

PubMed

Deboeck, Gaël; Van Muylem, Alain; Vachiéry, Jean Luc; Naeije, Robert

2014-08-01

The distance walked in 6 minutes (6MWD) has been reported to be linearly related to peak oxygen uptake (VO2) in cardiac diseases and in lung diseases. In these patients, the VO2 during a 6-min walk test (walkVO2) has been found to be nearly equivalent to peakVO2, but with a lower respiratory exchange ratio (RER). Whether these observations translate to the less functionally impaired patients or healthy control subjects is not exactly known. Thirty-two healthy control subjects and 15 chronic heart failure (CHF) patients performed a 6-min walk test and a maximal cardiopulmonary exercise test (CPET) both with measurements of gas exchange. The 6MWD and peakVO2 were linearly correlated, but with an increased slope appearing above 532 m. In CHF patients, walkVO2 was similar to peakVO2, but with lower heart rate and ventilation than measured at peak exercise. In healthy control subjects, VO2, ventilation and heart rate were lower during the 6-min walk than at maximal exercise but higher than at the anaerobic threshold. The RER during the 6-min walk remained <1 in both groups. Above 500 m, 6MWD becomes less sensitive to any increase in peakVO2. Furthermore, CHF patients and healthy control subjects exercise respectively at maximal and high VO2, but below the anaerobic threshold (as assessed by a CPET) during the 6-min walk test. © The European Society of Cardiology 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Identifying walking trips from GPS and accelerometer data in adolescent females

PubMed Central

Rodriguez, Daniel; Cho, GH; Elder, John; Conway, Terry; Evenson, Kelly R; Ghosh-Dastidar, Bonnie; Shay, Elizabeth; Cohen, Deborah A; Veblen-Mortenson, Sarah; Pickrell, Julie; Lytle, Leslie

2013-01-01

Background Studies that have combined accelerometers and global positioning systems (GPS) to identify walking have done so in carefully controlled conditions. This study tested algorithms for identifying walking trips from accelerometer and GPS data in free-living conditions. The study also assessed the accuracy of the locations where walking occurred compared to what participants reported in a diary. Methods A convenience sample of high school females was recruited (N=42) in 2007. Participants wore a GPS unit and an accelerometer, and recorded their out-of-school travel for six days. Split-sample validation was used to examine agreement in the daily and total number of walking trips with Kappa statistics and count regression models, while agreement in locations visited by walking was examined with geographic information systems. Results Agreement varied based on the parameters of the algorithm, with algorithms exhibiting moderate to substantial agreement with self-reported daily (Kappa = 0.33–0.48) and weekly (Kappa = 0.41–0.64) walking trips. Comparison of reported locations reached by walking and GPS data suggest that reported locations are accurate. Conclusions The use of GPS and accelerometers is promising for assessing the number of walking trips and the walking locations of adolescent females. PMID:21934163

North Star Ambulatory Assessment, 6-minute walk test and timed items in ambulant boys with Duchenne muscular dystrophy.

PubMed

Mazzone, Elena; Martinelli, Diego; Berardinelli, Angela; Messina, Sonia; D'Amico, Adele; Vasco, Gessica; Main, Marion; Doglio, Luca; Politano, Luisa; Cavallaro, Filippo; Frosini, Silvia; Bello, Luca; Carlesi, Adelina; Bonetti, Anna Maria; Zucchini, Elisabetta; De Sanctis, Roberto; Scutifero, Marianna; Bianco, Flaviana; Rossi, Francesca; Motta, Maria Chiara; Sacco, Annalisa; Donati, Maria Alice; Mongini, Tiziana; Pini, Antonella; Battini, Roberta; Pegoraro, Elena; Pane, Marika; Pasquini, Elisabetta; Bruno, Claudio; Vita, Giuseppe; de Waure, Chiara; Bertini, Enrico; Mercuri, Eugenio

2010-11-01

The North Star Ambulatory Assessment is a functional scale specifically designed for ambulant boys affected by Duchenne muscular dystrophy (DMD). Recently the 6-minute walk test has also been used as an outcome measure in trials in DMD. The aim of our study was to assess a large cohort of ambulant boys affected by DMD using both North Star Assessment and 6-minute walk test. More specifically, we wished to establish the spectrum of findings for each measure and their correlation. This is a prospective multicentric study involving 10 centers. The cohort included 112 ambulant DMD boys of age ranging between 4.10 and 17 years (mean 8.18±2.3 DS). Ninety-one of the 112 were on steroids: 37/91 on intermittent and 54/91 on daily regimen. The scores on the North Star assessment ranged from 6/34 to 34/34. The distance on the 6-minute walk test ranged from 127 to 560.6 m. The time to walk 10 m was between 3 and 15 s. The time to rise from the floor ranged from 1 to 27.5 s. Some patients were unable to rise from the floor. As expected the results changed with age and were overall better in children treated with daily steroids. The North Star assessment had a moderate to good correlation with 6-minute walk test and with timed rising from floor but less with 10 m timed walk/run test. The 6-minute walk test in contrast had better correlation with 10 m timed walk/run test than with timed rising from floor. These findings suggest that a combination of these outcome measures can be effectively used in ambulant DMD boys and will provide information on different aspects of motor function, that may not be captured using a single measure. Copyright © 2010. Published by Elsevier B.V.

The six-minute walk test predicts cardiorespiratory fitness in individuals with aneurysmal subarachnoid hemorrhage.

PubMed

Harmsen, Wouter J; Ribbers, Gerard M; Slaman, Jorrit; Heijenbrok-Kal, Majanka H; Khajeh, Ladbon; van Kooten, Fop; Neggers, Sebastiaan J C M M; van den Berg-Emons, Rita J

2017-05-01

Peak oxygen uptake (VO 2peak ) established during progressive cardiopulmonary exercise testing (CPET) is the "gold-standard" for cardiorespiratory fitness. However, CPET measurements may be limited in patients with aneurysmal subarachnoid hemorrhage (a-SAH) by disease-related complaints, such as cardiovascular health-risks or anxiety. Furthermore, CPET with gas-exchange analyses require specialized knowledge and infrastructure with limited availability in most rehabilitation facilities. To determine whether an easy-to-administer six-minute walk test (6MWT) is a valid clinical alternative to progressive CPET in order to predict VO 2peak in individuals with a-SAH. Twenty-seven patients performed the 6MWT and CPET with gas-exchange analyses on a cycle ergometer. Univariate and multivariate regression models were made to investigate the predictability of VO 2peak from the six-minute walk distance (6MWD). Univariate regression showed that the 6MWD was strongly related to VO 2peak (r = 0.75, p < 0.001), with an explained variance of 56% and a prediction error of 4.12 ml/kg/min, representing 18% of mean VO 2peak . Adding age and sex to an extended multivariate regression model improved this relationship (r = 0.82, p < 0.001), with an explained variance of 67% and a prediction error of 3.67 ml/kg/min corresponding to 16% of mean VO 2peak . The 6MWT is an easy-to-administer submaximal exercise test that can be selected to estimate cardiorespiratory fitness at an aggregated level, in groups of patients with a-SAH, which may help to evaluate interventions in a clinical or research setting. However, the relatively large prediction error does not allow for an accurate prediction in individual patients.

Minimum Performance on Clinical Tests of Physical Function to Predict Walking 6,000 Steps/Day in Knee Osteoarthritis: An Observational Study.

PubMed

Master, Hiral; Thoma, Louise M; Christiansen, Meredith B; Polakowski, Emily; Schmitt, Laura A; White, Daniel K

2018-07-01

Evidence of physical function difficulties, such as difficulty rising from a chair, may limit daily walking for people with knee osteoarthritis (OA). The purpose of this study was to identify minimum performance thresholds on clinical tests of physical function predictive to walking ≥6,000 steps/day. This benchmark is known to discriminate people with knee OA who develop functional limitation over time from those who do not. Using data from the Osteoarthritis Initiative, we quantified daily walking as average steps/day from an accelerometer (Actigraph GT1M) worn for ≥10 hours/day over 1 week. Physical function was quantified using 3 performance-based clinical tests: 5 times sit-to-stand test, walking speed (tested over 20 meters), and 400-meter walk test. To identify minimum performance thresholds for daily walking, we calculated physical function values corresponding to high specificity (80-95%) to predict walking ≥6,000 steps/day. Among 1,925 participants (mean ± SD age 65.1 ± 9.1 years, mean ± SD body mass index 28.4 ± 4.8 kg/m 2 , and 55% female) with valid accelerometer data, 54.9% walked ≥6,000 steps/day. High specificity thresholds of physical function for walking ≥6,000 steps/day ranged 11.4-14.0 seconds on the 5 times sit-to-stand test, 1.13-1.26 meters/second for walking speed, or 315-349 seconds on the 400-meter walk test. Not meeting these minimum performance thresholds on clinical tests of physical function may indicate inadequate physical ability to walk ≥6,000 steps/day for people with knee OA. Rehabilitation may be indicated to address underlying impairments limiting physical function. © 2017, American College of Rheumatology.

[A new procedure for the estimation of physical fitness of patients during clinical rehabilitation using the 6-minute-walk-test].

PubMed

Marek, W; Marek, E; Vogel, P; Mückenhoff, K; Kotschy-Lang, N

2008-11-01

AIMS OF THE INVESTIGATION: The 6-minute-walk-test (6-MW) is an effective tool for measuring physical fitness in elderly patients. The increased walking distance is taken as a parameter for improved physical conditions. Frequently an unaltered walking distance is found after clinical treatment, but heart rate is significantly lower in the second challenge, indicating an improved physical fitness. This positive effect is not recognised when only the walking distance is analysed. An analysis of the 6-MW test was performed on 263 patients before and after 3 - 4 weeks clinical rehabilitation. In a control group of 26 patients 6-MW was repeated after recovery at the beginning and the end of the clinical treatment. Instrumented by a mobile pulse oximeter for recording oxygen saturation and heart rate, patients were instructed to walk as fast as they can do during 6 minutes. Measurements were performed every 30 seconds and printed out. Two new parameters, efficiency (E = S/f (C)), the ratio of distance and mean heart rate, and the theoretical increase in walking distance (S (z) = Delta f (C1)/Delta f (C2) x S (2) - S (1)) were introduced and tested. S (z) = theoretical increase in distance, Delta f (C1) = difference in heart rate at rest and mean heart rate at steady state during the first walk test with distance, S1. Delta f (C2), and S2 are measured during the second walk. Thus, the increase in distance is calculated under the assumption that the second walk test would have been performed by the patient with the same difference in heart rate that he/she achieved in the first walk. The patient groups walked 353 +/- 80 m at 106 +/- 14.3 beats/min in the 1st. 6-MW and 368 +/- 76.9 m at a heart rate of 105 +/- 14.0 beats/min in the final test. The increase of the walking distance was most significant in patients with shorter distances in the 1st 6-MW. A significant increase in the walking distance and in efficiency was found in patients with shorter walking distances or

[Benefits of using rapid HIV testing at the PMU-FLON walk-in clinic in Lausanne].

PubMed

Gilgien, W; Aubert, J; Bischoff, T; Herzig, L; Perdrix, J

2012-05-16

Lab tests are frequently used in primary care to guide patient care. This is particularly the case when a severe disorder, or one that will affect patients' initial care, needs to be excluded rapidly. At the PMU-FLON walk-in clinic the use of HIV testing as recommended by the Swiss Office of Public Health was hampered by the delay in obtaining test results. This led us to introduce rapid HIV testing which provides results within 30 minutes. Following the first 250 tests the authors discuss the results as well as the benefits of rapid HIV testing in an urban walk-in clinic.

Investigation of the immediate pre-operative physical capacity of patients scheduled for elective abdominal surgery using the 6-minute walk test.

PubMed

Soares, S M T P; Jannuzzi, H P C; Kassab, M F O; Nucci, L B; Paschoal, M A

2015-09-01

To evaluate the effects of repetition of the 6-minute walk test in patients scheduled to undergo abdominal surgery within the next 48 hours, and to verify the physical capacity of these subjects before surgery. Cross-sectional study. University teaching hospital. Forty-two patients scheduled for elective abdominal surgery within the next 48 hours. Distance walked in the 6-minute walk test, heart rate, peripheral oxygen saturation, dyspnoea and leg fatigue. Thirty-one patients (74%) were able to walk for a longer distance when the test was repeated. In these subjects, the mean increase in distance walked was 35.4 [standard deviation (SD) 19.9]m. Heart rate, dyspnoea and leg fatigue increased significantly over time on both tests (P<0.05). The mean heart rate at the end of the sixth minute was significantly higher on the second test (P=0.022). Peripheral oxygen saturation remained above 90% in both tests. The furthest distance walked was, on average, 461.3 (SD 89.7)m. This value was significantly lower than that predicted for the sample (P<0.001). Patients scheduled to undergo abdominal surgery were able to walk further when they performed a second 6-minute walk test. Moreover, they showed reduced physical ability before surgery. These findings suggest that repetition of the 6-minute walk test may increase the accuracy of the distance walked, which is useful for studies assessing the physical capacity of patients undergoing abdominal surgery. Copyright © 2014 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

Phase walk analysis of leptokurtic time series.

PubMed

Schreiber, Korbinian; Modest, Heike I; Räth, Christoph

2018-06-01

The Fourier phase information play a key role for the quantified description of nonlinear data. We present a novel tool for time series analysis that identifies nonlinearities by sensitively detecting correlations among the Fourier phases. The method, being called phase walk analysis, is based on well established measures from random walk analysis, which are now applied to the unwrapped Fourier phases of time series. We provide an analytical description of its functionality and demonstrate its capabilities on systematically controlled leptokurtic noise. Hereby, we investigate the properties of leptokurtic time series and their influence on the Fourier phases of time series. The phase walk analysis is applied to measured and simulated intermittent time series, whose probability density distribution is approximated by power laws. We use the day-to-day returns of the Dow-Jones industrial average, a synthetic time series with tailored nonlinearities mimicing the power law behavior of the Dow-Jones and the acceleration of the wind at an Atlantic offshore site. Testing for nonlinearities by means of surrogates shows that the new method yields strong significances for nonlinear behavior. Due to the drastically decreased computing time as compared to embedding space methods, the number of surrogate realizations can be increased by orders of magnitude. Thereby, the probability distribution of the test statistics can very accurately be derived and parameterized, which allows for much more precise tests on nonlinearities.

The retest reliability of the six-minute walk test in patients referred to a cardiac rehabilitation programme.

PubMed

Hanson, Lisa C; McBurney, Helen; Taylor, Nicholas F

2012-03-01

The purpose of this paper was to determine if the Six-minute Walk Test (6MWT) was a reliable exercise test for patients referred to cardiac rehabilitation when up to three tests were performed and to determine if test scores differed according to between-test time interval. Thirty adults aged 63 ± 7.9 years referred to cardiac rehabilitation participated in a repeated measures reliability trial. Participants completed three 6MWTs within a one-week period. Participants were randomly allocated to one of three groups: on the first day, Group A completed three walks, Group B completed two walks and Group C completed one walk. Relative reliability was expressed in a ratio (ICC(2,1) ), and absolute reliability was expressed in metres (95% confidence intervals) for group and individuals. The 6MWT demonstrated a high level of relative reliability (intraclass correlation coefficients [ICC] = 0.94) across the three walks. There was no statistically significant difference between the test scores of the three groups. However, there was an increase in distance walked from the first to the second to the third 6MWT. Absolute reliability indicated that a change of at least 44 m would be required to be interpreted as true change in a group, and at least 95 m to be interpreted as true change in an individual with 95% confidence. Three 6MWTs completed in relatively short timeframes were not sufficient for reliable results as there was an increase in the distance walked, and relatively large increases in distances would be required to be interpreted as change. It did not make any difference whether the tests were all completed on one day or over one week. This study highlighted problems that may arise when relying on reliability coefficients alone to interpret reliability. These results suggest that the 6MWT may not have sufficient reliability to be a suitable test to evaluate exercise tolerance in patients referred to cardiac rehabilitation. Copyright © 2011 John

Narrowing beam-walking is a clinically feasible approach for assessing balance ability in lower-limb prosthesis users.

PubMed

Sawers, Andrew; Hafner, Brian J

2018-05-08

Challenging clinical balance tests are needed to expose balance deficits in lower-limb prost-hesis users. This study examined whether narrowing beam-walking could overcome conceptual and practical limitations identified in fixed-width beam-walking. Cross-sectional. Unilateral lower-limb prosthesis users. Participants walked 10 times along a low, narrowing beam. Performance was quantified using the normalized distance walked. Heuristic rules were applied to determine whether the narrowing beam task was "too easy," "too hard," or "appropriately challenging" for each participant. Linear regression and Bland-Altman plots were used to determine whether combinations of the first 5 trials could predict participants' stable beam-walking performance. Forty unilateral lower-limb prosthesis users participated. Narrowing beam-walking was appropriately challenging for 98% of participants. Performance stabilized for 93% of participants within 5 trials, while 62% were stable across all trials. The mean of trials 3-5 accurately predicted stable performance. A clinical narrowing beam-walking test is likely to challenge a range of lower-limb prosthesis users, have minimal administrative burden, and exhibit no floor or ceiling effects. Narrowing beam-walking is therefore a clinically viable method to evaluate lower-limb prosthesis users' balance ability, but requires psychometric testing before it is used to assess fall risk.

Value of Impedance Cardiography during 6‐Minute Walk Test in Pulmonary Hypertension

PubMed Central

Alkukhun, Laith; Arelli, Vineesha; Ramos, José; Newman, Jennie; McCarthy, Kevin; Pichurko, Bohdan; Minai, Omar A.; Dweik, Raed A.

2013-01-01

Abstract Background Methods that predict prognosis and response to therapy in pulmonary hypertension (PH) are lacking. We tested whether the noninvasive estimation of hemodynamic parameters during 6‐minute walk test (6MWT) in PH patients provides information that can improve the value of the test. Methods We estimated hemodynamic parameters during the 6MWT using a portable, signal‐morphology‐based, impedance cardiograph (PhysioFlow Enduro) with real‐time wireless monitoring via a bluetooth USB adapter. Results We recruited 48 subjects in the study (30 with PH and 18 healthy controls). PH patients had significantly lower maximum stroke volume (SV) and CI and slower cardiac output (CO) acceleration and decelerations slopes during the test when compared with healthy controls. In PH patients, CI change was associated with total distance walked (R = 0.62; P < 0.001) and percentage of predicted (R = 0.4, P = 0.03), HR recovery at 1 minute (0.57, P < 0.001), 2 minutes (0.65, P < 0.001), and 3 minutes (0.66, P < 0.001). Interestingly, in PH patients CO change during the test was predominantly related to an increase in SV instead of HR. Conclusions Estimation of hemodynamic parameters such as cardiac index during 6‐minute walk test is feasible and may provide useful information in patients with PH. Clin Trans Sci 2013; Volume #: 1–7 PMID:24330692

The Six-Minute Walk Test for Adults with Intellectual Disability: A Study of Validity and Reliability

ERIC Educational Resources Information Center

Nasuti, Gabriella; Stuart-Hill, Lynneth; Temple, Viviene A.

2013-01-01

Background: The Six-Minute Walk Test (6MWT) has been used with clinical and healthy populations to assess functional capacity and cardiovascular fitness. The aim of this study was to determine the test-retest reliability of a modified-6MWT as well as concurrent validity of walk distance with peak oxygen uptake (VO[subscript 2] peak). Method:…

Use of self-report to predict ability to walk 400 meters in mobility-limited older adults.

PubMed

Sayers, Stephen P; Brach, Jennifer S; Newman, Anne B; Heeren, Tim C; Guralnik, Jack M; Fielding, Roger A

2004-12-01

To determine whether the ability to walk 400 m could be predicted from self-reported walking habits and abilities in older adults and to develop an accurate self-report measure appropriate for observational trials of mobility when functional measures are impractical to collect. Cross-sectional. University-based human physiology laboratory. One hundred fifty community-dwelling older men and women (mean age+/-standard error= 79.8+/-0.3). An 18-item questionnaire assessing walking habits and ability was administered to each participant, followed by a 400-m walk test. Ninety-eight (65%) volunteers were able to complete the 400-m walk; 52 (35%) were unable. Logistic regression was performed using response items from a questionnaire as predictors and 400-m walk as the outcome. Three questions (Do you think you could walk one-quarter of a mile now without sitting down to rest. Because of a health or physical problem, do you have difficulty walking 1 mile? Could you walk up and down every aisle of a grocery store without sitting down to rest or leaning on a cart?) were predictive of 400-m walking ability and were included in the model. If participants answered all three questions compatible with the inability to walk 400 m, there was a 91% probability that they were unable to walk 400 m, with a sensitivity of 46% and a specificity of 97%. A three-item self-report developed in the study was able to accurately predict mobility disability. The utility of this instrument may be in evaluating self-reported mobility in large observational trials on mobility when functional mobility tasks are impractical to collect.

Spatio-temporal gait disorder and gait fatigue index in a six-minute walk test in women with fibromyalgia.

PubMed

Heredia-Jimenez, Jose; Latorre-Roman, Pedro; Santos-Campos, Maria; Orantes-Gonzalez, Eva; Soto-Hermoso, Victor M

2016-03-01

Gait disorders in fibromyalgia patients affect several gait parameters and different muscle recruitment patterns. The aim of this study was to assess the gait differences observed during a six-minute walk test between fibromyalgia patients and healthy controls. Forty-eight women with fibromyalgia and 15 healthy women were evaluated. Fibromyalgia patients met the American College of Rheumatology criteria for fibromyalgia selected of an ambulatory care. Both patients and controls had a negative history of musculoskeletal disease, neurological disorders, and gait abnormalities. The 15 controls were healthy women matched to the patients in age, height and body weight. Spatio-temporal gait variables and the rate of perceived exertion during the six-minute walk test (all subjects) and Fibromyalgia Impact Questionnaire (fibromyalgia subjects) were evaluated. All walking sets on the GaitRITE were collected and the gait variables were selected at three stages during the six-minute walk test: two sets at the beginning, two sets at 3 min and two sets at the end of the test. In addition, the Fibromyalgia Impact Questionnaire was used for the fibromyalgia patients. Fibromyalgia patients showed a significant decrease in all spatio-temporal gait variables at each of the three stages and had a lower walk distance covered in the six-minute walk test and higher rate of perceived exertion. No correlations were found between the Fibromyalgia Impact Questionnaire and gait variables. The fibromyalgia and control subjects showed lower gait fatigue indices between the middle and last stages. Gait analysis during a six-minute walk test is a good tool to assess the fatigue and physical symptoms of patients with fibromyalgia. Copyright © 2016 Elsevier Ltd. All rights reserved.

Determinants of distance walked during the six-minute walk test in patients undergoing cardiac surgery at hospital discharge

PubMed Central

2014-01-01

Introduction The aim of this study was to identify the determinants of distance walked in six-minute walk test (6MWD) in patients undergoing cardiac surgery at hospital discharge. Methods The assessment was performed preoperatively and at discharge. Data from patient records were collected and measurement of the Functional Independence Measure (FIM) and the Nottingham Health Profile (NHP) were performed. The six-minute walk test (6MWT) was performed at discharge. Patients undergoing elective cardiac surgery, coronary artery bypass grafting or valve replacement were eligible. Patients older than 75 years who presented arrhythmia during the protocol, with psychiatric disorders, muscular or neurological disorders were excluded from the study. Results Sixty patients (44.26% male, mean age 51.53 ± 13 years) were assessed. In multivariate analysis the following variables were selected: type of surgery (P = 0.001), duration of cardiopulmonary bypass (CPB) (P = 0.001), Functional Independence Measure - FIM (0.004) and body mass index - BMI (0.007) with r = 0.91 and r2 = 0.83 with P < 0.001. The equation derived from multivariate analysis: 6MWD = Surgery (89.42) + CPB (1.60) + MIF (2.79 ) - BMI (7.53) - 127.90. Conclusion In this study, the determinants of 6MWD in patients undergoing cardiac surgery were: the type of surgery, CPB time, functional capacity and body mass index. PMID:24885130

Effects of the six-minute walking test on dyspnea and activities of daily living in pneumoconiosis patients.

PubMed

Kim, Eun-Jin; Kim, Hye-Soon; Lee, Myung-Hee

2014-10-01

The purpose of this study was to examine the effects of walking exercise through a 6-min walking test on subjective dyspnea, pulmonary function test, arterial blood gas analysis, and activities of daily living to provide base data for the nursing intervention of pneumoconiosis patients. The subjects were pneumoconiosis patients men aged over 60. This quasi-experimental study was designed with a non-equivalent control group pre- and post-test design, and the study period was September to December 2013. Of the pneumoconiosis inpatient subjects, 39 were assigned to the experimental group and the 39 to the control group. Only the experimental group was subjected to a 6-min walking test three times a week for 10 weeks. Subjective dyspnea was measured based on anxiety about dyspnea during and after the exercise. FEV1% prediction and FEV1/FVC% were used to measure the pulmonary function. The arterial blood gas was measured based on the pH, PaO2, PaCO2, and activities of daily living. The data were analyzed through an χ(2) and t-test. The study results showed that the 6-min walking test reduced the anxiety about dyspnea of the pneumoconiosis patients during the exercise, moderated the dyspnea index after the performance of the activities, and improved the patients' ability to perform activities of daily living. Thus, walking exercise seems to be an effective nursing intervention to maintain the respiratory rehabilitation outcomes by minimizing the pneumoconiosis patients' burden.

Walking the walk while thinking about the talk: embodied interpretation of metaphorical narratives.

PubMed

Gibbs, Raymond W

2013-08-01

Two sets of experiments examined people's embodied understanding of metaphorical narratives. Participants heard one of two stories about a romantic relationship; either one that was successful or one that was not, that initially described it in metaphorical terms as "Your relationship was moving along in a good direction" or nonmetaphorical terms as "Your relationship was very important to you." Participants were then blindfolded and attempted to accurately walk, or imagine walking, to a marker 40 feet away while they thought about the story they just heard. People who heard about the successful metaphorical story walked longer and further than those presented with the unsuccessful relationship story. But these walking and imagining differences disappeared when the critical metaphorical statement "moving along in a good direction" was replaced by a nonmetaphorical expression. These findings, and those from another set of experiments, suggest that people's understanding of metaphorical narratives is partly based on their embodied simulations of the metaphorical actions referred to in these stories.

Heart failure: comparison between six-minute walk test and cardiopulmonary test.

PubMed

Carvalho, Eduardo Elias Vieira de; Costa, Daniela Caetano; Crescêncio, Júlio César; Santi, Giovani Luiz De; Papa, Valéria; Marques, Fabiana; Schmidt, André; Marin-Neto, José Antonio; Simões, Marcus Vinícius; Gallo Junior, Lourenço

2011-07-01

Chronic heart failure (HF) is a syndrome characterized by reduced cardiac output in relation to the metabolic needs of the organism, as well as metabolic and neurohormonal axis abnormalities. Symptoms such as fatigue and dyspnoea are notorious and stress tests are widely used to assess functional capacity, prognosis and effectiveness of therapeutic interventions in this syndrome. To evaluate the reproducibility of the six-minute walk test (6MW) in patients with HF and correlate the magnitude of the variables reached at peak exercise of the 6MWT with a cardiopulmonary exercise test (CPET). We studied 16 patients (12 men and 4 women) diagnosed with HF FC I-II (NYHA). The volunteers underwent two 6MWT (6MWT'1 and 6MWT'2) with 30-minute interval between them; then, they underwent a maximum CPET. All variables obtained in the two 6MWT' proved to be significant with high correlations: distance walked (DW) (r = 0.93, p < 0.0001), heart rate (HR) (r = 0.89, p < 0.0001), oxygen consumption (VO2) (r = 0.93, p < 0.0001) and scale of perceived exertion (r = 0.85, p < 0.0001). In turn, all variables analyzed in the 6MWT' showed significant and moderate correlations with the variables obtained from the CPET, namely: peak HR (r = 0.66; p = 0.005); VO2 (r = 0.57; p = 0.02) and VO2 in the CPET and DT in the 6MWT'2 (r = 0.70; p = 0.002). The 6MWT was reproducible in this group of patients with HF (NYHA - I-II) and correlated with the CPET. Therefore, it is a tool for reliable evaluation, and a suitable, safe and low-cost alternative for the prescription of aerobic exercise in patients with HF.

Reference values for the 6-minute walk test in healthy children and adolescents in Switzerland

PubMed Central

2013-01-01

Background The six-minute walk test (6MWT) is a simple, low tech, safe and well established, self-paced assessment tool to quantify functional exercise capacity in adults. The definition of normal 6MWT in children is especially demanding since not only parameters like height, weight and ethnical background influence the measurement, but may be as crucial as age and the developmental stage. The aim of this study is establishing reference values for the 6MWT in healthy children and adolescents in Switzerland and to investigate the influence of age, anthropometrics, heart rate, blood pressure and physical activity on the distance walked. Methods Children and adolescents between 5–17 years performed a 6MWT. Short questionnaire assessments about their health state and physical activities. anthropometrics and vitals were measured before and after a 6-minute walk test and were previously defined as secondary outcomes. Results Age, height, weight and the heart rate after the 6MWT all predicted the distance walked according to different regression models: age was the best single predictor and mostly influenced walk distance in younger age, anthropometrics were more important in adolescents and females. Heart rate after the 6MWT was an important distance predictor in addition to age and outreached anthropometrics in the majority of subgroups assessed. Conclusions The 6MWT in children and adolescents is feasible and practical. The 6MWT distance depends mainly on age; however, heart rate after the 6MWT, height and weight significantly add information and should be taken into account mainly in adolescents. Reference equations allow predicting 6-minute walk test distance and may help to better assess and compare outcomes in young patients with cardiovascular and respiratory diseases and are highly warranted for different populations. PMID:23915140

[Six-minute-walk test and maximum exercise test in cycloergometer in chronic obstructive pulmonary disease. Are the physiological demands equivalent?].

PubMed

Díaz, Orlando; Morales, Arturo; Osses, Rodrigo; Klaassen, Julieta; Lisboa, Carmen; Saldías, Fernando

2010-06-01

The physiological load imposed by the six minute walk test (SMWT) in chronic obstructive pulmonary disease (COPD) patients come from small studies where the influence of disease severity has not been assessed. The aim of the present study was to compare the SMWT with an incremental cardiopulmonary exercise test (CPET) in patients classified by disease severity according to FEV(1) (cutoff 50% predicted). Eighty-one COPD patients (53 with FEV(1) > or =50%) performed both tests on two consecutive days. Oxygen consumption (VO(2)), carbon dioxide production (VCO(2)), minute ventilation (V(E)), heart rate (HR) and pulse oximetry (SpO(2)) were measured during SMWT and CPET using portable equipment. Dyspnea and leg fatigue were measured with the Borg scale. In both groups, walking speed was constant during the SMWT and VO(2) showed a plateau after the 3rd minute. When comparing SMWT (6th min) and peak CPET, patients with FEV(1) > or =50% showed a greater VO(2), but lower values of VCO(2),V(E), HR, dyspnea, leg fatigue, and SpO(2) during walking. In contrast, in those with FEV(1) <50% predicted values were similar. Distance walked during the SMWT strongly correlated with VO(2) at peak CPET (r=0.78; P=0.0001). The SMWT is a constant load exercise in COPD patients, regardless of disease severity. It imposes high metabolic, ventilatory and cardiovascular requirements, which were closer to those of CPET in severe COPD. These findings may explain the close correlation between distance walked and peak CPET VO(2). 2009 SEPAR. Published by Elsevier Espana. All rights reserved.

Can Change in Prolonged Walking Be Inferred From a Short Test of Gait Speed Among Older Adults Who Are Initially Well-Functioning?

PubMed Central

Neogi, Tuhina; King, Wendy C.; LaValley, Michael P.; Kritchevsky, Stephen B.; Nevitt, Michael C.; Harris, Tamara B.; Ferrucci, Luigi; Simonsick, Eleanor M.; Satterfield, Suzanne; Strotmeyer, Elsa S.; Zhang, Yuqing

2014-01-01

Background The ability to walk for short and prolonged periods of time is often measured with separate walking tests. It is unclear whether decline in the 2-minute walk coincides with decline in a shorter 20-m walk among older adults. Objective The aim of this study was to describe patterns of change in the 20-m walk and 2-minute walk over 8 years among a large cohort of older adults. Should change be similar between tests of walking ability, separate retesting of prolonged walking may need to be reconsidered. Design A longitudinal, observational cohort study was conducted. Methods Data were from 1,893 older adults who were well-functioning (≥70 years of age). The 20-m walk and 2-minute walk were repeatedly measured over 8 years to measure change during short and prolonged periods of walking, respectively. Change was examined using a dual group-based trajectory model (dual model), and agreement between walking trajectories was quantified with a weighted kappa statistic. Results Three trajectory groups for the 20-m walk and 2-minute walk were identified. More than 86% of the participants were in similar trajectory groups for both tests from the dual model. There was high chance-corrected agreement (kappa=.84; 95% confidence interval=.82, .86) between the 20-m walk and 2-minute walk trajectory groups. Limitations One-third of the original Health, Aging and Body Composition (Health ABC) study cohort was excluded from analysis due to missing clinic visits, followed by being excluded for health reasons for performing the 2-minute walk, limiting generalizability to healthy older adults. Conclusions Patterns of change in the 2-minute walk are similar to those in the 20-m walk. Thus, separate retesting of the 2-minute walk may need to be reconsidered to gauge change in prolonged walking. PMID:24786943

Walking straight into circles.

PubMed

Souman, Jan L; Frissen, Ilja; Sreenivasa, Manish N; Ernst, Marc O

2009-09-29

Common belief has it that people who get lost in unfamiliar terrain often end up walking in circles. Although uncorroborated by empirical data, this belief has widely permeated popular culture. Here, we tested the ability of humans to walk on a straight course through unfamiliar terrain in two different environments: a large forest area and the Sahara desert. Walking trajectories of several hours were captured via global positioning system, showing that participants repeatedly walked in circles when they could not see the sun. Conversely, when the sun was visible, participants sometimes veered from a straight course but did not walk in circles. We tested various explanations for this walking behavior by assessing the ability of people to maintain a fixed course while blindfolded. Under these conditions, participants walked in often surprisingly small circles (diameter < 20 m), though rarely in a systematic direction. These results rule out a general explanation in terms of biomechanical asymmetries or other general biases [1-6]. Instead, they suggest that veering from a straight course is the result of accumulating noise in the sensorimotor system, which, without an external directional reference to recalibrate the subjective straight ahead, may cause people to walk in circles.

Six-minute walking test done in a hallway or on a treadmill: how close do the two methods agree?

PubMed

Lenssen, Antoine F; Wijnen, Lambert C A M; Vankan, Dion G; Van Eck, Bart H; Berghmans, Danielle P; Roox, George M

2010-12-01

The 6-min walking test (6-MWT) is probably the most widely used test to measure the functional capacity in cardiac rehabilitation. Although the American Thoracic Society recommends testing on a flat surface, treadmills are also used for testing. Therefore, we want to investigate the interchangeability of results of treadmill and hallway 6-MWT in a population of patients participating in a cardiac rehabilitation programme. Preexperimental design. University hospital Department of Cardiology and Physiotherapy. Patients entering the cardiac rehabilitation programme of the Maastricht University Cardiology Department. Agreement in 6-min walking distance between the hallway and treadmill test results were calculated by taking the mean difference between the two methods and the 95% confidence interval of the difference and plotting this against the average of the two test results. A Bland and Altman plot was constructed, showing the mean difference and the 95% limits of agreement between the two methods. Sixty-nine patients participated in this study. Mean difference between walking on a treadmill and walking in a hallway was 9 m in favour of the hallway test. The 95% limits of agreement were±118 m. Results of the 6-MWT conducted in a hallway or on a treadmill are not interchangeable, because of large between-test variations in the distances walked by individual participants.

Norepinephrine Remains Increased in the Six-Minute Walking Test after Heart Transplantation

PubMed Central

Guimarães, Guilherme Veiga; Avila, Veridiana D’; Bocchi, Edimar Alcides; Carvalho, Vitor Oliveira

2010-01-01

OBJECTIVE: We sought to evaluate the neurohormonal activity in heart transplant recipients and compare it with that in heart failure patients and healthy subjects during rest and just after a 6-minute walking test. INTRODUCTION: Despite the improvements in quality of life and survival provided by heart transplantation, the neurohormonal profile is poorly described. METHODS: Twenty heart transplantation (18 men, 49±11 years and 8.5±3.3 years after transplantation), 11 heart failure (8 men, 43±10 years), and 7 healthy subjects (5 men 39±8 years) were included in this study. Blood samples were collected immediately before and during the last minute of the exercise. RESULTS: During rest, patients’ norepinephrine plasma level (659±225 pg/mL) was higher in heart transplant recipients (463±167 pg/mL) and heathy subjects (512±132), p<0.05. Heart transplant recipient’s norepinephrine plasma level was not different than that of healthy subjects. Just after the 6-minute walking test, the heart transplant recipient’s norepinephrine plasma level (1248±692 pg/mL) was not different from that of heart failure patients (1174±653 pg/mL). Both these groups had a higher level than healthy subjects had (545±95 pg/mL), p<0.05. CONCLUSION: Neurohormonal activity remains increased after the 6-minute walking test after heart transplantation. PMID:20613934

The six-minute walk test and body weight-walk distance product in healthy Brazilian subjects.

PubMed

Iwama, A M; Andrade, G N; Shima, P; Tanni, S E; Godoy, I; Dourado, V Z

2009-11-01

We assessed the 6-min walk distance (6MWD) and body weight x distance product (6MWw) in healthy Brazilian subjects and compared measured 6MWD with values predicted in five reference equations developed for other populations. Anthropometry, spirometry, reported physical activity, and two walk tests in a 30-m corridor were evaluated in 134 subjects (73 females, 13-84 years). Mean 6MWD and 6MWw were significantly greater in males than in females (622 +/- 80 m, 46,322 +/- 10,539 kg.m vs 551 +/- 71 m, 36,356 +/- 8,289 kg.m, P < 0.05). Four equations significantly overestimated measured 6MWD (range, 32 +/- 71 to 137 +/- 74 m; P < 0.001), and one significantly underestimated it (-36 +/- 86 m; P < 0.001). 6MWD significantly correlated with age (r = -0.39), height (r = 0.44), body mass index (r = -0.24), and reported physical activity (r = 0.25). 6MWw significantly correlated with age (r = -0.21), height (r = 0.66) and reported physical activity (r = 0.25). The reference equation devised for walk distance was 6MWDm = 622.461 - (1.846 x Ageyears) + (61.503 x Gendermales = 1; females = 0); r2 = 0.300. In an additional group of 85 subjects prospectively studied, the difference between measured and the 6MWD predicted with the equation proposed here was not significant (-3 +/- 68 m; P = 0.938). The measured 6MWD represented 99.6 +/- 11.9% of the predicted value. We conclude that 6MWD and 6MWw variances were adequately explained by demographic and anthropometric attributes. This reference equation is probably most appropriate for evaluating the exercise capacity of Brazilian patients with chronic diseases.

Prediction of Maximal Oxygen Uptake by Six-Minute Walk Test and Body Mass Index in Healthy Boys.

PubMed

Jalili, Majid; Nazem, Farzad; Sazvar, Akbar; Ranjbar, Kamal

2018-05-14

To develop an equation to predict maximal oxygen uptake (VO2max) based on the 6-minute walk test (6MWT) and body composition in healthy boys. Direct VO2max, 6-minute walk distance, and anthropometric characteristics were measured in 349 healthy boys (12.49 ± 2.72 years). Multiple regression analysis was used to generate VO2max prediction equations. Cross-validation of the VO2max prediction equations was assessed with predicted residual sum of squares statistics. Pearson correlation was used to assess the correlation between measured and predicted VO2max. Objectively measured VO2max had a significant correlation with demographic and 6MWT characteristics (R = 0.11-0.723, P < .01). Multiple regression analysis revealed the following VO2max prediction equation: VO2max (mL/kg/min) = 12.701 + (0.06 × 6-minute walk distance m ) - (0.732 × body mass index kg/m2 ) (R 2 = 0.79, standard error of the estimate [SEE] = 2.91 mL/kg/min, %SEE = 6.9%). There was strong correlation between measured and predicted VO2max (r = 0.875, P < .001). Cross-validation revealed minimal shrinkage (R 2 p = 0.78 and predicted residual sum of squares SEE = 2.99 mL/kg/min). This study provides a relatively accurate and convenient VO2max prediction equation based on the 6MWT and body mass index in healthy boys. This model can be used for evaluation of cardiorespiratory fitness of boys in different settings. Copyright © 2018 Elsevier Inc. All rights reserved.

A new standardized treadmill walking test requiring low motor skills in children aged 4-10 years.

PubMed

Wäffler-Kammermann, Nathalie; Lacorcia, Ruth Stauffer; Wettstein, Markus; Radlinger, Lorenz; Frey, Urs

2008-02-01

Exercise intolerance may be reported by parents of young children with respiratory diseases. There is, however, a lack of standardized exercise protocols which allow verification of these reports especially in younger children. Consequently the aims of this pilot study were to develop a standardized treadmill walking test for children aged 4-10 years demanding low sensorimotor skills and achieving high physical exhaustion. In a prospective experimental cross sectional pilot study, 33 healthy Caucasian children were separated into three groups: G1 (4-6 years, n = 10), G2 (7-8 years, n = 12), and G3 (9-10 years, n = 11). Children performed the treadmill walking test with increasing exercise levels up to peak condition with maximal exhaustion. Gas exchange, heart rate, and lactate were measured during the test, spirometry before and after. Parameters were statistically calculated at all exercise levels as well as at 2 and 4 mmol/L lactate level for group differences (Kruskal-Wallis H-test, alpha = 0.05; post hoc: Mann-Whitney U-test with Bonferroni correction alpha = 0.05/n) and test-retest differences (Wilcoxon-rank-sum test) with SPSS. The treadmill walking test could be demonstrated to be feasible with a good repeatability within groups for most of the parameters. All children achieved a high exhaustion level. At peak level under exhaustion condition only the absolute VO2 and VCO2 differed significantly between age groups. In conclusion this newly designed treadmill walking test indicates a good feasibility, safety, and repeatability. It suggests the potential usefulness of exercise capacity monitoring for children aged from early 4 to 10 years. Various applications and test modifications will be investigated in further studies. Copyright 2007 Wiley-Liss, Inc.

Criterion validation of two submaximal aerobic fitness tests, the self-monitoring Fox-walk test and the Åstrand cycle test in people with rheumatoid arthritis.

PubMed

Nordgren, Birgitta; Fridén, Cecilia; Jansson, Eva; Österlund, Ted; Grooten, Wilhelmus Johannes; Opava, Christina H; Rickenlund, Anette

2014-09-17

Aerobic capacity tests are important to evaluate exercise programs and to encourage individuals to have a physically active lifestyle. Submaximal tests, if proven valid and reliable could be used for estimation of maximal oxygen uptake (VO2max). The purpose of the study was to examine the criterion-validity of the submaximal self-monitoring Fox-walk test and the submaximal Åstrand cycle test against a maximal cycle test in people with rheumatoid arthritis (RA). A secondary aim was to study the influence of different formulas for age predicted maximal heart rate when estimating VO2max by the Åstrand test. Twenty seven subjects (81% female), mean (SD) age 62 (8.1) years, diagnosed with RA since 17.9 (11.7) years, participated in the study. They performed the Fox-walk test (775 meters), the Åstrand test and the maximal cycle test (measured VO2max test). Pearson's correlation coefficients were calculated to determine the direction and strength of the association between the tests, and paired t-tests were used to test potential differences between the tests. Bland and Altman methods were used to assess whether there was any systematic disagreement between the submaximal tests and the maximal test. The correlation between the estimated and measured VO2max values were strong and ranged between r = 0.52 and r = 0.82 including the use of different formulas for age predicted maximal heart rate, when estimating VO2max by the Åstrand test. VO2max was overestimated by 30% by the Fox-walk test and underestimated by 10% by the Åstrand test corrected for age. When the different formulas for age predicted maximal heart rate were used, the results showed that two formulas better predicted maximal heart rate and consequently a more precise estimation of VO2max. Despite the fact that the Fox-walk test overestimated VO2max substantially, the test is a promising method for self-monitoring VO2max and further development of the test is encouraged. The Åstrand test should be

Comparison between the 6-minute walk tests performed in patients with chronic obstructive pulmonary disease at different altitudes

PubMed Central

Squassoni, Selma Denis; Machado, Nadine Cristina; Lapa, Mônica Silveira; Cordoni, Priscila Kessar; Bortolassi, Luciene Costa; de Oliveira, Juliana Nascimento; Tavares, Cecilia Melo Rosa; Fiss, Elie

2014-01-01

Objective To evaluate the influence of the altitude on the 6-minute walking test in patients with moderate to severe pulmonary disease. Methods Twenty-nine patients performed the 6-minute walk test at a pulmonary rehabilitation clinic in Santo André (above sea level), in São Paulo State, and at the Enseada Beach, in Guarujá (at sea level), also in São Paulo State. Of these 29 patients, 8 did the test both on hard sand and on asphalt to analyze if there were differences in performance during the tests. Data such as heart rate, oxygen saturation, test distance, and Borg scale were compared. Results We found no statistical difference in relation to oxygen saturation at rest before the beginning of the walking test in Santo André 94.67±2.26% and at sea level 95.56±2% (p=0.71). The minimum saturation measured during the test was 87.27±6.54% in Santo André and 89.10±5.41% in Guarujá (p=0.098). There were no differences in the performed distance between the different kinds of terrains; the distance on sand was 387.75±5.02m and on asphalt it was 375.00±6.54m (p=0.654). Regarding oxygen saturation during walking, the pulse oximetry on sand was 95.12±1.80% and on asphalt it was 96.87±1.64% (p=1.05). Conclusion Altitude did not affect the performance of the walking test in patients with moderate to severe pulmonary disease and the results were similar in both cases, on sand and on asphalt. PMID:25628195

The 1-mile walk test is a valid predictor of VO(2max) and is a reliable alternative fitness test to the 1.5-mile run in U.S. Air Force males.

PubMed

Weiglein, Laura; Herrick, Jeffery; Kirk, Stacie; Kirk, Erik P

2011-06-01

The purpose of this study was to assess the validity of the 1-mile walk (Rockport Walk Test) as a predictor of VO(2max) and determine whether the 1-mile walk is a reliable alternative to the 1.5-mile run in moderately fit to highly fit U.S. Air Force males. Twenty-four (33.0 +/- 1.5 years) males completed a maximal treadmill VO(2max) (50.3 +/- 1.4 mL/ kg/min), 1-mile walk, and 1.5-mile run. For the 1-mile walk, there were no significant differences between measured and predicted VO(2max) (p = 0.177, r = 0.817). There were no significant differences (p = 0.573) between points scored in the Air Force Fitness Test for the 1-mile walk and 1.5-mile run tests. In conclusion, the 1-mile walk test is a valid predictor of VO(2max) and can be used as an alternative fitness test to the 1.5-mile run in assessing cardiovascular fitness in Air Force males.

Reliability and validity of an audio signal modified shuttle walk test.

PubMed

Singla, Rupak; Rai, Richa; Faye, Abhishek Anil; Jain, Anil Kumar; Chowdhury, Ranadip; Bandyopadhyay, Debdutta

2017-01-01

The audio signal in the conventionally accepted protocol of shuttle walk test (SWT) is not well-understood by the patients and modification of the audio signal may improve the performance of the test. The aim of this study is to study the validity and reliability of an audio signal modified SWT, called the Singla-Richa modified SWT (SWTSR), in healthy normal adults. In SWTSR, the audio signal was modified with the addition of reverse counting to it. A total of 54 healthy normal adults underwent conventional SWT (CSWT) at one instance and two times SWTSRon the same day. The validity was assessed by comparing outcomes of the SWTSRto outcomes of CSWT using the Pearson correlation coefficient and Bland-Altman plot. Test-retest reliability of SWTSRwas assessed using the intraclass correlation coefficient (ICC). The acceptability of the modified test in comparison to the conventional test was assessed using Likert scale. The distance walked (mean ± standard deviation) in the CSWT and SWTSRtest was 853.33 ± 217.33 m and 857.22 ± 219.56 m, respectively (Pearson correlation coefficient - 0.98; P < 0.001) indicating SWTSRto be a valid test. The SWTSRwas found to be a reliable test with ICC of 0.98 (95% confidence interval: 0.97-0.99). The acceptability of SWTSRwas significantly higher than CSWT. The SWTSRwith modified audio signal with reverse counting is a reliable as well as a valid test when compared with CSWT in healthy normal adults. It better understood by subjects compared to CSWT.

Validity and reliability of the 1/4 mile run-walk test in physically active children and adolescents.

PubMed

Ruiz, Jonatan R; Ortega, Francisco B; Castro-Piñero, Jose

2014-11-30

We investigated the criterion-related validity and the reliability of the 1/4 mile run-walk test (MRWT) in children and adolescents. A total of 86 children (n=42 girls) completed a maximal graded treadmill test using a gas analyzer and the 1/4MRW test. We investigated the test-retest reliability of the 1/4MRWT in a different group of children and adolescents (n=995, n=418 girls). The 1/4MRWT time, sex, and BMI significantly contributed to predict measured VO2peak (R2= 0.32). There was no systematic bias in the cross-validation group (P>0.1). The root mean sum of squared errors (RMSE) and the percentage error were 6.9 ml/kg/min and 17.7%, respectively, and the accurate prediction (i.e. the percentage of estimations within ±4.5 ml/kg/min of VO2peak) was 48.8%. The reliability analysis showed that the mean inter-trial difference ranged from 0.6 seconds in children aged 6-11 years to 1.3 seconds in adolescents aged 12-17 years (all P. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

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Hazards of soil-borne Pb to wild birds may be more accurately quantified if the bioavailability of that Pb is known. To better understand the bioavailability of Pb to birds, we measured blood Pb concentrations in Japanese quail (Coturnix japonica) fed diets containing Pb-contaminated soils. Relative bioavailabilities were expressed by comparison with blood Pb concentrations in quail fed a Pb acetate reference diet. Diets containing soil from five Pb-contaminated Superfund sites had relative bioavailabilities from 33%-63%, with a mean of about 50%. Treatment of two of the soils with P significantly reduced the bioavailability of Pb. The bioaccessibility of the Pb in the test soils was then measured in six in vitro tests and regressed on bioavailability. They were: the “Relative Bioavailability Leaching Procedure” (RBALP) at pH 1.5, the same test conducted at pH 2.5, the “Ohio State University In vitro Gastrointestinal” method (OSU IVG), the “Urban Soil Bioaccessible Lead Test”, the modified “Physiologically Based Extraction Test” and the “Waterfowl Physiologically Based Extraction Test.” All regressions had positive slopes. Based on criteria of slope and coefficient of determination, the RBALP pH 2.5 and OSU IVG tests performed very well. Speciation by X-ray absorption spectroscopy demonstrated that, on average, most of the Pb in the sampled soils was sorbed to minerals (30%), bound to organic matter 24%, or present as Pb sulfate 18%. Ad

[A new procedure for the estimation of physical fitness of patients during clinical rehabilitation using the 6-minutes walk test].

PubMed

Marek, W; Marek, E; Friz, Y; Vogel, P; Mückenhoff, K; Kotschy-Lang, N

2010-03-01

AIMS OF THE INVESTIGATION: The repetition of the 6-minutes walk test (6 MWT) in older patients is frequently performed in order to document the maximal walking distance, although it is not recommended in any guidelines on exercise tests and although there is common consent to save clinical resources in terms of time and staff. Therefore, we have examined whether and to what extent the repetition of the walk tests helps patients to get more familiar with this kind of exercise test. Thus the acquired physiological data should reliably describe the physical fitness of the patients at the beginning and at the end of their clinical rehabilitation. 35 patients performed their walk tests before and after 3 - 4 weeks of clinical rehabilitation. Each test has been repeated after one hour of recovery. The patients were instructed to walk during 6 minutes as fast as possible. They were equipped with a mobile pulse oximeter for recording oxygen saturation and heart rate. The distance, S, and the heart rate, fc, were measured. Measurements were performed every 30 seconds and recorded. The efficiency, E (E = S/6/fc), was calculated as the ratio of distance per minute and the mean heart rate during the test. In the first test the patients walked 416 +/- 63 m at a heart rate of 104.7 +/- 15.7 beats/min, in the first repeated test 454 +/- 71 m at a heart of 106.3 +/- 17.4 beats/min. In the second test, after clinical therapy, they walked 438 +/- 58 m at a heart rate of 106.3 +/- 17.4 beats/min, in the second repeated test 473 +/- 56 m at 108.6 +/- 13.2/min. The difference of the walking distances of the tests at the entrance were found to be 38.4 +/- 26.2 m (+ 9.3 +/- 6.2%), at the end of clinical rehabilitation 35 +/- 26 m (+ 8.4 +/- 6.4%). Both differences are found to be independent from the distance of the first test. They are not significantly different. The efficiency was not significantly different in the initial and final test (0.673 +/- 0.129 and 0.689 +/- 0.085 m

Walking drawings and walking ability in children with cerebral palsy.

PubMed

Chong, Jimmy; Mackey, Anna H; Stott, N Susan; Broadbent, Elizabeth

2013-06-01

To investigate whether drawings of the self walking by children with cerebral palsy (CP) were associated with walking ability and illness perceptions. This was an exploratory study in 52 children with CP (M:F = 28:24), mean age 11.1 years (range 5-18), who were attending tertiary level outpatient clinics. Children were asked to draw a picture of themselves walking. Drawing size and content was used to investigate associations with clinical walk tests and children's own perceptions of their CP assessed using a CP version of the Brief Illness Perception Questionnaire. Larger drawings of the self were associated with less distance traveled, higher emotional responses to CP, and lower perceptions of pain or discomfort, independent of age. A larger self-to-overall drawing height ratio was related to walking less distance. Drawings of the self confined within buildings and the absence of other figures were also associated with reduced walking ability. Drawing size and content can reflect walking ability, as well as symptom perceptions and distress. Drawings may be useful for clinicians to use with children with cerebral palsy to aid discussion about their condition. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Six-minute walk test and heart rate variability: lack of association in advanced stages of heart failure.

PubMed

Woo, M A; Moser, D K; Stevenson, L W; Stevenson, W G

1997-09-01

The 6-minute walk and heart rate variability have been used to assess mortality risk in patients with heart failure, but their relationship to each other and their usefulness for predicting mortality at 1 year are unknown. To assess the relationships between the 6-minute walk test, heart rate variability, and 1-year mortality. A sample of 113 patients in advanced stages of heart failure (New York Heart Association Functional Class III-IV, left ventricular ejection < 0.25) were studied. All 6-minute walks took place in an enclosed, level, measured corridor and were supervised by the same nurse. Heart rate variability was measured by using (1) a standard-deviation method and (2) Poincaré plots. Data on RR intervals obtained by using 24-hour Holter monitoring were analyzed. Survival was determined at 1 year after the Holter recording. The results showed no significant associations between the results of the 6-minute walk and the two measures of heart rate variability. The results of the walk were related to 1-year mortality but not to the risk of sudden death. Both measures of heart rate variability had significant associations with 1-year mortality and with sudden death. However, only heart rate variability measured by using Poincaré plots was a predictor of total mortality and risk of sudden death, independent of left ventricular ejection fraction, serum levels of sodium, results of the 6-minute walk test, and the standard-deviation measure of heart rate variability. Results of the 6-minute walk have poor association with mortality and the two measures of heart rate variability in patients with advanced-stage heart failure and a low ejection fraction. Further studies are needed to determine the optimal clinical usefulness of the 6-minute walk and heart rate variability in patients with advanced-stage heart failure.

The Design and Evaluation of a Large-Scale Real-Walking Locomotion Interface

PubMed Central

Peck, Tabitha C.; Fuchs, Henry; Whitton, Mary C.

2014-01-01

Redirected Free Exploration with Distractors (RFED) is a large-scale real-walking locomotion interface developed to enable people to walk freely in virtual environments that are larger than the tracked space in their facility. This paper describes the RFED system in detail and reports on a user study that evaluated RFED by comparing it to walking-in-place and joystick interfaces. The RFED system is composed of two major components, redirection and distractors. This paper discusses design challenges, implementation details, and lessons learned during the development of two working RFED systems. The evaluation study examined the effect of the locomotion interface on users’ cognitive performance on navigation and wayfinding measures. The results suggest that participants using RFED were significantly better at navigating and wayfinding through virtual mazes than participants using walking-in-place and joystick interfaces. Participants traveled shorter distances, made fewer wrong turns, pointed to hidden targets more accurately and more quickly, and were able to place and label targets on maps more accurately, and more accurately estimate the virtual environment size. PMID:22184262

A New Method of Random Environmental Walking for Assessing Behavioral Preferences for Different Lighting Applications

PubMed Central

Patching, Geoffrey R.; Rahm, Johan; Jansson, Märit; Johansson, Maria

2017-01-01

Accurate assessment of people’s preferences for different outdoor lighting applications is increasingly considered important in the development of new urban environments. Here a new method of random environmental walking is proposed to complement current methods of assessing urban lighting applications, such as self-report questionnaires. The procedure involves participants repeatedly walking between different lighting applications by random selection of a lighting application and preferred choice or by random selection of a lighting application alone. In this manner, participants are exposed to all lighting applications of interest more than once and participants’ preferences for the different lighting applications are reflected in the number of times they walk to each lighting application. On the basis of an initial simulation study, to explore the feasibility of this approach, a comprehensive field test was undertaken. The field test included random environmental walking and collection of participants’ subjective ratings of perceived pleasantness (PP), perceived quality, perceived strength, and perceived flicker of four lighting applications. The results indicate that random environmental walking can reveal participants’ preferences for different lighting applications that, in the present study, conformed to participants’ ratings of PP and perceived quality of the lighting applications. As a complement to subjectively stated environmental preferences, random environmental walking has the potential to expose behavioral preferences for different lighting applications. PMID:28337163

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

PubMed

Evensen, Natalie M; Kvåle, Alice; Braekken, Ingeborg H

2015-09-01

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. 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. 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). 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. Copyright © 2015 John Wiley & Sons, Ltd.

Walk on Floor Eyes Closed Test: A Unique Test of Spaceflight Induced Ataxia

NASA Technical Reports Server (NTRS)

Reschke, M. F.; Fisher, E. A.; Kofman, I. S.; Cerisano, J. M.; Harm, D. L.; Bloomberg, J. J.

2011-01-01

Measurement and quantification of posture and locomotion following spaceflight is an evolving process. Based on the data obtained from the current investigation we believe that the walk on the floor line test with the eyes closed (WOFEC) provides a unique procedure for quantifying postflight ataxia. As a part of an ongoing investigation designed to look at functional changes in astronauts returning from spaceflight seven astronauts (5 short duration with flights of 12-16 days; 2 long duration crewmembers with flights of 6 months) were tested twice before flight, on landing day (short duration only), and 1, 6, and 30 days after flight. The WOFEC consisted of walking for 10 steps (repeated twice) with the feet heel to toe in tandem, arms folded across the chest and the eyes closed. The performance metric (scored by three examiners from video) was the percentage of correct steps completed over the three trials. A step was not counted as correct if the crewmember side-stepped, opened their eyes, or paused for more than three seconds between steps. The data reveled a significant decrease in percentage of correct steps on landing day (short duration crew) and on the first day following landing (long duration) with partial recovery the following day, and full recovery beginning on day sixth after flight. Both short and long duration fliers appeared to be unaware of foot position relative to their bodies or the floor. Postflight, deviation from a straight path was common, and seemed to be determined by the angle of foot placement relative to their body. While deviation from a straight line could be either left or right, primary deviations were observed to occur to the right. Furthermore, the test for two crewmembers elicited motion sickness symptoms. These data clearly demonstrate the sensorimotor challenges facing crewmembers after returning from spaceflight. The WOFEC test has value providing the investigator or crew surgeon with a simple method to quantify vestibular

Random walks with shape prior for cochlea segmentation in ex vivo μCT.

PubMed

Ruiz Pujadas, Esmeralda; Kjer, Hans Martin; Piella, Gemma; Ceresa, Mario; González Ballester, Miguel Angel

2016-09-01

Cochlear implantation is a safe and effective surgical procedure to restore hearing in deaf patients. However, the level of restoration achieved may vary due to differences in anatomy, implant type and surgical access. In order to reduce the variability of the surgical outcomes, we previously proposed the use of a high-resolution model built from [Formula: see text] images and then adapted to patient-specific clinical CT scans. As the accuracy of the model is dependent on the precision of the original segmentation, it is extremely important to have accurate [Formula: see text] segmentation algorithms. We propose a new framework for cochlea segmentation in ex vivo [Formula: see text] images using random walks where a distance-based shape prior is combined with a region term estimated by a Gaussian mixture model. The prior is also weighted by a confidence map to adjust its influence according to the strength of the image contour. Random walks is performed iteratively, and the prior mask is aligned in every iteration. We tested the proposed approach in ten [Formula: see text] data sets and compared it with other random walks-based segmentation techniques such as guided random walks (Eslami et al. in Med Image Anal 17(2):236-253, 2013) and constrained random walks (Li et al. in Advances in image and video technology. Springer, Berlin, pp 215-226, 2012). Our approach demonstrated higher accuracy results due to the probability density model constituted by the region term and shape prior information weighed by a confidence map. The weighted combination of the distance-based shape prior with a region term into random walks provides accurate segmentations of the cochlea. The experiments suggest that the proposed approach is robust for cochlea segmentation.

Heart rate recovery post 6-minute walking test in obstructive sleep apnea: cycle ergometry versus 6-minute walking test in OSA patients.

PubMed

Cholidou, Kyriaki G; Manali, Effrosyni D; Kapsimalis, Fotis; Kostakis, Ioannis D; Vougas, Konstantinos; Simoes, Davina; Markozannes, Evaggelos; Vogiatzis, Ioannis; Bakakos, Petros; Koulouris, Nikolaos; Alchanatis, Manos

2014-10-01

To examine the clinical usefulness of heart rate recovery (HRR) post 6-minute walking test (6MWT) as a simple marker of cardiovascular risk in obstructive sleep apnea (OSA) patients in comparison to HRR post cycle ergometry, the validated and more sophisticated protocol. Seventy-four participants underwent full overnight polysomnography, cycle ergometry and 6MWT. The HRR at 1, 2 and 3 min (HRR-1, HRR-2 and HRR-3) 6MWT was compared to HRR at 1, 2, and 3 min post cycle ergometry in normal subjects and in moderate and severe OSA patients before and after 6-month CPAP treatment. The HRR-1, HRR-2 and HRR-3 in 6MWT were significantly different between normal, moderate and severe OSA patients with higher rates achieved in normal. The higher the severity of OSA the lower the HRR was. There were also no differences found between work rate and distance walked during cycle ergometry or 6MWT, respectively, concerning normal, moderate and severe OSA patients. Heart rate recovery was further associated with minimum saturation of oxygen during sleep independently of the duration of apnea episodes of BMI and ESS. The treatment with CPAP had a beneficial effect on HRR both post-6MWT and post cycle ergometry. Autonomic nervous system dysfunction in OSA can be found even with submaximal exertion. Heart rate recovery post-6MWT, such as HRR post cycle ergometry, was significantly impaired in OSA patients in comparison to normals and was favorably influenced from CPAP treatment. Furthermore, it was found to be more sensitive compared with distance walked in 6MWT in discriminating severity of OSA. The HRR post-6MWT was found to be an easily measured and reliable marker of OSA severity both before and after CPAP treatment.

Reliability and intensity of the six-minute walk test in healthy elderly subjects.

PubMed

Kervio, Gaelle; Carre, Francois; Ville, Nathalie S

2003-01-01

The 6-min walk test (6-MWT) is an easy and validated field test, generally used in patients to assess their physical capacity. We think that the 6-MWT could also be conducted in the same perspective in healthy subjects, aged 60-70 yr. However, little is known about the effect of the familiarization on the 6-MWT performance and the relative intensity of this test. The aims of this study were therefore to bring precision to the 6-MWT reliability and intensity in this population. METHODS; Over 3 d, 12 subjects performed two maximal exercise tests on treadmill and five 6-MWT (two in the morning and three in the afternoon) with a portable metabolic measurement system (Cosmed K4, Rome, Italy). The distance, walking speed, oxygen uptake (VO2 (max)), and heart rate (HR) values were measured during the 6-MWT. Distance, walking speed, and VO2(max) were only lower during the first two 6-MWT (respectively, P< 0.001, P< 0.001, and P< 0.05). HR was reliable from the first 6-MWT and was higher during the tests performed in the afternoon (P< 0.001). The intensity of the 6-MWT corresponded to 79.6 +/- 4.5% of the VO2(max), 85.8 +/- 2.5% of the HR (max), and 78.0 +/- 6.3% of the HR (reserve). Moreover, it was higher than the ventilatory threshold in each subject (P< 0.01). In healthy elderly subjects, the 6-MWT represents a submaximal exercise, but at almost 80% of the VO2(max). To be exploitable, two familiarization attempts are required to limit the learning effect. Finally, the 6-MWT time of day must be taken into account when assessing HR.

Simplified biased random walk model for RecA-protein-mediated homology recognition offers rapid and accurate self-assembly of long linear arrays of binding sites

NASA Astrophysics Data System (ADS)

Kates-Harbeck, Julian; Tilloy, Antoine; Prentiss, Mara

2013-07-01

Inspired by RecA-protein-based homology recognition, we consider the pairing of two long linear arrays of binding sites. We propose a fully reversible, physically realizable biased random walk model for rapid and accurate self-assembly due to the spontaneous pairing of matching binding sites, where the statistics of the searched sample are included. In the model, there are two bound conformations, and the free energy for each conformation is a weakly nonlinear function of the number of contiguous matched bound sites.

Development and Psychometric Testing of the Dogs and WalkinG Survey (DAWGS)

ERIC Educational Resources Information Center

Richards, Elizabeth A.; McDonough, Meghan H.; Edwards, Nancy E.; Lyle, Roseann M.; Troped, Philip J.

2013-01-01

Purpose: Dog owners represent 40% of the population, a promising audience to increase population levels of physical activity. The purpose of this study was to develop and test the psychometric properties of a new instrument to assess social-cognitive theory constructs related to dog walking. Method: Dog owners ("N" = 431) completed the…

Use of the six-minute walk test to characterize golden retriever muscular dystrophy.

PubMed

Acosta, Austin R; Van Wie, Emiko; Stoughton, William B; Bettis, Amanda K; Barnett, Heather H; LaBrie, Nicholas R; Balog-Alvarez, Cynthia J; Nghiem, Peter P; Cummings, Kevin J; Kornegay, Joe N

2016-12-01

Duchenne muscular dystrophy (DMD) is an X-linked recessive disorder in which loss of the dystrophin protein causes progressive skeletal/cardiac muscle degeneration and death within the third decade. For clinical trials and supportive animal studies, DMD disease progression and response to treatment must be established using outcome parameters (biomarkers). The 6-minute walk test (6MWT), defined as the distance an individual can walk in 6 minutes, is commonly used in DMD clinical trials and has been employed in dogs to characterize cardiac and respiratory disease severity. Building on methods established in DMD and canine clinical studies, we assessed the 6MWT in dogs with the DMD genetic homolog, golden retriever muscular dystrophy (GRMD). Twenty-one cross-bred golden retrievers were categorized as affected (DMD mutation and GRMD phenotype), carrier (female heterozygous for DMD mutation and no phenotype), and normal (wild type DMD gene and normal phenotype). When compared to grouped normal/carrier dogs, GRMD dogs walked shorter height-adjusted distances at 6 and 12 months of age and their distances walked declined with age. Percent change in creatine kinase after 6MWT was greater in GRMD versus normal/carrier dogs at 6 months, providing another potential biomarker. While these data generally support use of the 6MWT as a biomarker for preclinical GRMD treatment trials, there were certain limitations. Results of the 6MWT did not correlate with other outcome parameters for GRMD dogs when considered alone and an 80% increase in mean distance walked would be necessary to achieve satisfactory power. Copyright © 2016 Elsevier B.V. All rights reserved.

Beam walking can detect differences in walking balance proficiency across a range of sensorimotor abilities.

PubMed

Sawers, Andrew; Ting, Lena H

2015-02-01

The ability to quantify differences in walking balance proficiency is critical to curbing the rising health and financial costs of falls. Current laboratory-based approaches typically focus on successful recovery of balance while clinical instruments often pose little difficulty for all but the most impaired patients. Rarely do they test motor behaviors of sufficient difficulty to evoke failures in balance control limiting their ability to quantify balance proficiency. Our objective was to test whether a simple beam-walking task could quantify differences in walking balance proficiency across a range of sensorimotor abilities. Ten experts, ten novices, and five individuals with transtibial limb loss performed six walking trials across three different width beams. Walking balance proficiency was quantified as the ratio of distance walked to total possible distance. Balance proficiency was not significantly different between cohorts on the wide-beam, but clear differences between cohorts on the mid and narrow-beams were identified. Experts walked a greater distance than novices on the mid-beam (average of 3.63±0.04m verus 2.70±0.21m out of 3.66m; p=0.009), and novices walked further than amputees (1.52±0.20m; p=0.03). Amputees were unable to walk on the narrow-beam, while experts walked further (3.07±0.14m) than novices (1.55±0.26m; p=0.0005). A simple beam-walking task and an easily collected measure of distance traveled detected differences in walking balance proficiency across sensorimotor abilities. This approach provides a means to safely study and evaluate successes and failures in walking balance in the clinic or lab. It may prove useful in identifying mechanisms underlying falls versus fall recoveries. Copyright © 2015 Elsevier B.V. All rights reserved.

Variability in energy cost and walking gait during race walking in competitive race walkers.

PubMed

Brisswalter, J; Fougeron, B; Legros, P

1998-09-01

The aim of this study was to examine the variability of energy cost (Cw) and race walking gait after a 3-h walk at the competition pace in race walkers of the same performance level. Nine competitive race walkers were studied. In the same week, after a first test of VO2max determination, each subject completed two submaximal treadmill walks (6 min length, 0% grade, 12 km X h(-1) speed) before and after a 3-h overground test completed at the individual competition speed of the race walker. During the two submaximal tests, subjects were filmed between the 2nd and the 4th min, and physiological parameters were recorded between the 4th and the 6th min. Results showed two trends. On the one hand, we observed a significant and systematic increase in energy cost of walking (mean deltaCw = 8.4%), whereas no variation in the gait kinematics prescribed by the rules of race walking was recorded. On the other hand, this increase in metabolic energy demand was accompanied by variations of different magnitude and direction of stride length, of the excursion of the heel and of the maximal ankle flexion at toe-off among the race walkers. These results indicated that competitive race walkers are able to maintain their walking gait with exercise duration apart from a systematic increase in energy cost. Moreover, in this form of locomotion the effect of fatigue on the gait variability seems to be an individual function of the race walk constraints and the constraints of the performer.

Criterion-Related Validity of the Distance- and Time-Based Walk/Run Field Tests for Estimating Cardiorespiratory Fitness: A Systematic Review and Meta-Analysis

PubMed Central

Mayorga-Vega, Daniel; Bocanegra-Parrilla, Raúl; Ornelas, Martha; Viciana, Jesús

2016-01-01

Objectives The main purpose of the present meta-analysis was to examine the criterion-related validity of the distance- and time-based walk/run tests for estimating cardiorespiratory fitness among apparently healthy children and adults. Materials and Methods Relevant studies were searched from seven electronic bibliographic databases up to August 2015 and through other sources. The Hunter-Schmidt’s psychometric meta-analysis approach was conducted to estimate the population criterion-related validity of the following walk/run tests: 5,000 m, 3 miles, 2 miles, 3,000 m, 1.5 miles, 1 mile, 1,000 m, ½ mile, 600 m, 600 yd, ¼ mile, 15 min, 12 min, 9 min, and 6 min. Results From the 123 included studies, a total of 200 correlation values were analyzed. The overall results showed that the criterion-related validity of the walk/run tests for estimating maximum oxygen uptake ranged from low to moderate (rp = 0.42–0.79), with the 1.5 mile (rp = 0.79, 0.73–0.85) and 12 min walk/run tests (rp = 0.78, 0.72–0.83) having the higher criterion-related validity for distance- and time-based field tests, respectively. The present meta-analysis also showed that sex, age and maximum oxygen uptake level do not seem to affect the criterion-related validity of the walk/run tests. Conclusions When the evaluation of an individual’s maximum oxygen uptake attained during a laboratory test is not feasible, the 1.5 mile and 12 min walk/run tests represent useful alternatives for estimating cardiorespiratory fitness. As in the assessment with any physical fitness field test, evaluators must be aware that the performance score of the walk/run field tests is simply an estimation and not a direct measure of cardiorespiratory fitness. PMID:26987118

Criterion-Related Validity of the Distance- and Time-Based Walk/Run Field Tests for Estimating Cardiorespiratory Fitness: A Systematic Review and Meta-Analysis.

PubMed

Mayorga-Vega, Daniel; Bocanegra-Parrilla, Raúl; Ornelas, Martha; Viciana, Jesús

2016-01-01

The main purpose of the present meta-analysis was to examine the criterion-related validity of the distance- and time-based walk/run tests for estimating cardiorespiratory fitness among apparently healthy children and adults. Relevant studies were searched from seven electronic bibliographic databases up to August 2015 and through other sources. The Hunter-Schmidt's psychometric meta-analysis approach was conducted to estimate the population criterion-related validity of the following walk/run tests: 5,000 m, 3 miles, 2 miles, 3,000 m, 1.5 miles, 1 mile, 1,000 m, ½ mile, 600 m, 600 yd, ¼ mile, 15 min, 12 min, 9 min, and 6 min. From the 123 included studies, a total of 200 correlation values were analyzed. The overall results showed that the criterion-related validity of the walk/run tests for estimating maximum oxygen uptake ranged from low to moderate (rp = 0.42-0.79), with the 1.5 mile (rp = 0.79, 0.73-0.85) and 12 min walk/run tests (rp = 0.78, 0.72-0.83) having the higher criterion-related validity for distance- and time-based field tests, respectively. The present meta-analysis also showed that sex, age and maximum oxygen uptake level do not seem to affect the criterion-related validity of the walk/run tests. When the evaluation of an individual's maximum oxygen uptake attained during a laboratory test is not feasible, the 1.5 mile and 12 min walk/run tests represent useful alternatives for estimating cardiorespiratory fitness. As in the assessment with any physical fitness field test, evaluators must be aware that the performance score of the walk/run field tests is simply an estimation and not a direct measure of cardiorespiratory fitness.

The accuracy of assessment of walking distance in the elective spinal outpatients setting.

PubMed

Okoro, Tosan; Qureshi, Assad; Sell, Beulah; Sell, Philip

2010-02-01

Self reported walking distance is a clinically relevant measure of function. The aim of this study was to define patient accuracy and understand factors that might influence perceived walking distance in an elective spinal outpatients setting. A prospective cohort study. 103 patients were asked to perform one test of distance estimation and 2 tests of functional distance perception using pre-measured landmarks. Standard spine specific outcomes included the patient reported claudication distance, Oswestry disability index (ODI), Low Back Outcome Score (LBOS), visual analogue score (VAS) for leg and back, and other measures. There are over-estimators and under-estimators. Overall, the accuracy to within 9.14 metres (m) (10 yards) was poor at only 5% for distance estimation and 40% for the two tests of functional distance perception. Distance: Actual distance 111 m; mean response 245 m (95% CI 176.3-314.7), Functional test 1 actual distance 29.2 m; mean response 71.7 m (95% CI 53.6-88.9) Functional test 2 actual distance 19.6 m; mean response 47.4 m (95% CI 35.02-59.95). Surprisingly patients over 60 years of age (n = 43) are twice as accurate with each test performed compared to those under 60 (n = 60) (average 70% overestimation compared to 140%; p = 0.06). Patients in social class I (n = 18) were more accurate than those in classes II-V (n = 85): There was a positive correlation between poor accuracy and increasing MZD (Pearson's correlation coefficient 0.250; p = 0.012). ODI, LBOS and other parameters measured showed no correlation. Subjective distance perception and estimation is poor in this population. Patients over 60 and those with a professional background are more accurate but still poor.

Validation of one-mile walk equations for the estimation of aerobic fitness in British military personnel under the age of 40 years.

PubMed

Lunt, Heather; Roiz De Sa, Daniel; Roiz De Sa, Julia; Allsopp, Adrian

2013-07-01

To provide an accurate estimate of peak oxygen uptake (VO2 peak) for British Royal Navy Personnel aged between 18 and 39, comparing a gold standard treadmill based maximal exercise test with a submaximal one-mile walk test. Two hundred military personnel consented to perform a treadmill-based VO2 peak test and two one-mile walk tests round an athletics track. The estimated VO2 peak values from three different one-mile walk equations were compared to directly measured VO2 peak values from the treadmill-based test. One hundred participants formed a validation group from which a new equation was derived and the other 100 participants formed the cross-validation group. Existing equations underestimated the VO2 peak values of the fittest personnel and overestimated the VO2 peak of the least aerobically fit by between 2% and 18%. The new equation derived from the validation group has less bias, the highest correlation with the measured values (r = 0.83), and classified the most people correctly according to the Royal Navy's Fitness Test standards, producing the fewest false positives and false negatives combined (9%). The new equation will provide a more accurate estimate of VO2 peak for a British military population aged 18 to 39. Reprint & Copyright © 2013 Association of Military Surgeons of the U.S.

Measuring Steady-State Oxygen Uptake during the 6-Min Walk Test in Adults with Cerebral Palsy: Feasibility and Construct Validity

ERIC Educational Resources Information Center

Maltais, Desiree B.; Robitaille, Nancy-Michelle; Dumas, Francine; Boucher, Normand; Richards, Carol L.

2012-01-01

This study evaluated the feasibility of measuring steady-state oxygen uptake (V[Combining Dot Above]O[subscript 2]) during the 6-min walk test (6MWT) in adults with cerebral palsy (CP) who walk without support and whether there is construct validity for net 6MWT V[Combining Dot Above]O[subscript 2] as a measure of their walking ability.…

Analysis of 6-minute walk test safety in pre-heart transplantation patients.

PubMed

Cipriano, Gerson; Yuri, Darlene; Bernardelli, Graziella França; Mair, Vanessa; Buffolo, Enio; Branco, João Nelson Rodrigues

2009-04-01

The 6-minute walk test (6WT) has been used as a means of assessment of the functional capacity, clinical staging and cardiovascular prognosis. Its safety and metabolic impact have not been frequently described in the literature, especially in patients with severe heart failure with clinical indication for cardiovascular transplantation. To evaluate the occurrence of arrhythmias and cardiovascular changes during 6WT. To correlate 6WT performance with clinical staging and cardiovascular prognosis. Twelve patients, 10 of whom males, aged 52 +/- 8 years were evaluated at baseline. 6WT was performed with telemetry electrocardiography, vital signs and lactate monitoring. The patients were followed-up for 12 months. The patients walked 399.4+/-122.5 (D, m), reaching a perceived exertion (PE) of 14.3+/-1.5 and a 34% baseline heart rate variation. Two patients presented more severe pre-6WT arrhythmia which did not worsen with the exercise, four patients presented a significant increase of blood lactate levels (>5 mmol/dl), and three interrupted the test. The distance walked correlated with the ejection fraction (%) and functional class (NYHA). After 12-month follow-up, three patients died and seven were rehospitalized for cardiac decompensation. The D/PE ratio and 2-minute heart rate recovery (HRR2, bpm) were lower in the death group. The clinical and electrocardiographic behaviors suggest that the method is safe, but it may be considered too strenuous for some patients with severe heart failure. Variables related to 6WT performance may be associated with the one-year follow-up mortality.

Anxiety sensitivity predicts increased perceived exertion during a 1-mile walk test among treatment-seeking smokers.

PubMed

Farris, Samantha G; Uebelacker, Lisa A; Brown, Richard A; Price, Lawrence H; Desaulniers, Julie; Abrantes, Ana M

2017-12-01

Smoking increases risk of early morbidity and mortality, and risk is compounded by physical inactivity. Anxiety sensitivity (fear of anxiety-relevant somatic sensations) is a cognitive factor that may amplify the subjective experience of exertion (effort) during exercise, subsequently resulting in lower engagement in physical activity. We examined the effect of anxiety sensitivity on ratings of perceived exertion (RPE) and physiological arousal (heart rate) during a bout of exercise among low-active treatment-seeking smokers. Adult daily smokers (n = 157; M age  = 44.9, SD = 11.13; 69.4% female) completed the Rockport 1.0 mile submaximal treadmill walk test. RPE and heart rate were assessed during the walk test. Multi-level modeling was used to examine the interactive effect of anxiety sensitivity × time on RPE and on heart rate at five time points during the walk test. There were significant linear and cubic time × anxiety sensitivity effects for RPE. High anxiety sensitivity was associated with greater initial increases in RPE during the walk test, with stabilized ratings towards the last 5 min, whereas low anxiety sensitivity was associated with lower initial increase in RPE which stabilized more quickly. The linear time × anxiety sensitivity effect for heart rate was not significant. Anxiety sensitivity is associated with increasing RPE during moderate-intensity exercise. Persistently rising RPE observed for smokers with high anxiety sensitivity may contribute to the negative experience of exercise, resulting in early termination of bouts of prolonged activity and/or decreased likelihood of future engagement in physical activity.

Reproducibility and responsiveness of quality of life assessment and six minute walk test in elderly heart failure patients.

PubMed

O'Keeffe, S T; Lye, M; Donnellan, C; Carmichael, D N

1998-10-01

To examine the reproducibility and responsiveness to change of a six minute walk test and a quality of life measure in elderly patients with heart failure. Longitudinal within patient study. 60 patients with heart failure (mean age 82 years) attending a geriatric outpatient clinic, 45 of whom underwent a repeat assessment three to eight weeks later. Subjects underwent a standardised six minute walk test and completed the chronic heart failure questionnaire (CHQ), a heart failure specific quality of life questionnaire. Intraclass correlation coefficients (ICC) were calculated using a random effects one way analysis of variance as a measure of reproducibility. Guyatt's responsiveness coefficient and effect sizes were calculated as measures of responsiveness to change. 24 patients reported no major change in cardiac status, while seven had deteriorated and 14 had improved between the two clinic visits. Reproducibility was satisfactory (ICC > 0.75) for the six minute walk test, for the total CHQ score, and for the dyspnoea, fatigue, and emotion domains of the CHQ. Effect sizes for all measures were large (> 0.8), and responsiveness coefficients were very satisfactory (> 0.7). Effect sizes for detecting deterioration were greater than those for detecting improvement. Quality of life assessment and a six minute walk test are reproducible and responsive measures of cardiac status in frail, very elderly patients with heart failure.

Walk test and school performance in mouth-breathing children.

PubMed

Boas, Ana Paula Dias Vilas; Marson, Fernando Augusto de Lima; Ribeiro, Maria Angela Gonçalves de Oliveira; Sakano, Eulália; Conti, Patricia Blau Margosian; Toro, Adyléia Dalbo Contrera; Ribeiro, José Dirceu

2013-01-01

In recent decades, many studies on mouth breathing (MB) have been published; however, little is known about many aspects of this syndrome, including severity, impact on physical and academic performances. Compare the physical performance in a six minutes walk test (6MWT) and the academic performance of MB and nasal-breathing (NB) children and adolescents. This is a descriptive, cross-sectional, and prospective study with MB and NB children submitted to the 6MWT and scholar performance assessment. We included 156 children, 87 girls (60 NB and 27 MB) and 69 boys (44 NB and 25 MB). Variables were analyzed during the 6MWT: heart rate (HR), respiratory rate, oxygen saturation, distance walked in six minutes and modified Borg scale. All the variables studied were statistically different between groups NB and MB, with the exception of school performance and HR in 6MWT. MB affects physical performance and not the academic performance, we noticed a changed pattern in the 6MWT in the MB group. Since the MBs in our study were classified as non-severe, other studies comparing the academic performance variables and 6MWT are needed to better understand the process of physical and academic performances in MB children.

[Trail walking test for assessment of motor cognitive interference in older adults. Development and evaluation of the psychometric properties of the procedure].

PubMed

Schott, Nadja

2015-12-01

Activities of daily living (ADL), such as walking, often involve the added complexity of walking while doing other activities (i.e. dual task walking). A complex walking task may require a greater motor and mental capacity, resulting in decrements in gait performance not seen for simple walking tasks. The purpose of this study was to determine if the trail walking test (TWT), the mobile adaptation of the trail making test (TMT), could be a reliable and valid early detection tool to discriminate between non-fallers and fallers. This study examined dual task costs of a cognitive and a sensorimotor task (walking) in 94 older adults aged 50-81 years (average age M = 67.4 years, SD ± 7.34). Based on the idea of the paper and pencil TMT, participants walked along a fixed pathway (TWT-1), stepped on targets with increasing sequential numbers (i.e. 1, 2, 3, TWT-2), and increasing sequential numbers and letters (i.e. 1, A, 2, B, 3, C, TWT-3). The dual task costs were calculated for each task. Additionally, the following tests were conducted: TMT, block tapping test (BTT), timed up and go (TUG) test, 30s chair rising test, 10 m walking time test with and without head turns, German physical activity questionnaire (German PAQ-50 +) and the activities-specific balance confidence (ABC-D) scale. The TWT performance times as well as errors increased with increasing age. Reliability coefficients were high (interclass correlation ICC > 0.90). Correlations between the different TWT conditions and potential falls-related predictors were moderate to high (r = -0.430 to 0.699). Of the participants 34 % reported falling in the past year. The stepwise logistic regression analysis revealed that the dual task costs for the numbers and letters (odds ratio OR 1.162, 95 % confidence interval CI 1.058-1.277, p = 0.002), the ABC-D (OR 0.767, 95 % CI 0.651-0.904, p = 0.002) and exercise (OR 1.027, 95 % CI 1.008-1.046, p = 0.006) were significantly related to

Increasing Walking in the Hartsfield-Jackson Atlanta International Airport: The Walk to Fly Study.

PubMed

Fulton, Janet E; Frederick, Ginny M; Paul, Prabasaj; Omura, John D; Carlson, Susan A; Dorn, Joan M

2017-07-01

To test the effectiveness of a point-of-decision intervention to prompt walking, versus motorized transport, in a large metropolitan airport. We installed point-of-decision prompt signage at 4 locations in the airport transportation mall at Hartsfield-Jackson Atlanta International Airport (Atlanta, GA) at the connecting corridor between airport concourses. Six ceiling-mounted infrared sensors counted travelers entering and exiting the study location. We collected traveler counts from June 2013 to May 2016 when construction was present and absent (preintervention period: June 2013-September 2014; postintervention period: September 2014-May 2016). We used a model that incorporated weekly walking variation to estimate the intervention effect on walking. There was an 11.0% to 16.7% relative increase in walking in the absence of airport construction where 580 to 810 more travelers per day chose to walk. Through May 2016, travelers completed 390 000 additional walking trips. The Walk to Fly study demonstrated a significant and sustained increase in the number of airport travelers choosing to walk. Providing signage about options to walk in busy locations where reasonable walking options are available may improve population levels of physical activity and therefore improve public health.

Neural decoding of treadmill walking from noninvasive electroencephalographic signals

PubMed Central

Presacco, Alessandro; Goodman, Ronald; Forrester, Larry

2011-01-01

Chronic recordings from ensembles of cortical neurons in primary motor and somatosensory areas in rhesus macaques provide accurate information about bipedal locomotion (Fitzsimmons NA, Lebedev MA, Peikon ID, Nicolelis MA. Front Integr Neurosci 3: 3, 2009). Here we show that the linear and angular kinematics of the ankle, knee, and hip joints during both normal and precision (attentive) human treadmill walking can be inferred from noninvasive scalp electroencephalography (EEG) with decoding accuracies comparable to those from neural decoders based on multiple single-unit activities (SUAs) recorded in nonhuman primates. Six healthy adults were recorded. Participants were asked to walk on a treadmill at their self-selected comfortable speed while receiving visual feedback of their lower limbs (i.e., precision walking), to repeatedly avoid stepping on a strip drawn on the treadmill belt. Angular and linear kinematics of the left and right hip, knee, and ankle joints and EEG were recorded, and neural decoders were designed and optimized with cross-validation procedures. Of note, the optimal set of electrodes of these decoders were also used to accurately infer gait trajectories in a normal walking task that did not require subjects to control and monitor their foot placement. Our results indicate a high involvement of a fronto-posterior cortical network in the control of both precision and normal walking and suggest that EEG signals can be used to study in real time the cortical dynamics of walking and to develop brain-machine interfaces aimed at restoring human gait function. PMID:21768121

Over ground walking and body weight supported walking improve mobility equally in cerebral palsy: a randomised controlled trial.

PubMed

Swe, Ni Ni; Sendhilnnathan, Sunitha; van Den Berg, Maayken; Barr, Christopher

2015-11-01

To assess partial body weight supported treadmill training versus over ground training for walking ability in children with mild to moderate cerebral palsy. Randomised controlled trial. A Special Needs school in Singapore. Thirty children with cerebral palsy, aged 6-18, with a Gross Motor Function Classification System score of II-III. Two times 30 minute sessions of walking training per week for 8 weeks, progressed as tolerated, either over ground (control) or using partial body weight supported treadmill training (intervention). The 10 metre walk test, and the 6 minute walk test. Secondary measures were sub-sections D and E on the Gross Motor Function Measure. Outcomes were assessed at baseline, and after 4 and 8 weeks of training. There was no effect of group allocation on any outcome measure, while time was a significant factor for all outcomes. Walking speed improved significantly more in the intervention group by week 4 (0.109 (0.067)m/s vs 0.048 (0.071)m/s, P=0.024) however by week 8 the change from baseline was similar (intervention 0.0160 (0.069)m/s vs control 0.173 (0.109)m/s, P=0.697). All gains made by week 4 were significantly improved on by week 8 for the 10 metre walk test, 6 minute walk test, and the gross motor function measure. Partial body weight supported treadmill training is no more effective than over ground walking at improving aspects of walking and function in children with mild to moderate cerebral palsy. Gains seen in 4 weeks can be furthered by 8 weeks. © The Author(s) 2015.

Perceived barriers to walking for physical activity.

PubMed

Dunton, Genevieve F; Schneider, Margaret

2006-10-01

Although the health benefits of walking for physical activity have received increasing research attention, barriers specific to walking are not well understood. In this study, questions to measure barriers to walking for physical activity were developed and tested among college students. The factor structure, test-retest and internal consistency reliability, and discriminant and criterion validity of the perceived barriers were evaluated. A total of 305 undergraduate students participated. Participants had a mean age (+/- SD) of 20.6 (+/- 3.02) years, and 70.3% were female. Participants responded to a questionnaire assessing barriers specific to walking for physical activity. Perceived barriers to vigorous exercise, walking for transportation and recreation, and participation in lifestyle activities (such as taking the stairs instead of the elevator) were also assessed. Subsamples completed the walking barriers instrument a second time after 5 days in order to determine test-retest reliability (n = 104) and wore an accelerometer to measure moderate-intensity physical activity (n = 85). Factor analyses confirmed the existence of three factors underlying the perceived barriers to walking questions: appearance (four items), footwear (three items), and situation (three items). Appearance and situational barriers demonstrated acceptable reliability, discriminant validity, and relations with physical activity criteria. After we controlled for barriers to vigorous exercise, appearance and situational barriers to walking explained additional variation in objectively-measured moderate physical activity. The prediction of walking for physical activity, especially walking that is unstructured and spontaneous, may be improved by considering appearance and situational barriers. Assessing barriers specific to walking may have important implications for interventions targeting walking as means for engaging in physical activity.

Tracking Steps on Apple Watch at Different Walking Speeds.

PubMed

Veerabhadrappa, Praveen; Moran, Matthew Duffy; Renninger, Mitchell D; Rhudy, Matthew B; Dreisbach, Scott B; Gift, Kristin M

2018-04-09

QUESTION: How accurate are the step counts obtained from Apple Watch? In this validation study, video steps vs. Apple Watch steps (mean ± SD) were 2965 ± 144 vs. 2964 ± 145 steps; P < 0.001. Lin's concordance correlation coefficient showed a strong correlation (r = 0.96; P < 0.001) between the two measurements. There was a total error of 0.034% (1.07 steps) for the Apple Watch steps when compared with the manual counts obtained from video recordings. Our study is one of the initial studies to objectively validate the accuracy of the step counts obtained from Apple watch at different walking speeds. Apple Watch tested to be an extremely accurate device for measuring daily step counts for adults.

Is one trial enough for repeated testing? Same-day assessments of walking, mobility and fine hand use in people with myotonic dystrophy type 1.

PubMed

Kierkegaard, Marie; Petitclerc, Emilie; Hébert, Luc J; Gagnon, Cynthia

2017-02-01

Performance-based assessments of physical function are essential in people with myotonic dystrophy type 1 (DM1) to monitor disease progression and evaluate interventions. Commonly used are the six-minute walk test, the 10 m-walk test, the timed up-and-go test, the timed-stands test, grip strength tests and the nine-hole peg test. The number of trials needed on a same-day test occasion and whether the first, best or average of trials should be reported as result is unknown. Thus, the aim was to describe and explore differences between trials in these measures of walking, mobility and fine hand use in 70 adults with DM1. Three trials were performed for each test except for the six-minute walk test where two trials were allowed. There were statistical significant differences over trials in all tests except for the 10 m-walk test and grip strength tests. Pair-wise comparisons showed that the second and third trials were in general better than the first, although effect sizes were small. At which trial the individuals performed their best differed between individuals and tests. People with severe muscular impairment had difficulties to perform repeated trials. Intraclass correlation coefficients were all high in analyses exploring how to report results. The conclusion and clinical implication is that, for a same-day test occasion, one trial is sufficient for the 10 m-walk test and grip strength tests, and that repeated trials should be allowed in the timed up-and-go test, timed-stands test and nine-hole peg tests. We recommend that two trials are performed for these latter tests as such a protocol could accommodate people with various levels of impairments and physical limitations. Copyright © 2016 Elsevier B.V. All rights reserved.

Field Test: Results of Tandem Walk Performance Following Long-Duration Spaceflight

NASA Technical Reports Server (NTRS)

Rosenberg, M. J. F.; Reschke, M. F.; Cerisano, J. M.; Kofman, I. S.; Fisher, E. A.; Gadd, N. E.; May-Phillips, T. R.; Lee, S. M. C.; Laurie, S. S.; Stenger, M. B.;

Sensory substitution information informs locomotor adjustments when walking through apertures.

PubMed

Kolarik, Andrew J; Timmis, Matthew A; Cirstea, Silvia; Pardhan, Shahina

2014-03-01

The study assessed the ability of the central nervous system (CNS) to use echoic information from sensory substitution devices (SSDs) to rotate the shoulders and safely pass through apertures of different width. Ten visually normal participants performed this task with full vision, or blindfolded using an SSD to obtain information regarding the width of an aperture created by two parallel panels. Two SSDs were tested. Participants passed through apertures of +0, +18, +35 and +70 % of measured body width. Kinematic indices recorded movement time, shoulder rotation, average walking velocity across the trial, peak walking velocities before crossing, after crossing and throughout a whole trial. Analyses showed participants used SSD information to regulate shoulder rotation, with greater rotation associated with narrower apertures. Rotations made using an SSD were greater compared to vision, movement times were longer, average walking velocity lower and peak velocities before crossing, after crossing and throughout the whole trial were smaller, suggesting greater caution. Collisions sometimes occurred using an SSD but not using vision, indicating that substituted information did not always result in accurate shoulder rotation judgements. No differences were found between the two SSDs. The data suggest that spatial information, provided by sensory substitution, allows the relative position of aperture panels to be internally represented, enabling the CNS to modify shoulder rotation according to aperture width. Increased buffer space indicated by greater rotations (up to approximately 35 % for apertures of +18 % of body width) suggests that spatial representations are not as accurate as offered by full vision.

Pedometer accuracy in slow walking older adults.

PubMed

Martin, Jessica B; Krč, Katarina M; Mitchell, Emily A; Eng, Janice J; Noble, Jeremy W

2012-07-03

The purpose of this study was to determine pedometer accuracy during slow overground walking in older adults (Mean age = 63.6 years). A total of 18 participants (6 males, 12 females) wore 5 different brands of pedometers over 3 pre-set cadences that elicited walking speeds between 0.3 and 0.9 m/s and one self-selected cadence over 80 meters of indoor track. Pedometer accuracy decreased with slower walking speeds with mean percent errors across all devices combined of 56%, 40%, 19% and 9% at cadences of 50, 66, and 80 steps/min, and self selected cadence, respectively. Percent error ranged from 45.3% for Omron HJ105 to 66.9% for Yamax Digiwalker 200. Due to the high level of error across the slowest cadences of all 5 devices, the use of pedometers to monitor step counts in healthy older adults with slower gait speeds is problematic. Further research is required to develop pedometer mechanisms that accurately measure steps at slower walking speeds.

The performance of stroke survivors in turning-while-walking while carrying out a concurrent cognitive task compared with controls.

PubMed

Chan, Wing-Nga; Tsang, William Wai-Nam

2017-01-01

Turning-while-walking is one of the commonest causes of falls in stroke survivors. It involves cognitive processing and may be challenging when performed concurrently with a cognitive task. Previous studies of dual-tasking involving turning-while-walking in stroke survivors show that the performance of physical tasks is compromised. However, the design of those studies did not address the response of stroke survivors under dual-tasking condition without specifying the task-preference and its effect on the performance of the cognitive task. First, to compare the performance of single-tasking and dual-tasking in stroke survivors. Second, to compare the performance of stroke survivors with non-stroke controls. Fifty-nine stroke survivors and 45 controls were assessed with an auditory Stroop test, a turning-while-walking test, and a combination of the two single tasks. The outcome of the cognitive task was measured by the reaction time and accuracy of the task. The physical task was evaluated by measuring the turning duration, number of steps to turn, and time to complete the turning-while-walking test. Stroke survivors showed a significantly reduced accuracy in the auditory Stroop test when dual-tasking, but there was no change in the reaction time. Their performance in the turning-while-walking task was similar under both single-tasking and dual-tasking condition. Additionally, stroke survivors demonstrated a significantly longer reaction time and lower accuracy than the controls both when single-tasking and dual-tasking. They took longer to turn, with more steps, and needed more time to complete the turning-while-walking task in both tasking conditions. The results show that stroke survivors with high mobility function performed the auditory Stroop test less accurately while preserving simultaneous turning-while-walking performance. They also demonstrated poorer performance in both single-tasking and dual-tasking as compared with controls.

Feasibility and Reliability of Two Different Walking Tests in People with Severe Intellectual and Sensory Disabilities

ERIC Educational Resources Information Center

Waninge, A.; Evenhuis, I. J.; van Wijck, R.; van der Schans, C. P.

2011-01-01

Background: The purpose of this study is to describe feasibility and test-retest reliability of the six-minute walking distance test (6MWD) and an adapted shuttle run test (aSRT) in persons with severe intellectual and sensory (multiple) disabilities. Materials and Methods: Forty-seven persons with severe multiple disabilities, with Gross Motor…

Does the 6-minute walk test predict the prognosis in patients with NYHA class II or III chronic heart failure?

PubMed

Roul, G; Germain, P; Bareiss, P

1998-09-01

We prospectively evaluated the potential of the 6-minute walk test compared with peak VO2 in predicting outcome of patients with New York Heart Association (NYHA) class II or III heart failure. Patients with a history of heart failure caused by systolic dysfunction were included. The combined final outcome (death or hospitalization for heart failure) was used as the judgment criterion. One hundred twenty-one patients (age 59+/-11 years; left ventricular ejection fraction 29.6%+/-13%) were included and followed for 1.53+/-0.98 years. Patients were separated into two groups according to outcome: group 1 (G1, 74 patients), without events, and group 2 (G2, 47 patients), who reached the combined end point. Peak VO2 was clearly different between G1 and G2 (18.5+/-4 vs. 13.9+/-4 ml/kg/min, p=0.0001) but not the distance walked (448+/-92 vs 410+/-126 m; p=0.084, not significant). Survival analysis showed that unlike peak VO2, the distance covered was barely distinguishable between the groups (p < 0.08). However, receiver operating characteristic curves revealed that the best performances for the 6-minute walk test were obtained for subjects walking < or =300 m. These patients had a worse prognosis than those walking farther (p=0.013). In this subset of patients, there was a significant correlation between distance covered and peak VO2 (r=0.65, p=0.011). Thus it appears that the more severely affected patients have a daily activity level relatively close to their maximal exercise capacity. Nevertheless, the 300 m threshold suggested by this study needs to be validated in an independent population. A distance walked in 6 minutes < or =300 m can predict outcome. Moreover, in these cases there is a significant correlation between the 6-minute walk test and peak VO2 demonstrating the potential of this simple procedure as a first-line screening test for this subset of patients.

[Clinical application of the "Stop walking while talking test". Relationship with geriatric assessment parameters and other tests of balance and gait].

PubMed

González-Ávila, Bárbara; Roqueta, Cristina; Farriols, Cristina; Álvaro, Margarita; Roig, Alba; Cervera, Anton Maria; Miralles, Ramón

To assess the relationship between the Stop Walking While Talking (SWWT) test and some parameters of the geriatric assessment, as well as other tests of balance and gait. A prospective, observational and cross-sectional study conducted on 108 patients (62% women), with a mean age of 80.5±8.4 years. Twenty-three of them were living at home, 24 in a nursing home, and 61 in an intermediate care unit. A record was made of the Barthel index, Mini-Mental State Examination of Folstein (MMSE), comorbidity (Charlson index), the presence of previous falls, and fear of falling. Timed Up and Go (TUG), Tinetti test, and Stop Walking While Talking (SWWT) test, were performed on all the patients. Based on the results of the SWWT test patients were divided in two groups: "stoppers" and "non-stoppers". All patients were able to walk (with or without walking aids). The stoppers group of patients had a mean age 82.2±8.7; Barthel index 64.6±20.7; MMSE 21.6±5.1; Charlson index 1.8±1.7, and the non-stoppers 78.5±7.6 (P=.024), 86.0±18.1 (P<.001), 24.3±4.0 (P=.004), and 1.3±1.6 (P=.130), respectively. Of the 58 stoppers patients, 39 (67.2%) had a previous fall, and 19 (32.8%) had not (P=.002); 43 (74.1%) had fear of falling, and 15 (25.9%) had not (P<0.009). Of the 63 patients with TUG>20seconds, 52 (82.5%) were stoppers and 11 (17.5%) non-stoppers. Of the 31 with TUG between 10-20seconds, 5 (16.1%) were stoppers and 26 (83.9%) non-stoppers. Of the 14 with TUG<10 seconds, 1 (7.1%) were stoppers, and 13 (92.9%) non-stoppers (P<0.0001). The score of Tinetti test in the stoppers group was 15.4±5.2, and in non-stoppers 23.9±4.6 (P<0.001). Those in the stopper group were significantly older, were more dependent in activities of daily living, had greater cognitive impairment, more previous falls, had greater fear of falling, lower scores on the Tinetti test, and longer times in the TUG. Copyright © 2016 SEGG. Publicado por Elsevier España, S.L.U. All rights reserved.

Path integration: effect of curved path complexity and sensory system on blindfolded walking.

PubMed

Koutakis, Panagiotis; Mukherjee, Mukul; Vallabhajosula, Srikant; Blanke, Daniel J; Stergiou, Nicholas

2013-02-01

Path integration refers to the ability to integrate continuous information of the direction and distance traveled by the system relative to the origin. Previous studies have investigated path integration through blindfolded walking along simple paths such as straight line and triangles. However, limited knowledge exists regarding the role of path complexity in path integration. Moreover, little is known about how information from different sensory input systems (like vision and proprioception) contributes to accurate path integration. The purpose of the current study was to investigate how sensory information and curved path complexity affect path integration. Forty blindfolded participants had to accurately reproduce a curved path and return to the origin. They were divided into four groups that differed in the curved path, circle (simple) or figure-eight (complex), and received either visual (previously seen) or proprioceptive (previously guided) information about the path before they reproduced it. The dependent variables used were average trajectory error, walking speed, and distance traveled. The results indicated that (a) both groups that walked on a circular path and both groups that received visual information produced greater accuracy in reproducing the path. Moreover, the performance of the group that received proprioceptive information and later walked on a figure-eight path was less accurate than their corresponding circular group. The groups that had the visual information also walked faster compared to the group that had proprioceptive information. Results of the current study highlight the roles of different sensory inputs while performing blindfolded walking for path integration. Copyright © 2012 Elsevier B.V. All rights reserved.

The Not-so-Random Drunkard's Walk

ERIC Educational Resources Information Center

Ehrhardt, George

2013-01-01

This dataset contains the results of a quasi-experiment, testing Karl Pearson's "drunkard's walk" analogy for an abstract random walk. Inspired by the alternate hypothesis that drunkards stumble to the side of their dominant hand, it includes data on intoxicated test subjects walking a 10' line. Variables include: the…

76 FR 48745 - Energy Conservation Program: Compliance Date Regarding the Test Procedures for Walk-In Coolers...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-09

...), specified a test procedure that must be followed when determining the insulation value of the insulating... tests must be performed on walk-in panels and when tests may be performed on insulation foam used in the... WICF doors: The door type, R-value of the door insulation, and a declaration that the manufacturer has...

Relationship between oxygen cost of walking and level of walking disability after stroke: An experimental study.

PubMed

Polese, Janaine C; Ada, Louise; Teixeira-Salmela, Luci F

2018-01-01

Since physical inactivity is the major risk factor for recurrent stroke, it is important to understand how level of disability impacts oxygen uptake by people after stroke. This study investigated the nature of the relationship between level of disability and oxygen cost in people with chronic stroke. Level of walking disability was measured as comfortable walking speed using the 10-m Walk Test reported in m/s with 55 ambulatory people 2 years after stroke. Oxygen cost was measured during 3 walking tasks: overground walking at comfortable speed, overground walking at fast speed, and stair walking at comfortable speed. Oxygen cost was calculated from oxygen uptake divided by distance covered during walking and reported in ml∙kg -1 ∙m -1 . The relationship between level of walking disability and oxygen cost was curvilinear for all 3 walking tasks. One quadratic model accounted for 81% (95% CI [74, 88]) of the variance in oxygen cost during the 3 walking tasks: [Formula: see text] DISCUSSION: The oxygen cost of walking was related the level of walking disability in people with chronic stroke, such that the more disabled the individual, the higher the oxygen cost of walking; with oxygen cost rising sharply as disability became severe. An equation that relates oxygen cost during different walking tasks according to the level of walking disability allows clinicians to determine oxygen cost indirectly without the difficulty of measuring oxygen uptake directly. Copyright © 2017 John Wiley & Sons, Ltd.

The two-minute walk test as a measure of functional capacity in cardiac surgery patients.

PubMed

Brooks, Dina; Parsons, Janet; Tran, Diem; Jeng, Bonnie; Gorczyca, Barbara; Newton, Janet; Lo, Vincent; Dear, Cheryl; Silaj, Ellen; Hawn, Therese

2004-09-01

To examine construct validity and sensitivity of the two-minute walk test (2MWT) in cardiac surgery patients. Measurements were made in patients preoperatively, during the postoperative in-hospital stay, and 6 to 8 weeks after discharge from hospital. Ambulatory and hospitalized care. Patients (N=122; mean age +/- standard deviation, 63+/-9 y) undergoing coronary artery bypass grafting. Not applicable. The 2MWT, New York Heart Association (NYHA) functional classification for cardiac disease, the Nottingham Extended Activities of Daily Living scale, and the Medical Outcomes Survey 36-Item Short-Form Health Questionnaire (SF-36). Distance walked in 2 minutes decreased significantly postoperatively (from 138+/-26 m to 84+/-33 m, P<.001), but increased again at follow-up (151+/-31 m, P<.0001). Distance walked on the 2MWT correlated significantly to SF-36 (physical function subscale) preoperatively (r=.44) and at follow-up (r=.48) (P<.001). There was a significant difference in distance walked between those with NYHA class I and II compared with those classified as III or IV (P=.04). However, there was no significant difference in distance walked in 2 minutes between those who developed cardiac or pulmonary complications postoperatively (P> or =0.2). The 2MWT was sensitive to change after cardiac surgery and showed moderate correlation with measures of physical functioning in this population. However, the 2MWT could not identify those who developed complications in the postoperative period.

76 FR 65362 - Energy Conservation Program: Compliance Date Regarding the Test Procedures for Walk-In Coolers...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-21

..., and refrigeration systems. See 76 FR 21580 (April 15, 2011) (final rule prescribing walk-in test...-Conditioning, Heating, and Refrigeration Institute (AHRI) did not agree with DOE's proposal to set the test... manufacturers to provide the panel's U-factor if the panel manufacturer is not providing refrigeration systems...

Effects of a 6-month exercise program pilot study on walking economy, peak physiological characteristics, and walking performance in patients with peripheral arterial disease.

PubMed

Crowther, Robert G; Leicht, Anthony S; Spinks, Warwick L; Sangla, Kunwarjit; Quigley, Frank; Golledge, Jonathan

2012-01-01

The purpose of this study was to examine the effects of a 6-month exercise program on submaximal walking economy in individuals with peripheral arterial disease and intermittent claudication (PAD-IC). Participants (n = 16) were randomly allocated to either a control PAD-IC group (CPAD-IC, n = 6) which received standard medical therapy, or a treatment PAD-IC group (TPAD-IC; n = 10) which took part in a supervised exercise program. During a graded treadmill test, physiological responses, including oxygen consumption, were assessed to calculate walking economy during submaximal and maximal walking performance. Differences between groups at baseline and post-intervention were analyzed via Kruskal-Wallis tests. At baseline, CPAD-IC and TPAD-IC groups demonstrated similar walking performance and physiological responses. Postintervention, TPAD-IC patients demonstrated significantly lower oxygen consumption during the graded exercise test, and greater maximal walking performance compared to CPAD-IC. These preliminary results indicate that 6 months of regular exercise improves both submaximal walking economy and maximal walking performance, without significant changes in maximal walking economy. Enhanced walking economy may contribute to physiological efficiency, which in turn may improve walking performance as demonstrated by PAD-IC patients following regular exercise programs.

Walking and cognition, but not symptoms, correlate with dual task cost of walking in multiple sclerosis.

PubMed

Motl, Robert W; Sosnoff, Jacob J; Dlugonski, Deirdre; Pilutti, Lara A; Klaren, Rachel; Sandroff, Brian M

2014-03-01

Performing a cognitive task while walking results in a reduction of walking performance among persons with MS. To date, very little is known about correlates of this dual task cost (DTC) of walking in MS. We examined walking performance, cognitive processing speed, and symptoms of fatigue, depression, anxiety, and pain as correlates of DTC of walking in MS. 82 persons with MS undertook a 6-min walk test (6MWT) and completed the Symbol Digit Modalities Test (SDMT), Fatigue Severity Scale (FSS), Short-form of the McGill Pain Questionnaire (SF-MPQ), Hospital Anxiety and Depression Scale (HADS), and self-reported Expanded Disability Status Scale (SR-EDSS). The participants completed 4 trials of walking at a self-selected pace on an electronic walkway that recorded spatiotemporal parameters of gait. The first 2 trials were performed without a cognitive task, whereas the second 2 trials were completed while performing a modified Word List Generation task. There were significant and large declines in gait performance with the addition of a cognitive task for velocity (p<.001, η2=.52), cadence (p<.001, η2=.49), and step length (p<.001, η2=.23). 6MWT and SDMT scores correlated with DTC for velocity (r=-.41, p<.001 and r=-.32, p<.001, respectively) and step length (r=-.45, p<.001 and r=-.37, p<.001, respectively); there were no significant associations between FSS, SF-MPQ, and HADS scores with the DTC of walking. Regression analyses indicated that 6MW, but not SDMT, explained variance in DTC for velocity (ΔR2=.11, p<.001) and step length (ΔR2=.13, p<.001), after controlling for SR-EDSS scores. Walking performance might be a target of interventions for reducing the DTC of walking in MS. Copyright © 2013 Elsevier B.V. All rights reserved.

Walk on Floor Eyes Closed Test as a Measure of Postflight Ataxia

NASA Technical Reports Server (NTRS)

Reschke, M. F.; Fisher, E. A.; Kofman, I. S.; Cerisano, J. M.; Harm, D.L.; Peters, B. T.; Bloomberg, J. J.

2010-01-01

INTRODUCTION: Astronauts returning from space flight universally exhibit impaired posture and locomotion. Measurement of this impairment is an evolving process. The walk on the floor line test with the eyes closed (WOFEC) provides a unique procedure for quantifying postflight ataxia. Data from a modified WOFEC were obtained as part of an ongoing NASA interdisciplinary pre- and postflight study (Functional Task Test, FTT) designed to evaluate astronaut postflight functional performance. METHODS: Seven astronauts (5 short duration with flights of 12-16 days; 2 long duration crewmembers with flights of 6 months) were tested twice before flight, on landing day (short duration only), and 1, 6, and 30 days after flight. The WOFEC consisted of walking for 10 steps (repeated twice) with the feet heel to toe in tandem, arms folded across the chest and the eyes closed. The performance metric (scored by three examiners from video) was the percentage of correct steps completed over the three trials. A step was not counted as correct if the crewmember sidestepped, opened their eyes, or paused for more than three seconds between steps. RESULTS/ CONCLUSIONS: There was a significant decrease in percentage of correct steps on landing day (short duration crew) and on first day following landing (long duration) with partial recovery the following day, and full recovery beginning on day sixth after flight. Both short and long duration fliers appeared to be unaware of foot position relative to their bodies or the floor. Postflight, deviation from a straight path was common, and the test for two crewmembers elicited motion sickness symptoms. These data clearly demonstrate the sensorimotor challenges facing crewmembers after returning from spaceflight. The WOFEC test has value providing the investigator or crew surgeon with a simple method to quantify vestibular ataxia, as well as providing instant feedback of postural ataxia without the use of complex test equipment.

The Relationship Between Walking Capacity, Biopsychosocial Factors, Self-Efficacy and Walking Activity in Individuals Post Stroke

PubMed Central

Danks, Kelly A.; Pohlig, Ryan T.; Roos, Margie; Wright, Tamara R.; Reisman, Darcy S.

2016-01-01

Background/Purpose Many factors appear to be related to physical activity after stroke, yet it is unclear how these factors interact and which ones might be the best predictors. Therefore, the purpose of this study was twofold: 1) to examine the relationship between walking capacity and walking activity, and 2) to investigate how biopsychosocial factors and self-efficacy relate to walking activity, above and beyond walking capacity impairment post-stroke. Methods Individuals greater than 3 months post-stroke (n=55) completed the Yesavage Geriatric Depression Scale (GDS), Fatigue Severity Scale (FSS), Modified Cumulative Illness Rating (MCIR) Scale, Walk 12, Activities Specific Balance Confidence (ABC) Scale, Functional Gait Assessment (FGA), and oxygen consumption testing. Walking activity data was collected via a StepWatch Activity Monitor (SAM). Predictors were grouped into 3 constructs: (1) Walking Capacity: oxygen consumption and FGA; (2) Biopsychosocial: GDS, FSS, and MCIR; (3) Self-Efficacy: Walk 12 and ABC. Moderated sequential regression models were used to examine what factors best predicted walking activity. Results Walking capacity explained 35.9% (p<0.001) of the variance in walking activity. Self-efficacy (ΔR2 = 0.15, p<0.001) and the interaction between the FGA*ABC (ΔR2 = 0.047, p<0.001) significantly increased the variability explained. FGA (β=0.37, p=0.01), MCIR (β=−0.26, p=0.01), and Walk 12 (β=−0.45, p=0.00) were each individually significantly associated with walking activity. Discussion/Conclusion While measures of walking capacity and self-efficacy significantly contributed to "real-world" walking activity, balance self-efficacy moderated the relationship between walking capacity and walking activity. Improving low balance self-efficacy may augment walking capacity and translate to improved walking activity post-stroke. PMID:27548750

Pedometer accuracy in slow walking older adults

PubMed Central

Martin, Jessica B.; Krč, Katarina M.; Mitchell, Emily A.; Eng, Janice J.; Noble, Jeremy W.

2013-01-01

The purpose of this study was to determine pedometer accuracy during slow overground walking in older adults (Mean age = 63.6 years). A total of 18 participants (6 males, 12 females) wore 5 different brands of pedometers over 3 pre-set cadences that elicited walking speeds between 0.3 and 0.9 m/s and one self-selected cadence over 80 meters of indoor track. Pedometer accuracy decreased with slower walking speeds with mean percent errors across all devices combined of 56%, 40%, 19% and 9% at cadences of 50, 66, and 80 steps/min, and self selected cadence, respectively. Percent error ranged from 45.3% for Omron HJ105 to 66.9% for Yamax Digiwalker 200. Due to the high level of error across the slowest cadences of all 5 devices, the use of pedometers to monitor step counts in healthy older adults with slower gait speeds is problematic. Further research is required to develop pedometer mechanisms that accurately measure steps at slower walking speeds. PMID:24795762

Testing self-regulation interventions to increase walking using factorial randomized N-of-1 trials.

PubMed

Sniehotta, Falko F; Presseau, Justin; Hobbs, Nicola; Araújo-Soares, Vera

2012-11-01

To investigate the suitability of N-of-1 randomized controlled trials (RCTs) as a means of testing the effectiveness of behavior change techniques based on self-regulation theory (goal setting and self-monitoring) for promoting walking in healthy adult volunteers. A series of N-of-1 RCTs in 10 normal and overweight adults ages 19-67 (M = 36.9 years). We randomly allocated 60 days within each individual to text message-prompted daily goal-setting and/or self-monitoring interventions in accordance with a 2 (step-count goal prompt vs. alternative goal prompt) × 2 (self-monitoring: open vs. blinded Omron-HJ-113-E pedometer) factorial design. Aggregated data were analyzed using random intercept multilevel models. Single cases were analyzed individually. The primary outcome was daily pedometer step counts over 60 days. Single-case analyses showed that 4 participants significantly increased walking: 2 on self-monitoring days and 2 on goal-setting days, compared with control days. Six participants did not benefit from the interventions. In aggregated analyses, mean step counts were higher on goal-setting days (8,499.9 vs. 7,956.3) and on self-monitoring days (8,630.3 vs. 7,825.9). Multilevel analyses showed a significant effect of the self-monitoring condition (p = .01), the goal-setting condition approached significance (p = .08), and there was a small linear increase in walking over time (p = .03). N-of-1 randomized trials are a suitable means to test behavioral interventions in individual participants.

The CHOICE study: a "taste-test" of utilitarian vs. leisure walking among older adults.

PubMed

Hekler, Eric B; Castro, Cynthia M; Buman, Matthew P; King, Abby C

2012-01-01

Utilitarian walking (e.g., walking for transport) and leisure walking (e.g., walking for health/recreation) are encouraged to promote health, yet few studies have explored specific preferences for these two forms of physical activity or factors that impact such preferences. A quasi-experimental crossover design was used to evaluate how training underactive midlife and older adults in each type of walking impacted total steps taken and how it was linked to their subsequent choice of walking types. Participants (N = 16) were midlife and older adults (M age = 64 ± 8 years) who were mostly women (81%) and white (75%). To control for order effects, participants were randomized to instruction in either utilitarian or leisure walking for 2 weeks and then the other type for 2 weeks. Participants then entered a 2-week "free choice" phase in which they chose any mixture of the walking types. Outcome variables included walking via OMRON pedometer and the ratio of utilitarian versus leisure walking during the free-choice phase. Participants completed surveys about their neighborhood (NEWS) and daily travel to multiple locations. Instruction in leisure-only, utilitarian-only, and a freely chosen mixture of the two each resulted in significant increases in steps taken relative to baseline (ps < 0.05). Having to go to multiple locations daily and traveling greater distances to locations were associated with engagement in more utilitarian walking. In contrast, good walking paths, neighborhood aesthetics, easy access to exercise facilities, and perceiving easier access to neighborhood services were associated with more leisure walking. Results from this pilot study suggest that midlife and older adults may most easily meet guidelines through either leisure only or a mixture of leisure and utilitarian walking, and tailored suggestions based on the person's neighborhood may be useful.

Energy cost of walking: solving the paradox of steady state in the presence of variable walking speed.

PubMed

Plasschaert, Frank; Jones, Kim; Forward, Malcolm

2009-02-01

Measurement of the energy cost of walking in children with cerebral palsy is used for baseline and outcome assessment. However, such testing relies on the establishment of steady state that is deemed present when oxygen consumption is stable. This is often assumed when walking speed is constant but in practice, speed can and does vary naturally. Whilst constant speed is achievable on a treadmill, this is often impractical clinically, thus rendering an energy cost test to an element of subjectivity. This paper attempts to address this issue by presenting a new method for calculating energy cost of walking that automatically applies a mathematically defined threshold for steady state within a (non-treadmill) walking trial and then strips out all of the non-steady state events within that trial. The method is compared with a generic approach that does not remove non-steady state data but rather uses an average value over a complete walking trial as is often used in the clinical environment. Both methods were applied to the calculation of several energy cost of walking parameters of self-selected walking speed in a cohort of unimpaired subjects and children with cerebral palsy. The results revealed that both methods were strongly correlated for each parameter but showed systematic significant differences. It is suggested that these differences are introduced by the rejection of non-steady state data that would otherwise have incorrectly been incorporated into the calculation of the energy cost of walking indices during self-selected walking with its inherent speed variation.

Gait Evaluation of Overground Walking and Treadmill Walking Using Compass-Type Walking Model

NASA Astrophysics Data System (ADS)

Nagata, Yousuke; Yamamoto, Masayoshi; Funabiki, Shigeyuki

A treadmill is a useful apparatus for the gait training and evaluation. However, many differences are reported between treadmill and overground walking. Experimental comparisons of the muscle activity of the leg and the heart rate have been carried out. However, the dynamic comparison has not been performed. The dynamic evaluation of the overground walking and the treadmill walking using a compass-type walking model (CTWM) which is a simple bipedal walking model, then their comparison is discussed. It is confirmed that the walking simulation using the CTWM can simulate the difference of that walk, it is clarified that there are the differences of the kick impulse on the ground and the turning impulse of the foot to the variation of the belt speed and then differences are the main factor of two walking.

Evaluating Walking in Patients with Multiple Sclerosis

PubMed Central

Bennett, Susan

2011-01-01

Walking limitations are among the most visible manifestations of multiple sclerosis (MS). Regular walking assessments should be a component of patient management and require instruments that are appropriate from the clinician's and the patient's perspectives. This article reviews frequently used instruments to assess walking in patients with MS, with emphasis on their validity, reliability, and practicality in the clinical setting. Relevant articles were identified based on PubMed searches using the following terms: “multiple sclerosis AND (walking OR gait OR mobility OR physical activity) AND (disability evaluation)”; references of relevant articles were also searched. Although many clinician- and patient-driven instruments are available, not all have been validated in MS, and some are not sensitive enough to detect small but clinically important changes. Choosing among these depends on what needs to be measured, psychometric properties, the clinical relevance of results, and practicality with respect to space, time, and patient burden. Of the instruments available, the clinician-observed Timed 25-Foot Walk and patient self-report 12-Item Multiple Sclerosis Walking Scale have properties that make them suitable for routine evaluation of walking performance. The Dynamic Gait Index and the Timed Up and Go test involve other aspects of mobility, including balance. Tests of endurance, such as the 2- or 6-Minute Walk, may provide information on motor fatigue not captured by other tests. Quantitative measurement of gait kinetics and kinematics, and recordings of mobility in the patient's environment via accelerometry or Global Positioning System odometry, are currently not routinely used in the clinical setting. PMID:24453700

Reference equations for 6-min walk test in healthy Indian subjects (25-80 years).

PubMed

Palaniappan Ramanathan, Ramanathan; Chandrasekaran, Baskaran

2014-01-01

Six-min walk test (6MWT), a simple functional capacity evaluation tool used globally to determine the prognosis and effectiveness of any therapeutic/medical intervention. However, variability in reference equations derived from western population (due to racial and ethnicity variations) hinders from adequate use of 6MWT clinically. Further, there are no valid Indian studies that predict reference values for 6-min walk distance (6MWD) in healthy Indian normal. We aimed for framing individualized reference equations for 6MWT in healthy Indian population. Anthropometric variables (age, weight, height, and body mass index (BMI)) and 6-min walk in a 30 m corridor were evaluated in 125 subjects (67 females) in a cross-sectional trial. 6MWD significantly correlated with age (r = -0.29), height (r = 0.393), weight (r = 0.08), and BMI (r = -0.17). The gender specific reference equations for healthy Indian individuals were: (1) Males: 561.022 - (2.507 × age [years]) + (1.505 × weight [kg]) - (0.055 × height [cm]). R (2) = 0.288. (2) Indian females: 30.325 - (0.809 × age [years]) - (2.074 × weight [kg]) + (4.235 × height [cm]). R (2) = 0.272. Though the equations possess a small coefficient of determination and larger standard error estimate, the former applicability to Indian population is justified. These reference equations are probably most appropriate for evaluating the walked capacity of Indian patients with chronic diseases.

Immediate effects of transcutaneous electrical nerve stimulation on six-minute walking test, Borg scale questionnaire and hemodynamic responses in patients with chronic heart failure.

PubMed

Ganguie, Majid Ashraf; Moghadam, Behrouz Attarbashi; Ghotbi, Nastaran; Shadmehr, Azadeh; Masoumi, Mohammad

2017-12-01

[Purpose] This study examined the immediate effects of transcutaneous electrical nerve stimulation on a six-minute walking test, Borg scale questionnaire and hemodynamic responses in patients with chronic heart failure. [Subjects and Methods] Thirty patients with stable systolic chronic heart failure came to the pathophysiology laboratory three times. The tests were randomly performed in three sessions. In one session, current was applied to the quadriceps muscles of both extremities for 30 minutes and a six-minute walking test was performed immediately afterward. In another session, the same procedure was followed except that the current intensity was set to zero. In the third session, the patients walked for six minutes without application of a current. The distance covered in each session was measured. At the end of each session, the subjects completed a Borg scale questionnaire. [Results] The mean distance traveled in the six-minute walking test and the mean score of the Borg scale questionnaire were significantly different across sessions. The mean systolic and diastolic pressures showed no significant differences across sessions. [Conclusion] The increase in distance traveled during the six-minute walking test and decrease in fatigue after the use of current may be due to a decrease in sympathetic overactivity and an increase in peripheral and muscular microcirculation in these patients.

Immediate effects of transcutaneous electrical nerve stimulation on six-minute walking test, Borg scale questionnaire and hemodynamic responses in patients with chronic heart failure

PubMed Central

Ganguie, Majid Ashraf; Moghadam, Behrouz Attarbashi; Ghotbi, Nastaran; Shadmehr, Azadeh; Masoumi, Mohammad

2017-01-01

[Purpose] This study examined the immediate effects of transcutaneous electrical nerve stimulation on a six-minute walking test, Borg scale questionnaire and hemodynamic responses in patients with chronic heart failure. [Subjects and Methods] Thirty patients with stable systolic chronic heart failure came to the pathophysiology laboratory three times. The tests were randomly performed in three sessions. In one session, current was applied to the quadriceps muscles of both extremities for 30 minutes and a six-minute walking test was performed immediately afterward. In another session, the same procedure was followed except that the current intensity was set to zero. In the third session, the patients walked for six minutes without application of a current. The distance covered in each session was measured. At the end of each session, the subjects completed a Borg scale questionnaire. [Results] The mean distance traveled in the six-minute walking test and the mean score of the Borg scale questionnaire were significantly different across sessions. The mean systolic and diastolic pressures showed no significant differences across sessions. [Conclusion] The increase in distance traveled during the six-minute walking test and decrease in fatigue after the use of current may be due to a decrease in sympathetic overactivity and an increase in peripheral and muscular microcirculation in these patients. PMID:29643590

Six-minute walking test predicts maximal fat oxidation in obese children.

PubMed

Makni, E; Moalla, W; Trabelsi, Y; Lac, G; Brun, J F; Tabka, Z; Elloumi, M

2012-07-01

Obesity is associated with reduced exercise maximal fat oxidation rate (FATmax), which is generally assessed by cardiopulmonary cycling test. The six-minute walking test (6MWT) presents an alternative method in patients. The aim of this study was to establish a practical reference equation facilitating the prediction of FATmax from the 6 MWT in obese children of both genders. This study is a cross-sectional study using mixed linear and multiple regression models. Anthropometric measurements were recorded and submaximal cycling test and 6 MWT conducted for 131 school-aged obese children, 68 boys and 63 girls. A multiple regression analysis for FATmax, including six-minute walking distance (6 MWD), anthropometric and cardiac parameters as the dependent variables, was performed for the two genders separately. Mean 6 MWD and FATmax were 564.9 ± 53.7 m and 126.5 ± 12.1 mg min(-1) for boys and 506.7 ± 55.0 m and 120.7 ± 10.0 mg min(-1) for girls, respectively. The 6MWD, body mass index, Z-score, fat-free mass, waist and hip circumferences (WC and HC), rest heart rate, and systolic and diastolic blood pressures were highly correlated with FATmax for both genders. There was a significant correlation between 6 MWD and FATmax in both boys and girls (r = 0.88 and r = 0.81, P<0.001, respectively). Stepwise regression analyses revealed that the combinations of 6 MWD with HC for boys and 6MWD with WC for girls improved the predictability of the model (R(2) = 0.81 for boys and R(2) = 0.72 for girls; P<0.001). In obese children, the 6MWT can be used to predict FATmax when formal test of exercise capacity and gas exchange analysis are unavailable or impractical. It is therefore possible to prescript targeted exercises at FATmax, without performing indirect calorimetry, just from a field test.

Reliability and validity of the 6-min walk test in adults and seniors with intellectual disabilities.

PubMed

Guerra-Balic, Myriam; Oviedo, Guillermo R; Javierre, Casimiro; Fortuño, Jesús; Barnet-López, Silvia; Niño, Oscar; Alamo, Juan; Fernhall, Bo

2015-12-01

Adults with intellectual disabilities (ID) have significantly lower rates of physical activity and fitness than adults without ID. The 6-min walk test (6 MWT) is an inexpensive and simple way to test mobility and submaximal work capacity. To evaluate the test-retest reliability and validity of the 6 MWT in adults and seniors with ID and explore factors contributing to the 6 MWT distance (6 MWD). 46 participants with mild, moderate and severe ID levels (age=41 ± 11 years) performed the 6 MWT three times (T1; T2; T3) to determine test-retest reliability. To test validity, peak oxygen uptake (VO2 peak) was measured using a treadmill protocol. To analyze factors contributing to the 6 MWD, sex, height, fat mass % and fat free mass %, ID level, isometric leg strength and relative VO2 peak were also measured. The walking distances for T1, T2 and T3 were 460.3 ± 76.9; 489.4 ± 81.2 and 491.4 ± 77.9 m, respectively. The 6 MWDs between T1-T2 and T1-T3 were significantly different (p<0.001), but T2 and T3 were not different. The intraclass correlation coefficient between T2 and T3 was 0.96 indicating high reliability. Relative VO2 peak and isometric leg strength significantly contributed to the 6 MWD (R(2)=0.55). The 6 MWT is an easy, inexpensive, reliable and valid test in adults and seniors with ID. Familiarization is necessary to obtain reliable values. Relative VO2 peak and leg strength have significant impact on the distance walked. Copyright © 2015 Elsevier Ltd. All rights reserved.

Reproducibility of the six-minute walking test in chronic heart failure patients.

PubMed

Pinna, G D; Opasich, C; Mazza, A; Tangenti, A; Maestri, R; Sanarico, M

2000-11-30

The six-minute walking test (WT) is used in trials and clinical practice as an easy tool to evaluate the functional capacity of chronic heart failure (CHF) patients. As WT measurements are highly variable both between and within individuals, this study aims at assessing the contribution of the different sources of variation and estimating the reproducibility of the test. A statistical model describing WT measurements as a function of fixed and random effects is proposed and its parameters estimated. We considered 202 stable CHF patients who performed two baseline WTs separated by a 30 minute rest; 49 of them repeated the two tests 3 months later (follow-up control). They had no changes in therapy or major clinical events. Another 31 subjects performed two baseline tests separated by 24 hours. Collected data were analysed using a mixed model methodology. There was no significant difference between measurements taken 30 minutes and 24 hours apart (p = 0.99). A trend effect of 17 (1.4) m (mean (SE)) was consistently found between duplicate tests (p < 0.001). REML estimates of variance components were: 5189 (674) for subject differences in the error-free value; 1280 (304) for subject differences in spontaneous clinical evolution between baseline and follow-up control, and 266 (23) for the within-subject error. Hence, the standard error of measurement was 16.3 m, namely 4 per cent of the average WT performance (403 m) in this sample. The intraclass correlation coefficient was 0.96. We conclude that WT measurements are characterized by good intrasubject reproducibility and excellent reliability. When follow-up studies > or = 3 months are performed, unpredictable changes in individual walking performance due to spontaneous clinical evolution are to be expected. Their clinical significance, however, is not known. Copyright 2000 John Wiley & Sons, Ltd.

Race walking gait and its influence on race walking economy in world-class race walkers.

PubMed

Gomez-Ezeiza, Josu; Torres-Unda, Jon; Tam, Nicholas; Irazusta, Jon; Granados, Cristina; Santos-Concejero, Jordan

2018-03-06

The aim of this study was to determine the relationships between biomechanical parameters of the gait cycle and race walking economy in world-class Olympic race walkers. Twenty-One world-class race walkers possessing the Olympic qualifying standard participated in this study. Participants completed an incremental race walking test starting at 10 km·h -1 , where race walking economy (ml·kg -1 ·km -1 ) and spatiotemporal gait variables were analysed at different speeds. 20-km race walking performance was related to race walking economy, being the fastest race walkers those displaying reduced oxygen cost at a given speed (R = 0.760, p < 0.001). Longer ground contact times, shorter flight times, longer midstance sub-phase and shorter propulsive sub-phase during stance were related to a better race walking economy (moderate effect, p < 0.05). According to the results of this study, the fastest race walkers were more economi cal than the lesser performers. Similarly, shorter flight times are associated with a more efficient race walking economy. Coaches and race walkers should avoid modifying their race walking style by increasing flight times, as it may not only impair economy, but also lead to disqualification.

Walking Robot Locomotion System Conception

NASA Astrophysics Data System (ADS)

Ignatova, D.; Abadjieva, E.; Abadjiev, V.; Vatzkitchev, Al.

2014-09-01

This work is a brief analysis on the application and perspective of using the walking robots in different areas in practice. The most common characteristics of walking four legs robots are presented here. The specific features of the applied actuators in walking mechanisms are also shown in the article. The experience of Institute of Mechanics - BAS is illustrated in creation of Spiroid and Helicon1 gears and their assembly in actuation of studied robots. Loading on joints reductors of robot legs is modelled, when the geometrical and the walking parameters of the studied robot are preliminary defined. The obtained results are purposed for designing the control of the loading of reductor type Helicon in the legs of the robot, when it is experimentally tested.

Reproducibility and Validity of the 6-Minute Walk Test Using the Gait Real-Time Analysis Interactive Lab in Patients with COPD and Healthy Elderly

PubMed Central

Meijer, Kenneth; Delbressine, Jeannet M.; Willems, Paul J.; Franssen, Frits M. E.; Wouters, Emiel F. M.; Spruit, Martijn A.

2016-01-01

Background The 6-minute walk test (6MWT) in a regular hallway is commonly used to assess functional exercise capacity in patients with chronic obstructive pulmonary disease (COPD). However, treadmill walking might provide additional advantages over overground walking, especially if virtual reality and self-paced treadmill walking are combined. Therefore, this study aimed to assess the reproducibility and validity of the 6MWT using the Gait Real-time Analysis Interactive Lab (GRAIL) in patients with COPD and healthy elderly. Methodology/Results Sixty-one patients with COPD and 48 healthy elderly performed two 6MWTs on the GRAIL. Patients performed two overground 6MWTs and healthy elderly performed one overground test. Differences between consecutive 6MWTs and the test conditions (GRAIL vs. overground) were analysed. Patients walked further in the second overground test (24.8 m, 95% CI 15.2–34.4 m, p<0.001) and in the second GRAIL test (26.8 m, 95% CI 13.9–39.6 m). Healthy elderly improved their second GRAIL test (49.6 m, 95% CI 37.0–62.3 m). The GRAIL 6MWT was reproducible (intra-class coefficients = 0.65–0.80). The best GRAIL 6-minute walk distance (6MWD) in patients was shorter than the best overground 6MWD (-27.3 ± 49.1 m, p<0.001). Healthy elderly walked further on the GRAIL than in the overground condition (23.6 ± 41.4 m, p<0.001). Validity of the GRAIL 6MWT was assessed and intra-class coefficient values ranging from 0.74–0.77 were found. Conclusion The GRAIL is a promising system to assess the 6MWD in patients with COPD and healthy elderly. The GRAIL 6MWD seems to be more comparable to the 6MWDs assessed overground than previous studies on treadmills have reported. Furthermore, good construct validity and reproducibility were established in assessing the 6MWD using the GRAIL in patients with COPD and healthy elderly. PMID:27607426

Relation between random walks and quantum walks

NASA Astrophysics Data System (ADS)

Boettcher, Stefan; Falkner, Stefan; Portugal, Renato

2015-05-01

Based on studies of four specific networks, we conjecture a general relation between the walk dimensions dw of discrete-time random walks and quantum walks with the (self-inverse) Grover coin. In each case, we find that dw of the quantum walk takes on exactly half the value found for the classical random walk on the same geometry. Since walks on homogeneous lattices satisfy this relation trivially, our results for heterogeneous networks suggest that such a relation holds irrespective of whether translational invariance is maintained or not. To develop our results, we extend the renormalization-group analysis (RG) of the stochastic master equation to one with a unitary propagator. As in the classical case, the solution ρ (x ,t ) in space and time of this quantum-walk equation exhibits a scaling collapse for a variable xdw/t in the weak limit, which defines dw and illuminates fundamental aspects of the walk dynamics, e.g., its mean-square displacement. We confirm the collapse for ρ (x ,t ) in each case with extensive numerical simulation. The exact values for dw themselves demonstrate that RG is a powerful complementary approach to study the asymptotics of quantum walks that weak-limit theorems have not been able to access, such as for systems lacking translational symmetries beyond simple trees.

Reliability and Concurrent Validity of the Narrow Path Walking Test in Persons With Multiple Sclerosis.

PubMed

Rosenblum, Uri; Melzer, Itshak

2017-01-01

About 90% of people with multiple sclerosis (PwMS) have gait instability and 50% fall. Reliable and clinically feasible methods of gait instability assessment are needed. The study investigated the reliability and validity of the Narrow Path Walking Test (NPWT) under single-task (ST) and dual-task (DT) conditions for PwMS. Thirty PwMS performed the NPWT on 2 different occasions, a week apart. Number of Steps, Trial Time, Trial Velocity, Step Length, Number of Step Errors, Number of Cognitive Task Errors, and Number of Balance Losses were measured. Intraclass correlation coefficients (ICC2,1) were calculated from the average values of NPWT parameters. Absolute reliability was quantified from standard error of measurement (SEM) and smallest real difference (SRD). Concurrent validity of NPWT with Functional Reach Test, Four Square Step Test (FSST), 12-item Multiple Sclerosis Walking Scale (MSWS-12), and 2 Minute Walking Test (2MWT) was determined using partial correlations. Intraclass correlation coefficients (ICCs) for most NPWT parameters during ST and DT ranged from 0.46-0.94 and 0.55-0.95, respectively. The highest relative reliability was found for Number of Step Errors (ICC = 0.94 and 0.93, for ST and DT, respectively) and Trial Velocity (ICC = 0.83 and 0.86, for ST and DT, respectively). Absolute reliability was high for Number of Step Errors in ST (SEM % = 19.53%) and DT (SEM % = 18.14%) and low for Trial Velocity in ST (SEM % = 6.88%) and DT (SEM % = 7.29%). Significant correlations for Number of Step Errors and Trial Velocity were found with FSST, MSWS-12, and 2MWT. In persons with PwMS performing the NPWT, Number of Step Errors and Trial Velocity were highly reliable parameters. Based on correlations with other measures of gait instability, Number of Step Errors was the most valid parameter of dynamic balance under the conditions of our test.Video Abstract available for more insights from the authors (see Supplemental Digital Content 1, available at: http

Oxygen desaturation in healthy subjects undergoing the incremental shuttle walk test*

PubMed Central

Seixas, Daniel Machado; Seixas, Daniela Miti Tsukumo; Pereira, Monica Corso; Moreira, Marcos Mello; Paschoal, Ilma Aparecida

2013-01-01

OBJECTIVE: To determine the probability of oxygen desaturation in healthy individuals undergoing the incremental shuttle walk test (ISWT). METHODS: We enrolled 83 healthy subjects: 55 males (including 1 smoker) and 28 females. We determined pre-ISWT FEV1, FEV6, HR and SpO2, as well as post-ISWT HR and SpO2. RESULTS: Mean values overall were as follows: age, 35.05 ± 12.53 years; body mass index, 24.30 ± 3.47 kg/m2; resting HR, 75.12 ± 12.48 bpm; resting SpO2, 97.96 ± 1.02%; FEV1, 3.75 ± 0.81 L; FEV6, 4.45 ± 0.87 L; FEV1/FEV6 ratio, 0.83 ± 0.08 (no restriction or obstruction); incremental shuttle walk distance, 958.30 ± 146.32 m; post-ISWT HR, 162.41 ± 18.24 bpm; and post-ISWT SpO2, 96.27 ± 2.21%. In 11 subjects, post-ISWT SpO2 was higher than was pre-ISWT SpO2. In 17 subjects, there was a 4% decrease in SpO2 after the ISWT. There were no statistically significant differences between the groups with and without post-ISWT oxygen desaturation in terms of age, gender, FEV1, FEV6, FEV1/FEV6, pre-ISWT SpO2, incremental shuttle walk distance, HR, or percentage of maximal HR. In the individuals with post-ISWT oxygen desaturation, the body mass index was higher (p = 0.01) and post-ISWT SpO2 was lower (p = 0.0001). CONCLUSIONS: Healthy individuals can present oxygen desaturation after the ISWT. Using the ISWT to predict subtle respiratory abnormalities can be misleading. In healthy subjects, oxygen desaturation is common after the ISWT, as it is during any intense physical activity. PMID:24068265

Cell phones change the way we walk.

PubMed

Lamberg, Eric M; Muratori, Lisa M

2012-04-01

Cell phone use among pedestrians leads to increased cognitive distraction, reduced situation awareness and increases in unsafe behavior. Performing a dual-task, such as talking or texting with a cell phone while walking, may interfere with working memory and result in walking errors. At baseline, thirty-three participants visually located a target 8m ahead; then vision was occluded and they were instructed to walk to the remembered target. One week later participants were assigned to either walk, walk while talking on a cell phone, or walk while texting on a cell phone toward the target with vision occluded. Duration and final location of the heel were noted. Linear distance traveled, lateral angular deviation from the start line, and gait velocity were derived. Changes from baseline to testing were analyzed with paired t-tests. Participants engaged in cell phone use presented with significant reductions in gait velocity (texting: 33% reduction, p=0.01; talking: 16% reduction, p=0.02). Moreover, participants who were texting while walking demonstrated a 61% increase in lateral deviation (p=0.04) and 13% increase in linear distance traveled (p=0.03). These results suggest that the dual-task of walking while using a cell phone impacts executive function and working memory and influences gait to such a degree that it may compromise safety. Importantly, comparison of the two cell phone conditions demonstrates texting creates a significantly greater interference effect on walking than talking on a cell phone. Copyright © 2011 Elsevier B.V. All rights reserved.

Walking Back to the Future.

PubMed

Loeffler, Jonna; Raab, Markus; Cañal-Bruland, Rouwen

2017-09-01

Embodied cognition frameworks suggest a direct link between sensorimotor experience and cognitive representations of concepts ( Shapiro, 2011 ). We examined whether this holds also true for concepts that cannot be directly perceived with the sensorimotor system (i.e., temporal concepts). To test this, participants learned object-space (Exp. 1) or object-time (Exp. 2) associations. Afterwards, participants were asked to assign the objects to their location in space/time meanwhile they walked backward, forward, or stood on a treadmill. We hypothesized that walking backward should facilitate the online processing of "behind"/"past"-related stimuli, but hinder the processing of "ahead"/"future"-related stimuli, and a reversed effect for forward walking. Indeed, "ahead"- and "future"-related stimuli were processed slower during backward walking. During forward walking and standing, stimuli were processed equally fast. The results provide partial evidence for the activation of specific spatial and temporal concepts by whole-body movements and are discussed in the context of movement familiarity.

Walking and wheelchair energetics in persons with paraplegia.

PubMed

Cerny, D; Waters, R; Hislop, H; Perry, J

1980-09-01

The energetics of walking with orthoses and wheelchair propulsion at free velocity were tested in 10 adults with low-level spinal cord injuries. Eight were subjects who customarily used wheelchairs as their primary mode of locomotion; the other two used orthoses and had discontinued use of their wheelchairs. All required bilateral knee-ankle-foot orthoses to walk. A third habitual walker also was tested during walking only. Patients walked or propelled their wheelchairs around a 60.5-meter outdoor cement track. Heart rate, respiratory rate, and step frequency were recorded and transmitted by radiotelemetry. Expired air was collected for gas analysis in a polyethylene bag during the activity after a three-minute warm-up. During wheelchair propulsion all subjects demonstrated physiological responses within normal limits. Walking was significantly more difficult to perform than wheelchair propulsion (p < .005). Subjects who customarily used orthoses walked at a mean velocity of 59 +/- 5 m/min; those who primarily used wheelchairs had a mean walking velocity of 22 +/- 13 m/min. Oxygen uptake per minute was similar for both groups. These data suggest that the wheelchair will be the primary mode of locomotion for persons with spinal cord injury who need two knee-ankle-foot orthoses to walk, unless they are willing to work under anaerobic conditions and can walk at a velocity of 54 m/min or better.

Influence of foot pain on walking ability of diabetic patients.

PubMed

Novak, Primoz; Burger, Helena; Marincek, Crt; Meh, Duska

2004-11-01

To assess foot pain and its correlation with walking ability in diabetic patients. Two groups of type 2 diabetic patients (30 with symptomatic neuropathy and 30 without symptomatic neuropathy) and 30 healthy volunteers were studied. Pain was assessed by the pain sub-scale of the Foot Function Index. Internal consistency for the pain sub-scale was tested. Walking ability was assessed by the 6-minute walking test. The pain was worse in diabetic patients, the pain sub-scale scores differed between the groups (p < 0.05). High internal consistency was found for the pain sub-scale of the Foot Function Index. Results of the 6-minute walking test differed among the 3 groups: healthy volunteers performed best, and diabetic patients with symptomatic neuropathy worst (p < 0.001). Foot pain correlated moderately with the result of walking test (r = -0.449, p < 0.001). The pain sub-scale of the Foot Function Index is suitable for the assessment of pain in diabetic patients. Patients with severe foot pain have more difficulties when walking long distances than patients with less severe or without any pain.

Evaluation of functional capacity for exercise in children and adolescents with sickle-cell disease through the six-minute walk test.

PubMed

Hostyn, Sandro V; Carvalho, Werther B de; Johnston, Cíntia; Braga, Josefina A P

2013-01-01

To evaluate lung functional capacity (FC) for physical exercise in children and adolescents with sickle cell disease (SCD) through the six-minute walk test (6MWT). A cross-sectional prospective study was performed to evaluate the FC of 46 patients with SCD through the 6MWT. The following parameters were assessed: heart rate (HR), respiratory rate (RR), peripheral pulse oxygen saturation (SpO2), peak expiratory flow (PEF), blood pressure (systolic and diastolic), dyspnea, and leg fatigue (modified Borg scale) at rest, in the end of the test, and ten minutes after the 6MWT. The total distance walked was also recorded. For statistical analysis, the parametric variables were analyzed using the paired Student's t-test, analysis of variance (ANOVA), and Bonferroni multiple comparisons, with a significance level set at p ≤ 0.05. The 46 patients were aged age 9.15±3.06 years, presented baseline Hb of 9.49±1.67g/dL, and walked 480.89±68.70 m. SCD diagnosis was as follows: group 1- HbSS (n=20)/HbSβ(0)-thalassemia (n=3) and group 2 - HbSC (n=20)/HbSβ(+)-thalassemia (n=3). Regarding total distance walked, patients in group 1 walked a shorter distance than patients in group 2 (459.39±57.19 vs. 502.39±73.60 m; p=0.032). There was no statistical difference regarding PEF in the three moments of evaluation. The SpO2 in ambient air and SpO2 with O2 differed between groups 1 and 2 (p<0.001 vs. p=0.002), as well as the RR (p=0.001). These patients showed a lower FC for exercise than that predicted for the age range in the literature. Patients diagnosed with HbSS/Sβ0-thalassemia had a lower performance in the test than those with HbSC/Sβ(+)-thalassemia regarding total distance walked, RR, and SpO2 after the 6MWT. Copyright © 2013 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Association between Modified Shuttle Walk Test and cardiorespiratory fitness in overweight/obese adults with primary hypertension: EXERDIET-HTA study.

PubMed

Jurio-Iriarte, Borja; Gorostegi-Anduaga, Ilargi; Aispuru, G Rodrigo; Pérez-Asenjo, Javier; Brubaker, Peter H; Maldonado-Martín, Sara

2017-04-01

The aims of the study were to evaluate the relationship between Modified Shuttle Walk Test (MSWT) with peak oxygen uptake (V˙O 2peak ) in overweight/obese people with primary hypertension (HTN) and to develop an equation for the MSWT to predict V˙O 2peak . Participants (N = 256, 53.9 ± 8.1 years old) with HTN and overweight/obesity performed a cardiorespiratory exercise test to peak exertion on an upright bicycle ergometer using an incremental ramp protocol and the 15-level MSWT. The formula of Singh et al was used as a template to predict V˙O 2peak , and a new equation was generated from the measured V˙O 2peak -MSWT relationship in this investigation. The correlation between measured and predicted V˙O 2peak for Singh et al equation was moderate (r = 0.60, P < .001) with a standard error of the estimate (SEE) of 4.92 mL·kg -1  minute -1 , SEE% = 21%. The correlation between MSWT and measured V˙O 2peak as well as for the new equation was strong (r = 0.72, P < .001) with a SEE of 4.35 mL·kg -1  minute -1 , SEE% = 19%. These results indicate that MSWT does not accurately predict functional capacity in overweight/obese people with HTN and questions the validity of using this test to evaluate exercise intolerance. A more accurate determination from a new equation in the current study incorporating more variables from MSWT to estimate V˙O 2peak has been performed but still results in substantial error. Copyright © 2017 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

Increasing walking among older people: A test of behaviour change techniques using factorial randomised N-of-1 trials

PubMed Central

Nyman, Samuel R.; Goodwin, Kelly; Kwasnicka, Dominika; Callaway, Andrew

2016-01-01

Objective: Evaluations of techniques to promote physical activity usually adopt a randomised controlled trial (RCT). Such designs inform how a technique performs on average but cannot be used for treatment of individuals. Our objective was to conduct the first N-of-1 RCTs of behaviour change techniques with older people and test the effectiveness of the techniques for increasing walking within individuals. Design: Eight adults aged 60–87 were randomised to a 2 (goal-setting vs. active control) × 2 (self-monitoring vs. active control) factorial RCT over 62 days. The time series data were analysed for each single case using linear regressions. Main outcome measures: Walking was objectively measured using pedometers. Results: Compared to control days, goal-setting increased walking in 4 out of 8 individuals and self-monitoring increased walking in 7 out of 8 individuals. While the probability for self-monitoring to be effective in 7 out of 8 participants was beyond chance (p = .03), no intervention effect was significant for individual participants. Two participants had a significant but small linear decrease in walking over time. Conclusion: We demonstrate the utility of N-of-1 trials for advancing scientific enquiry of behaviour change and in practice for increasing older people’s physical activity. PMID:26387689

Variety Wins: Soccer-Playing Robots and Infant Walking

PubMed Central

Ossmy, Ori; Hoch, Justine E.; MacAlpine, Patrick; Hasan, Shohan; Stone, Peter; Adolph, Karen E.

2018-01-01

Although both infancy and artificial intelligence (AI) researchers are interested in developing systems that produce adaptive, functional behavior, the two disciplines rarely capitalize on their complementary expertise. Here, we used soccer-playing robots to test a central question about the development of infant walking. During natural activity, infants' locomotor paths are immensely varied. They walk along curved, multi-directional paths with frequent starts and stops. Is the variability observed in spontaneous infant walking a “feature” or a “bug?” In other words, is variability beneficial for functional walking performance? To address this question, we trained soccer-playing robots on walking paths generated by infants during free play and tested them in simulated games of “RoboCup.” In Tournament 1, we compared the functional performance of a simulated robot soccer team trained on infants' natural paths with teams trained on less varied, geometric paths—straight lines, circles, and squares. Across 1,000 head-to-head simulated soccer matches, the infant-trained team consistently beat all teams trained with less varied walking paths. In Tournament 2, we compared teams trained on different clusters of infant walking paths. The team trained with the most varied combination of path shape, step direction, number of steps, and number of starts and stops outperformed teams trained with less varied paths. This evidence indicates that variety is a crucial feature supporting functional walking performance. More generally, we propose that robotics provides a fruitful avenue for testing hypotheses about infant development; reciprocally, observations of infant behavior may inform research on artificial intelligence. PMID:29867427

Variety Wins: Soccer-Playing Robots and Infant Walking.

PubMed

Ossmy, Ori; Hoch, Justine E; MacAlpine, Patrick; Hasan, Shohan; Stone, Peter; Adolph, Karen E

2018-01-01

Although both infancy and artificial intelligence (AI) researchers are interested in developing systems that produce adaptive, functional behavior, the two disciplines rarely capitalize on their complementary expertise. Here, we used soccer-playing robots to test a central question about the development of infant walking. During natural activity, infants' locomotor paths are immensely varied. They walk along curved, multi-directional paths with frequent starts and stops. Is the variability observed in spontaneous infant walking a "feature" or a "bug?" In other words, is variability beneficial for functional walking performance? To address this question, we trained soccer-playing robots on walking paths generated by infants during free play and tested them in simulated games of "RoboCup." In Tournament 1, we compared the functional performance of a simulated robot soccer team trained on infants' natural paths with teams trained on less varied, geometric paths-straight lines, circles, and squares. Across 1,000 head-to-head simulated soccer matches, the infant-trained team consistently beat all teams trained with less varied walking paths. In Tournament 2, we compared teams trained on different clusters of infant walking paths. The team trained with the most varied combination of path shape, step direction, number of steps, and number of starts and stops outperformed teams trained with less varied paths. This evidence indicates that variety is a crucial feature supporting functional walking performance. More generally, we propose that robotics provides a fruitful avenue for testing hypotheses about infant development; reciprocally, observations of infant behavior may inform research on artificial intelligence.

How Accurate Is Your Activity Tracker? A Comparative Study of Step Counts in Low-Intensity Physical Activities

PubMed Central

2017-01-01

Background As commercially available activity trackers are being utilized in clinical trials, the research community remains uncertain about reliability of the trackers, particularly in studies that involve walking aids and low-intensity activities. While these trackers have been tested for reliability during walking and running activities, there has been limited research on validating them during low-intensity activities and walking with assistive tools. Objective The aim of this study was to (1) determine the accuracy of 3 Fitbit devices (ie, Zip, One, and Flex) at different wearing positions (ie, pants pocket, chest, and wrist) during walking at 3 different speeds, 2.5, 5, and 8 km/h, performed by healthy adults on a treadmill; (2) determine the accuracy of the mentioned trackers worn at different sites during activities of daily living; and (3) examine whether intensity of physical activity (PA) impacts the choice of optimal wearing site of the tracker. Methods We recruited 15 healthy young adults to perform 6 PAs while wearing 3 Fitbit devices (ie, Zip, One, and Flex) on their chest, pants pocket, and wrist. The activities include walking at 2.5, 5, and 8 km/h, pushing a shopping cart, walking with aid of a walker, and eating while sitting. We compared the number of steps counted by each tracker with gold standard numbers. We performed multiple statistical analyses to compute descriptive statistics (ie, ANOVA test), intraclass correlation coefficient (ICC), mean absolute error rate, and correlation by comparing the tracker-recorded data with that of the gold standard. Results All the 3 trackers demonstrated good-to-excellent (ICC>0.75) correlation with the gold standard step counts during treadmill experiments. The correlation was poor (ICC<0.60), and the error rate was significantly higher in walker experiment compared to other activities. There was no significant difference between the trackers and the gold standard in the shopping cart experiment. The wrist

Relation of exercise capacity with lung volumes before and after 6-minute walk test in subjects with COPD.

PubMed

Wibmer, Thomas; Rüdiger, Stefan; Kropf-Sanchen, Cornelia; Stoiber, Kathrin M; Rottbauer, Wolfgang; Schumann, Christian

2014-11-01

There is growing evidence that exercise-induced variation in lung volumes is an important source of ventilatory limitation and is linked to exercise intolerance in COPD. The aim of this study was to compare the correlations of walk distance and lung volumes measured before and after a 6-min walk test (6MWT) in subjects with COPD. Forty-five subjects with stable COPD (mean pre-bronchodilator FEV1: 47 ± 18% predicted) underwent a 6MWT. Body plethysmography was performed immediately pre- and post-6MWT. Correlations were generally stronger between 6-min walk distance and post-6MWT lung volumes than between 6-min walk distance and pre-6MWT lung volumes, except for FEV1. These differences in Pearson correlation coefficients were significant for residual volume expressed as percent of total lung capacity (-0.67 vs -0.58, P = .043), percent of predicted residual volume expressed as percent of total lung capacity (-0.68 vs -0.59, P = .026), inspiratory vital capacity (0.65 vs 0.54, P = .019), percent of predicted inspiratory vital capacity (0.49 vs 0.38, P = .037), and percent of predicted functional residual capacity (-0.62 vs -0.47, P = .023). In subjects with stable COPD, lung volumes measured immediately after 6MWT are more closely related to exercise limitation than baseline lung volumes measured before 6MWT, except for FEV1. Therefore, pulmonary function testing immediately after exercise should be included in future studies on COPD for the assessment of exercise-induced ventilatory constraints to physical performance that cannot be adequately assessed from baseline pulmonary function testing at rest. Copyright © 2014 by Daedalus Enterprises.

Random Walk Quantum Clustering Algorithm Based on Space

NASA Astrophysics Data System (ADS)

Xiao, Shufen; Dong, Yumin; Ma, Hongyang

2018-01-01

In the random quantum walk, which is a quantum simulation of the classical walk, data points interacted when selecting the appropriate walk strategy by taking advantage of quantum-entanglement features; thus, the results obtained when the quantum walk is used are different from those when the classical walk is adopted. A new quantum walk clustering algorithm based on space is proposed by applying the quantum walk to clustering analysis. In this algorithm, data points are viewed as walking participants, and similar data points are clustered using the walk function in the pay-off matrix according to a certain rule. The walk process is simplified by implementing a space-combining rule. The proposed algorithm is validated by a simulation test and is proved superior to existing clustering algorithms, namely, Kmeans, PCA + Kmeans, and LDA-Km. The effects of some of the parameters in the proposed algorithm on its performance are also analyzed and discussed. Specific suggestions are provided.

Identification of walked-upon materials in auditory, kinesthetic, haptic, and audio-haptic conditions.

PubMed

Giordano, Bruno L; Visell, Yon; Yao, Hsin-Yun; Hayward, Vincent; Cooperstock, Jeremy R; McAdams, Stephen

2012-05-01

Locomotion generates multisensory information about walked-upon objects. How perceptual systems use such information to get to know the environment remains unexplored. The ability to identify solid (e.g., marble) and aggregate (e.g., gravel) walked-upon materials was investigated in auditory, haptic or audio-haptic conditions, and in a kinesthetic condition where tactile information was perturbed with a vibromechanical noise. Overall, identification performance was better than chance in all experimental conditions and for both solids and the better identified aggregates. Despite large mechanical differences between the response of solids and aggregates to locomotion, for both material categories discrimination was at its worst in the auditory and kinesthetic conditions and at its best in the haptic and audio-haptic conditions. An analysis of the dominance of sensory information in the audio-haptic context supported a focus on the most accurate modality, haptics, but only for the identification of solid materials. When identifying aggregates, response biases appeared to produce a focus on the least accurate modality--kinesthesia. When walking on loose materials such as gravel, individuals do not perceive surfaces by focusing on the most accurate modality, but by focusing on the modality that would most promptly signal postural instabilities.

Uphill and Downhill Walking in Multiple Sclerosis

PubMed Central

Samaei, Afshin; Hajihasani, Abdolhamid; Fatemi, Elham; Motaharinezhad, Fatemeh

2016-01-01

Background: Various exercise protocols have been recommended for patients with multiple sclerosis (MS). We investigated the effects of uphill and downhill walking exercise on mobility, functional activities, and muscle strength in MS patients. Methods: Thirty-four MS patients were randomly allocated to either the downhill or uphill treadmill walking group for 12 sessions (3 times/wk) of 30 minutes' walking on a 10% negative slope (n = 17) or a 10% positive slope (n = 17), respectively. Measurements were taken before and after the intervention and after 4-week follow-up and included fatigue by Modified Fatigue Impact Scale; mobility by Modified Rivermead Mobility Index; disability by Guy's Neurological Disability Scale; functional activities by 2-Minute Walk Test, Timed 25-Foot Walk test, and Timed Up and Go test; balance indices by Biodex Balance System; and quadriceps and hamstring isometric muscles by torque of left and right knee joints. Analysis of variance with repeated measures was used to investigate the intervention effects on the measurements. Results: After the intervention, significant improvement was found in the downhill group versus the uphill group in terms of fatigue, mobility, and disability indices; functional activities; balance indices; and quadriceps isometric torque (P < .05). The results were stable at 4-week follow-up. Conclusions: Downhill walking on a treadmill may improve muscle performance, functional activity, and balance control in MS patients. These findings support the idea of using eccentric exercise training in MS rehabilitation protocols. PMID:26917996

Give your ideas some legs: the positive effect of walking on creative thinking.

PubMed

Oppezzo, Marily; Schwartz, Daniel L

2014-07-01

Four experiments demonstrate that walking boosts creative ideation in real time and shortly after. In Experiment 1, while seated and then when walking on a treadmill, adults completed Guilford's alternate uses (GAU) test of creative divergent thinking and the compound remote associates (CRA) test of convergent thinking. Walking increased 81% of participants' creativity on the GAU, but only increased 23% of participants' scores for the CRA. In Experiment 2, participants completed the GAU when seated and then walking, when walking and then seated, or when seated twice. Again, walking led to higher GAU scores. Moreover, when seated after walking, participants exhibited a residual creative boost. Experiment 3 generalized the prior effects to outdoor walking. Experiment 4 tested the effect of walking on creative analogy generation. Participants sat inside, walked on a treadmill inside, walked outside, or were rolled outside in a wheelchair. Walking outside produced the most novel and highest quality analogies. The effects of outdoor stimulation and walking were separable. Walking opens up the free flow of ideas, and it is a simple and robust solution to the goals of increasing creativity and increasing physical activity. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Predictors of dynamic hyperinflation during the 6-minute walk test in stable chronic obstructive pulmonary disease patients

PubMed Central

Chen, Rui; Lin, Lin; Tian, Jing-Wei; Zeng, Bin; Zhang, Lei

2015-01-01

Background Dynamic hyperinflation (DH) is a major contributor to exercise limitation in chronic obstructive pulmonary disease (COPD). Therefore, we aimed to elucidate the physiological factors responsible for DH development during the 6-minute walk test (6MWT) in COPD patients and compare ventilatory response to the 6MWT in hyperinflators and non-hyperinflators. Methods A total of 105 consecutive subjects with stable COPD underwent a 6MWT, and the Borg dyspnea scale, oxygen saturation (SpO2), breathing pattern, and inspiratory capacity (IC) were recorded before and immediately after walking. The change in IC was measured, and subjects were divided into hyperinflators (ΔIC >0.0 L) and non-hyperinflators (ΔIC ≤0.0 L). Spirometry, the Modified Medical Research Council (MMRC) dyspnea scale and St George’s Respiratory Questionnaire (SGRQ) were also assessed. Results DH was present in 66.67% of subjects. ΔIC/IC was significantly and negatively correlated with the small airway function. On multiple stepwise regression analysis forced expiratory flow after exhaling 50% of the forced vital capacity (FEF50%) was the only predictor of ΔIC/IC. Non-hyperinflators had a higher post-walking VT (t=2.419, P=0.017) and post-walking VE (t=2.599, P=0.011) than the hyperinflators did. Age and resting IC were independent predictors of the 6-minute walk distance (6MWD) in hyperinflators. Conclusions DH was considerably common in subjects with COPD. Small airway function may partly contribute to the DH severity during walking. The ventilator response to the 6MWT differed between hyperinflators and non-hyperinflators. Resting hyperinflation is an important predictor of functional exercise capacity in hyperinflators. PMID:26380729

Research on Walking Wheel Slippage Control of Live Inspection Robot

NASA Astrophysics Data System (ADS)

Yan, Yu; Liu, Xiaqing; Guo, Hao; Li, Jinliang; Liu, Lanlan

2017-07-01

To solve the problem of walking wheel slippage of a live inspection robot during walking or climbing, this paper analyzes the climbing capacity of the robot with a statics method, designs a pressing wheel mechanism, and presents a method of indirectly identifying walking wheel slippage by reading speed of the pressing wheel due to the fact that the linear speed of the pressing wheel and the walking wheel at the contract point is the same; and finds that the slippage state can not be controlled through accurate mathematical models after identifying the slippage state, whereas slippage can be controlled with fuzzy control. The experiment results indicate that due to design of the pressing wheel mechanism, friction force of the walking wheel is increased, and the climbing capability of the robot is improved. Within the range of climbing capability of the robot, gradient is the key factor that has influence on slippage of robot, and slippage can be effectively eliminated through the fuzzy control method proposed in this paper.

Fire-Walking

ERIC Educational Resources Information Center

Willey, David

2010-01-01

This article gives a brief history of fire-walking and then deals with the physics behind fire-walking. The author has performed approximately 50 fire-walks, took the data for the world's hottest fire-walk and was, at one time, a world record holder for the longest fire-walk (www.dwilley.com/HDATLTW/Record_Making_Firewalks.html). He currently…

Walking economy is predictably determined by speed, grade, and gravitational load.

PubMed

Ludlow, Lindsay W; Weyand, Peter G

2017-11-01

The metabolic energy that human walking requires can vary by more than 10-fold, depending on the speed, surface gradient, and load carried. Although the mechanical factors determining economy are generally considered to be numerous and complex, we tested a minimum mechanics hypothesis that only three variables are needed for broad, accurate prediction: speed, surface grade, and total gravitational load. We first measured steady-state rates of oxygen uptake in 20 healthy adult subjects during unloaded treadmill trials from 0.4 to 1.6 m/s on six gradients: -6, -3, 0, 3, 6, and 9°. Next, we tested a second set of 20 subjects under three torso-loading conditions (no-load, +18, and +31% body weight) at speeds from 0.6 to 1.4 m/s on the same six gradients. Metabolic rates spanned a 14-fold range from supine rest to the greatest single-trial walking mean (3.1 ± 0.1 to 43.3 ± 0.5 ml O 2 ·kg -body -1 ·min -1 , respectively). As theorized, the walking portion (V̇o 2-walk  =  V̇o 2-gross - V̇o 2-supine-rest ) of the body's gross metabolic rate increased in direct proportion to load and largely in accordance with support force requirements across both speed and grade. Consequently, a single minimum-mechanics equation was derived from the data of 10 unloaded-condition subjects to predict the pooled mass-specific economy (V̇o 2-gross , ml O 2 ·kg -body + load -1 ·min -1 ) of all the remaining loaded and unloaded trials combined ( n = 1,412 trials from 90 speed/grade/load conditions). The accuracy of prediction achieved ( r 2  = 0.99, SEE = 1.06 ml O 2 ·kg -1 ·min -1 ) leads us to conclude that human walking economy is predictably determined by the minimum mechanical requirements present across a broad range of conditions. NEW & NOTEWORTHY Introduced is a "minimum mechanics" model that predicts human walking economy across a broad range of conditions from only three variables: speed, surface grade, and body-plus-load mass. The derivation

Muscle Synergies Facilitate Computational Prediction of Subject-Specific Walking Motions

PubMed Central

Meyer, Andrew J.; Eskinazi, Ilan; Jackson, Jennifer N.; Rao, Anil V.; Patten, Carolynn; Fregly, Benjamin J.

2016-01-01

Researchers have explored a variety of neurorehabilitation approaches to restore normal walking function following a stroke. However, there is currently no objective means for prescribing and implementing treatments that are likely to maximize recovery of walking function for any particular patient. As a first step toward optimizing neurorehabilitation effectiveness, this study develops and evaluates a patient-specific synergy-controlled neuromusculoskeletal simulation framework that can predict walking motions for an individual post-stroke. The main question we addressed was whether driving a subject-specific neuromusculoskeletal model with muscle synergy controls (5 per leg) facilitates generation of accurate walking predictions compared to a model driven by muscle activation controls (35 per leg) or joint torque controls (5 per leg). To explore this question, we developed a subject-specific neuromusculoskeletal model of a single high-functioning hemiparetic subject using instrumented treadmill walking data collected at the subject’s self-selected speed of 0.5 m/s. The model included subject-specific representations of lower-body kinematic structure, foot–ground contact behavior, electromyography-driven muscle force generation, and neural control limitations and remaining capabilities. Using direct collocation optimal control and the subject-specific model, we evaluated the ability of the three control approaches to predict the subject’s walking kinematics and kinetics at two speeds (0.5 and 0.8 m/s) for which experimental data were available from the subject. We also evaluated whether synergy controls could predict a physically realistic gait period at one speed (1.1 m/s) for which no experimental data were available. All three control approaches predicted the subject’s walking kinematics and kinetics (including ground reaction forces) well for the model calibration speed of 0.5 m/s. However, only activation and synergy controls could predict the

Walking speed and peak plantar pressure distribution during barefoot walking in persons with diabetes.

PubMed

Ko, Mansoo; Hughes, Lynne; Lewis, Harriet

2012-03-01

The impact of walking speed has not been evaluated as a feasible outcome measure associated with peak plantar pressure (PPP) distribution, which may result in tissue damage in persons with diabetic foot complications. The objective of this pilot study was to determine the walking speed and PPP distribution during barefoot walking in persons with diabetes.   Nine individuals with diabetes and nine age-gender matched individuals without diabetes participated in this study. Each individual was marked at 10 anatomical landmarks for vibration and tactile pressure sensation tests to determine the severity of sensory deficits on the plantar surface of the dominant limb foot. A steady state walking speed, PPP, the fore and rear foot (F/R) PPP ratio and gait variables were measured during barefoot walking.   Persons with diabetes had a significantly slower walking speed than the age-gender matched group resulting in a significant reduction of PPP at the F/R foot during barefoot walking (p < 0.05). There was no significant difference in F/R foot PPP ratio in the diabetic group compared with the age-gender matched group during barefoot walking (p > 0.05). There was a significant difference between the diabetic and non-diabetic groups for cadence, step time, toe out angle and the anterior-posterior excursion (APE) for centre of force (p < 0.05).   Walking speed may be a potential indicator for persons with diabetes to identify PPP distribution during barefoot walking in a diabetic foot. However, the diabetic group demonstrated a more cautious walking pattern than the age-gender matched group by decreasing cadence, step length and APE, and increasing step time and toe in/out angle. People with diabetes may reduce the risk of foot ulcerations as long as they are able to prevent severe foot deformities such as callus, hammer toe or charcot foot. Copyright © 2011 John Wiley & Sons, Ltd.

Preliminary exploration of the measurement of walking speed for the apoplectic people based on UHF RFID.

PubMed

Huang Hua-Lin; Mo Ling-Fei; Liu Ying-Jie; Li Cheng-Yang; Xu Qi-Meng; Wu Zhi-Tong

2015-08-01

The number of the apoplectic people is increasing while population aging is quickening its own pace. The precise measurement of walking speed is very important to the rehabilitation guidance of the apoplectic people. The precision of traditional measuring methods on speed such as stopwatch is relatively low, and high precision measurement instruments because of the high cost cannot be used widely. What's more, these methods have difficulty in measuring the walking speed of the apoplectic people accurately. UHF RFID tag has the advantages of small volume, low price, long reading distance etc, and as a wearable sensor, it is suitable to measure walking speed accurately for the apoplectic people. In order to measure the human walking speed, this paper uses four reader antennas with a certain distance to reads the signal strength of RFID tag. Because RFID tag has different RSSI (Received Signal Strength Indicator) in different distances away from the reader, researches on the changes of RSSI with time have been done by this paper to calculate walking speed. The verification results show that the precise measurement of walking speed can be realized by signal processing method with Gaussian Fitting-Kalman Filter. Depending on the variance of walking speed, doctors can predict the rehabilitation training result of the apoplectic people and give the appropriate rehabilitation guidance.

Validity of FitBit, Jawbone UP, Nike+ and other wearable devices for level and stair walking.

PubMed

Huang, Yangjian; Xu, Junkai; Yu, Bo; Shull, Peter B

2016-07-01

Increased physical activity can provide numerous health benefits. The relationship between physical activity and health assumes reliable activity measurements including step count and distance traveled. This study assessed step count and distance accuracy for Nike+ FuelBand, Jawbone UP 24, Fitbit One, Fitbit Flex, Fitbit Zip, Garmin Vivofit, Yamax CW-701, and Omron HJ-321 during level, upstairs, and downstairs walking in healthy adults. Forty subjects walked on flat ground (400m), upstairs (176 steps), and downstairs (176 steps), and a subset of 10 subjects performed treadmill walking trials to assess the influence of walking speed on accuracy. Activity monitor measured step count and distance values were compared with actual step count (determined from video recordings) and distance to determine accuracy. For level walking, step count errors in Yamax CW-701, Fitbit Zip, Fitbit One, Omron HJ-321, and Jawbone UP 24 were within 1% and distance errors in Fitbit Zip and Yamax CW-701 were within 5%. Garmin Vivofit and Omron HJ-321 were the most accurate in estimating step count for stairs with errors less than 4%. An important finding is that all activity monitors overestimated distance for stair walking by at least 45%. In general, there were not accuracy differences among activity monitors for stair walking. Accuracy did not change between moderate and fast walking speeds, though slow walking increased errors for some activity monitors. Nike+ FuelBand was the least accurate step count estimator during all walking tasks. Caution should be taken when interpreting step count and distance estimates for activities involving stairs. Copyright © 2016 Elsevier B.V. All rights reserved.

How might we increase physical activity through dog walking?: A comprehensive review of dog walking correlates.

PubMed

Westgarth, Carri; Christley, Robert M; Christian, Hayley E

2014-08-20

Physical inactivity and sedentary behaviour are major threats to population health. A considerable proportion of people own dogs, and there is good evidence that dog ownership is associated with higher levels of physical activity. However not all owners walk their dogs regularly. This paper comprehensively reviews the evidence for correlates of dog walking so that effective interventions may be designed to increase the physical activity of dog owners. Published findings from 1990-2012 in both the human and veterinary literature were collated and reviewed for evidence of factors associated with objective and self-reported measures of dog walking behaviour, or reported perceptions about dog walking. Study designs included cross-sectional observational, trials and qualitative interviews. There is good evidence that the strength of the dog-owner relationship, through a sense of obligation to walk the dog, and the perceived support and motivation a dog provides for walking, is strongly associated with increased walking. The perceived exercise requirements of the dog may also be a modifiable point for intervention. In addition, access to suitable walking areas with dog supportive features that fulfil dog needs such as off-leash exercise, and that also encourage human social interaction, may be incentivising. Current evidence suggests that dog walking may be most effectively encouraged through targeting the dog-owner relationship and by providing dog-supportive physical environments. More research is required to investigate the influence of individual owner and dog factors on 'intention' to walk the dog as well as the influence of human social interaction whilst walking a dog. The effects of policy and cultural practices relating to dog ownership and walking should also be investigated. Future studies must be of a higher quality methodological design, including accounting for the effects of confounding between variables, and longitudinal designs and testing of

A miniature shoe-mounted orientation determination system for accurate indoor heading and trajectory tracking.

PubMed

Zhang, Shengzhi; Yu, Shuai; Liu, Chaojun; Liu, Sheng

2016-06-01

Tracking the position of pedestrian is urgently demanded when the most commonly used GPS (Global Position System) is unavailable. Benefited from the small size, low-power consumption, and relatively high reliability, micro-electro-mechanical system sensors are well suited for GPS-denied indoor pedestrian heading estimation. In this paper, a real-time miniature orientation determination system (MODS) was developed for indoor heading and trajectory tracking based on a novel dual-linear Kalman filter. The proposed filter precludes the impact of geomagnetic distortions on pitch and roll that the heading is subjected to. A robust calibration approach was designed to improve the accuracy of sensors measurements based on a unified sensor model. Online tests were performed on the MODS with an improved turntable. The results demonstrate that the average RMSE (root-mean-square error) of heading estimation is less than 1°. Indoor heading experiments were carried out with the MODS mounted on the shoe of pedestrian. Besides, we integrated the existing MODS into an indoor pedestrian dead reckoning application as an example of its utility in realistic actions. A human attitude-based walking model was developed to calculate the walking distance. Test results indicate that mean percentage error of indoor trajectory tracking achieves 2% of the total walking distance. This paper provides a feasible alternative for accurate indoor heading and trajectory tracking.

Reference equation for prediction of a total distance during six-minute walk test using Indonesian anthropometrics.

PubMed

Nusdwinuringtyas, Nury; Widjajalaksmi; Yunus, Faisal; Alwi, Idrus

2014-04-01

to develop a reference equation for prediction of the total distance walk using Indonesian anthropometrics of sedentary healthy subjects. Subsequently, the prediction obtained was compared to those calculated by the Caucasian-based Enright prediction equation. the cross-sectional study was conducted among 123 healthy Indonesian adults with sedentary life style (58 male and 65 female subjects in an age range between 18 and 50 years). Heart rate was recorded using Polar with expectation in the sub-maximal zone (120-170 beats per minute). The subjects performed two six-minute walk tests, the first one on a 15-meter track according to the protocol developed by the investigator. The second walk was carried out on Biodex®gait trainer as gold standard. an average total distance of 547±54.24 m was found, not significantly different from the gold standard of 544.72±54.11 m (p>0.05). Multiple regression analysis was performed to develop the new equation. the reference equation for prediction of the total distance using Indonesian anthropometrics is more applicable in Indonesia.

Walking dreams in congenital and acquired paraplegia.

PubMed

Saurat, Marie-Thérèse; Agbakou, Maité; Attigui, Patricia; Golmard, Jean-Louis; Arnulf, Isabelle

2011-12-01

To test if dreams contain remote or never-experienced motor skills, we collected during 6 weeks dream reports from 15 paraplegics and 15 healthy subjects. In 9/10 subjects with spinal cord injury and in 5/5 with congenital paraplegia, voluntary leg movements were reported during dream, including feelings of walking (46%), running (8.6%), dancing (8%), standing up (6.3%), bicycling (6.3%), and practicing sports (skiing, playing basketball, swimming). Paraplegia patients experienced walking dreams (38.2%) just as often as controls (28.7%). There was no correlation between the frequency of walking dreams and the duration of paraplegia. In contrast, patients were rarely paraplegic in dreams. Subjects who had never walked or stopped walking 4-64 years prior to this study still experience walking in their dreams, suggesting that a cerebral walking program, either genetic or more probably developed via mirror neurons (activated when observing others performing an action) is reactivated during sleep. Copyright © 2011 Elsevier Inc. All rights reserved.

Factors Shaping the Decision of College Students to Walk or Drive under the Influence of Alcohol: A Test of Rational Choice Theory

ERIC Educational Resources Information Center

Mason, Ashley; Monk-Turner, Elizabeth

2010-01-01

Aims: Rational Choice theory was tested to better understand the differences in behaviour regarding walking and driving under the influence of alcohol. Methods: Students at a residential college campus in Virginia were surveyed. Findings: Results show that students were less likely to walk or drive while intoxicated if they believed such behaviour…

Validity of the Nike+ device during walking and running.

PubMed

Kane, N A; Simmons, M C; John, D; Thompson, D L; Bassett, D R; Basset, D R

2010-02-01

We determined the validity of the Nike+ device for estimating speed, distance, and energy expenditure (EE) during walking and running. Twenty trained individuals performed a maximal oxygen uptake test and underwent anthropometric and body composition testing. Each participant was outfitted with a Nike+ sensor inserted into the shoe and an Apple iPod nano. They performed eight 6-min stages on the treadmill, including level walking at 55, 82, and 107 m x min(-1), inclined walking (82 m x min(-1)) at 5 and 10% grades, and level running at 134, 161, and 188 m x min(-1). Speed was measured using a tachometer and EE was measured by indirect calorimetry. Results showed that the Nike+ device overestimated the speed of level walking at 55 m x min(-1) by 20%, underestimated the speed of level walking at 107 m x min(-1) by 12%, but closely estimated the speed of level walking at 82 m x min(-1), and level running at all speeds (p<0.05). Similar results were found for distance. The Nike+ device overestimated the EE of level walking by 18-37%, but closely estimated the EE of level running (p<0.05). In conclusion the Nike+ in-shoe device provided reasonable estimates of speed and distance during level running at the three speeds tested in this study. However, it overestimated EE during level walking and it did not detect the increased cost of inclined locomotion.

The Feasibility of Six-Minute and Two-Minute Walk Tests in In-patient Geriatric Rehabilitation

ERIC Educational Resources Information Center

Brooks, Dina; Davis, Aileen M.; Naglie, Gary

2007-01-01

Objective: To evaluate the feasibility of the 6-minute and 2-minute walk tests in frail older persons. Design: Pre/post-design with measures at admission and discharge to in-patient geriatric rehabilitation. Participants: Fifty-two subjects (35 women, 17 men; age 80 plus or minus 8 years). Results: Only 1 of the first 8 subjects could complete a…

Validity of the 6 min walk test in prediction of the anaerobic threshold before major non-cardiac surgery.

PubMed

Sinclair, R C F; Batterham, A M; Davies, S; Cawthorn, L; Danjoux, G R

2012-01-01

For perioperative risk stratification, a robust, practical test could be used where cardiopulmonary exercise testing (CPET) is unavailable. The aim of this study was to assess the utility of the 6 min walk test (6MWT) distance to discriminate between low and high anaerobic threshold (AT) in patients awaiting major non-cardiac surgery. In 110 participants, we obtained oxygen consumption at the AT from CPET and recorded the distance walked (in m) during a 6MWT. Receiver operating characteristic (ROC) curve analysis was used to derive two different cut-points for 6MWT distance in predicting an AT of <11 ml O(2) kg(-1) min(-1); one using the highest sum of sensitivity and specificity (conventional method) and the other adopting a 2:1 weighting in favour of sensitivity. In addition, using a novel linear regression-based technique, we obtained lower and upper cut-points for 6MWT distance that are predictive of an AT that is likely to be (P≥0.75) <11 or >11 ml O(2) kg(-1) min(-1). The ROC curve analysis revealed an area under the curve of 0.85 (95% confidence interval, 0.77-0.91). The optimum cut-points were <440 m (conventional method) and <502 m (sensitivity-weighted approach). The regression-based lower and upper 6MWT distance cut-points were <427 and >563 m, respectively. Patients walking >563 m in the 6MWT do not routinely require CPET; those walking <427 m should be referred for further evaluation. In situations of 'clinical uncertainty' (≥427 but ≤563 m), the number of clinical risk factors and magnitude of surgery should be incorporated into the decision-making process. The 6MWT is a useful clinical tool to screen and risk stratify patients in departments where CPET is unavailable.

Walking to health.

PubMed

Morris, J N; Hardman, A E

1997-05-01

Walking is a rhythmic, dynamic, aerobic activity of large skeletal muscles that confers the multifarious benefits of this with minimal adverse effects. Walking, faster than customary, and regularly in sufficient quantity into the 'training zone' of over 70% of maximal heart rate, develops and sustains physical fitness: the cardiovascular capacity and endurance (stamina) for bodily work and movement in everyday life that also provides reserves for meeting exceptional demands. Muscles of the legs, limb girdle and lower trunk are strengthened and the flexibility of their cardinal joints preserved; posture and carriage may improve. Any amount of walking, and at any pace, expends energy. Hence the potential, long term, of walking for weight control. Dynamic aerobic exercise, as in walking, enhances a multitude of bodily processes that are inherent in skeletal muscle activity, including the metabolism of high density lipoproteins and insulin/glucose dynamics. Walking is also the most common weight-bearing activity, and there are indications at all ages of an increase in related bone strength. The pleasurable and therapeutic, psychological and social dimensions of walking, whilst evident, have been surprisingly little studied. Nor has an economic assessment of the benefits and costs of walking been attempted. Walking is beneficial through engendering improved fitness and/or greater physiological activity and energy turnover. Two main modes of such action are distinguished as: (i) acute, short term effects of the exercise; and (ii) chronic, cumulative adaptations depending on habitual activity over weeks and months. Walking is often included in studies of exercise in relation to disease but it has seldom been specifically tested. There is, nevertheless, growing evidence of gains in the prevention of heart attack and reduction of total death rates, in the treatment of hypertension, intermittent claudication and musculoskeletal disorders, and in rehabilitation after heart

Weak limit of the three-state quantum walk on the line

NASA Astrophysics Data System (ADS)

Falkner, Stefan; Boettcher, Stefan

2014-07-01

We revisit the one-dimensional discrete time quantum walk with three states and the Grover coin, the simplest model that exhibits localization in a quantum walk. We derive analytic expressions for the localization and a long-time approximation for the entire probability density function (PDF). We find the possibility for asymmetric localization to the extreme that it vanishes completely on one site of the initial conditions. We also connect the time-averaged approximation of the PDF found by Inui et al. [Phys. Rev. E 72, 056112 (2005), 10.1103/PhysRevE.72.056112] to a spatial average of the walk. We show that this smoothed approximation predicts moments of the real PDF accurately.

Walking to transit.

DOT National Transportation Integrated Search

2011-12-01

Using a real-life setting, WalkBostons project focused on developing and testing techniques to broaden the scope and range of public participation in transportation planning in a large neighborhood in Boston. The team explored methods of seeking o...

Six-Minute Walk Test Performance in Persons With Multiple Sclerosis While Using Passive or Powered Ankle-Foot Orthoses.

PubMed

Boes, Morgan K; Bollaert, Rachel E; Kesler, Richard M; Learmonth, Yvonne C; Islam, Mazharul; Petrucci, Matthew N; Motl, Robert W; Hsiao-Wecksler, Elizabeth T

2018-03-01

To determine whether a powered ankle-foot orthosis (AFO) that provides dorsiflexor and plantar flexor assistance at the ankle can improve walking endurance of persons with multiple sclerosis (MS). Short-term intervention. University research laboratory. Participants (N=16) with a neurologist-confirmed diagnosis of MS and daily use of a prescribed custom unilateral passive AFO. Three 6-minute walk tests (6MWTs), 1 per footwear condition: shoes (no AFO), prescribed passive AFO, and portable powered AFO (PPAFO). Assistive devices were worn on the impaired limb. Distance walked and metabolic cost of transport were recorded during each 6MWT and compared between footwear conditions. Each participant completed all three 6MWTs within the experimental design. PPAFO use resulted in a shorter 6MWT distance than did a passive AFO or shoe use. No differences were observed in metabolic cost of transport between footwear conditions. The current embodiment of this PPAFO did not improve endurance walking performance during the 6MWT in a sample of participants with gait impairment due to MS. Further research is required to determine whether expanded training or modified design of this powered orthosis can be effective in improving endurance walking performance in persons with gait impairment due to MS. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

[Interpretation and use of routine pulmonary function tests: Spirometry, static lung volumes, lung diffusion, arterial blood gas, methacholine challenge test and 6-minute walk test].

PubMed

Bokov, P; Delclaux, C

2016-02-01

Resting pulmonary function tests (PFT) include the assessment of ventilatory capacity: spirometry (forced expiratory flows and mobilisable volumes) and static volume assessment, notably using body plethysmography. Spirometry allows the potential definition of obstructive defect, while static volume assessment allows the potential definition of restrictive defect (decrease in total lung capacity) and thoracic hyperinflation (increase in static volumes). It must be kept in mind that this evaluation is incomplete and that an assessment of ventilatory demand is often warranted, especially when facing dyspnoea: evaluation of arterial blood gas (searching for respiratory insufficiency) and measurement of the transfer coefficient of the lung, allowing with the measurement of alveolar volume to calculate the diffusing capacity of the lung for CO (DLCO: assessment of alveolar-capillary wall and capillary blood volume). All these pulmonary function tests have been the subject of an Americano-European Task force (standardisation of lung function testing) published in 2005, and translated in French in 2007. Interpretative strategies for lung function tests have been recommended, which define abnormal lung function tests using the 5th and 95th percentiles of predicted values (lower and upper limits of normal values). Thus, these recommendations need to be implemented in all pulmonary function test units. A methacholine challenge test will only be performed in the presence of an intermediate pre-test probability for asthma (diagnostic uncertainty), which is an infrequent setting. The most convenient exertional test is the 6-minute walk test that allows the assessment of walking performance, the search for arterial desaturation and the quantification of dyspnoea complaint. Copyright © 2015 Société nationale française de médecine interne (SNFMI). Published by Elsevier SAS. All rights reserved.

Effect of Body Weight-supported Walking on Exercise Capacity and Walking Speed in Patients with Knee Osteoarthritis: A Randomized Controlled Trial

PubMed Central

Someya, Fujiko

2013-01-01

Abstract Objective: To compare the effect of body-weight-supported treadmill training (BWSTT) and full-body-weight treadmill training (FBWTT) on patients with knee osteoarthritis (OA). Methods: Design was Randomized controlled trial. Patients with knee osteoarthritis (n = 30; mean age, 76.0±7.5 y) were randomly assigned to BWSTT or FBWTT group. All patients performed 20 min walking exercise twice a week for 6 weeks under the supervision of the therapist. Main measures were 10-meter walking test (10MWT), functional reach test (FRT), timed get up and go test (TUG), one-leg standing test, 6-minute walking test (6MWT), the parameters set on the treadmill, MOS Short-Form 36-Item Health Survey (SF36), Japanese Knee Osteoarthritis Measure (JKOM). Results: Twenty-five patients (10 men, 15 women; mean age, 76.5 ± 8.0 y) completed the experiment. Exercise capacity, indicated by the heart rate, was similar in both groups. After 3 weeks of BWSTT, the patients performed significantly better in the 10-m and 6-min walking tests. This was not the case with FBWTT even after 6 weeks training. Pain levels assessed were significantly improved after 3 weeks of BWSTT and 6 weeks of FBWTT. There were no significant improvements in either group assessed by the FRT, one-leg standing time test, TUG, or SF -36 questionnaire. Conclusions: BWSTT enhanced exercise capacity in terms of walking speed and pain reduction after 3 weeks; however, there was no significant improvement in patients' functional abilities or quality of life. PMID:25792901

Evaluation of the microsoft kinect skeletal versus depth data analysis for timed-up and go and figure of 8 walk tests.

PubMed

Hotrabhavananda, Benjamin; Mishra, Anup K; Skubic, Marjorie; Hotrabhavananda, Nijaporn; Abbott, Carmen

2016-08-01

We compared the performance of the Kinect skeletal data with the Kinect depth data in capturing different gait parameters during the Timed-up and Go Test (TUG) and Figure of 8 Walk Test (F8W). The gait parameters considered were stride length, stride time, and walking speed for the TUG, and number of steps and completion time for the F8W. A marker-based Vicon motion capture system was used for the ground-truth measurements. Five healthy participants were recruited for the experiment and were asked to perform three trials of each task. Results show that depth data analysis yields stride length and stride time measures with significantly low percentile errors as compared to the skeletal data analysis. However, the skeletal and depth data performed similar with less than 3% of absolute mean percentile error in determining the walking speed for the TUG and both parameters of F8W. The results show potential capabilities of Kinect depth data analysis in computing many gait parameters, whereas, the Kinect skeletal data can also be used for walking speed in TUG and F8W gait parameters.

Cochlea segmentation using iterated random walks with shape prior

NASA Astrophysics Data System (ADS)

Ruiz Pujadas, Esmeralda; Kjer, Hans Martin; Vera, Sergio; Ceresa, Mario; González Ballester, Miguel Ángel

2016-03-01

Cochlear implants can restore hearing to deaf or partially deaf patients. In order to plan the intervention, a model from high resolution µCT images is to be built from accurate cochlea segmentations and then, adapted to a patient-specific model. Thus, a precise segmentation is required to build such a model. We propose a new framework for segmentation of µCT cochlear images using random walks where a region term is combined with a distance shape prior weighted by a confidence map to adjust its influence according to the strength of the image contour. Then, the region term can take advantage of the high contrast between the background and foreground and the distance prior guides the segmentation to the exterior of the cochlea as well as to less contrasted regions inside the cochlea. Finally, a refinement is performed preserving the topology using a topological method and an error control map to prevent boundary leakage. We tested the proposed approach with 10 datasets and compared it with the latest techniques with random walks and priors. The experiments suggest that this method gives promising results for cochlea segmentation.

Application of the clinical version of the narrow path walking test to identify elderly fallers.

PubMed

Gimmon, Yoav; Barash, Avi; Debi, Ronen; Snir, Yoram; Bar David, Yair; Grinshpon, Jacob; Melzer, Itshak

2016-01-01

Falling during walking is a common problem among the older population. Hence, the challenge facing clinicians is identifying who is at risk of falling during walking, for providing an effective intervention to reduce that risk. We aimed to assess whether the clinical version of the narrow path walking test (NPWT) could identify older adults who are reported falls. A total of 160 older adults were recruited and asked to recall fall events during the past year. Subjects were instructed to walk in the laboratory at a comfortable pace within a 6 meter long narrow path, 3 trials under single task (ST) and 3 trials dual task (DT) conditions without stepping outside the path (i.e., step errors). The average trial time, number of steps, trial velocity, number of step errors, and number of cognitive task errors were calculated for ST and DT. Fear of falling, performance oriented mobility assessment (POMA) and mini-metal state examination (MMSE) were measured as well. Sixty-one subjects reported that they had fallen during the past year and 99 did not. Fallers performed more steps, and were slower than non-fallers. There were no significant differences, however, in the number of steps errors, the cognitive task errors in ST and DT in POMA and MMSE. Our data demonstrates slower gait speed and more steps during the NPWT in ST and DT in fallers. There is no added value of DT over the ST for identification of faller's older adults. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The walking robot project

NASA Technical Reports Server (NTRS)

Williams, P.; Sagraniching, E.; Bennett, M.; Singh, R.

1991-01-01

A walking robot was designed, analyzed, and tested as an intelligent, mobile, and a terrain adaptive system. The robot's design was an application of existing technologies. The design of the six legs modified and combines well understood mechanisms and was optimized for performance, flexibility, and simplicity. The body design incorporated two tripods for walking stability and ease of turning. The electrical hardware design used modularity and distributed processing to drive the motors. The software design used feedback to coordinate the system and simple keystrokes to give commands. The walking machine can be easily adapted to hostile environments such as high radiation zones and alien terrain. The primary goal of the leg design was to create a leg capable of supporting a robot's body and electrical hardware while walking or performing desired tasks, namely those required for planetary exploration. The leg designers intent was to study the maximum amount of flexibility and maneuverability achievable by the simplest and lightest leg design. The main constraints for the leg design were leg kinematics, ease of assembly, degrees of freedom, number of motors, overall size, and weight.

Walk Score(TM), Perceived Neighborhood Walkability, and walking in the US.

PubMed

Tuckel, Peter; Milczarski, William

2015-03-01

To investigate both the Walk Score(TM) and a self-reported measure of neighborhood walkability ("Perceived Neighborhood Walkability") as estimators of transport and recreational walking among Americans. The study is based upon a survey of a nationally-representative sample of 1224 American adults. The survey gauged walking for both transport and recreation and included a self-reported measure of neighborhood walkability and each respondent's Walk Score(TM). Binary logistic and linear regression analyses were performed on the data. The Walk Score(TM) is associated with walking for transport, but not recreational walking nor total walking. Perceived Neighborhood Walkability is associated with transport, recreational and total walking. Perceived Neighborhood Walkability captures the experiential nature of walking more than the Walk Score(TM).

Walking adaptability therapy after stroke: study protocol for a randomized controlled trial.

PubMed

Timmermans, Celine; Roerdink, Melvyn; van Ooijen, Marielle W; Meskers, Carel G; Janssen, Thomas W; Beek, Peter J

2016-08-26

Walking in everyday life requires the ability to adapt walking to the environment. This adaptability is often impaired after stroke, and this might contribute to the increased fall risk after stroke. To improve safe community ambulation, walking adaptability training might be beneficial after stroke. This study is designed to compare the effects of two interventions for improving walking speed and walking adaptability: treadmill-based C-Mill therapy (therapy with augmented reality) and the overground FALLS program (a conventional therapy program). We hypothesize that C-Mill therapy will result in better outcomes than the FALLS program, owing to its expected greater amount of walking practice. This is a single-center parallel group randomized controlled trial with pre-intervention, post-intervention, retention, and follow-up tests. Forty persons after stroke (≥3 months) with deficits in walking or balance will be included. Participants will be randomly allocated to either C-Mill therapy or the overground FALLS program for 5 weeks. Both interventions will incorporate practice of walking adaptability and will be matched in terms of frequency, duration, and therapist attention. Walking speed, as determined by the 10 Meter Walking Test, will be the primary outcome measure. Secondary outcome measures will pertain to walking adaptability (10 Meter Walking Test with context or cognitive dual-task and Interactive Walkway assessments). Furthermore, commonly used clinical measures to determine walking ability (Timed Up-and-Go test), walking independence (Functional Ambulation Category), balance (Berg Balance Scale), and balance confidence (Activities-specific Balance Confidence scale) will be used, as well as a complementary set of walking-related assessments. The amount of walking practice (the number of steps taken per session) will be registered using the treadmill's inbuilt step counter (C-Mill therapy) and video recordings (FALLS program). This process measure will

Clinical determinants of the 6-Minute Walk Test in bronchiectasis.

PubMed

Lee, A L; Button, B M; Ellis, S; Stirling, R; Wilson, J W; Holland, A E; Denehy, L

2009-05-01

The 6-Minute Walk Test (6MWT) is a widely used measurement of functional exercise capacity in chronic lung disease. While exercise intolerance has been identified in patients with bronchiectasis, the clinical determinants of the 6MWT in this population have not been examined. The aim of this study was to 1) establish the relationship between the 6-Minute Walk Distance (6MWD), disease severity and Health-Related Quality of Life (HRQOL) and 2) identify predictors of exercise tolerance in adults with bronchiectasis. The 6MWT was performed in 27 patients with bronchiectasis (mean [SD] FEV(1) 73.9% predicted [23.4]). Disease severity was assessed using spirometry and HRCT scoring while HRQOL was evaluated using the St George's Respiratory Questionnaire (SGRQ) and the Short-Form 36 (SF-36). The relationships were evaluated using correlation and multiple regression. The 6MWD correlated positively with FVC (r=0.52, p<0.01), generations of bronchopulmonary divisions (r(s)=0.38, p<0.05) and SF-36 physical summary (r=0.71, p<0.001) while a negative correlation was observed between all domains of the SGRQ (all correlations r>0.5, p<0.001). Multiple regression analysis indicated that the SGRQ activity, symptom scores and generations of bronchial divisions involved were identified as independent predictors of the 6MWD, explaining 76% of the variance. Measures of HRQOL demonstrated a stronger association with the 6MWD compared to physiological measures of disease severity in patients with predominantly mild to moderate bronchiectasis.

Walking with eyes closed is easier than walking with eyes open without visual cues: The Romberg task versus the goggle task.

PubMed

Yelnik, A P; Tasseel Ponche, S; Andriantsifanetra, C; Provost, C; Calvalido, A; Rougier, P

2015-12-01

The Romberg test, with the subject standing and with eyes closed, gives diagnostic arguments for a proprioceptive disorder. Closing the eyes is also used in balance rehabilitation as a main way to stimulate neural plasticity with proprioceptive, vestibular and even cerebellar disorders. Nevertheless, standing and walking with eyes closed or with eyes open in the dark are certainly 2 different tasks. We aimed to compare walking with eyes open, closed and wearing black or white goggles in healthy subjects. A total of 50 healthy participants were randomly divided into 2 protocols and asked to walk on a 5-m pressure-sensitive mat, under 3 conditions: (1) eyes open (EO), eyes closed (EC) and eyes open with black goggles (BG) and (2) EO, EO with BG and with white goggles (WG). Gait was described by velocity (m·s(-1)), double support (% gait cycle), gait variability index (GVI/100) and exit from the mat (%). Analysis involved repeated measures Anova, Holm-Sidak's multiple comparisons test for parametric parameters (GVI) and Dunn's multiple comparisons test for non-parametric parameters. As compared with walking with EC, walking with BG produced lower median velocity, by 6% (EO 1.26; BG 1.01 vs EC 1.07 m·s(-1), P=0.0328), and lower mean GVI, by 8% (EO 91.8; BG 66.8 vs EC 72.24, P=0.009). Parameters did not differ between walking under the BG and WG conditions. The goggle task increases the difficulty in walking with visual deprivation compared to the Romberg task, so the goggle task can be proposed to gradually increase the difficulty in walking with visual deprivation (from eyes closed to eyes open in black goggles). Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Biomechanics of stair walking and jumping.

PubMed

Loy, D J; Voloshin, A S

1991-01-01

Physical activities such as stair walking and jumping result in increased dynamic loading on the human musculoskeletal system. Use of light weight, externally attached accelerometers allows for in-vivo monitoring of the shock waves invading the human musculoskeletal system during those activities. Shock waves were measured in four subjects performing stair walking up and down, jumping in place and jumping off a fixed elevation. The results obtained show that walking down a staircase induced shock waves with amplitude of 130% of that observed in walking up stairs and 250% of the shock waves experienced in level gait. The jumping test revealed levels of the shock waves nearly eight times higher than that in level walking. It was also shown that the shock waves invading the human musculoskeletal system may be generated not only by the heel strike, but also by the metatarsal strike. To moderate the risk of degenerative joint disorders four types of viscoelastic insoles were utilized to reduce the impact generated shock waves. The insoles investigated were able to reduce the amplitude of the shock wave by between 9% and 41% depending on the insole type and particular physical activity. The insoles were more effective in the reduction of the heel strike impacts than in the reduction of the metatarsal strike impacts. In all instances, the shock attenuation capacities of the insoles tested were greater in the jumping trials than in the stair walking studies. The insoles were ranked in three groups on the basis of their shock absorbing capacity.

Performance in the 6-minute walk test and postoperative pulmonary complications in pulmonary surgery: an observational study.

PubMed

Santos, Bruna F A; Souza, Hugo C D; Miranda, Aline P B; Cipriano, Federico G; Gastaldi, Ada C

2016-01-01

To assess functional capacity in the preoperative phase of pulmonary surgery by comparing predicted and obtained values for the six-minute walk test (6MWT) in patients with and without postoperative pulmonary complication (PPC) METHOD: Twenty-one patients in the preoperative phase of open thoracotomy were evaluated using the 6MWT, followed by monitoring of the postoperative evolution of each participant who underwent the routine treatment. Participants were then divided into two groups: the group with PPC and the group without PPC. The results were also compared with the predicted values using reference equations for the 6MWT RESULTS: Over half (57.14%) of patients developed PPC. The 6MWT was associated with the odds for PPC (odds ratio=22, p=0.01); the group without PPC in the postoperative period walked 422.38 (SD=72.18) meters during the 6MWT, while the group with PPC walked an average of 340.89 (SD=100.93) meters (p=0.02). The distance traveled by the group without PPC was 80% of the predicted value, whereas the group with PPC averaged less than 70% (p=0.03), with more appropriate predicted values for the reference equations The 6MWT is an easy, safe, and feasible test for routine preoperative evaluation in pulmonary surgery and may indicate patients with a higher chance of developing PPC.

How Accurate Is Your Activity Tracker? A Comparative Study of Step Counts in Low-Intensity Physical Activities.

PubMed

Alinia, Parastoo; Cain, Chris; Fallahzadeh, Ramin; Shahrokni, Armin; Cook, Diane; Ghasemzadeh, Hassan

2017-08-11

As commercially available activity trackers are being utilized in clinical trials, the research community remains uncertain about reliability of the trackers, particularly in studies that involve walking aids and low-intensity activities. While these trackers have been tested for reliability during walking and running activities, there has been limited research on validating them during low-intensity activities and walking with assistive tools. The aim of this study was to (1) determine the accuracy of 3 Fitbit devices (ie, Zip, One, and Flex) at different wearing positions (ie, pants pocket, chest, and wrist) during walking at 3 different speeds, 2.5, 5, and 8 km/h, performed by healthy adults on a treadmill; (2) determine the accuracy of the mentioned trackers worn at different sites during activities of daily living; and (3) examine whether intensity of physical activity (PA) impacts the choice of optimal wearing site of the tracker. We recruited 15 healthy young adults to perform 6 PAs while wearing 3 Fitbit devices (ie, Zip, One, and Flex) on their chest, pants pocket, and wrist. The activities include walking at 2.5, 5, and 8 km/h, pushing a shopping cart, walking with aid of a walker, and eating while sitting. We compared the number of steps counted by each tracker with gold standard numbers. We performed multiple statistical analyses to compute descriptive statistics (ie, ANOVA test), intraclass correlation coefficient (ICC), mean absolute error rate, and correlation by comparing the tracker-recorded data with that of the gold standard. All the 3 trackers demonstrated good-to-excellent (ICC>0.75) correlation with the gold standard step counts during treadmill experiments. The correlation was poor (ICC<0.60), and the error rate was significantly higher in walker experiment compared to other activities. There was no significant difference between the trackers and the gold standard in the shopping cart experiment. The wrist worn tracker, Flex, counted several

Environmental perceptions and objective walking trail audits inform a community-based participatory research walking intervention

PubMed Central

2012-01-01

Background Given the documented physical activity disparities that exist among low-income minority communities and the increased focused on socio-ecological approaches to address physical inactivity, efforts aimed at understanding the built environment to support physical activity are needed. This community-based participatory research (CBPR) project investigates walking trails perceptions in a high minority southern community and objectively examines walking trails. The primary aim is to explore if perceived and objective audit variables predict meeting recommendations for walking and physical activity, MET/minutes/week of physical activity, and frequency of trail use. Methods A proportional sampling plan was used to survey community residents in this cross-sectional study. Previously validated instruments were pilot tested and appropriately adapted and included the short version of the validated International Physical Activity Questionnaire, trail use, and perceptions of walking trails. Walking trails were assessed using the valid and reliable Path Environmental Audit Tool which assesses four content areas including: design features, amenities, maintenance, and pedestrian safety from traffic. Analyses included Chi-square, one-way ANOVA's, multiple linear regression, and multiple logistic models. Results Numerous (n = 21) high quality walking trails were available. Across trails, there were very few indicators of incivilities and safety features rated relatively high. Among the 372 respondents, trail use significantly predicted meeting recommendations for walking and physical activity, and MET/minutes/week. While controlling for other variables, significant predictors of trail use included proximity to trails, as well as perceptions of walking trail safety, trail amenities, and neighborhood pedestrian safety. Furthermore, while controlling for education, gender, and income; for every one time per week increase in using walking trails, the odds for meeting walking

Who walks? Factors associated with walking behavior in disabled older women with and without self-reported walking difficulty.

PubMed

Simonsick, E M; Guralnik, J M; Fried, L P

1999-06-01

To determine how severity of walking difficulty and sociodemographic, psychosocial, and health-related factors influence walking behavior in disabled older women. Cross-sectional analyses of baseline data from the Women's Health and Aging Study (WHAS). An urban community encompassing 12 contiguous zip code areas in the eastern portion of Baltimore City and part of Baltimore County, Maryland. A total of 920 moderately to severely disabled community-resident women, aged 65 years and older, identified from an age-stratified random sample of Medicare beneficiaries. Walking behavior was defined as minutes walked for exercise and total blocks walked per week. Independent variables included self-reported walking difficulty, sociodemographic factors, psychological status (depression, mastery, anxiety, and cognition), and health-related factors (falls and fear of falling, fatigue, vision and balance problems, weight, smoking, and cane use). Walking at least 8 blocks per week was strongly negatively related to severity of walking difficulty. Independent of difficulty level, older age, black race, fatigue, obesity, and cane use were also negatively associated with walking; living alone and high mastery had a positive association with walking. Even among functionally limited women, sociocultural, psychological, and health-related factors were independently associated with walking behavior. Thus, programs aimed at improving walking ability need to address these factors in addition to walking difficulties to maximize participation and compliance.

Identification of walking human model using agent-based modelling

NASA Astrophysics Data System (ADS)

Shahabpoor, Erfan; Pavic, Aleksandar; Racic, Vitomir

2018-03-01

The interaction of walking people with large vibrating structures, such as footbridges and floors, in the vertical direction is an important yet challenging phenomenon to describe mathematically. Several different models have been proposed in the literature to simulate interaction of stationary people with vibrating structures. However, the research on moving (walking) human models, explicitly identified for vibration serviceability assessment of civil structures, is still sparse. In this study, the results of a comprehensive set of FRF-based modal tests were used, in which, over a hundred test subjects walked in different group sizes and walking patterns on a test structure. An agent-based model was used to simulate discrete traffic-structure interactions. The occupied structure modal parameters found in tests were used to identify the parameters of the walking individual's single-degree-of-freedom (SDOF) mass-spring-damper model using 'reverse engineering' methodology. The analysis of the results suggested that the normal distribution with the average of μ = 2.85Hz and standard deviation of σ = 0.34Hz can describe human SDOF model natural frequency. Similarly, the normal distribution with μ = 0.295 and σ = 0.047 can describe the human model damping ratio. Compared to the previous studies, the agent-based modelling methodology proposed in this paper offers significant flexibility in simulating multi-pedestrian walking traffics, external forces and simulating different mechanisms of human-structure and human-environment interaction at the same time.

Development of a Subject-Specific Foot-Ground Contact Model for Walking.

PubMed

Jackson, Jennifer N; Hass, Chris J; Fregly, Benjamin J

2016-09-01

Computational walking simulations could facilitate the development of improved treatments for clinical conditions affecting walking ability. Since an effective treatment is likely to change a patient's foot-ground contact pattern and timing, such simulations should ideally utilize deformable foot-ground contact models tailored to the patient's foot anatomy and footwear. However, no study has reported a deformable modeling approach that can reproduce all six ground reaction quantities (expressed as three reaction force components, two center of pressure (CoP) coordinates, and a free reaction moment) for an individual subject during walking. This study proposes such an approach for use in predictive optimizations of walking. To minimize complexity, we modeled each foot as two rigid segments-a hindfoot (HF) segment and a forefoot (FF) segment-connected by a pin joint representing the toes flexion-extension axis. Ground reaction forces (GRFs) and moments acting on each segment were generated by a grid of linear springs with nonlinear damping and Coulomb friction spread across the bottom of each segment. The stiffness and damping of each spring and common friction parameter values for all springs were calibrated for both feet simultaneously via a novel three-stage optimization process that used motion capture and ground reaction data collected from a single walking trial. The sequential three-stage process involved matching (1) the vertical force component, (2) all three force components, and finally (3) all six ground reaction quantities. The calibrated model was tested using four additional walking trials excluded from calibration. With only small changes in input kinematics, the calibrated model reproduced all six ground reaction quantities closely (root mean square (RMS) errors less than 13 N for all three forces, 25 mm for anterior-posterior (AP) CoP, 8 mm for medial-lateral (ML) CoP, and 2 N·m for the free moment) for both feet in all walking trials. The

Development of a Subject-Specific Foot-Ground Contact Model for Walking

PubMed Central

Jackson, Jennifer N.; Hass, Chris J.; Fregly, Benjamin J.

2016-01-01

Computational walking simulations could facilitate the development of improved treatments for clinical conditions affecting walking ability. Since an effective treatment is likely to change a patient's foot-ground contact pattern and timing, such simulations should ideally utilize deformable foot-ground contact models tailored to the patient's foot anatomy and footwear. However, no study has reported a deformable modeling approach that can reproduce all six ground reaction quantities (expressed as three reaction force components, two center of pressure (CoP) coordinates, and a free reaction moment) for an individual subject during walking. This study proposes such an approach for use in predictive optimizations of walking. To minimize complexity, we modeled each foot as two rigid segments—a hindfoot (HF) segment and a forefoot (FF) segment—connected by a pin joint representing the toes flexion–extension axis. Ground reaction forces (GRFs) and moments acting on each segment were generated by a grid of linear springs with nonlinear damping and Coulomb friction spread across the bottom of each segment. The stiffness and damping of each spring and common friction parameter values for all springs were calibrated for both feet simultaneously via a novel three-stage optimization process that used motion capture and ground reaction data collected from a single walking trial. The sequential three-stage process involved matching (1) the vertical force component, (2) all three force components, and finally (3) all six ground reaction quantities. The calibrated model was tested using four additional walking trials excluded from calibration. With only small changes in input kinematics, the calibrated model reproduced all six ground reaction quantities closely (root mean square (RMS) errors less than 13 N for all three forces, 25 mm for anterior–posterior (AP) CoP, 8 mm for medial–lateral (ML) CoP, and 2 N·m for the free moment) for both feet in all walking

The 6-minute walk test, motor function measure and quantitative thigh muscle MRI in Becker muscular dystrophy: A cross-sectional study.

PubMed

Fischer, Dirk; Hafner, Patricia; Rubino, Daniela; Schmid, Maurice; Neuhaus, Cornelia; Jung, Hans; Bieri, Oliver; Haas, Tanja; Gloor, Monika; Fischmann, Arne; Bonati, Ulrike

2016-07-01

Becker muscular dystrophy (BMD) has an incidence of 1 in 16 000 male births. This cross-sectional study investigated the relation between validated functional scores and quantitative MRI (qMRI) of thigh muscles in 20 ambulatory BMD patients, aged 18.3-60 years (mean 31.2; SD 11.1). Clinical assessments included the motor function measure (MFM) and its subscales, as well as timed function tests such as the 6-minute walk test (6MWT) and the timed 10-m run/walk test. Quantitative MRI of the thigh muscles included the mean fat fraction (MFF) using a 2-point Dixon (2-PD) technique, and transverse relaxation time (T2) measurements. The mean MFM value was 80.4%, SD 9.44 and the D1 subscore 54.5%, SD 19.9. The median 6MWT was 195m, IQR 160-330.2. The median 10-m run/walk test was 7.4 seconds, IQR 6.1-9.3. The mean fat fraction of the thigh muscles was 55.6%, SD 17.4%, mean T2 relaxation times of all muscles: 69.9 ms, SD 14.4. The flexors had the highest MFF and T2 relaxation times, followed by the extensors and the adductors. MFF and global T2 relaxation times were highly negatively correlated with the MFM total, D1-subscore and 6MWT, and positively correlated with the 10 m run/walk test time (p < 0.01). Age was not correlated with MFF, global T2 relaxation time or clinical assessments. Both MFF and T2 measures in the thigh muscle were well correlated with clinical function in BMD and may serve as a surrogate outcome measure in clinical trials. Copyright © 2016 Elsevier B.V. All rights reserved.

Allele-sharing models: LOD scores and accurate linkage tests.

PubMed

Kong, A; Cox, N J

1997-11-01

Starting with a test statistic for linkage analysis based on allele sharing, we propose an associated one-parameter model. Under general missing-data patterns, this model allows exact calculation of likelihood ratios and LOD scores and has been implemented by a simple modification of existing software. Most important, accurate linkage tests can be performed. Using an example, we show that some previously suggested approaches to handling less than perfectly informative data can be unacceptably conservative. Situations in which this model may not perform well are discussed, and an alternative model that requires additional computations is suggested.

Allele-sharing models: LOD scores and accurate linkage tests.

PubMed Central

Kong, A; Cox, N J

1997-01-01

Starting with a test statistic for linkage analysis based on allele sharing, we propose an associated one-parameter model. Under general missing-data patterns, this model allows exact calculation of likelihood ratios and LOD scores and has been implemented by a simple modification of existing software. Most important, accurate linkage tests can be performed. Using an example, we show that some previously suggested approaches to handling less than perfectly informative data can be unacceptably conservative. Situations in which this model may not perform well are discussed, and an alternative model that requires additional computations is suggested. PMID:9345087

Walking Behavior of Zoo Elephants: Associations between GPS-Measured Daily Walking Distances and Environmental Factors, Social Factors, and Welfare Indicators

PubMed Central

Holdgate, Matthew R.; Meehan, Cheryl L.; Hogan, Jennifer N.; Miller, Lance J.; Soltis, Joseph; Andrews, Jeff; Shepherdson, David J.

2016-01-01

Research with humans and other animals suggests that walking benefits physical health. Perhaps because these links have been demonstrated in other species, it has been suggested that walking is important to elephant welfare, and that zoo elephant exhibits should be designed to allow for more walking. Our study is the first to address this suggestion empirically by measuring the mean daily walking distance of elephants in North American zoos, determining the factors that are associated with variations in walking distance, and testing for associations between walking and welfare indicators. We used anklets equipped with GPS data loggers to measure outdoor daily walking distance in 56 adult female African (n = 33) and Asian (n = 23) elephants housed in 30 North American zoos. We collected 259 days of data and determined associations between distance walked and social, housing, management, and demographic factors. Elephants walked an average of 5.3 km/day with no significant difference between species. In our multivariable model, more diverse feeding regimens were correlated with increased walking, and elephants who were fed on a temporally unpredictable feeding schedule walked 1.29 km/day more than elephants fed on a predictable schedule. Distance walked was also positively correlated with an increase in the number of social groupings and negatively correlated with age. We found a small but significant negative correlation between distance walked and nighttime Space Experience, but no other associations between walking distances and exhibit size were found. Finally, distance walked was not related to health or behavioral outcomes including foot health, joint health, body condition, and the performance of stereotypic behavior, suggesting that more research is necessary to determine explicitly how differences in walking may impact elephant welfare. PMID:27414411

Walking Behavior of Zoo Elephants: Associations between GPS-Measured Daily Walking Distances and Environmental Factors, Social Factors, and Welfare Indicators.

PubMed

Holdgate, Matthew R; Meehan, Cheryl L; Hogan, Jennifer N; Miller, Lance J; Soltis, Joseph; Andrews, Jeff; Shepherdson, David J

2016-01-01

Research with humans and other animals suggests that walking benefits physical health. Perhaps because these links have been demonstrated in other species, it has been suggested that walking is important to elephant welfare, and that zoo elephant exhibits should be designed to allow for more walking. Our study is the first to address this suggestion empirically by measuring the mean daily walking distance of elephants in North American zoos, determining the factors that are associated with variations in walking distance, and testing for associations between walking and welfare indicators. We used anklets equipped with GPS data loggers to measure outdoor daily walking distance in 56 adult female African (n = 33) and Asian (n = 23) elephants housed in 30 North American zoos. We collected 259 days of data and determined associations between distance walked and social, housing, management, and demographic factors. Elephants walked an average of 5.3 km/day with no significant difference between species. In our multivariable model, more diverse feeding regimens were correlated with increased walking, and elephants who were fed on a temporally unpredictable feeding schedule walked 1.29 km/day more than elephants fed on a predictable schedule. Distance walked was also positively correlated with an increase in the number of social groupings and negatively correlated with age. We found a small but significant negative correlation between distance walked and nighttime Space Experience, but no other associations between walking distances and exhibit size were found. Finally, distance walked was not related to health or behavioral outcomes including foot health, joint health, body condition, and the performance of stereotypic behavior, suggesting that more research is necessary to determine explicitly how differences in walking may impact elephant welfare.

Reduced Gravity Walking Simulator

NASA Image and Video Library

1964-06-20

A "suited" test subject on the Reduced Gravity Walking Simulator located in the hanger at Langley Research Center. The initial version of this simulator was located inside the hanger. Later a larger version would be located at the Lunar Landing Facility. The purpose of this simulator was to study the subject while walking, jumping or running. Researchers conducted studies of various factors such as fatigue limit, energy expenditure, and speed of locomotion. Francis B. Smith wrote in "Simulators For Manned Space Research:" "The cables which support the astronaut are supported by an overhead trolley about 150 feet above the center line of the walkway and the support is arranged so that the subject is free to walk, run, jump, and perform other self-locomotive tasks in a more-or-less normal manner, even though he is constrained to move in one place." "The studies thus far show that an astronaut should have no particular difficulty in walking in a pressurized space suit on a hard lunar surface. Rather, the pace was faster and the suit was found to be more comfortable and less fatiguing under lunar "g" than under earth "g." When the test subject wished to travel hurriedly any appreciable distance, a long loping gait at about 10 feet per second was found to be most comfortable." -- Published in James R. Hansen, Spaceflight Revolution: NASA Langley Research Center From Sputnik to Apollo, (Washington: NASA, 1995), p. 377; Francis B. Smith, "Simulators For Manned Space Research," Paper for 1966 IEEE International Convention, New York, NY, March 21-25, 1966.

Prescribing Aerobic Exercise Intensity without a Cardiopulmonary Exercise Test Post Stroke: Utility of the Six-Minute Walk Test.

PubMed

Marzolini, Susan; Oh, Paul; Corbett, Dale; Dooks, Daryl; Calouro, Marcella; MacIntosh, Bradley J; Goodman, Rachel; Brooks, Dina

2016-09-01

The cardiopulmonary exercise test (CPET) is an established method for determining target exercise training intensity (ventilatory threshold [VAT]) and cardiovascular risk; unfortunately, CPET is not readily accessible to people post stroke. The objective of this study was to determine the utility of the 6-minute walk test (6MWT) as a less resource-intensive alternative to CPET for prescribing exercise intensity to people post stroke with motor impairments. Sixty participants (male, 71.7%; 13.5 ± 22.5 [mean ± standard deviation] months post stroke; age 64.5 ± 12.5 years, with a Chedoke-McMaster Stroke Assessment score of 4.9 ± .9 of the leg) underwent 6MWT, CPET, balance, strength, and cognition assessments. 6MWT heart rate (hr) was significantly lower than VAT-hr (92.3 ± 14.8 beats⋅min(-1) versus 99.8 ± 15.7 beats⋅min(-1), respectively, P < .001; correlation r = .7, P < .001). Bland-Altman analysis revealed that the 6MWT underestimated the VAT-hr by 7.7 ± 11.5%. The 95% confidence interval of the mean bias was large (14.8% and -30.3%), reflecting poor agreement, with 71.7% (n = 43) of the participants unable to reach a walking intensity at or above the VAT-hr. Lower oxygen uptake at the VAT (β = .655, P = .004), higher 6MWT-hr (β = 1.07, P = .01), and better balance (β = 1.128, P = .04) were associated with greater utility of the 6MWT for prescribing exercise. The 6MWT-hr was not interchangeable with the target training VAT-hr determined by CPET. However, in combination with CPET, the 6MWT will indicate when deficits preclude walking alone as the primary exercise modality for optimizing cardiovascular fitness. Future studies to develop a less resource-intensive, multimodal alternative to the CPET for prescribing exercise are needed. A modality that minimizes the effect of stroke deficits, specifically poor balance, should be included. Copyright © 2016 National Stroke Association

Walking Perception by Walking Observers

ERIC Educational Resources Information Center

Jacobs, Alissa; Shiffrar, Maggie

2005-01-01

People frequently analyze the actions of other people for the purpose of action coordination. To understand whether such self-relative action perception differs from other-relative action perception, the authors had observers either compare their own walking speed with that of a point-light walker or compare the walking speeds of 2 point-light…

A mechanical protocol to replicate impact in walking footwear.

PubMed

Price, Carina; Cooper, Glen; Graham-Smith, Philip; Jones, Richard

2014-01-01

Impact testing is undertaken to quantify the shock absorption characteristics of footwear. The current widely reported mechanical testing method mimics the heel impact in running and therefore applies excessive energy to walking footwear. The purpose of this study was to modify the ASTM protocol F1614 (Procedure A) to better represent walking gait. This was achieved by collecting kinematic and kinetic data while participants walked in four different styles of walking footwear (trainer, oxford shoe, flip-flop and triple-density sandal). The quantified heel-velocity and effective mass at ground-impact were then replicated in a mechanical protocol. The kinematic data identified different impact characteristics in the footwear styles. Significantly faster heel velocity towards the floor was recorded walking in the toe-post sandals (flip-flop and triple-density sandal) compared with other conditions (e.g. flip-flop: 0.36±0.05 ms(-1) versus trainer: 0.18±0.06 ms(-1)). The mechanical protocol was adapted by altering the mass and drop height specific to the data captured for each shoe (e.g. flip-flop: drop height 7 mm, mass 16.2 kg). As expected, the adapted mechanical protocol produced significantly lower peak force and accelerometer values than the ASTM protocol (p<.001). The mean difference between the human and adapted protocol was 12.7±17.5% (p<.001) for peak acceleration and 25.2±17.7% (p=.786) for peak force. This paper demonstrates that altered mechanical test protocols can more closely replicate loading on the lower limb in walking. This therefore suggests that testing of material properties of footbeds not only needs to be gait style specific (e.g. running versus walking), but also footwear style specific. Copyright © 2014 Elsevier B.V. All rights reserved.

Does walking strategy in older people change as a function of walking distance?

PubMed

Najafi, Bijan; Helbostad, Jorunn L; Moe-Nilssen, Rolf; Zijlstra, Wiebren; Aminian, Kamiar

2009-02-01

This study investigates whether the spatio-temporal parameters of gait in the elderly vary as a function of walking distance. The gait pattern of older subjects (n=27) over both short (SWD<10 m) and long (LWD>20 m) walking was evaluated using an ambulatory device consisting of body-worn sensors (Physilog). The stride velocity (SV), gait cycle time (GCT), and inter-cycle variability of each parameter (CV) were evaluated for each subject. Analysis was undertaken after evaluating the errors and the test-retest reliability of the Physilog device compared with an electronic walkway system (GaitRite) over the SWD with different walking speeds. While both systems were highly reliable with respect to the SV and GCT parameters (ICC>0.82), agreement for the gait variability was poor. Interestingly, our data revealed that the measured gait parameters over SWD and LWD were significantly different. LWD trials had a mean increase of 5.2% (p<0.05) in SV, and a mean decrease of 3.7% (p<0.05) in GCT compared with SWD trials. Although variability in both the SV and GCT measured during LWD trials decreased by an average of 1% relative to the SWD case, the drop was not significant. Moreover, reliability for gait variability measures was poor, irrespective of the instrument and despite a moderate improvement for LWD trials. Taken together, our findings indicate that for valid and reliable comparisons, test and retest should be performed under identical distance conditions. Furthermore, our findings suggest that the older subjects may choose different walking strategies for SWD and LWD conditions.

An Evaluation of Commercial Pedometers for Monitoring Slow Walking Speed Populations.

PubMed

Beevi, Femina H A; Miranda, Jorge; Pedersen, Christian F; Wagner, Stefan

2016-05-01

Pedometers are considered desirable devices for monitoring physical activity. Two population groups of interest include patients having undergone surgery in the lower extremities or who are otherwise weakened through disease, medical treatment, or surgery procedures, as well as the slow walking senior population. For these population groups, pedometers must be able to perform reliably and accurately at slow walking speeds. The objectives of this study were to evaluate the step count accuracy of three commercially available pedometers, the Yamax (Tokyo, Japan) Digi-Walker(®) SW-200 (YM), the Omron (Kyoto, Japan) HJ-720 (OM), and the Fitbit (San Francisco, CA) Zip (FB), at slow walking speeds, specifically at 1, 2, and 3 km/h, and to raise awareness of the necessity of focusing research on step-counting devices and algorithms for slow walking populations. Fourteen participants 29.93 ±4.93 years of age were requested to walk on a treadmill at the three specified speeds, in four trials of 100 steps each. The devices were worn by the participants on the waist belt. The pedometer counts were recorded, and the error percentage was calculated. The error rate of all three evaluated pedometers decreased with the increase of speed: at 1 km/h the error rates varied from 87.11% (YM) to 95.98% (FB), at 2 km/h the error rates varied from 17.27% (FB) to 46.46% (YM), and at 3 km/h the error rates varied from 22.46% (YM) to a slight overcount of 0.70% (FB). It was observed that all the evaluated devices have high error rates at 1 km/h and mixed error rates at 2 km/h, and at 3 km/h the error rates are the smallest of the three assessed speeds, with the OM and the FB having a slight overcount. These results show that research on pedometers' software and hardware should focus more on accurate step detection at slow walking speeds.

Walk Score®

PubMed Central

Brown, Scott C.; Pantin, Hilda; Lombard, Joanna; Toro, Matthew; Huang, Shi; Plater-Zyberk, Elizabeth; Perrino, Tatiana; Perez-Gomez, Gianna; Barrera-Allen, Lloyd; Szapocznik, José

2013-01-01

Background Walk Score® is a nationally and publicly available metric of neighborhood walkability based on proximity to amenities (e.g., retail, food, schools). However, few studies have examined the relationship of Walk Score to walking behavior. Purpose To examine the relationship of Walk Score to walking behavior in a sample of recent Cuban immigrants, who overwhelmingly report little choice in their selection of neighborhood built environments when they arrive in the U.S. Methods Participants were 391 recent healthy Cuban immigrants (M age=37.1 years) recruited within 90 days of arrival in the U.S., and assessed within 4 months of arrival (M=41.0 days in the U.S.), who resided throughout Miami-Dade County FL. Data on participants’ addresses, walking and sociodemographics were collected prospectively from 2008 to 2010. Analyses conducted in 2011 examined the relationship of Walk Score for each participant’s residential address in the U.S. to purposive walking, controlling for age, gender, education, BMI, days in the U.S., and habitual physical activity level in Cuba. Results For each 10-point increase in Walk Score, adjusting for covariates, there was a significant 19% increase in the likelihood of purposive walking, a 26% increase in the likelihood of meeting physical activity recommendations by walking, and 27% more minutes walked in the previous week. Conclusions Results suggest that Walk Score is associated with walking in a sample of recent immigrants who initially had little choice in where they lived in the U.S. These results support existing guidelines indicating that mixed land use (such as parks and restaurants near homes) should be included when designing walkable communities. PMID:23867028

Shared and task-specific muscle synergies of Nordic walking and conventional walking.

PubMed

Boccia, G; Zoppirolli, C; Bortolan, L; Schena, F; Pellegrini, B

2018-03-01

Nordic walking is a form of walking that includes a poling action, and therefore an additional subtask, with respect to conventional walking. The aim of this study was to assess whether Nordic walking required a task-specific muscle coordination with respect to conventional walking. We compared the electromyographic (EMG) activity of 15 upper- and lower-limb muscles of 9 Nordic walking instructors, while executing Nordic walking and conventional walking at 1.3 ms -1 on a treadmill. Non-negative matrix factorization method was applied to identify muscle synergies, representing the spatial and temporal organization of muscle coordination. The number of muscle synergies was not different between Nordic walking (5.2 ± 0.4) and conventional walking (5.0 ± 0.7, P = .423). Five muscle synergies accounted for 91.2 ± 1.1% and 92.9 ± 1.2% of total EMG variance in Nordic walking and conventional walking, respectively. Similarity and cross-reconstruction analyses showed that 4 muscle synergies, mainly involving lower-limb and trunk muscles, are shared between Nordic walking and conventional walking. One synergy acting during upper limb propulsion is specific to Nordic walking, modifying the spatial organization and the magnitude of activation of upper limb muscles compared to conventional walking. The inclusion of the poling action in Nordic walking does not increase the complexity of movement control and does not change the coordination of lower limb muscles. This makes Nordic walking a physical activity suitable also for people with low motor skill. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Quantum Ultra-Walks: Walks on a Line with Spatial Disorder

NASA Astrophysics Data System (ADS)

Boettcher, Stefan; Falkner, Stefan

We discuss the model of a heterogeneous discrete-time walk on a line with spatial disorder in the form of a set of ultrametric barriers. Simulations show that such an quantum ultra-walk spreads with a walk exponent dw that ranges from ballistic (dw = 1) to complete confinement (dw = ∞) for increasing separation 1 <= 1 / ɛ < ∞ in barrier heights. We develop a formalism by which the classical random walk as well as the quantum walk can be treated in parallel using a coined walk with internal degrees of freedom. For the random walk, this amounts to a 2nd -order Markov process with a stochastic coin, better know as an (anti-)persistent walk. The exact analysis, based on the real-space renormalization group (RG), reproduces the results of the well-known model of ``ultradiffusion,'' dw = 1 -log2 ɛ for 0 < ɛ <= 1 / 2 . However, while the evaluation of the RG fixed-points proceeds virtually identical, for the corresponding quantum walk with a unitary coin it fails to reproduce the numerical results. A new way to analyze the RG is indicated. Supported by NSF-DMR 1207431.

Comparison of the Effect of Lateral and Backward Walking Training on Walking Function in Patients with Poststroke Hemiplegia: A Pilot Randomized Controlled Trial.

PubMed

Kim, Chang-Yong; Lee, Jung-Sun; Kim, Hyeong-Dong

2017-02-01

The purposes of the present study were to compare the effects of backward and lateral walking training and to identify whether additional backward or lateral walking training would be more effective in increasing the walking function of poststroke patients. Fifty-one subjects with hemiplegic stroke were randomly allocated to 3 groups, each containing 17 subjects: the control group, the backward walking training group, and the lateral walking training group. The walking abilities of each group were assessed using a 10-m walk test and the GAITRite system for spatiotemporal gait. The results show that there were significantly greater posttest increases in gait velocity (F = -12.09, P = 0.02) and stride length (F = -11.50, P = 0.02), decreases in the values of the 10-m walk test (F = -7.10, P = 0.03) (P < 0.05) and double-limb support period (F = 40.15, P = 0.000), and improvements in gait asymmetry (F = 13.88, P = 0.002) (P < 0.01) in subjects in the lateral walking training group compared with those in the other 2 groups. These findings demonstrate that asymmetric gait patterns in poststroke patients could be improved by receiving additional lateral walking training therapy rather than backward walking training. Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES: Upon completion of this article, the reader should be able to: (1) understand the potential benefits of backward walking (BW) and lateral walking (LW) training on improving muscle strength and gait; (2) appreciate the potential value of backward and lateral walking gait training in the treatment of hemiplegic stroke patients; and (3) appropriately incorporate backward and lateral walking gait training into the treatment plan of hemiplegic stroke patients. Advanced ACCREDITATION: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for

Rapid and Accurate Multiple Testing Correction and Power Estimation for Millions of Correlated Markers

PubMed Central

Han, Buhm; Kang, Hyun Min; Eskin, Eleazar

2009-01-01

With the development of high-throughput sequencing and genotyping technologies, the number of markers collected in genetic association studies is growing rapidly, increasing the importance of methods for correcting for multiple hypothesis testing. The permutation test is widely considered the gold standard for accurate multiple testing correction, but it is often computationally impractical for these large datasets. Recently, several studies proposed efficient alternative approaches to the permutation test based on the multivariate normal distribution (MVN). However, they cannot accurately correct for multiple testing in genome-wide association studies for two reasons. First, these methods require partitioning of the genome into many disjoint blocks and ignore all correlations between markers from different blocks. Second, the true null distribution of the test statistic often fails to follow the asymptotic distribution at the tails of the distribution. We propose an accurate and efficient method for multiple testing correction in genome-wide association studies—SLIDE. Our method accounts for all correlation within a sliding window and corrects for the departure of the true null distribution of the statistic from the asymptotic distribution. In simulations using the Wellcome Trust Case Control Consortium data, the error rate of SLIDE's corrected p-values is more than 20 times smaller than the error rate of the previous MVN-based methods' corrected p-values, while SLIDE is orders of magnitude faster than the permutation test and other competing methods. We also extend the MVN framework to the problem of estimating the statistical power of an association study with correlated markers and propose an efficient and accurate power estimation method SLIP. SLIP and SLIDE are available at http://slide.cs.ucla.edu. PMID:19381255

Oxygen Costs of the Incremental Shuttle Walk Test in Cardiac Rehabilitation Participants: An Historical and Contemporary Analysis.

PubMed

Buckley, John P; Cardoso, Fernando M F; Birkett, Stefan T; Sandercock, Gavin R H

2016-12-01

The incremental shuttle walk test (ISWT) is a standardised assessment for cardiac rehabilitation. Three studies have reported oxygen costs (VO 2 )/metabolic equivalents (METs) of the ISWT. In spite of classic representations from these studies graphically showing curvilinear VO 2 responses to incremented walking speeds, linear regression techniques (also used by the American College of Sports Medicine [ACSM]) have been used to estimate VO 2 . The two main aims of this study were to (i) resolve currently reported discrepancies in the ISWT VO 2 -walking speed relationship, and (ii) derive an appropriate VO 2 versus walking speed regression equation. VO 2 was measured continuously during an ISWT in 32 coronary heart disease [cardiac] rehabilitation (CHD-CR) participants and 30 age-matched controls. Both CHD-CR and control group VO 2 responses were curvilinear in nature. For CHD-CR VO 2  = 4.4e 0.23 × walkingspeed (km/h) . The integrated area under the curve (iAUC) VO 2 across nine ISWT stages was greater in the CHD-CR group versus the control group (p < 0.001): CHD-CR = 423 (±86) ml·kg -1 ·min -1 ·km·h -1 ; control = 316 (±52) ml·kg -1 ·min -1 ·km·h -1 . CHD-CR group vs. control VO 2 was up to 30 % greater at higher ISWT stages. The curvilinear nature of VO 2 responses during the ISWT concur with classic studies reported over 100 years. VO 2 estimates for walking using linear regression models (including the ACSM) clearly underestimate values in healthy and CHD-CR participants, and this study provides a resolution to this when the ISWT is used for CHD-CR populations.

The Accuracy of Pedometers in Measuring Walking Steps on a Treadmill in College Students.

PubMed

Husted, Hannah M; Llewellyn, Tamra L

2017-01-01

Pedometers are a popular way for people to track if they have reached the recommended 10,000 daily steps. Therefore, the purpose of this study was to determine the accuracy of four brands of pedometers at measuring steps, and to determine if a relationship exists between pedometer cost and accuracy. The hypothesis was that the more expensive brands of pedometers (the Fitbit Charge™ and Omron HJ-303™) would yield more accurate step counts than less expensive brands (the SmartHealth - Walking FIT™ and Sportline™). While wearing all pedometers at once, one male and eleven female college students (mean ± SD; age = 20.8 ± 0.94 years) walked 400 meters on a treadmill for 5 minutes at 3.5 miles per hour. The pedometer step counts were recorded at the end. Video analysis of the participants' feet was later completed to count the number of steps actually taken (actual steps). When compared to the actual steps, the Sportline™ brand (-3.83 ± 22.05) was the only pedometer that was significantly similar. The other three brands significantly under-estimated steps (Fitbit™ 55.00 ± 42.58, SmartHealth™ 43.50 ± 49.71, and Omron™ 28.58 ± 33.86), with the Fitbit being the least accurate. These results suggest an inverse relationship between cost and accuracy for the four specific brands tested, and that waist pedometers are more accurate than wrist pedometers. The results concerning the Fitbit are striking considering its high cost and popularity among consumers today. Further research should be conducted to improve the accuracy of pedometers.

Give Your Ideas Some Legs: The Positive Effect of Walking on Creative Thinking

ERIC Educational Resources Information Center

Oppezzo, Marily; Schwartz, Daniel L.

2014-01-01

Four experiments demonstrate that walking boosts creative ideation in real time and shortly after. In Experiment 1, while seated and then when walking on a treadmill, adults completed Guilford's alternate uses (GAU) test of creative divergent thinking and the compound remote associates (CRA) test of convergent thinking. Walking increased 81% of…

Correlation of 6-min walk test with left ventricular function and quality of life in heart failure due to Chagas disease.

PubMed

Chambela, Mayara C; Mediano, Mauro F F; Ferreira, Roberto R; Japiassú, André M; Waghabi, Mariana C; da Silva, Gilberto M S; Saraiva, Roberto M

2017-10-01

To evaluate the correlation of the total distance walked during the six-minute walk test (6MWT) with left ventricular function and quality of life in patients with Chagas Disease (ChD) complicated by heart failure. This is a cross-sectional study of adult patients with ChD and heart failure diagnosed based on Framingham criteria. 6MWT was performed following international guidelines. New York Heart Association functional class, brain natriuretic peptide (BNP) serum levels, echocardiographic parameters and quality of life (SF-36 and MLHFQ questionnaires) were determined and their correlation with the distance covered at the 6MWT was tested. Forty adult patients (19 male; 60 ± 12 years old) with ChD and heart failure were included in this study. The mean left ventricular ejection fraction was 35 ± 12%. Only two patients (5%) ceased walking before 6 min had elapsed. There were no cardiac events during the test. The average distance covered was 337 ± 105 metres. The distance covered presented a negative correlation with BNP (r = -0.37; P = 0.02), MLHFQ quality-of-life score (r = -0.54; P = 0.002), pulmonary artery systolic pressure (r = -0.42; P = 0.02) and the degree of diastolic dysfunction (r = -0.36; P = 0.03) and mitral regurgitation (r = -0.53; P = 0.0006) and positive correlation with several domains of the SF-36 questionnaire. The distance walked during the 6MWT correlates with BNP, quality of life and parameters of left ventricular diastolic function in ChD patients with heart failure. We propose this test to be adopted in endemic areas with limited resources to aid in the identification of patients who need referral for tertiary centres for further evaluation and treatment. © 2017 John Wiley & Sons Ltd.

Validity of the microsoft kinect system in assessment of compensatory stepping behavior during standing and treadmill walking.

PubMed

Shani, Guy; Shapiro, Amir; Oded, Goldstein; Dima, Kagan; Melzer, Itshak

2017-01-01

Rapid compensatory stepping plays an important role in preventing falls when balance is lost; however, these responses cannot be accurately quantified in the clinic. The Microsoft Kinect™ system provides real-time anatomical landmark position data in three dimensions (3D), which may bridge this gap. Compensatory stepping reactions were evoked in 8 young adults by a sudden platform horizontal motion on which the subject stood or walked on a treadmill. The movements were recorded with both a 3D-APAS motion capture and Microsoft Kinect™ systems. The outcome measures consisted of compensatory step times (milliseconds) and length (centimeters). The average values of two standing and walking trials for Microsoft Kinect™ and the 3D-APAS systems were compared using t -test, Pearson's correlation, Altman-bland plots, and the average difference of root mean square error (RMSE) of joint position. The Microsoft Kinect™ had high correlations for the compensatory step times ( r  = 0.75-0.78, p  = 0.04) during standing and moderate correlations for walking ( r  = 0.53-0.63, p  = 0.05). The step length, however had a very high correlations for both standing and walking ( r  > 0.97, p  = 0.01). The RMSE showed acceptable differences during the perturbation trials with smallest relative error in anterior-posterior direction (2-3%) and the highest in the vertical direction (11-13%). No systematic bias were evident in the Bland and Altman graphs. The Microsoft Kinect™ system provides comparable data to a video-based 3D motion analysis system when assessing step length and less accurate but still clinically acceptable for step times during balance recovery when balance is lost and fall is initiated.

The Effects of Walking Workstations on Biomechanical Performance.

PubMed

Grindle, Daniel M; Baker, Lauren; Furr, Mike; Puterio, Tim; Knarr, Brian; Higginson, Jill

2018-04-03

Prolonged sitting has been associated with negative health effects. Walking workstations have become increasingly popular in the workplace. There is a lack of research on the biomechanical effect of walking workstations. This study analyzed whether walking while working alters normal gait patterns. Nine participants completed four walking trials at 2.4 km·h -1 and 4.0 km·h -1 : baseline walking condition, walking while performing a math task, a reading task, and a typing task. Biomechanical data were collected using standard motion capture procedures. The first maximum vertical ground reaction force, stride width, stride length, minimum toe clearance, peak swing hip abduction and flexion angles, peak swing and stance ankle dorsiflexion and knee flexion angles were analyzed. Differences between conditions were evaluated using analysis of variance tests with Bonferroni correction (p ≤ 0.05). Stride width decreased during the reading task at both speeds. Although other parameters exhibited significant differences when multitasking, these changes were within the normal range of gait variability. It appears that for short periods, walking workstations do not negatively impact gait in healthy young adults.

Walk well: a randomised controlled trial of a walking intervention for adults with intellectual disabilities: study protocol

PubMed Central

2013-01-01

Background Walking interventions have been shown to have a positive impact on physical activity (PA) levels, health and wellbeing for adult and older adult populations. There has been very little work carried out to explore the effectiveness of walking interventions for adults with intellectual disabilities. This paper will provide details of the Walk Well intervention, designed for adults with intellectual disabilities, and a randomised controlled trial (RCT) to test its effectiveness. Methods/design This study will adopt a RCT design, with participants allocated to the walking intervention group or a waiting list control group. The intervention consists of three PA consultations (baseline, six weeks and 12 weeks) and an individualised 12 week walking programme. A range of measures will be completed by participants at baseline, post intervention (three months from baseline) and at follow up (three months post intervention and six months from baseline). All outcome measures will be collected by a researcher who will be blinded to the study groups. The primary outcome will be steps walked per day, measured using accelerometers. Secondary outcome measures will include time spent in PA per day (across various intensity levels), time spent in sedentary behaviour per day, quality of life, self-efficacy and anthropometric measures to monitor weight change. Discussion Since there are currently no published RCTs of walking interventions for adults with intellectual disabilities, this RCT will examine if a walking intervention can successfully increase PA, health and wellbeing of adults with intellectual disabilities. Trial registration ISRCTN: ISRCTN50494254 PMID:23816316

Daily intermittent hypoxia enhances walking after chronic spinal cord injury

PubMed Central

Hayes, Heather B.; Jayaraman, Arun; Herrmann, Megan; Mitchell, Gordon S.; Rymer, William Z.

2014-01-01

Objectives: To test the hypothesis that daily acute intermittent hypoxia (dAIH) and dAIH combined with overground walking improve walking speed and endurance in persons with chronic incomplete spinal cord injury (iSCI). Methods: Nineteen subjects completed the randomized, double-blind, placebo-controlled, crossover study. Participants received 15, 90-second hypoxic exposures (dAIH, fraction of inspired oxygen [Fio2] = 0.09) or daily normoxia (dSHAM, Fio2 = 0.21) at 60-second normoxic intervals on 5 consecutive days; dAIH was given alone or combined with 30 minutes of overground walking 1 hour later. Walking speed and endurance were quantified using 10-Meter and 6-Minute Walk Tests. The trial is registered at ClinicalTrials.gov (NCT01272349). Results: dAIH improved walking speed and endurance. Ten-Meter Walk time improved with dAIH vs dSHAM after 1 day (mean difference [MD] 3.8 seconds, 95% confidence interval [CI] 1.1–6.5 seconds, p = 0.006) and 2 weeks (MD 3.8 seconds, 95% CI 0.9–6.7 seconds, p = 0.010). Six-Minute Walk distance increased with combined dAIH + walking vs dSHAM + walking after 5 days (MD 94.4 m, 95% CI 17.5–171.3 m, p = 0.017) and 1-week follow-up (MD 97.0 m, 95% CI 20.1–173.9 m, p = 0.014). dAIH + walking increased walking distance more than dAIH after 1 day (MD 67.7 m, 95% CI 1.3–134.1 m, p = 0.046), 5 days (MD 107.0 m, 95% CI 40.6–173.4 m, p = 0.002), and 1-week follow-up (MD 136.0 m, 95% CI 65.3–206.6 m, p < 0.001). Conclusions: dAIH ± walking improved walking speed and distance in persons with chronic iSCI. The impact of dAIH is enhanced by combination with walking, demonstrating that combinatorial therapies may promote greater functional benefits in persons with iSCI. Classification of evidence: This study provides Class I evidence that transient hypoxia (through measured breathing treatments), along with overground walking training, improves walking speed and endurance after iSCI. PMID:24285617

Accurate Cold-Test Model of Helical TWT Slow-Wave Circuits

NASA Technical Reports Server (NTRS)

Kory, Carol L.; Dayton, James A., Jr.

1997-01-01

Recently, a method has been established to accurately calculate cold-test data for helical slow-wave structures using the three-dimensional electromagnetic computer code, MAFIA. Cold-test parameters have been calculated for several helical traveling-wave tube (TWT) slow-wave circuits possessing various support rod configurations, and results are presented here showing excellent agreement with experiment. The helical models include tape thickness, dielectric support shapes and material properties consistent with the actual circuits. The cold-test data from this helical model can be used as input into large-signal helical TWT interaction codes making it possible, for the first time, to design a complete TWT via computer simulation.

Comparison of two- and six-minute walk tests in detecting oxygen desaturation in patients with severe chronic obstructive pulmonary disease - A randomized crossover trial.

PubMed

Gloeckl, Rainer; Teschler, Sebastian; Jarosch, Inga; Christle, Jeffrey W; Hitzl, Wolfgang; Kenn, Klaus

2016-03-08

The two-minute walk test (2MWT) is less well validated than the well-known six-minute walk test (6MWT) as a field walking test in patients with chronic obstructive pulmonary disease (COPD). The primary objective of this study was to compare the accuracy of the 2MWT to the 6MWT in detecting exercise-induced oxygen desaturation in patients with severe COPD. Twenty-six patients with COPD (age: 61 ± 10 years, forced expired volume in one second: 37 ± 10%) that were normoxemic at rest performed a 2MWT and a 6MWT under normal ambient conditions on two consecutive days in random order. Oxygen saturation, total walking distance, heart rate, breathing frequency, dyspnea, and leg fatigue were evaluated. Average walking distances were 150 m (95% confidence interval (95% CI): 134-165 m) and 397 m (95% CI: 347-447 m) for the 2MWT and 6MWT, respectively (r = 0.80, p < 0.0001). The difference in minimum oxygen saturation during the 2MWT (83%, 95% CI: 81-86%) and 6MWT (mean 82%, 95% CI: 80-84%) was not statistically different and the data strongly correlated between the groups (r = 0.81, p < 0.0001). Other measurements from the 6MWT, including heart rate, breathing rate, and levels of perceived exertion were also comparable in 2MWT. The 2MWT showed comparable validity in detecting exercise-induced oxygen desaturation in patients with severe COPD compared to the 6MWT. © The Author(s) 2016.

Trunk, head, and step characteristics during normal and narrow-based walking under deteriorated sensory conditions.

PubMed

Deshpande, Nandini; Zhang, Fang

2014-01-01

The ability to maintain stability in the frontal plane (medialateral direction) while walking is commonly included as a component of motor performance assessment. Postural control in the frontal plane may deteriorate faster and earlier with increasing age, compared to that in the sagittal plane (anteroposterior direction). Fifteen young (20-30 years old) and 15 older (>65 years old) healthy participants were recruited to investigate age-related differences in postural control during the normal and narrow-based walking when performed under suboptimal vestibular and lower limb somatosensory conditions achieved by galvanic stimulation and compliant surfaces, respectively. Gait speed decreased in the narrow-based walking condition, with larger decrease in the elderly (by 6%). In the elderly head roll increased with perturbed vestibular information in impaired somatosensory condition (by 40.70%). In both age groups trunk roll increased under impaired somatosensation in the narrow-based walking condition (by 43.62%) but not in normal walking condition. Older participants adopted a more cautious strategy characterized by lower walking speed when walking on a narrow base and exhibited deteriorated integrative ability of the CNS for head control. Accurate lower limb somatosensation may play a critical role in narrow-based walking.

Effect of ambient light and age-related macular degeneration on precision walking.

PubMed

Alexander, M Scott; Lajoie, Kim; Neima, David R; Strath, Robert A; Robinovitch, Stephen N; Marigold, Daniel S

2014-08-01

To determine how age-related macular degeneration (AMD) and changes in ambient light affect the control of foot placement while walking. Ten older adults with AMD and 11 normal-sighted controls performed a precision walking task under normal (∼600 lx), dim (∼0.7 lx), and after a sudden reduction (∼600 to 0.7 lx) of light. The precision walking task involved subjects walking and stepping to the center of a series of irregularly spaced, low-contrast targets. Habitual visual acuity and contrast sensitivity and visual field function were also assessed. There were no differences between groups when performing the walking task in normal light (p > 0.05). In reduced lighting, older adults with AMD were less accurate and more variable when stepping across the targets compared to controls (p < 0.05). A sudden reduction of light proved the most challenging for this population. In the AMD group, contrast sensitivity and visual acuity were not significantly correlated with walking performance. Visual field thresholds in the AMD group were only associated with greater foot placement error and variability in the dim light walking condition (r = -0.69 to -0.87, p < 0.05). While walking performance is similar between groups in normal light, poor ambient lighting results in decreased foot placement accuracy in older adults with AMD. Improper foot placement while walking can lead to a fall and possible injury. Thus, to improve the mobility of those with AMD, strategies to enhance the environment in reduced lighting situations are necessary.

Mobile gaze tracking system for outdoor walking behavioral studies

PubMed Central

Tomasi, Matteo; Pundlik, Shrinivas; Bowers, Alex R.; Peli, Eli; Luo, Gang

2016-01-01

Most gaze tracking techniques estimate gaze points on screens, on scene images, or in confined spaces. Tracking of gaze in open-world coordinates, especially in walking situations, has rarely been addressed. We use a head-mounted eye tracker combined with two inertial measurement units (IMU) to track gaze orientation relative to the heading direction in outdoor walking. Head movements relative to the body are measured by the difference in output between the IMUs on the head and body trunk. The use of the IMU pair reduces the impact of environmental interference on each sensor. The system was tested in busy urban areas and allowed drift compensation for long (up to 18 min) gaze recording. Comparison with ground truth revealed an average error of 3.3° while walking straight segments. The range of gaze scanning in walking is frequently larger than the estimation error by about one order of magnitude. Our proposed method was also tested with real cases of natural walking and it was found to be suitable for the evaluation of gaze behaviors in outdoor environments. PMID:26894511

Horse-like walking, trotting, and galloping derived from kinematic Motion Primitives (kMPs) and their application to walk/trot transitions in a compliant quadruped robot.

PubMed

Moro, Federico L; Spröwitz, Alexander; Tuleu, Alexandre; Vespignani, Massimo; Tsagarakis, Nikos G; Ijspeert, Auke J; Caldwell, Darwin G

2013-06-01

This manuscript proposes a method to directly transfer the features of horse walking, trotting, and galloping to a quadruped robot, with the aim of creating a much more natural (horse-like) locomotion profile. A principal component analysis on horse joint trajectories shows that walk, trot, and gallop can be described by a set of four kinematic Motion Primitives (kMPs). These kMPs are used to generate valid, stable gaits that are tested on a compliant quadruped robot. Tests on the effects of gait frequency scaling as follows: results indicate a speed optimal walking frequency around 3.4 Hz, and an optimal trotting frequency around 4 Hz. Following, a criterion to synthesize gait transitions is proposed, and the walk/trot transitions are successfully tested on the robot. The performance of the robot when the transitions are scaled in frequency is evaluated by means of roll and pitch angle phase plots.

Oxygen desaturation during the six-minute walk test in COPD patients*

PubMed Central

Moreira, Maria Ângela Fontoura; de Medeiros, Gabriel Arriola; Boeno, Francesco Pinto; Sanches, Paulo Roberto Stefani; da Silva, Danton Pereira; Müller, André Frotta

2014-01-01

Objective: To evaluate the behavior of oxygen saturation curves throughout the six-minute walk test (6MWT) in patients with COPD. Methods: We included 85 patients, all of whom underwent spirometry and were classified as having moderate COPD (modCOPD, n = 30) or severe COPD (sevCOPD, n = 55). All of the patients performed a 6MWT, in a 27-m corridor with continuous SpO2 and HR monitoring by telemetry. We studied the SpO2 curves in order to determine the time to a 4% decrease in SpO2, the time to the minimum SpO2 (Tmin), and the post-6MWT time to return to the initial SpO2, the last designated recovery time (RT). For each of those curves, we calculated the slope. Results: The mean age in the modCOPD and sevCOPD groups was 66 ± 10 years and 62 ± 11 years, respectively. At baseline, SpO2 was > 94% in all of the patients; none received supplemental oxygen during the 6MWT; and none of the tests were interrupted. The six-minute walk distance did not differ significantly between the groups. The SpO2 values were lowest in the sevCOPD group. There was no difference between the groups regarding RT. In 71% and 63% of the sevCOPD and modCOPD group patients, respectively, a ≥ 4% decrease in SpO2 occurred within the first minute. We found that FEV1% correlated significantly with the ΔSpO2 (r = −0.398; p < 0.001), Tmin (r = −0.449; p < 0.001), and minimum SpO2 (r = 0.356; p < 0.005). Conclusions: In the sevCOPD group, in comparison with the modCOPD group, SpO2 was lower and the Tmin was greater, suggesting a worse prognosis in the former. PMID:25029644

Noninvasive Assessment of Neuromuscular Disease in Dogs: Use of the 6-minute Walk Test to Assess Submaximal Exercise Tolerance in Dogs with Centronuclear Myopathy.

PubMed

Cerda-Gonzalez, S; Talarico, L; Todhunter, R

2016-05-01

Noninvasive methods of quantitating exercise tolerance in dogs with neuromuscular disease are needed both for clinical and research use. The 6-minute walk test (6MWT) has been validated as a reliable test of exercise tolerance in dogs with pulmonary and cardiac disease, but not in dogs with neuromuscular disease. Distance walked and number of steps taken during 6MWT will differ between Labrador retriever dogs with centronuclear myopathy (CNM) and control (ie, healthy) littermates. Eight purebred Labrador retrievers were drawn from a purpose-bred research colony (status: 3 clear, 2 carrier, and 3 homozygous mutants for the protein tyrosine phosphatase-like A (PTPLA) gene mutation associated with CNM). Pilot, prospective, Case-controlled study. Researchers were blinded to disease status. Each dog was leash-trained and acclimatized to the testing area (length, 12.8 m). At the start of testing, each animal was fitted with a pedometer, a timer was started, and dogs were allowed to walk at their own pace for 6 minutes. Distance walked and pedometer readings were recorded. Degree of paresis varied among affected dogs, and was reflected by significant differences in distance walked between CNM-affected dogs and those with clear and carrier genotypes (P = .048). Pedometer readings did not vary according to genotype (P = .86). The 6MWT appears to differentiate between the ambulatory capacity of normal and CNM-affected dogs. Additional studies are needed to confirm this relationship in a larger number of dogs, and to evaluate the ability of the 6MWT to differentiate between dogs with variable severity of neuromuscular disease-associated exercise intolerance. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Reliability, agreement, and responsiveness of a 6-minute walk/run test in patients with heart disease.

PubMed

Berghmans, Danielle D; Lenssen, Antoine F; Bastiaenen, Carolien H; Ilhan, Mustafa; Lencer, Nicole H; Roox, George M

2013-02-01

The 6-minute walk test (6 MWT) is widely used to assess exercise tolerance in cardiac rehabilitation (CR). However, previous research shows it to be insufficiently responsive, especially for patients with a relatively high maximal exercise tolerance at baseline. We therefore designed a 6-minute walk/run test (6 MWRT), which has the same duration as the 6 MWT but allows running. The objective of this study was to determine the test-retest reproducibility and responsiveness of this 6 MWRT. Responsiveness was investigated in a prospective cohort study among a group of patients entering CR at Maastricht University Medical Center, with a cross-sectional part to assess the test-retest reproducibility. Test-retest reproducibility (reliability and agreement) was investigated using the intraclass correlation (ICC) and a Bland-Altman plot of two measurements implemented in the first week of rehabilitation. Responsiveness of the 6 MWT and the 6 MWRT was calculated using the standard response mean (SRM) over a 6-week period. The first reproducibility analysis included 34 patients, the second 22 patients. The ICCs were 0.935 and 0.906, respectively, with limits of agreement of ± 79 and ± 61 m. The responsiveness analysis included 27 patients. The SRM values were 0.83 for the 6 MWT and 0.71 for the 6 MWRT. Although the 6 MWRT is a reproducible test in CR, its responsiveness is not superior to that of the 6 MWT. We therefore prefer the conventional 6 MWT as an evaluative measurement in CR and advise against using the 6 MWRT as (evaluative) measurement in CR for this purpose.

Improved Leg Tracking Considering Gait Phase and Spline-Based Interpolation during Turning Motion in Walk Tests.

PubMed

Yorozu, Ayanori; Moriguchi, Toshiki; Takahashi, Masaki

2015-09-04

Falling is a common problem in the growing elderly population, and fall-risk assessment systems are needed for community-based fall prevention programs. In particular, the timed up and go test (TUG) is the clinical test most often used to evaluate elderly individual ambulatory ability in many clinical institutions or local communities. This study presents an improved leg tracking method using a laser range sensor (LRS) for a gait measurement system to evaluate the motor function in walk tests, such as the TUG. The system tracks both legs and measures the trajectory of both legs. However, both legs might be close to each other, and one leg might be hidden from the sensor. This is especially the case during the turning motion in the TUG, where the time that a leg is hidden from the LRS is longer than that during straight walking and the moving direction rapidly changes. These situations are likely to lead to false tracking and deteriorate the measurement accuracy of the leg positions. To solve these problems, a novel data association considering gait phase and a Catmull-Rom spline-based interpolation during the occlusion are proposed. From the experimental results with young people, we confirm   that the proposed methods can reduce the chances of false tracking. In addition, we verify the measurement accuracy of the leg trajectory compared to a three-dimensional motion analysis system (VICON).

The effects of clothes on independent walking in toddlers.

PubMed

Théveniau, Nicolas; Boisgontier, Matthieu P; Varieras, Sabine; Olivier, Isabelle

2014-01-01

The spatiotemporal features of walking in toddlers are known to be related to the level of maturation of the central nervous system. However, previous studies did not assess whether there could be an effect of clothes on the acquisition of walking. In this study, it was hypothesized that clothes modify the toddlers' walking. To test this hypothesis, 22 healthy toddlers divided into 3 groups of walking experience were assessed in four clothing conditions (Diaper+Trousers; Diaper+Pants of tracksuit; Diaper; Underwear). Results revealed significant effects of clothing on velocity and step length of toddlers from 6 to 18 months of walking experience. These results suggested that biomechanical constraints induced by the textile features alter the walking of toddlers. Therefore, in studies of toddler's gait, the clothing worn should be carefully mentioned and controlled. Copyright © 2013 Elsevier B.V. All rights reserved.

The mouse beam walking assay offers improved sensitivity over the mouse rotarod in determining motor coordination deficits induced by benzodiazepines.

PubMed

Stanley, Joanna L; Lincoln, Rachael J; Brown, Terry A; McDonald, Louise M; Dawson, Gerard R; Reynolds, David S

2005-05-01

The mouse rotarod test of motor coordination/sedation is commonly used to predict clinical sedation caused by novel drugs. However, past experience suggests that it lacks the desired degree of sensitivity to be predictive of effects in humans. For example, the benzodiazepine, bretazenil, showed little impairment of mouse rotarod performance, but marked sedation in humans. The aim of the present study was to assess whether the mouse beam walking assay demonstrates: (i) an increased sensitivity over the rotarod and (ii) an increased ability to predict clinically sedative doses of benzodiazepines. The study compared the effects of the full benzodiazepine agonists, diazepam and lorazepam, and the partial agonist, bretazenil, on the mouse rotarod and beam walking assays. Diazepam and lorazepam significantly impaired rotarod performance, although relatively high GABA-A receptor occupancy was required (72% and 93%, respectively), whereas beam walking performance was significantly affected at approximately 30% receptor occupancy. Bretazenil produced significant deficits at 90% and 53% receptor occupancy on the rotarod and beam walking assays, respectively. The results suggest that the mouse beam walking assay is a more sensitive tool for determining benzodiazepine-induced motor coordination deficits than the rotarod. Furthermore, the GABA-A receptor occupancy values at which significant deficits were determined in the beam walking assay are comparable with those observed in clinical positron emission tomography studies using sedative doses of benzodiazepines. These data suggest that the beam walking assay may be able to more accurately predict the clinically sedative doses of novel benzodiazepine-like drugs.

Independent evolution of knuckle-walking in African apes shows that humans did not evolve from a knuckle-walking ancestor.

PubMed

Kivell, Tracy L; Schmitt, Daniel

2009-08-25

Despite decades of debate, it remains unclear whether human bipedalism evolved from a terrestrial knuckle-walking ancestor or from a more generalized, arboreal ape ancestor. Proponents of the knuckle-walking hypothesis focused on the wrist and hand to find morphological evidence of this behavior in the human fossil record. These studies, however, have not examined variation or development of purported knuckle-walking features in apes or other primates, data that are critical to resolution of this long-standing debate. Here we present novel data on the frequency and development of putative knuckle-walking features of the wrist in apes and monkeys. We use these data to test the hypothesis that all knuckle-walking apes share similar anatomical features and that these features can be used to reliably infer locomotor behavior in our extinct ancestors. Contrary to previous expectations, features long-assumed to indicate knuckle-walking behavior are not found in all African apes, show different developmental patterns across species, and are found in nonknuckle-walking primates as well. However, variation among African ape wrist morphology can be clearly explained if we accept the likely independent evolution of 2 fundamentally different biomechanical modes of knuckle-walking: an extended wrist posture in an arboreal environment (Pan) versus a neutral, columnar hand posture in a terrestrial environment (Gorilla). The presence of purported knuckle-walking features in the hominin wrist can thus be viewed as evidence of arboreality, not terrestriality, and provide evidence that human bipedalism evolved from a more arboreal ancestor occupying the ecological niche common to all living apes.

The association between the maximum step length test and the walking efficiency in children with cerebral palsy.

PubMed

Kimoto, Minoru; Okada, Kyoji; Sakamoto, Hitoshi; Kondou, Takanori

2017-05-01

[Purpose] To improve walking efficiency could be useful for reducing fatigue and extending possible period of walking in children with cerebral palsy (CP). For this purpose, current study compared conventional parameters of gross motor performance, step length, and cadence in the evaluation of walking efficiency in children with CP. [Subjects and Methods] Thirty-one children with CP (21 boys, 10 girls; mean age, 12.3 ± 2.7 years) participated. Parameters of gross motor performance, including the maximum step length (MSL), maximum side step length, step number, lateral step up number, and single leg standing time, were measured in both dominant and non-dominant sides. Spatio-temporal parameters of walking, including speed, step length, and cadence, were calculated. Total heart beat index (THBI), a parameter of walking efficiency, was also calculated from heartbeats and walking distance in 10 minutes of walking. To analyze the relationships between these parameters and the THBI, the coefficients of determination were calculated using stepwise analysis. [Results] The MSL of the dominant side best accounted for the THBI (R 2 =0.759). [Conclusion] The MSL of the dominant side was the best explanatory parameter for walking efficiency in children with CP.

KidsWalk-to-School: A Guide To Promote Walking to School.

ERIC Educational Resources Information Center

Center for Chronic Disease Prevention and Health Promotion (DHHS/CDC), Atlanta, GA.

This guide encourages people to create safe walking and biking routes to school, promoting four issues: physically active travel, safe and walkable routes to school, crime prevention, and health environments. The chapters include: "KidsWalk-to-School: A Guide to Promote Walking to School" (Is there a solution? Why is walking to school important?…

Gait Pattern Alterations during Walking, Texting and Walking and Texting during Cognitively Distractive Tasks while Negotiating Common Pedestrian Obstacles

PubMed Central

Licence, Sammy; Smith, Robynne; McGuigan, Miranda P.; Earnest, Conrad P.

2015-01-01

Objectives Mobile phone texting is a common daily occurrence with a paucity of research examining corresponding gait characteristics. To date, most studies have participants walk in a straight line vs. overcoming barriers and obstacles that occur during regular walking. The aim of our study is to examine the effect of mobile phone texting during periods of cognitive distraction while walking and negotiating barriers synonymous with pedestrian traffic. Methods Thirty participants (18-50y) completed three randomized, counter-balanced walking tasks over a course during: (1) normal walking (control), (2) texting and walking, and (3) texting and walking whilst being cognitively distraction via a standard mathematical test performed while negotiating the obstacle course. We analyzed gait characteristics during course negotiation using a 3-dimensional motion analysis system and a general linear model and Dunnet-Hsu post-hoc procedure the normal walking condition to assess gait characteristic differences. Primary outcomes included the overall time to complete the course time and barrier contact. Secondary outcomes included obstacle clearance height, step frequency, step time, double support phase and lateral deviation. Results Participants took significantly longer (mean ± SD) to complete the course while texting (24.96±4.20 sec) and during cognitive distraction COG (24.09±3.36 sec) vs. normal walking (19.32±2.28 sec; all, P<0.001). No significant differences were noted for barrier contacts (P = 0.28). Step frequency, step time, double support phase and lateral deviation all increased in duration during the texting and cognitive distraction trial. Texting and being cognitively distracted also increased obstacle clearance versus the walking condition (all, P<0.02). Conclusions Texting while walking and/or being cognitively distracted significantly affect gait characteristics concordant to mobile phone usage resulting in a more cautious gate pattern. Future research

The Use of the 6-Min Walk Test as a Proxy for the Assessment of Energy Expenditure during Gait in Individuals with Lower-Limb Amputation

ERIC Educational Resources Information Center

Kark, Laurena; McIntosh, Andrew S.B; Simmons, Annea

2011-01-01

The objective of this study was to determine, and compare, the utility of the 6-min walk test (6 MWT) and self-selected walking speed over 15 m as proxies for the assessment of energy expenditure during gait in individuals with lower-limb amputation. Patients with unilateral, transfemoral amputation (n = 6) and patients with unilateral,…

Walking Beliefs in Women With Fibromyalgia: Clinical Profile and Impact on Walking Behavior.

PubMed

Peñacoba, Cecilia; Pastor, María-Ángeles; López-Roig, Sofía; Velasco, Lilian; Lledo, Ana

2017-10-01

Although exercise is essential for the treatment of fibromyalgia, adherence is low. Walking, as a form of physical exercise, has significant advantages. The aim of this article is to describe, in 920 women with fibromyalgia, the prevalence of certain walking beliefs and analyze their effects both on the walking behavior itself and on the associated symptoms when patients walk according to a clinically recommended way. The results highlight the high prevalence of beliefs related to pain and fatigue as walking-inhibitors. In the whole sample, beliefs are associated with an increased perception that comorbidity prevents walking, and with higher levels of pain and fatigue. In patients who walk regularly, beliefs are only associated with the perception that comorbidity prevents them from walking. It is necessary to promote walking according to the established way (including breaks to prevent fatigue) and to implement interventions on the most prevalent beliefs that inhibit walking.

Comparison of two- and six-minute walk tests in detecting oxygen desaturation in patients with severe chronic obstructive pulmonary disease — A randomized crossover trial

PubMed Central

Teschler, Sebastian; Jarosch, Inga; Christle, Jeffrey W; Hitzl, Wolfgang; Kenn, Klaus

2016-01-01

The two-minute walk test (2MWT) is less well validated than the well-known six-minute walk test (6MWT) as a field walking test in patients with chronic obstructive pulmonary disease (COPD). The primary objective of this study was to compare the accuracy of the 2MWT to the 6MWT in detecting exercise-induced oxygen desaturation in patients with severe COPD. Twenty-six patients with COPD (age: 61 ± 10 years, forced expired volume in one second: 37 ± 10%) that were normoxemic at rest performed a 2MWT and a 6MWT under normal ambient conditions on two consecutive days in random order. Oxygen saturation, total walking distance, heart rate, breathing frequency, dyspnea, and leg fatigue were evaluated. Average walking distances were 150 m (95% confidence interval (95% CI): 134–165 m) and 397 m (95% CI: 347–447 m) for the 2MWT and 6MWT, respectively (r = 0.80, p < 0.0001). The difference in minimum oxygen saturation during the 2MWT (83%, 95% CI: 81–86%) and 6MWT (mean 82%, 95% CI: 80–84%) was not statistically different and the data strongly correlated between the groups (r = 0.81, p < 0.0001). Other measurements from the 6MWT, including heart rate, breathing rate, and levels of perceived exertion were also comparable in 2MWT. The 2MWT showed comparable validity in detecting exercise-induced oxygen desaturation in patients with severe COPD compared to the 6MWT. PMID:26961775

Influence of non-level walking on pedometer accuracy.

PubMed

Leicht, Anthony S; Crowther, Robert G

2009-05-01

The YAMAX Digiwalker pedometer has been previously confirmed as a valid and reliable monitor during level walking, however, little is known about its accuracy during non-level walking activities or between genders. Subsequently, this study examined the influence of non-level walking and gender on pedometer accuracy. Forty-six healthy adults completed 3-min bouts of treadmill walking at their normal walking pace during 11 inclines (0-10%) while another 123 healthy adults completed walking up and down 47 stairs. During walking, participants wore a YAMAX Digiwalker SW-700 pedometer with the number of steps taken and registered by the pedometer recorded. Pedometer difference (steps registered-steps taken), net error (% of steps taken), absolute error (absolute % of steps taken) and gender were examined by repeated measures two-way ANOVA and Tukey's post hoc tests. During incline walking, pedometer accuracy indices were similar between inclines and gender except for a significantly greater step difference (-7+/-5 steps vs. 1+/-4 steps) and net error (-2.4+/-1.8% for 9% vs. 0.4+/-1.2% for 2%). Step difference and net error were significantly greater during stair descent compared to stair ascent while absolute error was significantly greater during stair ascent compared to stair descent. The current study demonstrated that the YAMAX Digiwalker SW-700 pedometer exhibited good accuracy during incline walking up to 10% while it overestimated steps taken during stair ascent/descent with greater overestimation during stair descent. Stair walking activity should be documented in field studies as the YAMAX Digiwalker SW-700 pedometer overestimates this activity type.

Oxygen uptake on-kinetics during six-minute walk test predicts short-term outcomes after off-pump coronary artery bypass surgery.

PubMed

Rocco, Isadora Salvador; Viceconte, Marcela; Pauletti, Hayanne Osiro; Matos-Garcia, Bruna Caroline; Marcondi, Natasha Oliveira; Bublitz, Caroline; Bolzan, Douglas William; Moreira, Rita Simone Lopes; Reis, Michel Silva; Hossne, Nelson Américo; Gomes, Walter José; Arena, Ross; Guizilini, Solange

2017-12-26

We aimed to investigate the ability of oxygen uptake kinetics to predict short-term outcomes after off-pump coronary artery bypass grafting. Fifty-two patients aged 60.9 ± 7.8 years waiting for off-pump coronary artery bypass surgery were evaluated. The 6-min walk test distance was performed pre-operatively, while simultaneously using a portable cardiopulmonary testing device. The transition of oxygen uptake kinetics from rest to exercise was recorded to calculate oxygen uptake kinetics fitting a monoexponential regression model. Oxygen uptake at steady state, constant time, and mean response time corrected by work rate were analysed. Short-term clinical outcomes were evaluated during the early post-operative of off-pump coronary artery bypass surgery. Multivariate analysis showed body mass index, surgery time, and mean response time corrected by work rate as independent predictors for short-term outcomes. The optimal mean response time corrected by work rate cut-off to estimate short-term clinical outcomes was 1.51 × 10 -3  min 2 /ml. Patients with slower mean response time corrected by work rate demonstrated higher rates of hypertension, diabetes, EuroSCOREII, left ventricular dysfunction, and impaired 6-min walk test parameters. The per cent-predicted distance threshold of 66% in the pre-operative was associated with delayed oxygen uptake kinetics. Pre-operative oxygen uptake kinetics during 6-min walk test predicts short-term clinical outcomes after off-pump coronary artery bypass surgery. From a clinically applicable perspective, a threshold of 66% of pre-operative predicted 6-min walk test distance indicated slower kinetics, which leads to longer intensive care unit and post-surgery hospital length of stay. Implications for rehabilitation Coronary artery bypass grafting is a treatment aimed to improve expectancy of life and prevent disability due to the disease progression; The use of pre-operative submaximal functional capacity test enabled the

Effects of Nordic walking and walking on spatiotemporal gait parameters and ground reaction force.

PubMed

Park, Seung Kyu; Yang, Dae Jung; Kang, Yang Hun; Kim, Je Ho; Uhm, Yo Han; Lee, Yong Seon

2015-09-01

[Purpose] The purpose of this study was to investigate the effects of Nordic walking and walking on spatiotemporal gait parameters and ground reaction force. [Subjects] The subjects of this study were 30 young adult males, who were divided into a Nordic walking group of 15 subjects and a walking group of 15 subjects. [Methods] To analyze the spatiotemporal parameters and ground reaction force during walking in the two groups, the six-camera Vicon MX motion analysis system was used. The subjects were asked to walk 12 meters using the more comfortable walking method for them between Nordic walking and walking. After they walked 12 meters more than 10 times, their most natural walking patterns were chosen three times and analyzed. To determine the pole for Nordic walking, each subject's height was multiplied by 0.68. We then measured the spatiotemporal gait parameters and ground reaction force. [Results] Compared with the walking group, the Nordic walking group showed an increase in cadence, stride length, and step length, and a decrease in stride time, step time, and vertical ground reaction force. [Conclusion] The results of this study indicate that Nordic walking increases the stride and can be considered as helping patients with diseases affecting their gait. This demonstrates that Nordic walking is more effective in improving functional capabilities by promoting effective energy use and reducing the lower limb load, because the weight of the upper and lower limbs is dispersed during Nordic walking.

Development of a mechatronic platform and validation of methods for estimating ankle stiffness during the stance phase of walking.

PubMed

Rouse, Elliott J; Hargrove, Levi J; Perreault, Eric J; Peshkin, Michael A; Kuiken, Todd A

2013-08-01

The mechanical properties of human joints (i.e., impedance) are constantly modulated to precisely govern human interaction with the environment. The estimation of these properties requires the displacement of the joint from its intended motion and a subsequent analysis to determine the relationship between the imposed perturbation and the resultant joint torque. There has been much investigation into the estimation of upper-extremity joint impedance during dynamic activities, yet the estimation of ankle impedance during walking has remained a challenge. This estimation is important for understanding how the mechanical properties of the human ankle are modulated during locomotion, and how those properties can be replicated in artificial prostheses designed to restore natural movement control. Here, we introduce a mechatronic platform designed to address the challenge of estimating the stiffness component of ankle impedance during walking, where stiffness denotes the static component of impedance. The system consists of a single degree of freedom mechatronic platform that is capable of perturbing the ankle during the stance phase of walking and measuring the response torque. Additionally, we estimate the platform's intrinsic inertial impedance using parallel linear filters and present a set of methods for estimating the impedance of the ankle from walking data. The methods were validated by comparing the experimentally determined estimates for the stiffness of a prosthetic foot to those measured from an independent testing machine. The parallel filters accurately estimated the mechatronic platform's inertial impedance, accounting for 96% of the variance, when averaged across channels and trials. Furthermore, our measurement system was found to yield reliable estimates of stiffness, which had an average error of only 5.4% (standard deviation: 0.7%) when measured at three time points within the stance phase of locomotion, and compared to the independently determined

Concurrent Validity of Walking Speed Values Calculated via the GAITRite Electronic Walkway and 3 Meter Walk Test in the Chronic Stroke Population

PubMed Central

Peters, Denise M.; Middleton, Addie; Donley, Jonathan W.; Blanck, Erika L.; Fritz, Stacy L.

2014-01-01

The purpose of this study was to provide novel information regarding the concurrent validity (primary aim) and reliability (secondary aim) of walking speed (WS) calculated via the GAITRite1 electronic walkway system and 3 meter walk test (3MWT) in the chronic stroke population. The 3MWT is a feasible option for clinicians working in environments where space is limited. Psychometric properties of the test have not been established. Participants with chronic stroke were stratified into three groups: household ambulators (HA) (self-selected WS <0.4 m/s, 12 participants, 31 observations), limited community ambulators (LCA) (self-selected WS 0.4–0.8 m/s, 24 participants, 60 observations), and community ambulators (CA) (self-selected WS >0.8 m/s, 26 participants, 71 observations). Three consecutive trials of GAITRite1 and 3MWT were performed at participant’s self-selected WS. Average WS measurements differed significantly (p <0.05) between GAITRite1 and 3MWT for all three groups. HA group: GAITRite1 0.25 (0.11) m/s, 3MWT 0.27 (0.11) m/s; LCA group: GAITRite1 0.56 (0.11) m/s, 3MWT 0.52 (0.10) m/s; CA group: GAITRite1 1.03 (0.16) m/s, 3MWT 0.89 (0.15) m/s. Both WS measures had excellent within-session reliability (ICC’s ranging from 0.85 to 0.97, SEM95 from 0.04 to 0.12 m/s, and MDC95 from 0.05 to 0.16 m/s). Reliability was highest for HA on both measures. Although both the 3MWT and the GAITRite1 are reliable measures of WS for individuals with chronic stroke, the two measures do not demonstrate concurrent validity. PMID:24164441

Concurrent validity of walking speed values calculated via the GAITRite electronic walkway and 3 meter walk test in the chronic stroke population.

PubMed

Peters, Denise M; Middleton, Addie; Donley, Jonathan W; Blanck, Erika L; Fritz, Stacy L

2014-04-01

The purpose of this study was to provide novel information regarding the concurrent validity (primary aim) and reliability (secondary aim) of walking speed (WS) calculated via the GAITRite electronic walkway system and 3 meter walk test (3MWT) in the chronic stroke population. The 3MWT is a feasible option for clinicians working in environments where space is limited. Psychometric properties of the test have not been established. Participants with chronic stroke were stratified into three groups: (1) household ambulators (HA) (self-selected WS < 0.4 m/s, 12 participants, 31 observations); (2) limited community ambulators (LCA) (self-selected WS 0.4-0.8 m/s, 24 participants, 60 observations); and (3) community ambulators (CA) (self-selected WS > 0.8 m/s, 26 participants, 71 observations). Three consecutive trials of GAITRite and 3MWT were performed at participant's self-selected WS. Average WS measurements differed significantly (p < 0.05) between GAITRite and 3MWT for all three groups. HA group: GAITRite 0.25 (0.11) m/s, 3MWT 0.27 (0.11) m/s; LCA group: GAITRite 0.56 (0.11) m/s, 3MWT 0.52 (0.10) m/s; CA group: GAITRite 1.03 (0.16) m/s, 3MWT 0.89 (0.15) m/s. Both WS measures had excellent within-session reliability (ICC's ranging from 0.85 to 0.97, SEM95 from 0.04 to 0.12 m/s and MDC95 from 0.05 to 0.16 m/s). Reliability was highest for HA on both measures. Although both the 3MWT and the GAITRite are reliable measures of WS for individuals with chronic stroke, the two measures do not demonstrate concurrent validity.

Walking Performance: Correlation between Energy Cost of Walking and Walking Participation. New Statistical Approach Concerning Outcome Measurement

PubMed Central

Franceschini, Marco; Rampello, Anais; Agosti, Maurizio; Massucci, Maurizio; Bovolenta, Federica; Sale, Patrizio

2013-01-01

Walking ability, though important for quality of life and participation in social and economic activities, can be adversely affected by neurological disorders, such as Spinal Cord Injury, Stroke, Multiple Sclerosis or Traumatic Brain Injury. The aim of this study is to evaluate if the energy cost of walking (CW), in a mixed group of chronic patients with neurological diseases almost 6 months after discharge from rehabilitation wards, can predict the walking performance and any walking restriction on community activities, as indicated by Walking Handicap Scale categories (WHS). One hundred and seven subjects were included in the study, 31 suffering from Stroke, 26 from Spinal Cord Injury and 50 from Multiple Sclerosis. The multivariable binary logistical regression analysis has produced a statistical model with good characteristics of fit and good predictability. This model generated a cut-off value of.40, which enabled us to classify correctly the cases with a percentage of 85.0%. Our research reveal that, in our subjects, CW is the only predictor of the walking performance of in the community, to be compared with the score of WHS. We have been also identifying a cut-off value of CW cost, which makes a distinction between those who can walk in the community and those who cannot do it. In particular, these values could be used to predict the ability to walk in the community when discharged from the rehabilitation units, and to adjust the rehabilitative treatment to improve the performance. PMID:23468871

Effects of aquatic exercises in a rat model of brainstem demyelination with ethidium bromide on the beam walking test.

PubMed

Nassar, Cíntia Cristina Souza; Bondan, Eduardo Fernandes; Alouche, Sandra Regina

2009-09-01

Multiple sclerosis is a demyelinating disease of the central nervous system associated with varied levels of disability. The impact of early physiotherapeutic interventions in the disease progression is unknown. We used an experimental model of demyelination with the gliotoxic agent ethidium bromide and early aquatic exercises to evaluate the motor performance of the animals. We quantified the number of footsteps and errors during the beam walking test. The demyelinated animals walked fewer steps with a greater number of errors than the control group. The demyelinated animals that performed aquatic exercises presented a better motor performance than those that did not exercise. Therefore aquatic exercising was beneficial to the motor performance of rats in this experimental model of demyelination.

Six-minute-walk test in idiopathic pulmonary fibrosis: test validation and minimal clinically important difference.

PubMed

du Bois, Roland M; Weycker, Derek; Albera, Carlo; Bradford, Williamson Z; Costabel, Ulrich; Kartashov, Alex; Lancaster, Lisa; Noble, Paul W; Sahn, Steven A; Szwarcberg, Javier; Thomeer, Michiel; Valeyre, Dominique; King, Talmadge E

2011-05-01

The 6-minute-walk test (6MWT) is a practical and clinically meaningful measure of exercise tolerance with favorable performance characteristics in various cardiac and pulmonary diseases. Performance characteristics in patients with idiopathic pulmonary fibrosis (IPF) have not been systematically evaluated. To assess the reliability, validity, and responsiveness of the 6MWT and estimate the minimal clinically important difference (MCID) in patients with IPF. The study population included all subjects completing a 6MWT in a clinical trial evaluating interferon gamma-1b (n = 822). Six-minute walk distance (6MWD) and other parameters were measured at baseline and at 24-week intervals using a standardized protocol. Parametric and distribution-independent correlation coefficients were used to assess the strength of the relationships between 6MWD and measures of pulmonary function, dyspnea, and health-related quality of life. Both distribution-based and anchor-based methods were used to estimate the MCID. Comparison of two proximal measures of 6MWD (mean interval, 24 d) demonstrated good reliability (coefficient = 0.83; P < 0.001). 6MWD was weakly correlated with measures of physiologic function and health-related quality of life; however, values were consistently and significantly lower for patients with the poorest functional status, suggesting good construct validity. Importantly, change in 6MWD was highly predictive of mortality; a 24-week decline of greater than 50 m was associated with a fourfold increase in risk of death at 1 year (hazard ratio, 4.27; 95% confidence interval, 2.57- 7.10; P < 0.001). The estimated MCID was 24-45 m. The 6MWT is a reliable, valid, and responsive measure of disease status and a valid endpoint for clinical trials in IPF.

Walking adaptability after a stroke and its assessment in clinical settings.

PubMed

Balasubramanian, Chitralakshmi K; Clark, David J; Fox, Emily J

2014-01-01

Control of walking has been described by a tripartite model consisting of stepping, equilibrium, and adaptability. This review focuses on walking adaptability, which is defined as the ability to modify walking to meet task goals and environmental demands. Walking adaptability is crucial to safe ambulation in the home and community environments and is often severely compromised after a stroke. Yet quantification of walking adaptability after stroke has received relatively little attention in the clinical setting. The objectives of this review were to examine the conceptual challenges for clinical measurement of walking adaptability and summarize the current state of clinical assessment for walking adaptability. We created nine domains of walking adaptability from dimensions of community mobility to address the conceptual challenges in measurement and reviewed performance-based clinical assessments of walking to determine if the assessments measure walking adaptability in these domains. Our literature review suggests the lack of a comprehensive well-tested clinical assessment tool for measuring walking adaptability. Accordingly, recommendations for the development of a comprehensive clinical assessment of walking adaptability after stroke have been presented. Such a clinical assessment will be essential for gauging recovery of walking adaptability with rehabilitation and for motivating novel strategies to enhance recovery of walking adaptability after stroke.

Walking Adaptability after a Stroke and Its Assessment in Clinical Settings

PubMed Central

Balasubramanian, Chitralakshmi K.; Clark, David J.; Fox, Emily J.

2014-01-01

Control of walking has been described by a tripartite model consisting of stepping, equilibrium, and adaptability. This review focuses on walking adaptability, which is defined as the ability to modify walking to meet task goals and environmental demands. Walking adaptability is crucial to safe ambulation in the home and community environments and is often severely compromised after a stroke. Yet quantification of walking adaptability after stroke has received relatively little attention in the clinical setting. The objectives of this review were to examine the conceptual challenges for clinical measurement of walking adaptability and summarize the current state of clinical assessment for walking adaptability. We created nine domains of walking adaptability from dimensions of community mobility to address the conceptual challenges in measurement and reviewed performance-based clinical assessments of walking to determine if the assessments measure walking adaptability in these domains. Our literature review suggests the lack of a comprehensive well-tested clinical assessment tool for measuring walking adaptability. Accordingly, recommendations for the development of a comprehensive clinical assessment of walking adaptability after stroke have been presented. Such a clinical assessment will be essential for gauging recovery of walking adaptability with rehabilitation and for motivating novel strategies to enhance recovery of walking adaptability after stroke. PMID:25254140

Markerless Knee Joint Position Measurement Using Depth Data during Stair Walking

PubMed Central

Mita, Akira; Yorozu, Ayanori; Takahashi, Masaki

2017-01-01

Climbing and descending stairs are demanding daily activities, and the monitoring of them may reveal the presence of musculoskeletal diseases at an early stage. A markerless system is needed to monitor such stair walking activity without mentally or physically disturbing the subject. Microsoft Kinect v2 has been used for gait monitoring, as it provides a markerless skeleton tracking function. However, few studies have used this device for stair walking monitoring, and the accuracy of its skeleton tracking function during stair walking has not been evaluated. Moreover, skeleton tracking is not likely to be suitable for estimating body joints during stair walking, as the form of the body is different from what it is when it walks on level surfaces. In this study, a new method of estimating the 3D position of the knee joint was devised that uses the depth data of Kinect v2. The accuracy of this method was compared with that of the skeleton tracking function of Kinect v2 by simultaneously measuring subjects with a 3D motion capture system. The depth data method was found to be more accurate than skeleton tracking. The mean error of the 3D Euclidian distance of the depth data method was 43.2 ± 27.5 mm, while that of the skeleton tracking was 50.4 ± 23.9 mm. This method indicates the possibility of stair walking monitoring for the early discovery of musculoskeletal diseases. PMID:29165396

A study of the 200-metre fast walk test as a possible new assessment tool to predict maximal heart rate and define target heart rate for exercise training of coronary heart disease patients.

PubMed

Casillas, Jean-Marie; Joussain, Charles; Gremeaux, Vincent; Hannequin, Armelle; Rapin, Amandine; Laurent, Yves; Benaïm, Charles

2015-02-01

To develop a new predictive model of maximal heart rate based on two walking tests at different speeds (comfortable and brisk walking) as an alternative to a cardiopulmonary exercise test during cardiac rehabilitation. Evaluation of a clinical assessment tool. A Cardiac Rehabilitation Department in France. A total of 148 patients (133 men), mean age of 59 ±9 years, at the end of an outpatient cardiac rehabilitation programme. Patients successively performed a 6-minute walk test, a 200 m fast-walk test (200mFWT), and a cardiopulmonary exercise test, with measure of heart rate at the end of each test. An all-possible regression procedure was used to determine the best predictive regression models of maximal heart rate. The best model was compared with the Fox equation in term of predictive error of maximal heart rate using the paired t-test. Results of the two walking tests correlated significantly with maximal heart rate determined during the cardiopulmonary exercise test, whereas anthropometric parameters and resting heart rate did not. The simplified predictive model with the most acceptable mean error was: maximal heart rate = 130 - 0.6 × age + 0.3 × HR200mFWT (R(2) = 0.24). This model was superior to the Fox formula (R(2) = 0.138). The relationship between training target heart rate calculated from measured reserve heart rate and that established using this predictive model was statistically significant (r = 0.528, p < 10(-6)). A formula combining heart rate measured during a safe simple fast walk test and age is more efficient than an equation only including age to predict maximal heart rate and training target heart rate. © The Author(s) 2014.

Alzheimer random walk

NASA Astrophysics Data System (ADS)

Odagaki, Takashi; Kasuya, Keisuke

2017-09-01

Using the Monte Carlo simulation, we investigate a memory-impaired self-avoiding walk on a square lattice in which a random walker marks each of sites visited with a given probability p and makes a random walk avoiding the marked sites. Namely, p = 0 and p = 1 correspond to the simple random walk and the self-avoiding walk, respectively. When p> 0, there is a finite probability that the walker is trapped. We show that the trap time distribution can well be fitted by Stacy's Weibull distribution b(a/b){a+1}/{b}[Γ({a+1}/{b})]-1x^a\\exp(-a/bx^b)} where a and b are fitting parameters depending on p. We also find that the mean trap time diverges at p = 0 as p- α with α = 1.89. In order to produce sufficient number of long walks, we exploit the pivot algorithm and obtain the mean square displacement and its Flory exponent ν(p) as functions of p. We find that the exponent determined for 1000 step walks interpolates both limits ν(0) for the simple random walk and ν(1) for the self-avoiding walk as [ ν(p) - ν(0) ] / [ ν(1) - ν(0) ] = pβ with β = 0.388 when p ≪ 0.1 and β = 0.0822 when p ≫ 0.1. Contribution to the Topical Issue "Continuous Time Random Walk Still Trendy: Fifty-year History, Current State and Outlook", edited by Ryszard Kutner and Jaume Masoliver.

The relationship between walking, manual dexterity, cognition and activity/participation in persons with multiple sclerosis.

PubMed

Kierkegaard, Marie; Einarsson, Ulrika; Gottberg, Kristina; von Koch, Lena; Holmqvist, Lotta Widén

2012-05-01

Multiple sclerosis has a vast impact on health, but the relationship between walking, manual dexterity, cognition and activity/participation is unclear. The specific aims were to explore the discriminative ability of measures of walking, manual dexterity and cognition, and to identify cut-off values in these measures, for prediction of independence in personal and instrumental activities of daily living (ADL) and activity/participation in social and lifestyle activities. Data from 164 persons with multiple sclerosis were collected during home visits with the following measures: the 2 × 5 m walk test, the Nine-hole Peg Test, the Symbol Digit Modalities Test, the Katz Personal and Instrumental ADL Indexes, and the Frenchay Activities Index (measuring frequency in social and lifestyle activities). The 2 × 5 m walk test and the Nine-hole Peg Test had high and better discriminative and predictive ability than the Symbol Digit Modalities Test. Cut-off values were identified. The accuracy of predictions was increased above all by combining the 2 × 5 m walk test and the Nine-hole Peg Test. The proposed cut-off values in the 2 × 5 m walk test and the Nine-hole Peg Test may be used as indicators of functioning and to identify persons risking activity limitations and participation restrictions. However, further studies are needed to confirm the usefulness in clinical practice.

At similar angles, slope walking has a greater fall risk than stair walking.

PubMed

Sheehan, Riley C; Gottschall, Jinger S

2012-05-01

According to the CDC, falls are the leading cause of injury for all age groups with over half of the falls occurring during slope and stair walking. Consequently, the purpose of this study was to compare and contrast the different factors related to fall risk as they apply to these walking tasks. More specifically, we hypothesized that compared to level walking, slope and stair walking would have greater speed standard deviation, greater ankle dorsiflexion, and earlier peak activity of the tibialis anterior. Twelve healthy, young male participants completed level, slope, and stair trials on a 25-m walkway. Overall, during slope and stair walking, medial-lateral stability was less, anterior-posterior stability was less, and toe clearance was greater in comparison to level walking. In addition, there were fewer differences between level and stair walking than there were between level and slope walking, suggesting that at similar angles, slope walking has a greater fall risk than stair walking. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Compensatory balance reactions during forward and backward walking on a treadmill.

PubMed

Bolton, D A E; Misiaszek, J E

2012-04-01

Previous work suggests that balance perturbations to the body opposing the direction of progression during walking lead to larger amplitude corrective reactions than perturbations concurrent with walking direction. To test this hypothesis, subjects received forward and backward perturbations applied to the pelvis through a padded harness, while walking forwards or backwards on a treadmill. Contrary to our hypothesis, the greatest responses were associated with backward perturbations regardless of the direction of walking. Copyright © 2011 Elsevier B.V. All rights reserved.

D.U.C.K. Walking.

ERIC Educational Resources Information Center

Steller, Jenifer J.

This manual presents a schoolwide walking program that includes aerobic fitness information, curriculum integration, and walking tours. "Discover and Understand Carolina Kids by Walking" is D.U.C.K. Walking. An aerobic walking activity, D.U.C.K. Walking has two major goals: (1) to promote regular walking as a way to exercise at any age;…

Sidewalks promote walking

DOT National Transportation Integrated Search

2004-12-01

Of Americas 205 million adults, 86% took walks during the summer months of 2002, and 40% of those walkers walked more than 15 days per month. Fourteen percent of adult Americans state they never take walks. The presence of sidewalks has a ...

Detection of Abnormal Muscle Activations during Walking Following Spinal Cord Injury (SCI)

ERIC Educational Resources Information Center

Wang, Ping; Low, K. H.; McGregor, Alison H.; Tow, Adela

2013-01-01

In order to identify optimal rehabilitation strategies for spinal cord injury (SCI) participants, assessment of impaired walking is required to detect, monitor and quantify movement disorders. In the proposed assessment, ten healthy and seven SCI participants were recruited to perform an over-ground walking test at slow walking speeds. SCI…

Why does walking economy improve after weight loss in obese adolescents?

PubMed

Peyrot, Nicolas; Thivel, David; Isacco, Laurie; Morin, Jean-Benoît; Belli, Alain; Duche, Pascale

2012-04-01

This study tested the hypothesis that the increase in walking economy (i.e., decrease in net metabolic rate per kilogram) after weight loss in obese adolescents is induced by a lower metabolic rate required to support the lower body weight and maintain balance during walking. Sixteen obese adolescent boys and girls were tested before and after a weight reduction program. Body composition and oxygen uptake while standing and walking at four preset speeds (0.75, 1, 1.25, and 1.5 m·s⁻¹) and at the preferred speed were quantified. Net metabolic rate and gross metabolic cost of walking-versus-speed relationships were determined. A three-compartment model was used to distinguish the respective parts of the metabolic rate associated with standing (compartment 1), maintaining balance and supporting body weight during walking (compartment 2), and muscle contractions required to move the center of mass and limbs (compartment 3). Standing metabolic rate per kilogram (compartment 1) significantly increased after weight loss, whereas net metabolic rate per kilogram during walking decreased by 9% on average across speeds. Consequently, the gross metabolic cost of walking per unit of distance-versus-speed relationship and hence preferred walking speeds did not change with weight loss. Compartment 2 of the model was significantly lower after weight loss, whereas compartment 3 did not change. The model showed that the improvement in walking economy after weight loss in obese adolescents was likely related to the lower metabolic rate of the isometric muscular contractions required to support the lower body weight and maintain balance during walking. Contrastingly, the part of the total metabolic rate associated with muscle contractions required to move the center of mass and limbs did not seem to be related to the improvement in walking economy in weight-reduced individuals.

Running for exercise mitigates age-related deterioration of walking economy.

PubMed

Ortega, Justus D; Beck, Owen N; Roby, Jaclyn M; Turney, Aria L; Kram, Rodger

2014-01-01

Impaired walking performance is a key predictor of morbidity among older adults. A distinctive characteristic of impaired walking performance among older adults is a greater metabolic cost (worse economy) compared to young adults. However, older adults who consistently run have been shown to retain a similar running economy as young runners. Unfortunately, those running studies did not measure the metabolic cost of walking. Thus, it is unclear if running exercise can prevent the deterioration of walking economy. To determine if and how regular walking vs. running exercise affects the economy of locomotion in older adults. 15 older adults (69 ± 3 years) who walk ≥ 30 min, 3x/week for exercise, "walkers" and 15 older adults (69 ± 5 years) who run ≥ 30 min, 3x/week, "runners" walked on a force-instrumented treadmill at three speeds (0.75, 1.25, and 1.75 m/s). We determined walking economy using expired gas analysis and walking mechanics via ground reaction forces during the last 2 minutes of each 5 minute trial. We compared walking economy between the two groups and to non-aerobically trained young and older adults from a prior study. Older runners had a 7-10% better walking economy than older walkers over the range of speeds tested (p = .016) and had walking economy similar to young sedentary adults over a similar range of speeds (p =  .237). We found no substantial biomechanical differences between older walkers and runners. In contrast to older runners, older walkers had similar walking economy as older sedentary adults (p =  .461) and ∼ 26% worse walking economy than young adults (p<.0001). Running mitigates the age-related deterioration of walking economy whereas walking for exercise appears to have minimal effect on the age-related deterioration in walking economy.

The clinical relevance of selecting resting data at different points in an energy cost of walking test in cerebral palsy.

PubMed

Plasschaert, Frank; Jones, Kim; Forward, Malcolm

2011-03-01

Energy cost of walking (ECOW) is defined as 'walking oxygen consumption minus resting oxygen consumption divided by speed', where 'resting' data can be obtained either at the start or cessation of a test. This study aimed to ascertain when resting data should be taken during an ECOW test in children with cerebral palsy (CP). Resting oxygen consumption per unit mass (VO(2) ) and heart rate were recorded in children without physical impairment (18 males, 13 females; mean age 11 y [SD 2 y 1 mo]) and children with diplegic CP (18 males, 13 females; mean age 11 y [SD 2 y 6 mo, Gross Motor Function Classification System levels I and II]) at three stages, namely pre- and posttest sitting and pretest standing before and after an 8-minute ECOW test using the Cosmed K4b. Heart rate and VO(2) differed significantly between groups and stages (p ≤ 0.05) except for heart rate in standing and posttest sitting in the unimpaired children and for VO(2) during pretest sitting between groups. These differences impacted on the calculation of non-dimensional net oxygen cost (NDNOC) and physiological cost index (PCI) in CP but not in the unimpaired group. PCI was correlated with NDNOC in CP but not in the unimpaired cohort. Pretest sitting resting data appear to be the most appropriate for use in the calculation of NDNOC and PCI. PCI may still have relevance in pathology where walking efficiency is compromised. © The Authors. Journal compilation © Mac Keith Press 2010.

The relationship of walking distances estimated by the patient, on the corridor and on a treadmill, and the Walking Impairment Questionnaire in intermittent claudication.

PubMed

Frans, Franceline Alkine; Zagers, Marjolein B; Jens, Sjoerd; Bipat, Shandra; Reekers, Jim A; Koelemay, Mark J W

2013-03-01

Physicians and patients consider the limited walking distance and perceived disability when they make decisions regarding (invasive) treatment of intermittent claudication (IC). We investigated the relationship between walking distances estimated by the patient, on the corridor and on a treadmill, and the Walking Impairment Questionnaire (WIQ) in patients with IC due to peripheral arterial disease. This was a single-center, prospective observational cohort study at a vascular laboratory in a university hospital in the Netherlands. The study consisted of 60 patients (41 male) with a median age of 64 years (range, 44-86 years) with IC and a walking distance ≤ 250 m on a standardized treadmill test. Main outcome measures were differences and Spearman rank correlations between pain-free walking distance, maximum walking distance (MWD) estimated by the patient, on the corridor and on a standardized treadmill test, and their correlation with the WIQ. The median patients' estimated, corridor, and treadmill MWD were 200, 200, and 123, respectively (P < .05). Although the median patients' estimated and corridor MWD were not significantly different, there was a difference on an individual basis. The correlation between the patients' estimated and corridor MWD was moderate (r = 0.61; 95% confidence interval [CI], 0.42-0.75). The correlation between patients' estimated and treadmill MWD was weak (r = 0.39; 95%, CI 0.15-0.58). Respective correlations for the pain-free walking distance were comparable. The patients' estimated MWD was moderately correlated with WIQ total score (r = 0.63; 95%, CI 0.45-0.76) and strongly correlated with WIQ distance score (r = 0.81; 95% CI, 0.69-0.88). The correlation between the corridor MWD and WIQ distance score was moderate (r = 0.59; 95% CI, 0.40-0.74). Patients' estimated walking distances and on a treadmill do not reflect walking distances in daily life. Instruments that take into account the perceived walking impairment, such as the WIQ

Isolating gait-related movement artifacts in electroencephalography during human walking.

PubMed

Kline, Julia E; Huang, Helen J; Snyder, Kristine L; Ferris, Daniel P

2015-08-01

High-density electroencephelography (EEG) can provide an insight into human brain function during real-world activities with walking. Some recent studies have used EEG to characterize brain activity during walking, but the relative contributions of movement artifact and electrocortical activity have been difficult to quantify. We aimed to characterize movement artifact recorded by EEG electrodes at a range of walking speeds and to test the efficacy of artifact removal methods. We also quantified the similarity between movement artifact recorded by EEG electrodes and a head-mounted accelerometer. We used a novel experimental method to isolate and record movement artifact with EEG electrodes during walking. We blocked electrophysiological signals using a nonconductive layer (silicone swim cap) and simulated an electrically conductive scalp on top of the swim cap using a wig coated with conductive gel. We recorded motion artifact EEG data from nine young human subjects walking on a treadmill at speeds from 0.4 to 1.6 m s(-1). We then tested artifact removal methods including moving average and wavelet-based techniques. Movement artifact recorded with EEG electrodes varied considerably, across speed, subject, and electrode location. The movement artifact measured with EEG electrodes did not correlate well with head acceleration. All of the tested artifact removal methods attenuated low-frequency noise but did not completely remove movement artifact. The spectral power fluctuations in the movement artifact data resembled data from some previously published studies of EEG during walking. Our results suggest that EEG data recorded during walking likely contains substantial movement artifact that: cannot be explained by head accelerations; varies across speed, subject, and channel; and cannot be removed using traditional signal processing methods. Future studies should focus on more sophisticated methods for removal of EEG movement artifact to advance the field.

Isolating gait-related movement artifacts in electroencephalography during human walking

PubMed Central

Kline, Julia E.; Huang, Helen J.; Snyder, Kristine L.; Ferris, Daniel P.

2016-01-01

Objective High-density electroencephelography (EEG) can provide insight into human brain function during real-world activities with walking. Some recent studies have used EEG to characterize brain activity during walking, but the relative contributions of movement artifact and electrocortical activity have been difficult to quantify. We aimed to characterize movement artifact recorded by EEG electrodes at a range of walking speeds and to test the efficacy of artifact removal methods. We also quantified the similarity between movement artifact recorded by EEG electrodes and a head-mounted accelerometer. Approach We used a novel experimental method to isolate and record movement artifact with EEG electrodes during walking. We blocked electrophysiological signals using a nonconductive layer (silicone swim cap) and simulated an electrically conductive scalp on top of the swim cap using a wig coated with conductive gel. We recorded motion artifact EEG data from nine young human subjects walking on a treadmill at speeds from 0.4–1.6 m/s. We then tested artifact removal methods including moving average and wavelet-based techniques. Main Results Movement artifact recorded with EEG electrodes varied considerably, across speed, subject, and electrode location. The movement artifact measured with EEG electrodes did not correlate well with head acceleration. All of the tested artifact removal methods attenuated low-frequency noise but did not completely remove movement artifact. The spectral power fluctuations in the movement artifact data resembled data from some previously published studies of EEG during walking. Significance Our results suggest that EEG data recorded during walking likely contains substantial movement artifact that: cannot be explained by head accelerations; varies across speed, subject, and channel; and cannot be removed using traditional signal processing methods. Future studies should focus on more sophisticated methods for removing of EEG movement

Footwear effects on walking balance at elevation.

PubMed

Simeonov, Peter; Hsiao, Hongwei; Powers, John; Ammons, Douglas; Amendola, Alfred; Kau, Tsui-Ying; Cantis, Douglas

2008-12-01

The study evaluated the effects of shoe style on workers' instability during walking at elevation. Twenty-four construction workers performed walking tasks on roof planks in a surround-screen virtual reality system, which simulated a residential roof environment. Three common athletic and three work shoe styles were tested on wide, narrow and tilted planks on a simulated roof and on an unrestricted surface at simulated ground. Dependent variables included lateral angular velocities of the trunk and the rear foot, as well as the workers' rated perceptions of instability. The results demonstrated that shoe style significantly affected workers walking instability at elevated work environments. The results highlighted two major shoe-design pathways for improving walking balance at elevation: enhancing rear foot motion control; and improving ankle proprioception. This study also outlined some of the challenges in optimal shoe selection and specific shoe-design needs for improved walking stability during roof work. The study adds to the knowledge in the area of balance control, by emphasising the role of footwear as a critical human-support surface interface during work on narrow surfaces at height. The results can be used for footwear selection and improvements to reduce risk of falls from elevation.

Changes in resting and walking energy expenditure and walking speed during pregnancy in obese women.

PubMed

Byrne, Nuala M; Groves, Ainsley M; McIntyre, H David; Callaway, Leonie K

2011-09-01

Energy-conserving processes reported in undernourished women during pregnancy are a recognized strategy for providing the energy required to support fetal development. Women who are obese before conceiving arguably have sufficient fat stores to support the energy demands of pregnancy without the need to provoke energy-conserving mechanisms. We tested the hypothesis that obese women would show behavioral adaptation [ie, a decrease in self-selected walking (SSW) speed] but not metabolic compensation [ie, a decrease in resting metabolic rate (RMR) or the metabolic cost of walking] during gestation. RMR, SSW speed, metabolic cost of walking, and anthropometric variables were measured in 23 women aged 31 ± 4 y with a BMI (in kg/m(2)) of 33.6 ± 2.5 (mean ± SD) at ≈15 and 30 wk of gestation. RMR was also measured in 2 cohorts of nonpregnant control subjects matched for the age, weight, and height of the pregnant cohort at 15 (n = 23) and 30 (n = 23) wk. Gestational weight gain varied widely (11.3 ± 5.4 kg), and 52% of the women gained more weight than is recommended. RMR increased significantly by an average of 177 ± 176 kcal/d (11 ± 12%; P < 0.0001); however, the within-group variability was large. Both the metabolic cost of walking and SSW speed decreased significantly (P < 0.01). Whereas RMR increased in >80% of the cohort, the net oxygen cost of walking decreased in the same proportion of women. Although the increase in RMR was greater than that explained by weight gain, evidence of both behavioral and biological compensation in the metabolic cost of walking was observed in obese women during gestation. The trial is registered with the Australian Clinical Trials Registry as ACTRN012606000271505.

Objectively assessing treadmill walking during the second and third pregnancy trimesters.

PubMed

DiNallo, Jennifer M; Downs, Danielle Symons; Le Masurier, Guy

2012-01-01

To effectively promote physical activity (PA) and quantify the effects of PA interventions for pregnant women, PA measurement during pregnancy needs improvement. The purpose of this study was to assess PA monitor output during a controlled, treadmill walking protocol among pregnant women at 20- and 32-weeks gestation. Women (N = 43) wore an Actigraph accelerometer, NL1000, and Yamax pedometer during a 20-minute treadmill walking test [5-minute periods at 4 different speeds (54, 67, 80, and 94 m·min(-1))] at 20- and 32-weeks gestation. Repeated-measures ANOVAs indicated that Actigraph total counts/minute and minutes of moderate-vigorous PA (MVPA), NL1000 steps and minutes MVPA, and Yamax steps decreased from 20- to 32-weeks gestation (P ≤ .05), while body girth circumference and activity monitor tilt increased (P ≤ .05). Repeated measures ANCOVAs, controlling for changes in body girth and monitor tilt, yielded no significant differences in any outcome measures from 20- to 32-weeks gestation. Preliminary results suggest physical changes during pregnancy impact activity monitor output in controlled settings. Accurately measuring and statistically controlling for changes in body girth at monitor placement site and monitor tilt may improve the accuracy of activity monitors for use with pregnant populations.

Lévy walks

NASA Astrophysics Data System (ADS)

Zaburdaev, V.; Denisov, S.; Klafter, J.

2015-04-01

Random walk is a fundamental concept with applications ranging from quantum physics to econometrics. Remarkably, one specific model of random walks appears to be ubiquitous across many fields as a tool to analyze transport phenomena in which the dispersal process is faster than dictated by Brownian diffusion. The Lévy-walk model combines two key features, the ability to generate anomalously fast diffusion and a finite velocity of a random walker. Recent results in optics, Hamiltonian chaos, cold atom dynamics, biophysics, and behavioral science demonstrate that this particular type of random walk provides significant insight into complex transport phenomena. This review gives a self-consistent introduction to Lévy walks, surveys their existing applications, including latest advances, and outlines further perspectives.

Effects of walking speed on the step-by-step control of step width.

PubMed

Stimpson, Katy H; Heitkamp, Lauren N; Horne, Joscelyn S; Dean, Jesse C

2018-02-08

Young, healthy adults walking at typical preferred speeds use step-by-step adjustments of step width to appropriately redirect their center of mass motion and ensure mediolateral stability. However, it is presently unclear whether this control strategy is retained when walking at the slower speeds preferred by many clinical populations. We investigated whether the typical stabilization strategy is influenced by walking speed. Twelve young, neurologically intact participants walked on a treadmill at a range of prescribed speeds (0.2-1.2 m/s). The mediolateral stabilization strategy was quantified as the proportion of step width variance predicted by the mechanical state of the pelvis throughout a step (calculated as R 2 magnitude from a multiple linear regression). Our ability to accurately predict the upcoming step width increased over the course of a step. The strength of the relationship between step width and pelvis mechanics at the start of a step was reduced at slower speeds. However, these speed-dependent differences largely disappeared by the end of a step, other than at the slowest walking speed (0.2 m/s). These results suggest that mechanics-dependent adjustments in step width are a consistent component of healthy gait across speeds and contexts. However, slower walking speeds may ease this control by allowing mediolateral repositioning of the swing leg to occur later in a step, thus encouraging slower walking among clinical populations with limited sensorimotor control. Published by Elsevier Ltd.

Effect of walking speed on lower extremity joint loading in graded ramp walking.

PubMed

Schwameder, Hermann; Lindenhofer, Elke; Müller, Erich

2005-07-01

Lower extremity joint loading during walking is strongly affected by the steepness of the slope and might cause pain and injuries in lower extremity joint structures. One feasible measure to reduce joint loading is the reduction of walking speed. Positive effects have been shown for level walking, but not for graded walking or hiking conditions. The aim of the study was to quantify the effect of walking speed (separated into the two components, step length and cadence) on the joint power of the hip, knee and ankle and to determine the knee joint forces in uphill and downhill walking. Ten participants walked up and down a ramp with step lengths of 0.46, 0.575 and 0.69 m and cadences of 80, 100 and 120 steps per minute. The ramp was equipped with a force platform and the locomotion was filmed with a 60 Hz video camera. Loading of the lower extremity joints was determined using inverse dynamics. A two-dimensional knee model was used to calculate forces in the knee structures during the stance phase. Walking speed affected lower extremity joint loading substantially and significantly. Change of step length caused much greater loading changes for all joints compared with change of cadence; the effects were more distinct in downhill than in uphill walking. The results indicate that lower extremity joint loading can be effectively controlled by varying step length and cadence during graded uphill and downhill walking. Hikers can avoid or reduce pain and injuries by reducing walking speed, particularly in downhill walking.

Does walking explain associations between access to greenspace and lower mortality?

PubMed Central

Lachowycz, Kate; Jones, Andy P.

2014-01-01

Despite emerging evidence that access to greenspace is associated with longer life expectancy, little is understood about what causal mechanisms may explain this relationship. Based on social-ecological theories of health, greenspace has multifaceted potential to influence mortality but the potential alternative mediating pathways have not been empirically tested. This study evaluates relationships between access to greenspace, walking and mortality. Firstly, we test for an association between access to greenspace and self-reported levels of walking using a survey of 165,424 adults across England collected during 2007 and 2008. Negative binomial regression multilevel models were used to examine associations between greenspace access and self reported number of days walked in the last month, in total and for recreational and health purposes, after controlling for relevant confounders. Secondly we use an area level analysis of 6781 middle super output areas across England to examine if recreational walking mediates relationships between greenspace access and reduced premature mortality from circulatory disease. Results show clear evidence of better greenspace access being associated with higher reported recreational walking. There were between 13% and 18% more days of recreational walking in the greenest quintile compared with the least green after adjustment for confounders. Tests for mediation found no evidence that recreational walking explain the associations between greenspace and mortality. Futhermore, whilst the relationship between greenspace access and walking was observed for all areas, the relationship between greenspace access and reduced mortality was only apparent in the most deprived areas. These findings indicate that the association between greenspace and mortality, if causal, may be explained by mediators other than walking, such as psychosocial factors. Future research should concentrate on understanding the causal mechanisms underlying observed

Walking Aids Moderate Exercise Effects on Gait Speed in People With Dementia: A Randomized Controlled Trial.

PubMed

Toots, Annika; Littbrand, Håkan; Holmberg, Henrik; Nordström, Peter; Lundin-Olsson, Lillemor; Gustafson, Yngve; Rosendahl, Erik

2017-03-01

To investigate the effects of exercise on gait speed, when tested using walking aids and without, and whether effects differed according to amount of support in the test. A cluster-randomized controlled trial. The Umeå Dementia and Exercise (UMDEX) study was set in 16 nursing homes in Umeå, Sweden. One hundred forty-one women and 45 men (mean age 85 years) with dementia, of whom 145 (78%) habitually used walking aids. Participants were randomized to the high-intensity functional exercise program or a seated attention control activity. Blinded assessors measured 4-m usual gait speed with walking aids if any gait speed (GS), and without walking aids and with minimum amount of support, at baseline, 4 months (on intervention completion), and 7 months. Linear mixed models showed no between-group effect in either gait speed test at 4 or 7 months. In interaction analyses exercise effects differed significantly between participants who walked unsupported compared with when walking aids or minimum support was used. Positive between-group exercise effects on gait speed (m/s) were found in subgroups that walked unsupported at 4 and 7 months (GS: 0.07, P = .009 and 0.13, P < .001; and GS test without walking aids: 0.05, P = .011 and 0.07, P = .029, respectively). In people with dementia living in nursing homes exercise had positive effects on gait when tested unsupported compared with when walking aids or minimum support was used. The study suggests that the use of walking aids in gait speed tests may conceal exercise effects. Copyright © 2016 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

Ant-inspired density estimation via random walks

PubMed Central

Musco, Cameron; Su, Hsin-Hao

2017-01-01

Many ant species use distributed population density estimation in applications ranging from quorum sensing, to task allocation, to appraisal of enemy colony strength. It has been shown that ants estimate local population density by tracking encounter rates: The higher the density, the more often the ants bump into each other. We study distributed density estimation from a theoretical perspective. We prove that a group of anonymous agents randomly walking on a grid are able to estimate their density within a small multiplicative error in few steps by measuring their rates of encounter with other agents. Despite dependencies inherent in the fact that nearby agents may collide repeatedly (and, worse, cannot recognize when this happens), our bound nearly matches what would be required to estimate density by independently sampling grid locations. From a biological perspective, our work helps shed light on how ants and other social insects can obtain relatively accurate density estimates via encounter rates. From a technical perspective, our analysis provides tools for understanding complex dependencies in the collision probabilities of multiple random walks. We bound the strength of these dependencies using local mixing properties of the underlying graph. Our results extend beyond the grid to more general graphs, and we discuss applications to size estimation for social networks, density estimation for robot swarms, and random walk-based sampling for sensor networks. PMID:28928146

Ant-inspired density estimation via random walks.

PubMed

Musco, Cameron; Su, Hsin-Hao; Lynch, Nancy A

2017-10-03

Many ant species use distributed population density estimation in applications ranging from quorum sensing, to task allocation, to appraisal of enemy colony strength. It has been shown that ants estimate local population density by tracking encounter rates: The higher the density, the more often the ants bump into each other. We study distributed density estimation from a theoretical perspective. We prove that a group of anonymous agents randomly walking on a grid are able to estimate their density within a small multiplicative error in few steps by measuring their rates of encounter with other agents. Despite dependencies inherent in the fact that nearby agents may collide repeatedly (and, worse, cannot recognize when this happens), our bound nearly matches what would be required to estimate density by independently sampling grid locations. From a biological perspective, our work helps shed light on how ants and other social insects can obtain relatively accurate density estimates via encounter rates. From a technical perspective, our analysis provides tools for understanding complex dependencies in the collision probabilities of multiple random walks. We bound the strength of these dependencies using local mixing properties of the underlying graph. Our results extend beyond the grid to more general graphs, and we discuss applications to size estimation for social networks, density estimation for robot swarms, and random walk-based sampling for sensor networks.

Reduced Gravity Walking Simulator

NASA Image and Video Library

1965-10-15

Cable system which supports the test subject on the Reduced Gravity Walking Simulator. The purpose of this simulator was to study the subject while walking, jumping or running. Researchers conducted studies of various factors such as fatigue limit, energy expenditure, and speed of locomotion. A.W. Vigil described the purpose of the simulator as follows: "When the astronauts land on the moon they will be in an unfamiliar environment involving, particularly, a gravitational field only one-sixth as strong as on earth. A novel method of simulating lunar gravity has been developed and is supported by a puppet-type suspension system at the end of a long pendulum. A floor is provided at the proper angle so that one-sixth of the subject's weight is supported by the floor with the remainder being supported by the suspension system. This simulator allows almost complete freedom in vertical translation and pitch and is considered to be a very realistic simulation of the lunar walking problem. For this problem this simulator suffers only slightly from the restrictions in lateral movement it puts on the test subject. This is not considered a strong disadvantage for ordinary walking problems since most of the motions do, in fact, occur in the vertical plane. However, this simulation technique would be severely restrictive if applied to the study of the extra-vehicular locomotion problem, for example, because in this situation complete six degrees of freedom are rather necessary. This technique, in effect, automatically introduces a two-axis attitude stabilization system into the problem. The technique could, however, be used in preliminary studies of extra-vehicular locomotion where, for example, it might be assumed that one axis of the attitude control system on the astronaut maneuvering unit may have failed." -- Published in James R. Hansen, Spaceflight Revolution: NASA Langley Research Center From Sputnik to Apollo, (Washington: NASA, 1995); A.W. Vigil, "Discussion of

Hypoxemia and arrhythmia during daily activities and six-minute walk test in fibrotic interstitial lung diseases.

PubMed

Park, Jeong Hyun; Jegal, Yangjin; Shim, Tae Sun; Lim, Chae-Man; Lee, Sang Do; Koh, Younsuck; Kim, Woo Sung; Kim, Won Dong; du Bois, Roland; Do, Kyung-Hyun; Kim, Dong Soon

2011-03-01

We performed 24-hr monitoring of pulse oximetric saturation (SpO(2)) with ECG and six-minute walk test (6MWT) in 19 patients with fibrotic interstitial lung diseases (ILD) to investigate; 1) The frequency and severity of hypoxemia and dysrhythmia during daily activities and 6MWT, 2) safety of 6MWT, and 3) the parameters of 6MWT which can replace 24-hr continuous monitoring of SpO(2) to predict hypoxemia during daily activities. All patients experienced waking hour hypoxemia, and eight of nineteen patients spent > 10% of waking hours in hypoxemic state. Most patients experienced frequent arrhythmia, mostly atrial premature contractions (APCs) and ventricular premature contractions (VPCs). There were significant correlation between the variables of 6MWT and hypoxemia during daily activities. All of the patients who desaturated below 80% before 300 meters spent more than 10% of waking hour in hypoxemia (P = 0.018). In contrast to waking hour hypoxemia, SpO(2) did not drop significantly during sleep except in the patients whose daytime resting SpO(2) was already low. In conclusion, patients with fibrotic ILD showed significant period of hypoxemia during daily activities and frequent VPCs and APCs. Six-minute walk test is a useful surrogate marker of waking hour hypoxemia and seems to be safe without continuous monitoring of SpO(2).

Adults' Daily Walking for Travel and Leisure: Interaction Between Attitude Toward Walking and the Neighborhood Environment.

PubMed

Yang, Yong; Diez-Roux, Ana V

2017-09-01

Studies on how the interaction of psychological and environmental characteristics influences walking are limited, and the results are inconsistent. Our aim is to examine how the attitude toward walking and neighborhood environments interacts to influence walking. Cross-sectional phone and mail survey. Participants randomly sampled from 6 study sites including Los Angeles, Chicago, Baltimore, Minneapolis, Manhattan, and Bronx Counties in New York City, and Forsyth and Davidson Counties in North Carolina. The final sample consisted of 2621 persons from 2011 to 2012. Total minutes of walking for travel or leisure, attitude toward walking, and perceptions of the neighborhood environments were self-reported. Street Smart (SS) Walk Score (a measure of walkability derived from a variety of geographic data) was obtained for each residential location. Linear regression models adjusting for age, gender, race/ethnicity, education, and income. Attitude toward walking was positively associated with walking for both purposes. Walking for travel was significantly associated with SS Walk Score, whereas walking for leisure was not. The SS Walk Score and selected perceived environment characteristics were associated with walking in people with a very positive attitude toward walking but were not associated with walking in people with a less positive attitude. Attitudes toward walking and neighborhood environments interact to affect walking behavior.

Effects of a Flexibility and Relaxation Programme, Walking, and Nordic Walking on Parkinson's Disease

PubMed Central

Reuter, I.; Mehnert, S.; Leone, P.; Kaps, M.; Oechsner, M.; Engelhardt, M.

2011-01-01

Symptoms of Parkinson's disease (PD) progress despite optimized medical treatment. The present study investigated the effects of a flexibility and relaxation programme, walking, and Nordic walking (NW) on walking speed, stride length, stride length variability, Parkinson-specific disability (UPDRS), and health-related quality of life (PDQ 39). 90 PD patients were randomly allocated to the 3 treatment groups. Patients participated in a 6-month study with 3 exercise sessions per week, each lasting 70 min. Assessment after completion of the training showed that pain was reduced in all groups, and balance and health-related quality of life were improved. Furthermore, walking, and Nordic walking improved stride length, gait variability, maximal walking speed, exercise capacity at submaximal level, and PD disease-specific disability on the UPDRS in addition. Nordic walking was superior to the flexibility and relaxation programme and walking in improving postural stability, stride length, gait pattern and gait variability. No significant injuries occurred during the training. All patients of the Nordic walking group continued Nordic walking after completing the study. PMID:21603199

Consumer-Based Physical Activity Monitor as a Practical Way to Measure Walking Intensity During Inpatient Stroke Rehabilitation.

PubMed

Klassen, Tara D; Semrau, Jennifer A; Dukelow, Sean P; Bayley, Mark T; Hill, Michael D; Eng, Janice J

2017-09-01

Identifying practical ways to accurately measure exercise intensity and dose in clinical environments is essential to advancing stroke rehabilitation. This is especially relevant in monitoring walking activity during inpatient rehabilitation where recovery is greatest. This study evaluated the accuracy of a readily available consumer-based physical activity monitor during daily inpatient stroke rehabilitation physical therapy sessions. Twenty-one individuals admitted to inpatient rehabilitation were monitored for a total of 471 one-hour physical therapy sessions which consisted of walking and nonwalking therapeutic activities. Participants wore a consumer-based physical activity monitor (Fitbit One) and the gold standard for assessing step count (StepWatch Activity Monitor) during physical therapy sessions. Linear mixed modeling was used to assess the relationship of the step count of the Fitbit to the StepWatch Activity Monitor. Device accuracy is reported as the percent error of the Fitbit compared with the StepWatch Activity Monitor. A strong relationship (slope=0.99; 95% confidence interval, 0.97-1.01) was found between the number of steps captured by the Fitbit One and the StepWatch Activity Monitor. The Fitbit One had a mean error of 10.9% (5.3) for participants with walking velocities <0.4 m/s, 6.8% (3.0) for walking velocities between 0.4 and 0.8 m/s, and 4.4% (2.8) for walking velocities >0.8 m/s. This study provides preliminary evidence that the Fitbit One, when positioned on the nonparetic ankle, can accurately measure walking steps early after stroke during inpatient rehabilitation physical therapy sessions. URL: https://www.clinicaltrials.gov. Unique identifier: NCT01915368. © 2017 American Heart Association, Inc.

Is the impact of fatigue related to walking capacity and perceived ability in persons with multiple sclerosis? A multicenter study.

PubMed

Dalgas, U; Langeskov-Christensen, M; Skjerbæk, A; Jensen, E; Baert, I; Romberg, A; Santoyo Medina, C; Gebara, B; Maertens de Noordhout, B; Knuts, K; Béthoux, F; Rasova, K; Severijns, D; Bibby, B M; Kalron, A; Norman, B; Van Geel, F; Wens, I; Feys, P

2018-04-15

The relationship between fatigue impact and walking capacity and perceived ability in patients with multiple sclerosis (MS) is inconclusive in the existing literature. A better understanding might guide new treatment avenues for fatigue and/or walking capacity in patients with MS. To investigate the relationship between the subjective impact of fatigue and objective walking capacity as well as subjective walking ability in MS patients. A cross-sectional multicenter study design was applied. Ambulatory MS patients (n = 189, age: 47.6 ± 10.5 years; gender: 115/74 women/men; Expanded Disability Status Scale (EDSS): 4.1 ± 1.8 [range: 0-6.5]) were tested at 11 sites. Objective tests of walking capacity included short walking tests (Timed 25-Foot Walk (T25FW), 10-Metre Walk Test (10mWT) at usual and fastest speed and the timed up and go (TUG)), and long walking tests (2- and 6-Minute Walk Tests (MWT). Subjective walking ability was tested applying the Multiple Sclerosis Walking Scale-12 (MSWS-12). Fatigue impact was measured by the self-reported modified fatigue impact scale (MFIS) consisting of a total score (MFIS total ) and three subscales (MFIS physical , MFIS cognitive and MFIS psychosocial ). Uni- and multivariate regression analysis were performed to evaluate the relation between walking and fatigue impact. MFIS total was negatively related with long (6MWT, r = -0.14, p = 0.05) and short composite (TUG, r = -0.22, p = 0.003) walking measures. MFIS physical showed a significant albeit weak relationship to walking speed in all walking capacity tests (r = -0.22 to -0.33, p < .0001), which persisted in the multivariate linear regression analysis. Subjective walking ability (MSWS-12) was related to MFIS total (r = 0.49, p < 0.0001), as well as to all other subscales of MFIS (r = 0.24-0.63, p < 0.001), showing stronger relationships than objective measures of walking. The physical impact of fatigue is weakly

Dynamic Visual Acuity While Walking in Normals and Labyrinthine-Deficient Patients

NASA Technical Reports Server (NTRS)

Hillman, Edward J.; Bloomberg, Jacob J.; McDonald, P. Vernon; Cohen, Helen S.

1996-01-01

We describe a new, objective, easily administered test of dynamic visual acuity (DVA) while walking. Ten normal subjects and five patients with histories of severe bilateral vestibular dysfunctions participated in this study. Subjects viewed a visual display of numerals of different font sizes presented on a laptop computer while they stood still and while they walked on a motorized treadmill. Treadmill speed was adapted for 4 of 5 patients. Subjects were asked to identify the numerals as they appeared on the computer screen. Test results were reasonably repeatable in normals. The percent correct responses at each font size dropped slightly while walking in normals and dropped significantly more in patients. Patients performed significantly worse than normals while standing still and while walking. This task may be useful for evaluating post-flight astronauts and vestibularly impaired patients.

Compliant walking appears metabolically advantageous at extreme step lengths.

PubMed

Kim, Jaehoon; Bertram, John E A

2018-05-19

Humans alter gait in response to unusual gait circumstances to accomplish the task of walking. For instance, subjects spontaneously increase leg compliance at a step length threshold as step length increases. Here we test the hypothesis that this transition occurs based on the level of energy expenditure, where compliant walking becomes less energetically demanding at long step lengths. To map and compare the metabolic cost of normal and compliant walking as step length increases. 10 healthy individuals walked on a treadmill using progressively increasing step lengths (100%, 120%, 140% and 160% of preferred step length), in both normal and compliant leg walking as energy expenditure was recorded via indirect calorimetry. Leg compliance was controlled by lowering the center-of-mass trajectory during stance, forcing the leg to flex and extend as the body moved over the foot contact. For normal step lengths, compliant leg walking was more costly than normal walking gait, but compliant leg walking energetic cost did not increase as rapidly for longer step lengths. This led to an intersection between normal and compliant walking cost curves at 114% relative step length (regression analysis; r 2  = 0.92 for normal walking; r 2  = 0.65 for compliant walking). Compliant leg walking is less energetically demanding at longer step lengths where a spontaneous shift to compliant walking has been observed, suggesting the human motor control system is sensitive to energetic requirements and will employ alternate movement patterns if advantageous strategies are available. The transition could be attributed to the interplay between (i) leg work controlling body travel during single stance and (ii) leg work to control energy loss in the step-to-step transition. Compliant leg walking requires more stance leg work at normal step lengths, but involves less energy loss at the step-to-step transition for very long steps. Copyright © 2018 Elsevier B.V. All rights reserved.

Combining Fast-Walking Training and a Step Activity Monitoring Program to Improve Daily Walking Activity After Stroke: A Preliminary Study.

PubMed

Danks, Kelly A; Pohlig, Ryan; Reisman, Darcy S

2016-09-01

To determine preliminary efficacy and to identify baseline characteristics predicting who would benefit most from fast walking training plus a step activity monitoring program (FAST+SAM) compared with fast walking training (FAST) alone in persons with chronic stroke. Randomized controlled trial with blinded assessors. Outpatient clinical research laboratory. Individuals (N=37) >6 months poststroke. Subjects were assigned to either FAST, which was walking training at their fastest possible speed on the treadmill (30min) and overground 3 times per week for 12 weeks, or FAST+SAM. The step activity monitoring program consisted of daily step monitoring with an activity monitor, goal setting, and identification of barriers to activity and strategies to overcome barriers. Daily step activity metrics (steps/day [SPD], time walking per day), walking speed, and 6-minute walk test (6MWT) distance. There was a significant effect of time for both groups, with all outcomes improving from pre- to posttraining (all P values <.05). The FAST+SAM was superior to FAST for 6MWT (P=.018), with a larger increase in the FAST+SAM group. The interventions had differential effectiveness based on baseline step activity. Sequential moderated regression models demonstrated that for subjects with baseline levels of step activity and 6MWT distances that were below the mean, the FAST+SAM intervention was more effective than FAST (1715±1584 vs 254±933 SPD; P<.05 for overall model and ΔR(2) for SPD and 6MWT). The addition of a step activity monitoring program to a fast walking training intervention may be most effective in persons with chronic stroke who have initial low levels of walking endurance and activity. Regardless of baseline performance, the FAST+SAM intervention was more effective for improving walking endurance. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Validity and Responsiveness of the Two-Minute Walk Test for Measuring Functional Recovery After Total Knee Arthroplasty.

PubMed

Unnanuntana, Aasis; Ruangsomboon, Pakpoom; Keesukpunt, Worawut

2018-06-01

The 2-minute walk test (2mwt) is a performance-based test that evaluates functional recovery after total knee arthroplasty (TKA). This study evaluated its validity compared with the modified Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Oxford Knee Score (OKS), modified Knee Score, Numerical Pain Rating Scale, and Timed Up and Go test, and its responsiveness in assessing functional recovery in TKA patients. This prospective cohort study included 162 patients undergoing primary TKA between 2013 and 2015. We used patient-reported outcome measures (modified WOMAC, OKS, modified Knee Score, Numerical Pain Rating Scale) and performance-based tests (2mwt and Timed Up and Go test) at baseline and 3, 6, and 12 months postoperatively. The construct validity of 2mwt was determined between the 2mwt distances walked and other outcome measurements. To assess responsiveness, effect size and standardized response mean were analyzed. Minimal clinically important difference of 2mwt at 12 months after TKA was also calculated. All outcome measurements improved significantly from baseline to 3, 6, and 12 months postoperatively. Bivariate analysis revealed mild to moderate associations between the 2mwt and modified WOMAC function subscales, and moderate to strong associations with OKS. Mild to moderate correlations were found for pain and stiffness between 2mwt and other outcome measurements. The effect size and standardized response mean at 12 months were large, with a minimal clinically important difference of 12.7 m. 2mwt is a validated performance-based test with responsiveness properties. Being simple and easy to perform, it can be used routinely in clinical practice to evaluate functional recovery after TKA. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Effects of jumping skill training on walking balance for children with mental retardation and Down's syndrome.

PubMed

Wang, W Y; Chang, J J

1997-08-01

In the present study, we hypothesized that the enhancements obtained from the practice of jumping activity could be transferred to improve the walking balance in children with mental retardation (MR) and Down's syndrome (DS). Fourteen children with the diagnosis of MR or DS, aged 3 to 6 years, were recruited from a day care institution. They were ambulant but without jumping ability. Sixty-one non-handicapped children was used to serve as a normative comparison group. Before the training program, the performances of walking balance, jump skills and jumping distances were assessed individually by one physical therapist. The balance sub-test in the Bruininks Oseretsky Test of Motor Proficiency (BOTMP) was administered to assess the walking balance. Motor Skill Inventory (MSI) was used to assess the qualitative levels of jumping skills. A jumping skill training lesson that included horizontal jumps and vertical jumps was designed and integrated into the educational program. The recruited children received 3 sessions of training per-week for 6 weeks. A post-training test and a follow-up test were administered to the handicapped children. In BOTMP scores, statistical differences exited between the pre-training and post-training tests in the tested items of floor walk and beam walk. However, no significant difference was found in the items of floor stand, beam stand and floor heel-toe walk. MSI scales revealed there were significant differences between pre-training and post-training tests. There was no significant difference between the scores of post-training test and the follow-up test. The results implicated that the jumping activity might effectively evoke the automatic and dynamic postural control. Moreover, the significant improvements of the floor walk and beam walk performances might be due to the transferred effects via the practice of dynamic jumping activity. Furthermore, implications and suggestions are discussed.

The effectiveness of body weight-supported gait training and floor walking in patients with chronic stroke.

PubMed

Peurala, Sinikka H; Tarkka, Ina M; Pitkänen, Kauko; Sivenius, Juhani

2005-08-01

To compare body weight-supported exercise on a gait trainer with walking exercise overground. Randomized controlled trial. Rehabilitation hospital. Forty-five ambulatory patients with chronic stroke. Patients were randomized to 3 groups: (1) gait trainer exercise with functional electric stimulation (GTstim), (2) gait trainer exercise without stimulation (GT), and (3) walking overground (WALK). All patients practiced gait for 15 sessions during 3 weeks (each session, 20 min), and they received additional physiotherapy 55 minutes daily. Ten-meter walk test (10MWT), six-minute walk test (6MWT), lower-limb spasticity and muscle force, postural sway tests, Modified Motor Assessment Scale (MMAS), and FIM instrument scores were recorded before, during, and after the rehabilitation and at 6 months follow-up. The mean walking distance using the gait trainer was 6900+/-1200 m in the GTstim group and 6500+/-1700 m in GT group. In the WALK group, the distance was 4800+/-2800 m, which was less than the walking distance obtained in the GTstim group (P=.027). The body-weight support was individually reduced from 30% to 9% of the body weight over the course of the program. In the pooled 45 patients, the 10MWT (P<.001), 6MWT (P<.001), MMAS (P<.001), dynamic balance test time (P<.001), and test trip (P=.005) scores improved; however, no differences were found between the groups. Both the body weight-supported training and walking exercise training programs resulted in faster gait after the intensive rehabilitation program. Patients' motor performance remained improved at the follow-up.

Real-time feedback enhances forward propulsion during walking in old adults.

PubMed

Franz, Jason R; Maletis, Michela; Kram, Rodger

2014-01-01

Reduced propulsive function during the push-off phase of walking plays a central role in the deterioration of walking ability with age. We used real-time propulsive feedback to test the hypothesis that old adults have an underutilized propulsive reserve available during walking. 8 old adults (mean [SD], age: 72.1 [3.9] years) and 11 young adults (age: 21.0 [1.5] years) participated. For our primary aim, old subjects walked: 1) normally, 2) with visual feedback of their peak propulsive ground reaction forces, and 3) with visual feedback of their medial gastrocnemius electromyographic activity during push-off. We asked those subjects to match a target set to 20% and 40% greater propulsive force or push-off muscle activity than normal walking. We tested young subjects walking normally only to provide reference ground reaction force values. Walking normally, old adults exerted 12.5% smaller peak propulsive forces than young adults (P<0.01). However, old adults significantly increased their propulsive forces and push-off muscle activities when we provided propulsive feedback. Most notably, force feedback elicited propulsive forces that were equal to or 10.5% greater than those of young adults (+20% target, P=0.87; +40% target, P=0.02). With electromyographic feedback, old adults significantly increased their push-off muscle activities but without increasing their propulsive forces. Old adults with propulsive deficits have a considerable and underutilized propulsive reserve available during level walking. Further, real-time propulsive feedback represents a promising therapeutic strategy to improve the forward propulsion of old adults and thus maintain their walking ability and independence. © 2013.

A comparison of the shuttle and 6 minute walking tests with measured peak oxygen consumption in patients with heart failure.

PubMed

Green, D J; Watts, K; Rankin, S; Wong, P; O'Driscoll, J G

2001-09-01

This study investigated the use of an incremental, externally-paced 10 m shuttle walk test (SWT) as an objective, reliable and predictive test of functional capacity in patients with heart failure (CHF). The SWT was compared to a 6 minute walk test (6WT) and a maximal symptom-limited treadmill peak oxygen consumption (VO2peak) test. Experiment 1 examined the reproducibility of the SWT. Two SWF trials were performed and distance ambulated (DA), heart rate (HR) and rate of perceived exertion (RPE) results compared. In experiment 2, SWT, 6WT, and VO2 peak tests were performed and HR. RPE and ambulatory VO2 compared. The SWT demonstrated strong test/retest reliability for DA (r = 0.98). HR (r = 0.96) and RPE (r = 0.89). Treadmill VO2 peak was significantly correlated with DA during the SWT (r = 0.83, P < 0.05), but not the 6WT. SWT peak VO2 (18.5 +/- 1.8 ml.kg(-1) x min(-1)) and treadmill VO2 peak (18.3 +/-2.0 ml.kg(-1) x min(-1)) were also highly correlated (r = 0.78, P < 0.05). Conversely, 6WT peak VO2 and treadmill VO2 peak were not significantly correlated. This study suggests the SWT is a reliable, objective test, highly predictive of VO2 peak which may be a more optimal field exercise test than the self paced 6WT.

The clinical significance of 10-m walk test standardizations in Parkinson's disease.

PubMed

Lindholm, Beata; Nilsson, Maria H; Hansson, Oskar; Hagell, Peter

2018-06-06

The 10-m walk test (10MWT) is a widely used measure of gait speed in Parkinson's disease (PD). However, it is unclear if different standardizations of its conduct impact test results. We examined the clinical significance of two aspects of the standardization of the 10MWT in mild PD: static vs. dynamic start, and a single vs. repeated trials. Implications for fall prediction were also explored. 151 people with PD (mean age and PD duration, 68 and 4 years, respectively) completed the 10MWT in comfortable gait speed with static and dynamic start (two trials each), and gait speed (m/s) was recorded. Participants then registered all prospective falls for 6 months. Absolute mean differences between outcomes from the various test conditions ranged between 0.016 and 0.040 m/s (effect sizes, 0.06-0.14) with high levels of agreement (intra-class correlation coefficients, 0.932-0.987) and small standard errors of measurement (0.032-0.076 m/s). Receiver operating characteristic curves showed similar discriminate abilities for prediction of future falls across conditions (areas under curves, 0.70-0.73). Cut-off points were estimated at 1.1-1.2 m/s. Different 10MWT standardizations yield very similar results, suggesting that there is no practical need for an acceleration distance or repeated trials when conducting this test in mild PD.

Quantum walk computation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kendon, Viv

2014-12-04

Quantum versions of random walks have diverse applications that are motivating experimental implementations as well as theoretical studies. Recent results showing quantum walks are “universal for quantum computation” relate to algorithms, to be run on quantum computers. We consider whether an experimental implementation of a quantum walk could provide useful computation before we have a universal quantum computer.

Reproducibility of oxygen saturation monitoring during six-minute walk test and exercise stress test in patients with pulmonary arteriovenous malformations associated with hereditary hemorrhagic telangiectasia.

PubMed

Li, Walter; Niu, Bolin; Henderson, Katherine; Northrup, Veronika; Pollak, Jeffery S; Trow, Terence; Fahey, John; White, Robert I

2011-06-01

Patients with pulmonary arteriovenous malformations (PAVMs) are at risk for multiple complications and require close follow-up. We investigated the reproducibility of the 6-minute walk test (6MWT) and exercise stress test (EST) for the evaluation of low oxygen saturation in patients with PAVMs. Twenty-two patients with PAVMs, most of whom had hereditary hemorrhagic telangiectasia (HHT), participated in a Human Investigations Committee-approved protocol. Patients ranged from 9 to 74 years of age (mean 28) and had a broad spectrum of anatomic subtypes of PAVMs, including focal and diffuse. Standard 6MWT and cycle ergometry EST were both performed twice with adequate rest between tests. Heart rate (HR) and oxygen saturation were measured at the beginning and end of each test. Distance walked and maximum resistance was also recorded. The intraclass correlation coefficients (r(i)) at the end of 6MWT were as follows: HR (r(i) = 0.940; 95% confidence interval [CI] 0.863-0.975), oxygen saturation (r(i) = 0.973; 95% CI 0.933-0.989), and distance (r(i) = 0.942; 95% CI 0.867-0.975). The r(i)s at the end of EST were as follows: HR (r(i) = 0.941; 95% CI 0.865-0.975), oxygen saturation (r(i) = 0.993; 95% CI 0.982-0.997), and maximum resistance (r(i) = 0.941; 95% CI 0.864-0.975). 6MWT and EST were reproducible measures of exercise capacity and oxygen saturation and are potential adjunct tests in the follow-up assessment for patients with PAVMs.

Relation Between Six-Minute Walk Test Performance and Outcomes After Transcatheter Aortic Valve Implantation (from the PARTNER Trial)

PubMed Central

Green, Philip; Cohen, David J.; Généreux, Philippe; McAndrew, Tom; Arnold, Suzanne V.; Alu, Maria; Beohar, Nirat; Rihal, Charanjit S.; Mack, Michael J.; Kapadia, Samir; Dvir, Danny; Maurer, Mathew S.; Williams, Mathew R.; Kodali, Susheel; Leon, Martin B.; Kirtane, Ajay J.

2013-01-01

Functional capacity as assessed by 6-minute walk test distance (6MWTD) has been shown to predict outcomes in selected cohorts with cardiovascular disease. To evaluate the association between 6MWTD and outcomes after transcatheter aortic valve implantation (TAVI) among participants in the Placement of AoRTic TraNscathetER valve (PARTNER) trial, TAVI recipients (n = 484) were stratified into 3 groups according to baseline 6MWTD: unable to walk (n = 218), slow walkers (n = 133), in whom 6MWTD was below the median (128.5 meters), and fast walkers (n = 133) with 6MWTD >128.5 meters. After TAVI, among fast walkers, follow-up 6MWTD decreased by 44 ± 148 meters at 12 months (p <0.02 compared with baseline). In contrast, among slow walkers, 6MWTD improved after TAVI by 58 ± 126 meters (p <0.001 compared with baseline). Similarly, among those unable to walk, 6MWTD distance increased by 66 ± 109 meters (p <0.001 compared with baseline). There were no differences in 30-day outcomes among 6MWTD groups. At 2 years, the rate of death from any cause was 42.5% in those unable to walk, 31.2% in slow walkers, and 28.8% in fast walkers (p = 0.02), driven primarily by differences in noncardiac death. In conclusion, among high-risk older adults undergoing TAVI, baseline 6MWTD does not predict procedural outcomes but does predict long-term mortality. Nonetheless, patients with poor baseline functional status exhibit the greatest improvement in 6MWTD. Additional work is required to identify those with poor functional status who stand to benefit the most from TAVI. PMID:23725996

Walking Distance as a Predictor of Falls in People With Multiple Sclerosis.

PubMed

Nilsagård, Ylva; Westerdahl, Elisabeth; Wittrin, Anna; Gunnarsson, Martin

2016-06-01

People with multiple sclerosis (PwMS) experience falls, usually when walking and transferring. The aim was to investigate if walking distance and patient overestimate of walking distance are predictors of falls in PwMS. A prospective study was conducted, with a single test occasion followed by prospective registration of falls for 3 months. All PwMS in Region Örebro County with a previously registered Expanded Disability Status Scale score between 3.0 and 7.0 in the Swedish MS Registry were invited to participate (n = 149). Altogether, data from 49 PwMS being relapse free for at least 3 months and with a confirmed Expanded Disability Status Scale between 1.5 and 7.0 upon study entry were analysed. Twenty-two PwMS (45%) fell during the study period, providing information of 66 falls. Walking distance or overestimate of one's walking distance, as compared with test results, did not predict falls in this MS sample. Walking and standing activities are associated with numerous falls in PwMS. Our data do not clearly support routine measurements of walking distance in assessing individual fall risk. © 2015 The Authors. Physiotherapy Research International published by John Wiley & Sons, Ltd. © 2015 The Authors. Physiotherapy Research International published by John Wiley & Sons, Ltd.

Modeling spatial segregation and travel cost influences on utilitarian walking: Towards policy intervention

PubMed Central

Yang, Yong; Auchincloss, Amy H.; Rodriguez, Daniel A.; Brown, Daniel G.; Riolo, Rick; Diez-Roux, Ana V.

2015-01-01

We develop an agent-based model of utilitarian walking and use the model to explore spatial and socioeconomic factors affecting adult utilitarian walking and how travel costs as well as various educational interventions aimed at changing attitudes can alter the prevalence of walking and income differentials in walking. The model is validated against US national data. We contrast realistic and extreme parameter values in our model and test effects of changing these parameters across various segregation and pricing scenarios while allowing for interactions between travel choice and place and for behavioral feedbacks. Results suggest that in addition to income differences in the perceived cost of time, the concentration of mixed land use (differential density of residences and businesses) are important determinants of income differences in walking (high income walk less), whereas safety from crime and income segregation on their own do not have large influences on income differences in walking. We also show the difficulty in altering walking behaviors for higher income groups who are insensitive to price and how adding to the cost of driving could increase the income differential in walking particularly in the context of segregation by income and land use. We show that strategies to decrease positive attitudes towards driving can interact synergistically with shifting cost structures to favor walking in increasing the percent of walking trips. Agent-based models, with their ability to capture dynamic processes and incorporate empirical data, are powerful tools to explore the influence on health behavior from multiple factors and test policy interventions. PMID:25733776

Walking Stability during Cell Phone Use in Healthy Adults

PubMed Central

Kao, Pei-Chun; Higginson, Christopher I.; Seymour, Kelly; Kamerdze, Morgan; Higginson, Jill S.

2015-01-01

The number of falls and/or accidental injuries associated with cellular phone use during walking is growing rapidly. Understanding the effects of concurrent cell phone use on human gait may help develop safety guidelines for pedestrians. It was shown previously that older adults had more pronounced dual-task interferences than younger adults when concurrent cognitive task required visual information processing. Thus, cell phone use might have greater impact on walking stability in older than in younger adults. This study examined gait stability and variability during a cell phone dialing task (phone) and two classic cognitive tasks, the Paced Auditory Serial Addition Test (PASAT) and Symbol Digit Modalities Test (SDMT). Nine older and seven younger healthy adults walked on a treadmill at four different conditions: walking only, PASAT, phone, and SDMT. We computed short-term local divergence exponent (LDE) of the trunk motion (local stability), dynamic margins of stability (MOS), step spatiotemporal measures, and kinematic variability. Older and younger adults had similar values of short-term LDE during all conditions, indicating that local stability was not affected by the dual-task. Compared to walking only, older and younger adults walked with significantly greater average mediolateral MOS during phone and SDMT conditions but significantly less ankle angle variability during all dual-tasks and less knee angle variability during PASAT. The current findings demonstrate that healthy adults may try to control foot placement and joint kinematics during cell phone use or another cognitive task with a visual component to ensure sufficient dynamic margins of stability and maintain local stability. PMID:25890490

Unleashing physical activity: an observational study of park use, dog walking, and physical activity.

PubMed

Temple, Viviene; Rhodes, Ryan; Wharf Higgins, Joan

2011-08-01

Walking has been identified as a low resourced yet effective means of achieving physical activity levels required for optimal health. From studies conducted around the world, we know that dog owners walk more than nondog owners. However, this evidence is largely self-reported which may not accurately reflect dog-owners' behaviors. To address this concern, we systematically observed the use of 6 different public parks in Victoria, British Columbia during fair and inclement weather. Using a modified version of the SOPARC tool, we documented visitors' types of physical activity, and the presence or absence of dogs. The Physical Activity Resource Assessment was used to consider park features, amenities, and incivilities. More people without dogs (73%) visited the parks than those with dogs (27%), largely because of attendance at the multiuse sport parks during the summer months. Despite the opportunities to engage in multiple sports, most people used the parks to walk. However, when inclement weather struck, dog owners continued visiting parks and sustained their walking practices significantly more than nondog owners. Our observational snapshot of park use supports earlier work that dogs serve as a motivational support for their owners' walking practices through fair and foul weather.

Stilt walking: how do we learn those first steps?

PubMed

Akram, Sakineh B; Frank, James S

2009-09-01

This study examined how young healthy adults learn stilt walking. Ten healthy male university students attended two sessions of testing held on two consecutive days. In each session participants performed three blocks of 10 stilt-walking trials. Angular movements of head and trunk and the spatial and temporal gait parameters were recorded. When walking on stilts young adults improved their gait velocity through modifications of step parameters while maintaining trunk movements close to that observed during normal over-ground walking. Participants improved their performance by increasing their step frequency and step length and reducing the double support percentage of the gait cycle. Stilts are often used for drywall installation, painting over-the-head areas and raising workers above the ground without the burden of erecting scaffolding. This research examines the locomotor adaptation as young healthy adults learn the complex motor task of stilt walking; a task that is frequently used in the construction industry.

Heightening Walking Above its Pedestrian Status : Walking and Travel Behavior in California

DOT National Transportation Integrated Search

2016-06-30

People walk a lotto walk pets, to exercise and recreate, and to access public transit and local shops. Walk trips begin and end almost every journey, even trips made by automobile. Data from the current California Household Travel Survey (CHTS) sh...

Walk Score® and Transit Score® and Walking in the Multi-Ethnic Study of Atherosclerosis

PubMed Central

Hirsch, Jana A.; Moore, Kari A.; Evenson, Kelly R.; Rodriguez, Daniel A; Diez Roux, Ana V.

2013-01-01

Background Walk Score® and Transit Score® are open-source measures of the neighborhood built environment to support walking (“walkability”) and access to transportation. Purpose To investigate associations of Street Smart Walk Score and Transit Score with self-reported transport and leisure walking using data from a large multi-city and diverse population-based sample of adults. Methods Data from a sample of 4552 residents of Baltimore MD; Chicago IL; Forsyth County NC; Los Angeles CA; New York NY; and St. Paul MN from the Multi-Ethnic Study of Atherosclerosis (2010–2012) were linked to Walk Score and Transit Score (collected in 2012). Logistic and linear regression models estimated ORs of not walking and mean differences in minutes walked, respectively, associated with continuous and categoric Walk Score and Transit Score. All analyses were conducted in 2012. Results After adjustment for site, key sociodemographic, and health variables, a higher Walk Score was associated with lower odds of not walking for transport and more minutes/week of transport walking. Compared to those in a “walker’s paradise,” lower categories of Walk Score were associated with a linear increase in odds of not transport walking and a decline in minutes of leisure walking. An increase in Transit Score was associated with lower odds of not transport walking or leisure walking, and additional minutes/week of leisure walking. Conclusions Walk Score and Transit Score appear to be useful as measures of walkability in analyses of neighborhood effects. PMID:23867022

Metabolic Rate and Perceived Exertion of Walking in Older Adults With Idiopathic Chronic Fatigue

PubMed Central

Corbett, Duane B.; Knaggs, Jeffrey D.; Manini, Todd M.

2016-01-01

Abstract Background: Fatigue is a common complaint in older adults, often not associated with underlying medical conditions. The purpose of this study was to investigate metabolic rate (MR) of walking, walking performance, and perception-based exertion during walking in older adults with and without idiopathic chronic fatigue (ICF). Methods: 20 older adults (aged 70.8±4.9 years), reporting 2 SD above normative values of the Functional Assessment of Chronic Illness Therapy-Fatigue scale and without overt health conditions that explained their symptoms, were compared with 25 age-matched older adults (73.2±5.1 years) without fatigue symptoms. Participants walked 400 m at a rapid pace on a 20-m course. On a separate visit, oxygen consumption was measured during treadmill test at standard (40.2 m/min), preferred paces (40–83 m/min) and peak capacity. Ratings of perceived exertion (RPE) were measured at each treadmill stage and after each lap of the 400-m walk test. Results: During the 400-m walk test, individuals with ICF showed lower overall walking speed and reported a steady increase in RPE with no change observed in non-fatigued group (1.63±1.72 vs 0.27±0.68, p < .01). Similar findings on RPE were noted on treadmill test. Gross MR, mass-specific MR, mass-specific net MR, and MR as a percent of peak oxygen consumption of walking were similar between groups during standard, preferred paces and peak capacity on treadmill. Conclusions: This study suggests that ICF in older adults is not related to elevated metabolic cost of walking. Higher RPE without concomitant decreases in performance indicate a potential disconnect between metabolic output and sensations during movement. PMID:27271253

Generalized teleportation by quantum walks

NASA Astrophysics Data System (ADS)

Wang, Yu; Shang, Yun; Xue, Peng

2017-09-01

We develop a generalized teleportation scheme based on quantum walks with two coins. For an unknown qubit state, we use two-step quantum walks on the line and quantum walks on the cycle with four vertices for teleportation. For any d-dimensional states, quantum walks on complete graphs and quantum walks on d-regular graphs can be used for implementing teleportation. Compared with existing d-dimensional states teleportation, prior entangled state is not required and the necessary maximal entanglement resource is generated by the first step of quantum walk. Moreover, two projective measurements with d elements are needed by quantum walks on the complete graph, rather than one joint measurement with d^2 basis states. Quantum walks have many applications in quantum computation and quantum simulations. This is the first scheme of realizing communicating protocol with quantum walks, thus opening wider applications.

Validity and reliability of the 6 minute walk in persons with fibromyalgia.

PubMed

King, S; Wessel, J; Bhambhani, Y; Maikala, R; Sholter, D; Maksymowych, W

1999-10-01

To assess the reliability and construct validity of the 6 minute walk (6MW) in persons with fibromyalgia (FM) and to determine an equation for predicting peak oxygen consumption (pVO2) from the distance covered in 6 minutes. Ninety-six women who met the American College of Rheumatology (ACR) criteria for FM were tested on the 6MW and the Fibromyalgia Impact Questionnaire (FIQ). A subset (n = 23) were tested on a separate day for pVO2 during a symptom-limited, incremental treadmill test. Twelve subjects repeated the 6MW five times over 10 days. Heart rate and rating of perceived exertion (RPE) were recorded for each walk. Intraclass correlations were used to determine the reliability of the 6MW. Validity was examined by correlating the 6MW with pVO2 and the FIQ. Body mass index (BMI) and 6MW were independent variables in a stepwise regression to predict pVO2. A significant increase in distance occurred from Walk 1 to Walk 2 (p = 0.000) with the distance maintained on the remaining walks (p = 0.148) The correlations of the 6MW with the FIQ and pVO2 were -0.325 and 0.657, respectively. The regression equation to predict pVO2 from 6MW distance and BMI was: pVO2 (ml/kg/min) = 21.48 + (-0.4316 x BMI) + [0.0304 x distance(m)] (R = 0.76, R2 = 0.66). When using the 6MW it is necessary to conduct a practice walk, with the second walk taken as the baseline measure. It was determined from the correlations that the 6MW cannot replace the FIQ as a measure of function. The 6MW may be used as an indicator of aerobic fitness, although obtaining VO2 by means of a graded exercise test is preferable.

Walking economy during cued versus non-cued self-selected treadmill walking in persons with Parkinson's disease.

PubMed

Gallo, Paul M; McIsaac, Tara L; Garber, Carol Ewing

2014-01-01

Gait impairments related to Parkinson's disease (PD) include variable step length and decreased walking velocity, which may result in poorer walking economy. Auditory cueing is a common method used to improve gait mechanics in PD that has been shown to worsen walking economy at set treadmill walking speeds. It is unknown if auditory cueing has the same effects on walking economy at self-selected treadmill walking speeds. To determine if auditory cueing will affect walking economy at self-selected treadmill walking speeds and at speeds slightly faster and slower than self-selected. Twenty-two participants with moderate PD performed three, 6-minute bouts of treadmill walking at three speeds (self-selected and ± 0.22 m·sec-1). One session used cueing and the other without cueing. Energy expenditure was measured and walking economy was calculated (energy expenditure/power). Poorer walking economy and higher energy expenditure occurred during cued walking at a self-selected and a slightly faster walking speed, but there was no apparent difference at the slightly slower speed. These results suggest that potential gait benefits of auditory cueing may come at an energy cost and poorer walking economy for persons with PD at least at some treadmill walking speeds.

The 10m incremental shuttle walk test is a highly reliable field exercise test for patients referred to cardiac rehabilitation: a retest reliability study.

PubMed

Hanson, Lisa C; Taylor, Nicholas F; McBurney, Helen

2016-09-01

To determine the retest reliability of the 10m incremental shuttle walk test (ISWT) in a mixed cardiac rehabilitation population. Participants completed two 10m ISWTs in a single session in a repeated measures study. Ten participants completed a third 10m ISWT as part of a pilot study. Hospital physiotherapy department. 62 adults aged a mean of 68 years (SD 10) referred to a cardiac rehabilitation program. Retest reliability of the 10m ISWT expressed as relative reliability and measurement error. Relative reliability was expressed in a ratio in the form of an intraclass correlation coefficient (ICC) and measurement error in the form of the standard error of measurement (SEM) and 95% confidence intervals for the group and individual. There was a high level of relative reliability over the two walks with an ICC of .99. The SEMagreement was 17m, and a change of at least 23m for the group and 54m for the individual would be required to be 95% confident of exceeding measurement error. The 10m ISWT demonstrated good retest reliability and is sufficiently reliable to be applied in practice in this population without the use of a practice test. Copyright © 2015 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

"On" freezing in Parkinson's disease: resistance to visual cue walking devices.

PubMed

Kompoliti, K; Goetz, C G; Leurgans, S; Morrissey, M; Siegel, I M

2000-03-01

To measure "on" freezing during unassisted walking (UW) and test if two devices, a modified inverted stick (MIS) and a visual laser beam stick (LBS) improved walking speed and number of "on" freezing episodes in patients with Parkinson's disease (PD). Multiple visual cues can overcome "off' freezing episodes and can be useful in improving gait function in parkinsonian patients. These devices have not been specifically tested in "on" freezing, which is unresponsive to pharmacologic manipulations. Patients with PD, motor fluctuations and freezing while "on," attempted walking on a 60-ft track with each of three walking conditions in a randomized order: UW, MIS, and LBS. Total time to complete a trial, number of freezes, and the ratio of walking time to the number of freezes were compared using Friedman's test. Twenty-eight patients with PD, mean age 67.81 years (standard deviation [SD] 7.54), mean disease duration 13.04 years (SD 7.49), and mean motor Unified Parkinson's Disease Rating Scale score "on" 32.59 (SD 10.93), participated in the study. There was a statistically significant correlation of time needed to complete a trial and number of freezes for all three conditions (Spearman correlations: UW 0.973, LBS 0.0.930, and MIS 0.842). The median number of freezes, median time to walk in each condition, and median walking time per freeze were not significantly different in pairwise comparisons of the three conditions (Friedman's test). Of the 28 subjects, six showed improvement with the MIS and six with the LBS in at least one outcome measure. Assisting devices, specifically based on visual cues, are not consistently beneficial in overcoming "on" freezing in most patients with PD. Because this is an otherwise untreatable clinical problem and because occasional subjects do respond, cautious trials of such devices under the supervision of a health professional should be conducted to identify those patients who might benefit from their long-term use.

Evaluation of the implementation of a whole-workplace walking programme using the RE-AIM framework.

PubMed

Adams, Emma J; Chalkley, Anna E; Esliger, Dale W; Sherar, Lauren B

2017-05-18

Promoting walking for the journey to/from work and during the working day is one potential approach to increase physical activity in adults. Walking Works was a practice-led, whole-workplace walking programme delivered by employees (walking champions). This study aimed to evaluate the implementation of Walking Works using the RE-AIM framework and provide recommendations for future delivery of whole-workplace walking programmes. Two cross sectional surveys were conducted; 1544 (28%) employees completed the baseline survey and 918 employees (21%) completed the follow-up survey. Effectiveness was assessed using baseline and follow-up data; reach, implementation and maintenance were assessed using follow-up data only. For categorical data, Chi square tests were conducted to assess differences between surveys or groups. Continuous data were analysed to test for significant differences using a Mann-Whitney U test. Telephone interviews were conducted with the lead organisation co-ordinator, eight walking champions and three business representatives at follow-up. Interviews were transcribed verbatim and analysed to identify key themes related to adoption, implementation and maintenance. Adoption: Five workplaces participated in Walking Works. Reach: 480 (52.3%) employees were aware of activities and 221 (24.1%) participated. A variety of walking activities were delivered. Some programme components were not delivered as planned which was partly due to barriers in using walking champions to deliver activities. These included the walking champions' capacity, skills, support needs, ability to engage senior management, and the number and type of activities they could deliver. Other barriers included lack of management support, difficulties communicating information about activities and challenges embedding the programme into normal business activities. Effectiveness: No significant changes in walking to/from work or walking during the working day were observed. Maintenance

Neighborhood design and walking trips in ten U.S. metropolitan areas.

PubMed

Boer, Rob; Zheng, Yuhui; Overton, Adrian; Ridgeway, Gregory K; Cohen, Deborah A

2007-04-01

Despite substantial evidence for neighborhood characteristics correlating with walking, so far there has been limited attention to possible practical implications for neighborhood design. This study investigates to what extent design guidelines are likely to stimulate walking. Four of the New Urbanism Smart Scorecard criteria and two other measures were tested for their influence on walking. Data were obtained from the 1995 National Personal Transportation Survey, U.S. Census 2000, and InfoUSA. Propensity-score methodology was used to control for potential confounders. Higher levels of business diversity and higher percentages of four-way intersections were associated with more walking. For example, the odds ratio (OR) for walking in a neighborhood with four business types present compared to three business types was 1.24 (confidence interval [CI] 1.07-1.44) and neighborhoods with 50%-74% four-way intersections had an OR for walking of 1.4 (CI 1.09-1.78) relative to those with 25%-49% four-way intersections. The effects of housing density on walking are mixed. Higher parking pressure and older median housing age did not significantly affect walking after covariate adjustment. Block length did not appear to be associated with walking. When considering the New Urbanism Smart Scorecard from the perspective walking, some, but not all, of its criteria that appear to have a correlation with walking are likely to be useful for designing walkable communities.

Detection of walking periods and number of steps in older adults and patients with Parkinson's disease: accuracy of a pedometer and an accelerometry-based method.

PubMed

Dijkstra, Baukje; Zijlstra, Wiebren; Scherder, Erik; Kamsma, Yvo

2008-07-01

The aim of this study was to examine if walking periods and number of steps can accurately be detected by a single small body-fixed device in older adults and patients with Parkinson's disease (PD). Results of an accelerometry-based method (DynaPort MicroMod) and a pedometer (Yamax Digi-Walker SW-200) worn on each hip were evaluated against video observation. Twenty older adults and 32 PD patients walked straight-line trajectories at different speeds, of different lengths and while doing secondary tasks in an indoor hallway. Accuracy of the instruments was expressed as absolute percentage error (older adults versus PD patients). Based on the video observation, a total of 236.8 min of gait duration and 24,713 steps were assessed. The DynaPort method predominantly overestimated gait duration (10.7 versus 11.1%) and underestimated the number of steps (7.4 versus 6.9%). Accuracy decreased significantly as walking distance decreased. Number of steps were also mainly underestimated by the pedometers, the left Yamax (6.8 versus 11.1%) being more accurate than the right Yamax (11.1 versus 16.3%). Step counting of both pedometers was significantly less accurate for short trajectories (3 or 5 m) and as walking pace decreased. It is concluded that the Yamax pedometer can be reliably used for this study population when walking at sufficiently high gait speeds (>1.0 m/s). The accelerometry-based method is less speed-dependent and proved to be more appropriate in the PD patients for walking trajectories of 5 m or more.

Modulation of walking speed by changing optic flow in persons with stroke

PubMed Central

Lamontagne, Anouk; Fung, Joyce; McFadyen, Bradford J; Faubert, Jocelyn

2007-01-01

Background Walking speed, which is often reduced after stroke, can be influenced by the perception of optic flow (OF) speed. The present study aims to: 1) compare the modulation of walking speed in response to OF speed changes between persons with stroke and healthy controls and 2) investigate whether virtual environments (VE) manipulating OF speed can be used to promote volitional changes in walking speed post stroke. Methods Twelve persons with stroke and 12 healthy individuals walked on a self-paced treadmill while viewing a virtual corridor in a helmet-mounted display. Two experiments were carried out on the same day. In experiment 1, the speed of an expanding OF was varied sinusoidally at 0.017 Hz (sine duration = 60 s), from 0 to 2 times the subject's comfortable walking speed, for a total duration of 5 minutes. In experiment 2, subjects were exposed to expanding OFs at discrete speeds that ranged from 0.25 to 2 times their comfortable speed. Each test trial was paired with a control trial performed at comfortable speed with matching OF. For each of the test trials, subjects were instructed to walk the distance within the same time as during the immediately preceding control trial. VEs were controlled by the CAREN-2 system (Motek). Instantaneous changes in gait speed (experiment 1) and the ratio of speed changes in the test trial over the control trial (experiment 2) were contrasted between the two groups of subjects. Results When OF speed was changing continuously (experiment 1), an out-of-phase modulation was observed in the gait speed of healthy subjects, such that slower OFs induced faster walking speeds, and vice versa. Persons with stroke displayed weaker (p < 0.05, T-test) correlation coefficients between gait speed and OF speed, due to less pronounced changes and an altered phasing of gait speed modulation. When OF speed was manipulated discretely (experiment 2), a negative linear relationship was generally observed between the test-control ratio of

Walking economy during cued versus non-cued treadmill walking in persons with Parkinson's disease.

PubMed

Gallo, Paul M; McIsaac, Tara L; Garber, Carol Ewing

2013-01-01

Gait impairment is common in Parkinson's disease (PD) and may result in greater energy expenditure, poorer walking economy, and fatigue during activities of daily living. Auditory cueing is an effective technique to improve gait; but the effects on energy expenditure are unknown. To determine whether energy expenditure differs in individuals with PD compared with healthy controls and if auditory cueing improves walking economy in PD. Twenty participants (10 PD and 10 controls) came to the laboratory for three sessions. Participants performed two, 6-minute bouts of treadmill walking at two speeds (1.12 m·sec-1 and 0.67 m·sec-1). One session used cueing and the other without cueing. A metabolic cart measured energy expenditure and walking economy was calculated (energy expenditure/power). PD had worse walking economy and higher energy expenditure than control participants during cued and non-cued walking at the 0.67 m·sec-1 speed and during non-cued walking at the 1.12 m·sec-1. With auditory cueing, energy expenditure and walking economy worsened in both participant groups. People with PD use more energy and have worse walking economy than adults without PD. Walking economy declines further with auditory cuing in persons with PD.

Walk This Way

ERIC Educational Resources Information Center

Mason, Nick

2007-01-01

A generation ago, it was part of growing up for all kids when they biked or walked to school. But in the last 30 years, heavier traffic, wider roads and more dangerous intersections have made it riskier for students walking or pedaling. Today, fewer than 15 percent of kids bike or walk to school compared with more than 50 percent in 1969. In the…

Can an aversive, extinction-resistant memory trigger impairments in walking adaptability? An experimental study using adult rats.

PubMed

Medeiros, Filipe Mello; de Carvalho Myskiw, Jociane; Baptista, Pedro Porto Alegre; Neves, Laura Tartari; Martins, Lucas Athaydes; Furini, Cristiane Regina Guerino; Izquierdo, Iván; Xavier, Léder Leal; Hollands, Kristen; Mestriner, Régis Gemerasca

2018-02-05

Cognitive demands can influence the adaptation of walking, a crucial skill to maintain body stability and prevent falls. Whilst previous research has shown emotional load tunes goal-directed movements, little attention has been given to this finding. This study sought to assess the effects of suffering an extinction-resistant memory on skilled walking performance in adult rats, as an indicator of walking adaptability. Thus, 36 Wistar rats were divided in a two-part experiment. In the first part (n=16), the aversive, extinction-resistance memory paradigm was established using a fear-conditioning chamber. In the second, rats (n=20) were assessed in a neutral room using the ladder rung walking test before and tree days after inducing an extinction-resistance memory. In addition, the elevated plus-maze test was used to control the influence of the anxiety-like status on gait adaptability. Our results revealed the shock group exhibited worse walking adaptability (lower skilled walking score), when compared to the sham group. Moreover, the immobility time in the ladder rung walking test was similar to the controls, suggesting that gait adaptability performance was not a consequence of the fear generalization. No anxiety-like behavior was observed in the plus maze test. Finally, correlation coefficients also showed the skilled walking performance score was positively correlated with the number of gait cycles and trial time in the ladder rung walking test and the total crossings in the plus maze. Overall, these preliminary findings provide evidence to hypothesize an aversive, extinction-resistant experience might change the emotional load, affecting the ability to adapt walking. Copyright © 2017. Published by Elsevier B.V.

Walking performance and muscle strength in the later stage poststroke: a nonlinear relationship.

PubMed

Carvalho, Cristiane; Sunnerhagen, Katharina S; Willén, Carin

2013-05-01

To evaluate the relation between muscle strength in the lower extremities and walking performance (speed and distance) in subjects in the later stage poststroke and to compare this with normative data. A cross-sectional observational study. University hospital department. Subjects poststroke (n=41; 31 men, 10 women) with a mean age of 59±5.8 years and a time from stroke onset of 52±36 months were evaluated. An urban sample (n=144) of 40- to 79-year-olds (69 men, 75 women) formed the healthy reference group. Not applicable. Muscle strength in the lower extremities was measured with an isokinetic dynamometer and combined into a strength index. Values for the 30-meter walk test for self-selected and maximum speed and the 6-minute walk test were measured. A nonlinear regression model was used. The average strength index was 730±309 in the subjects after stroke compared with 1112±362 in the healthy group. A nonlinear relation between walking performance and muscle strength was evident. The model explained 37% of the variance in self-selected speed in the stroke group and 20% in the healthy group, and 63% and 38%, respectively, in the maximum walking speed. For the 6-minute walk test, the model explained 44% of the variance in the stroke group. Subjects in the later stage poststroke were weaker than the healthy reference group, and their weakness was associated with walking performance. At the same strength index, subjects walked at lower speeds and shorter distances after stroke, indicating that there are multiple impairments that affect walking ability. Treatments focused on increasing muscle strength thus continue to hold promise. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Effects of Progressive Body Weight Support Treadmill Forward and Backward Walking Training on Stroke Patients' Affected Side Lower Extremity's Walking Ability.

PubMed

Kim, Kyunghoon; Lee, Sukmin; Lee, Kyoungbo

2014-12-01

[Purpose] The purpose of the present study was to examine the effects of progressive body weight supported treadmill forward and backward walking training (PBWSTFBWT), progressive body weight supported treadmill forward walking training (PBWSTFWT), progressive body weight supported treadmill backward walking training (PBWSTBWT), on stroke patients' affected side lower extremity's walking ability. [Subjects and Methods] A total of 36 chronic stroke patients were divided into three groups with 12 subjects in each group. Each of the groups performed one of the progressive body weight supported treadmill training methods for 30 minute, six times per week for three weeks, and then received general physical therapy without any other intervention until the follow-up tests. For the assessment of the affected side lower extremity's walking ability, step length of the affected side, stance phase of the affected side, swing phase of the affected side, single support of the affected side, and step time of the affected side were measured using optogait and the symmetry index. [Results] In the within group comparisons, all the three groups showed significant differences between before and after the intervention and in the comparison of the three groups, the PBWSTFBWT group showed more significant differences in all of the assessed items than the other two groups. [Conclusion] In the present study progressive body weight supported treadmill training was performed in an environment in which the subjects were actually walked, and PBWSTFBWT was more effective at efficiently training stroke patients' affected side lower extremity's walking ability.

Cellular telephone use during free-living walking significantly reduces average walking speed.

PubMed

Barkley, Jacob E; Lepp, Andrew

2016-03-31

Cellular telephone (cell phone) use decreases walking speed in controlled laboratory experiments and there is an inverse relationship between free-living walking speed and heart failure risk. The purpose of this study was to examine the impact of cell phone use on walking speed in a free-living environment. Subjects (n = 1142) were randomly observed walking on a 50 m University campus walkway. The time it took each subject to walk 50 m was recorded and subjects were coded into categories: cell phone held to the ear (talking, n = 95), holding and looking at the cell phone (texting, n = 118), not visibly using the cell phone (no use, n = 929). Subjects took significantly (p < 0.001) longer traversing the walkway when talking (39.3 s) and texting (37.9 s) versus no use (35.3 s). As was the case with the previous laboratory experiments, cell phone use significantly reduces average speed during free-living walking.

Validation of the Narrowing Beam Walking Test in Lower Limb Prosthesis Users.

PubMed

Sawers, Andrew; Hafner, Brian

2018-04-11

To evaluate the content, construct, and discriminant validity of the Narrowing Beam Walking Test (NBWT), a performance-based balance test for lower limb prosthesis users. Cross-sectional study. Research laboratory and prosthetics clinic. Unilateral transtibial and transfemoral prosthesis users (N=40). Not applicable. Content validity was examined by quantifying the percentage of participants receiving maximum or minimum scores (ie, ceiling and floor effects). Convergent construct validity was examined using correlations between participants' NBWT scores and scores or times on existing clinical balance tests regularly administered to lower limb prosthesis users. Known-groups construct validity was examined by comparing NBWT scores between groups of participants with different fall histories, amputation levels, amputation etiologies, and functional levels. Discriminant validity was evaluated by analyzing the area under each test's receiver operating characteristic (ROC) curve. No minimum or maximum scores were recorded on the NBWT. NBWT scores demonstrated strong correlations (ρ=.70‒.85) with scores/times on performance-based balance tests (timed Up and Go test, Four Square Step Test, and Berg Balance Scale) and a moderate correlation (ρ=.49) with the self-report Activities-specific Balance Confidence scale. NBWT performance was significantly lower among participants with a history of falls (P=.003), transfemoral amputation (P=.011), and a lower mobility level (P<.001). The NBWT also had the largest area under the ROC curve (.81) and was the only test to exhibit an area that was statistically significantly >.50 (ie, chance). The results provide strong evidence of content, construct, and discriminant validity for the NBWT as a performance-based test of balance ability. The evidence supports its use to assess balance impairments and fall risk in unilateral transtibial and transfemoral prosthesis users. Copyright © 2018 American Congress of Rehabilitation Medicine

Talk the Walk: Does Socio-Cognitive Resource Reallocation Facilitate the Development of Walking?

PubMed

Geva, Ronny; Orr, Edna

2016-01-01

Walking is of interest to psychology, robotics, zoology, neuroscience and medicine. Human's ability to walk on two feet is considered to be one of the defining characteristics of hominoid evolution. Evolutionary science propses that it emerged in response to limited environmental resources; yet the processes supporting its emergence are not fully understood. Developmental psychology research suggests that walking elicits cognitive advancements. We postulate that the relationship between cognitive development and walking is a bi-directional one; and further suggest that the initiation of novel capacities, such as walking, is related to internal socio-cognitive resource reallocation. We shed light on these notions by exploring infants' cognitive and socio-communicative outputs prospectively from 6-18 months of age. Structured bi/tri weekly evaluations of symbolic and verbal development were employed in an urban cohort (N = 9) for 12 months, during the transition from crawling to walking. Results show links between preemptive cognitive changes in socio-communicative output, symbolic-cognitive tool-use processes, and the age of emergence of walking. Plots of use rates of lower symbolic play levels before and after emergence of new skills illustrate reductions in use of previously attained key behaviors prior to emergence of higher symbolic play, language and walking. Further, individual differences in age of walking initiation were strongly related to the degree of reductions in complexity of object-use (r = .832, p < .005), along with increases, counter to the general reduction trend, in skills that serve recruitment of external resources [socio-communication bids before speech (r = -.696, p < .01), and speech bids before walking; r = .729, p < .01)]. Integration of these proactive changes using a computational approach yielded an even stronger link, underscoring internal resource reallocation as a facilitator of walking initiation (r = .901, p<0.001). These

Talk the Walk: Does Socio-Cognitive Resource Reallocation Facilitate the Development of Walking?

PubMed Central

Orr, Edna

2016-01-01

Walking is of interest to psychology, robotics, zoology, neuroscience and medicine. Human’s ability to walk on two feet is considered to be one of the defining characteristics of hominoid evolution. Evolutionary science propses that it emerged in response to limited environmental resources; yet the processes supporting its emergence are not fully understood. Developmental psychology research suggests that walking elicits cognitive advancements. We postulate that the relationship between cognitive development and walking is a bi-directional one; and further suggest that the initiation of novel capacities, such as walking, is related to internal socio-cognitive resource reallocation. We shed light on these notions by exploring infants’ cognitive and socio-communicative outputs prospectively from 6–18 months of age. Structured bi/tri weekly evaluations of symbolic and verbal development were employed in an urban cohort (N = 9) for 12 months, during the transition from crawling to walking. Results show links between preemptive cognitive changes in socio-communicative output, symbolic-cognitive tool-use processes, and the age of emergence of walking. Plots of use rates of lower symbolic play levels before and after emergence of new skills illustrate reductions in use of previously attained key behaviors prior to emergence of higher symbolic play, language and walking. Further, individual differences in age of walking initiation were strongly related to the degree of reductions in complexity of object-use (r = .832, p < .005), along with increases, counter to the general reduction trend, in skills that serve recruitment of external resources [socio-communication bids before speech (r = -.696, p < .01), and speech bids before walking; r = .729, p < .01)]. Integration of these proactive changes using a computational approach yielded an even stronger link, underscoring internal resource reallocation as a facilitator of walking initiation (r = .901, p<0.001). These

Automatic identification of inertial sensor placement on human body segments during walking

PubMed Central

2013-01-01

Background Current inertial motion capture systems are rarely used in biomedical applications. The attachment and connection of the sensors with cables is often a complex and time consuming task. Moreover, it is prone to errors, because each sensor has to be attached to a predefined body segment. By using wireless inertial sensors and automatic identification of their positions on the human body, the complexity of the set-up can be reduced and incorrect attachments are avoided. We present a novel method for the automatic identification of inertial sensors on human body segments during walking. This method allows the user to place (wireless) inertial sensors on arbitrary body segments. Next, the user walks for just a few seconds and the segment to which each sensor is attached is identified automatically. Methods Walking data was recorded from ten healthy subjects using an Xsens MVN Biomech system with full-body configuration (17 inertial sensors). Subjects were asked to walk for about 6 seconds at normal walking speed (about 5 km/h). After rotating the sensor data to a global coordinate frame with x-axis in walking direction, y-axis pointing left and z-axis vertical, RMS, mean, and correlation coefficient features were extracted from x-, y- and z-components and magnitudes of the accelerations, angular velocities and angular accelerations. As a classifier, a decision tree based on the C4.5 algorithm was developed using Weka (Waikato Environment for Knowledge Analysis). Results and conclusions After testing the algorithm with 10-fold cross-validation using 31 walking trials (involving 527 sensors), 514 sensors were correctly classified (97.5%). When a decision tree for a lower body plus trunk configuration (8 inertial sensors) was trained and tested using 10-fold cross-validation, 100% of the sensors were correctly identified. This decision tree was also tested on walking trials of 7 patients (17 walking trials) after anterior cruciate ligament reconstruction, which

Automatic identification of inertial sensor placement on human body segments during walking.

PubMed

Weenk, Dirk; van Beijnum, Bert-Jan F; Baten, Chris T M; Hermens, Hermie J; Veltink, Peter H

2013-03-21

Current inertial motion capture systems are rarely used in biomedical applications. The attachment and connection of the sensors with cables is often a complex and time consuming task. Moreover, it is prone to errors, because each sensor has to be attached to a predefined body segment. By using wireless inertial sensors and automatic identification of their positions on the human body, the complexity of the set-up can be reduced and incorrect attachments are avoided.We present a novel method for the automatic identification of inertial sensors on human body segments during walking. This method allows the user to place (wireless) inertial sensors on arbitrary body segments. Next, the user walks for just a few seconds and the segment to which each sensor is attached is identified automatically. Walking data was recorded from ten healthy subjects using an Xsens MVN Biomech system with full-body configuration (17 inertial sensors). Subjects were asked to walk for about 6 seconds at normal walking speed (about 5 km/h). After rotating the sensor data to a global coordinate frame with x-axis in walking direction, y-axis pointing left and z-axis vertical, RMS, mean, and correlation coefficient features were extracted from x-, y- and z-components and magnitudes of the accelerations, angular velocities and angular accelerations. As a classifier, a decision tree based on the C4.5 algorithm was developed using Weka (Waikato Environment for Knowledge Analysis). After testing the algorithm with 10-fold cross-validation using 31 walking trials (involving 527 sensors), 514 sensors were correctly classified (97.5%). When a decision tree for a lower body plus trunk configuration (8 inertial sensors) was trained and tested using 10-fold cross-validation, 100% of the sensors were correctly identified. This decision tree was also tested on walking trials of 7 patients (17 walking trials) after anterior cruciate ligament reconstruction, which also resulted in 100% correct identification

Reliability, Validity, and Responsiveness of the Incremental Shuttle Walk Test in Patients With Interstitial Lung Disease.

PubMed

Singh, Sumedha; Moiz, Jamal Ali; Ali, Mir Shad; Talwar, Deepak

2018-05-11

To determine the reliability, validity, and responsiveness of the incremental shuttle walk test (ISWT) in patients with interstitial lung disease (ILD). This was a cross-sectional longitudinal study. Patients (n = 27, 10 males; mean age ± SD, 61 ± 9.8 y) with ILD of any etiology, who participated in an outpatient pulmonary rehabilitation (PR) program, were recruited. Reliability was determined by comparing the distance covered in meters between the ISWT-1 and the ISWT-2. Validity was assessed by correlating the distance covered in the ISWT-1, with the maximum oxygen consumption (VO2max) obtained through cardiopulmonary exercise testing and distance covered during the 6-min walk test (6MWT). Responsiveness was assessed by comparing the distance covered in the ISWT-3, undertaken after the completion of PR, to the ISWT-1. The distance covered was equivalent between the ISWT-1 (216.7 ± 64.9 m) and the ISWT-2 (220.7 ± 67.3 m), with an excellent intraclass correlation coefficient (ICC2,1 = 0.91; 95% CI, 0.81-0.95). The standard error of measurement and minimal detectable change at the 95% CI (MDC95) values for the ISWT were 19.5 m and 53.9m, respectively. There were significant correlations between the distance covered on the ISWT and VO2max (r = 0.79, P < .0001) and the distance covered on the 6MWT (r = 0.76, P < .0001). Following PR, the change in the ISWT distance showed large effect size (ES = 0.85) and standardized response mean (SRM = 1.58). The ISWT is a reliable, valid, and responsive measure of estimated functional capacity in patients with ILD.

The 6 minute walk test and performance of upper limb in ambulant duchenne muscular dystrophy boys.

PubMed

Pane, Marika; Mazzone, Elena Stacy; Sivo, Serena; Fanelli, Lavinia; De Sanctis, Roberto; D'Amico, Adele; Messina, Sonia; Battini, Roberta; Bianco, Flaviana; Scutifero, Marianna; Petillo, Roberta; Frosini, Silvia; Scalise, Roberta; Vita, Gian Luca; Bruno, Claudio; Pedemonte, Marina; Mongini, Tiziana; Pegoraro, Elena; Brustia, Francesca; Gardani, Alice; Berardinelli, Angela; Lanzillotta, Valentina; Viggiano, Emanuela; Cavallaro, Filippo; Sframeli, Maria; Bello, Luca; Barp, Andrea; Busato, Fabio; Bonfiglio, Serena; Rolle, Enrica; Colia, Giulia; Bonetti, Annamaria; Palermo, Concetta; Graziano, Alessandra; D'Angelo, Grazia; Pini, Antonella; Corlatti, Alice; Gorni, Ksenija; Baranello, Giovanni; Antonaci, Laura; Bertini, Enrico; Politano, Luisa; Mercuri, Eugenio

2014-10-07

The Performance of Upper Limb (PUL) test was specifically developed for the assessment of upper limbs in Duchenne muscular dystrophy (DMD). The first published data have shown that early signs of involvement can also be found in ambulant DMD boys. The aim of this longitudinal Italian multicentric study was to evaluate the correlation between the 6 Minute Walk Test (6MWT) and the PUL in ambulant DMD boys. Both 6MWT and PUL were administered to 164 ambulant DMD boys of age between 5.0 and 16.17 years (mean 8.82). The 6 minute walk distance (6MWD) ranged between 118 and 557 (mean: 376.38, SD: 90.59). The PUL total scores ranged between 52 and 74 (mean: 70.74, SD: 4.66). The correlation between the two measures was 0.499. The scores on the PUL largely reflect the overall impairment observed on the 6MWT but the correlation was not linear. The use of the PUL appeared to be less relevant in the very strong patients with 6MWD above 400 meters, who, with few exceptions had near full scores. In patients with lower 6MWD the severity of upper limb involvement was more variable and could not always be predicted by the 6MWD value or by the use of steroids. Our results confirm that upper limb involvement can already be found in DMD boys even in the ambulant phase.

Beam Walking in Special Education

ERIC Educational Resources Information Center

Broadhead, Geoffrey D.

1974-01-01

An experimental test on beam walking (for balance), administered to 189 minimally brain injured and 226 educable mentally retarded (EMR) 8- to 13-year-old children, yielded results such as reliability estimates for the mean of three trials were high and there was greater performance reliability for EMR children. (MC)

Safety of early performance of the six-minute walk test following acute myocardial infarction: a cross-sectional study.

PubMed

Diniz, Lívia S; Neves, Victor R; Starke, Ana C; Barbosa, Marco P T; Britto, Raquel R; Ribeiro, Antônio L P

The six-minute walk test (6MWT) is a simple, low cost, reliable, and valid method for evaluating the functional capacity of cardiac patients. However, its early use and safety following acute myocardial infarction (AMI) is recent and has been little investigated. To evaluate and to compare the safety and the cardiac behavior of early performance of the 6MWT in patients following uncomplicated AMI up to 4 days or more than 4 days after the event. Following discharge from the Coronary Care Unit, 152 stable asymptomatic patients diagnosed with uncomplicated AMI performed the 6MWT. During the test, in addition to the distance walked, heart rate (HR), blood pressure (BP), and adverse events were also recorded. Electrocardiography was recorded using a Holter monitor in 105 patients. Patients were allocated considering two groups according to the number of days since AMI: Up to 4 Days Group and After 4 Days Group. All patients completed the 6MWT, 66 in the Up to 4 Days Group and 86 in the After 4 Days Group. The walking distance was similar in both groups (85% of the predicted value), as well as the physiological responses (increase in systolic BP and HR), reaching 63% (median) of maximum HR. Only 3.9% of patients had major complications (angina, drop in BP, or ventricular tachycardia), with no difference between the groups. None of the complications regarded as severe led to truly significant complications or death. The 6MWT was proven to be safe and feasible for early functional evaluation following uncomplicated AMI. Copyright © 2017 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. Publicado por Elsevier Editora Ltda. All rights reserved.

Poorer clock draw test scores are associated with greater functional impairment in peripheral artery disease: the Walking and Leg Circulation Study II.

PubMed

Zimmermann, Laura J; Ferrucci, Luigi; Kiang Liu; Lu Tian; Guralnik, Jack M; Criqui, Michael H; Yihua Liao; McDermott, Mary M

2011-06-01

We hypothesized that, in the absence of clinically recognized dementia, cognitive dysfunction measured by the clock draw test (CDT) is associated with greater functional impairment in men and women with peripheral artery disease (PAD). Participants were men and women aged 60 years and older with Mini-Mental Status Examination scores ≥ 24 with PAD (n = 335) and without PAD (n = 234). We evaluated the 6-minute walk test, 4-meter walking velocity at usual and fastest pace, the Short Physical Performance Battery (SPPB), and accelerometer-measured physical activity. CDTs were scored using the Shulman system as follows: Category 1 (worst): CDT score 0-2; Category 2: CDT score 3; Category 3 (best): CDT score 4-5. Results were adjusted for age, sex, race, education, ankle-brachial index (ABI), and comorbidities. In individuals with PAD, lower CDT scores were associated with slower 4-meter usual-paced walking velocity (Category 1: 0.78 meters/second; Category 2: 0.83 meters/second; Category 3: 0.86 meters/second; p-trend = 0.025) and lower physical activity (Category 1: 420 activity units; Category 2: 677 activity units; Category 3: 701 activity units; p-trend = 0.045). Poorer CDT scores were also associated with worse functional performance in individuals without PAD (usual and fast-paced walking velocity and SPPB, p-trend = 0.022, 0.043, and 0.031, respectively). In conclusion, cognitive impairment identified with CDT is independently associated with greater functional impairment in older, dementia-free individuals with and without PAD. Longitudinal studies are necessary to explore whether baseline CDT scores and changes in CDT scores over time can predict long-term decline in functional performance in individuals with and without PAD.

Walking speed and subclinical atherosclerosis in healthy older adults: the Whitehall II study.

PubMed

Hamer, Mark; Kivimaki, Mika; Lahiri, Avijit; Yerramasu, Ajay; Deanfield, John E; Marmot, Michael G; Steptoe, Andrew

2010-03-01

Extended walking speed is a predictor of incident cardiovascular disease (CVD) in older individuals, but the ability of an objective short-distance walking speed test to stratify the severity of preclinical conditions remains unclear. This study examined whether performance in an 8-ft walking speed test is associated with metabolic risk factors and subclinical atherosclerosis. Cross-sectional. Setting Epidemiological cohort. 530 adults (aged 63 + or - 6 years, 50.3% male) from the Whitehall II cohort study with no known history or objective signs of CVD. Electron beam computed tomography and ultrasound was used to assess the presence and extent of coronary artery calcification (CAC) and carotid intima-media thickness (IMT), respectively. High levels of CAC (Agatston score >100) were detected in 24% of the sample; the mean IMT was 0.75 mm (SD 0.15). Participants with no detectable CAC completed the walking course 0.16 s (95% CI 0.04 to 0.28) faster than those with CAC > or = 400. Objectively assessed, but not self-reported, faster walking speed was associated with a lower risk of high CAC (odds ratio 0.62, 95% CI 0.40 to 0.96) and lower IMT (beta=-0.04, 95% CI -0.01 to -0.07 mm) in comparison with the slowest walkers (bottom third), after adjusting for conventional risk factors. Faster walking speed was also associated with lower adiposity, C-reactive protein and low-density lipoprotein cholesterol. Short-distance walking speed is associated with metabolic risk and subclinical atherosclerosis in older adults without overt CVD. These data suggest that a non-aerobically challenging walking test reflects the presence of underlying vascular disease.

Walking stability during cell phone use in healthy adults.

PubMed