Reference values on the 6-minute walk test for children living in the United States

Reference Values in the 6-Minute Walk Test in Chilean Children Aged 3-10 Years and Relationship With Cardiometabolic Risk

PURPOSE

The aim of this study was to evaluate the performance of healthy Chilean children aged 3-10 years in the 6-minute walking test (6MWT) and cardiometabolic risk variables and to determine sex- and age-specific reference values.

METHODS

This study involved 1165 healthy children (age = 6.36 [1.70] y old). The 6MWT was used to evaluate exercise performance. Furthermore, anthropometric measures were collected, like weight, height, body mass index, waist circumference, and skin folds. Resting heart rate and blood pressure (BP) were also evaluated.

RESULTS

The prevalence of overweight and obesity was 35.0% and 25.4% in preschoolers and 29.0% and 36.2% in school-age children, respectively, showing significant differences (P < .05) between age groups. The distance walked (6-min walk distance) increased significantly year on year at ages from 3 to 10 years. According to the regression analysis, 6MWT performance was positively related to age, systolic BP, and height, whereas it was negatively related to ∑4 skinfold fat, resting heart rate, diastolic BP, and waist circumference.

CONCLUSIONS

This study provides a reference equation and an age- and sex-adjusted percentile curve to assess the predicted 6MWT performance in a cohort of prepubertal Chilean children. The 6-minute walk distance depends mainly on age; however, other variables, such as resting heart rate, BP, skinfold fat, and waist circumference, add significant information and should be taken into account.

Feasibility of a Child-Friendly 2-Minute Walk Test: A Crossover Randomized Controlled Trial

AIMS

Most studies that use the NIH Toolbox 2-Minute Walk Test with young children, modify the protocol, compromising the generalizability of outcomes. A standardizable protocol is needed. The purpose of this study was to compare the 2MWT performance of children ages 3-6 years on the standard NIH Toolbox protocol and on a modified protocol designed to support young children.

METHODS

Cross-over randomized controlled trial. Fifteen typically developing children ages 3-6 years were randomly assigned to the performance order of the NIH toolbox 2MWT protocol and the Modified Accessibility Path (MAP) 2MWT protocol. Outcome variables and statistical analyses included test completion (McNemar test), distance walked (Wilcoxon signed-rank test), and accuracy (general estimating equation model with Poisson distribution).

RESULTS

All children completed 2 min of walking with the MAP protocol. Only 40% of children completed the NIH Toolbox protocol, with 83% of these NIH completers bolstered by previous exposure to the MAP protocol. Collapsed across the order, children also had significantly fewer errors per lap with the MAP protocol (p < 0.0001), despite walking a significantly greater distance (p = 0.006).

CONCLUSIONS

These findings lend preliminary support for standardized application of a 2MWT with young children when the protocol is designed to be child-friendly.

Physical Fitness Among Adolescents Who are Hispanic With Overweight or Obesity

PURPOSE

To describe cardiorespiratory, strength, muscular endurance, and flexibility fitness outcomes in a sample of adolescents who are Hispanic aged 11 to 15 years with overweight or obesity, stratified by age and sex.

METHODS

The sample included 280 adolescents (mean age: 13.0 ± 0.83 years, mean body mass index percentile: 94.6). Anthropometric measures included height, weight, body mass index percentile, and waist and hip circumference. Fitness measures included handgrip strength, sit-ups in 60 seconds, sit-and-reach test, and 6-minute walk test. We report mean scores for each fitness outcome measure and correlation coefficients with anthropometric measures.

RESULTS

Mean handgrip was 23.7 ± 6.48 kg, sit-and-reach test was 25.3 ± 8.13 cm, average sit-ups in 60 seconds were 19.4 ± 9.28, and 6-minute walk distance was 1960 ± 271 ft. Males outperformed females in all tests except sit-and-reach test.

DISCUSSION

Compared with published fitness values of healthy weight adolescents, our sample of adolescents who are Hispanic with overweight/obesity living in southern Florida is unconditioned in terms of cardiorespiratory fitness, strength, muscular endurance, and flexibility.

Diagnostic workup of childhood interstitial lung disease

Childhood interstitial lung diseases (chILDs) are rare and heterogeneous diseases with significant morbidity and mortality. An accurate and quick aetiological diagnosis may contribute to better management and personalised treatment. On behalf of the European Respiratory Society Clinical Research Collaboration for chILD (ERS CRC chILD-EU), this review summarises the roles of the general paediatrician, paediatric pulmonologists and expert centres in the complex diagnostic workup. Each patient's aetiological chILD diagnosis must be reached without prolonged delays in a stepwise approach from medical history, signs, symptoms, clinical tests and imaging, to advanced genetic analysis and specialised procedures including bronchoalveolar lavage and biopsy, if necessary. Finally, as medical progress is fast, the need to revisit a diagnosis of "undefined chILD" is stressed.

Reference values and equations for the 6-minute walk distance of Nigerian children aged 6-11 years: A cross-sectional study

BACKGROUND

The 6-minute walk test (6MWT), a simple, reliable, and valid test that uses the distance walked in 6 minute walk distance (6MWD) to quantify functional capacity, is widely used in the management of chronic disorders. However, the absence of reference standards from sub-Saharan African, including Nigerian, school-aged children limits its utility in this age group.

OBJECTIVES

To develop normative values and equations for the 6MWD of school-aged Nigerian children.

METHODS

In a cross-sectional study, healthy children aged 6-11 years in Lagos, Nigeria, completed the 6MWT on 20-m-long straight outdoor courses in their schools. The primary outcome was the 6MWD in meters while potential predictors included demographic (age, sex), anthropometric (height, weight, chest circumference, leg length) and physiologic variables (pre-walk, immediate post-walk, and fifth min-post-walk heart rate [HR], oxygen saturation [SpO₂ ], systolic blood pressure [SBP], diastolic blood pressure [DBP], and rating of perceived exertion [RPE]; and the difference between pre-walk and post-walk HR [∆HR], SpO₂ [∆SpO₂ ], SBP [∆SBP], DBP [∆DBP], and RPE [∆RPE]).

RESULTS

Overall, 627 pupils (52.1% girls) walked 504.6 ± 66.6 m (95% CI: 499.4, 509.8; range: 326.6-673.0 m); 16 m longer in boys (p = 0.002). A stepwise linear regression model yielded: 6MWD (m) = 347.9 + 14(Age_years ) + 1.6 (∆HR_beats/min ) + 17.6(Sex_{male=1, female=0} ) + 1.2(∆SBP_mmHg ); R²  = 0.25. Previously published reference equations mostly over-estimated Nigerian children's 6MWD.

CONCLUSION

These reference standards add to the global normative data on pediatric 6MWT and may be useful for the functional evaluation of Nigerian school-aged children with chronic childhood disorders.

Loaded Functional Strength Training versus Traditional Physical Therapy on Hip and Knee Extensors Strength and Function Walking Capacity in Children with Hemiplegic Cerebral Palsy: Randomized Comparative Study

Objective: This study’s objective was to see how loaded functional strengthening exercises using a plantigrade foot position and a shoe supporter affected muscle strength and walking ability in spastic hemiplegic children. Methods: Seventy-two children with spastic hemiplegic cerebral palsy, both sexes, aged ten to twelve years, were randomly assigned into two groups equal in number (control and intervention groups). The control group received a specially designed physical therapy program, whereas the intervention group received a loaded functional strengthening exercises program using a shoe supporter to maintain a plantigrade foot position. The training program was carried out for 60 min, three times per week for three consecutive months. All participants were evaluated both before and after the therapy program by using a Medical Commander Echo Manual Muscle Tester dynamometer to assess isometric muscle power of hip and knee extensors on the affected side. To assess functional walking capacity, a 6 min walking (6MWT) test was used. Results: Study groups were comparable with respect to all outcome measures at entry (p > 0.05). Within-group comparison showed significant improvements in all measured variables. Furthermore, between-group comparison revealed significantly greater improvements (p < 0.05) in hip and knee extensors strength as well as the functional walking capacity in favor of the intervention group. Conclusions: In all the analyzed variables, loaded functional strength exercises from the plantigrade foot position were found to be considerably more effective in the intervention group than in the control group.

Do different foot types affect the 6-min walk test capacity of younths with Charcot-Marie-Tooth neuropathy ?

BACKGROUND

The present study aimed to assess the gait capacity of youths with Charcot Marie Tooth disease (CMT), considering the different foot postures as a grouping variable.  METHODS: The total distance, the predicted distance, and gait velocity obtained during the six-minute walking test (6MWT) were compared between participants with and without CMT. In addition, part of the CMT group completed a 12-month follow-up. The study evaluated 63 participants (CMT group = 31; Non-CMT group = 32) aged 6 to 18, both sexes. Data included anthropometric measures, foot posture index (FPI), the distance (D6), percentage of predicted distance (%D6), and walking velocity(V) in 6MWT.

RESULTS

The D6% presented no significant difference between the types of feet in CMT or Non-CMT (p < 0.05, Kruskal Wallis test). CMT presented reduced values of D6, %D6, and V when compared to Non-CMT.

CONCLUSIONS

These findings indicate that gait performance was decreased in youths with CMT in comparison to non-CMT. Contrary to what was expected, the cavus foot type did not show lower gait capacity than the flatfoot, suggesting that the types of feet alone did not determine differences in gait capacity within the CMT group.

Reference Values for the Six Minute Walk Test in Children with Juvenile Idiopathic Arthritis

AIMS

To (1) describe six-minute walk test (6MWT) reference values for children with Juvenile Idiopathic Arthritis (JIA) and (2) explore predictors of 6MWT distance. A secondary objective was to determine how 6MWT distances of children with JIA compare to those of children without JIA reported in the literature.

METHODS

Demographic, clinical, height, weight and 6MWT data were extracted from clinical records of 120 children with JIA (70.8% female, mean age=12.4 ± 3.2 years) who attended a follow-up rheumatology clinic. A total of 272 6MWTs were included in the analyses. Linear mixed effects modeling was used to determine the relationship between predictive variables and 6MWT distance. 6MWT distances were compared to predicted values using published equations for estimating 6MWT distances in children without JIA.

RESULTS

Height, weight, and age were predictive of 6MWT distance (R² = 0.62). Mean 6MWT distances for children with JIA were lower than those reported for children without JIA (p < 0.001). Mean 6MWT distance was 84% and 78% of predicted values for children without JIA.

CONCLUSION

The reference values and associated predictive model have application for assessing exercise capacity in children with JIA.

The influence of body composition on the six-minute walk test in Chilean preschool and school children

BACKGROUND

the six minutes' walk test (6MWT) measures submaximal physical activity.

OBJECTIVE

this study determines the association of children´s nutritional status and body composition with the results of the 6MWT.

METHODS

a sample of 1419 Chilean children, 4 to 10 years of age, were assessed including anthropometry, body composition by validated equations, the 6MWT test, and in 50 % of the sample heart rate prior the test, at one minute into the test, and at one minute posttest with a Polar watch.

RESULTS

the distance walked ranged from 473.1 ± 47.8 m in preschool children to 584.2 ± 65.7 meters in school children. In heart rate there was a significant difference between obese and eutrophic children. The distance walked in the 6MWT was positively associated with fat-free mass (p < 0.05) and BMI (r2 = 0.49). Body composition influences 6MWT quartile distribution, as well as nutritional status. Age and height explained 49 % of the variance (R2 = 0.42 and 0.47, respectively) in the 6MWT, and there are significant differences in this variable by sex, body composition, and nutritional status.

CONCLUSIONS

body composition was associated with walking performance in children. Thus, it is important to evaluate height and body composition when assessing the six-minute walk test because of this important relationship.

Normative data for the 6-min walk test in 11-14 year-olds: a population-based study

BACKGROUND

The 6-min walk test (6MWT) has become an established measure for assessing exercise capacity in children with chronic diseases. However, little evidence has been provided regarding population-based normal data in healthy children. The main purpose of the study was to provide normative data in a large sample of children.

METHODS

In this cross-sectional study, 4352 children between 11 and 14 years were recruited (66% girls). The main outcome measure was the distance walked for six minutes. Sex- and age-specific percentile values (5th, 15th, 25th, 50th, 75th, 85th and 95th) for the 6MWT were created and the differences and correlations were examined by the analysis of variance and Pearson's coefficient of correlation.

RESULTS

The mean distance walked in 6 min was 576 ± 93 m in boys and 545 ± 92 m in girls, respectively. The mean walking speed for boys and girls was 98 ± 5 m/min and 91 ± 6 m/min. Older boys and girls performed better, compared to their younger counterparts (p for age < 0.001). The 6MWT was significantly correlated with age (r = 0.24, p < 0.001), height (r = 0.09, p < 0.001), weight (r =  - 0.13, p < 0.001) and body-mass index (r =  - 0.26, p < 0.001).

CONCLUSIONS

This is the first population-based study aiming to provide normative data for the 6MWT in healthy children between 11 to 14 years. Children in lower percentiles are 'target groups' for special intervention aiming to enhance the performance.

Arm span as a predictor of the six-minute walk test in healthy children

BACKGROUND

Six-minute walk test (6MWT) is the most used test to assess functional capacity. Including arm span in the prediction equations for 6MWT performance might be an alternative for use in traditional reference equations.

OBJECTIVE

The aim was to investigate the usability of arm span to predict the 6MWT distance in healthy children.

METHODS

262 healthy children aged between 6 and 12 years old participated in this study. 6MWT was conducted according to the standardized protocol. Height, weight, and arm span were measured before performing the 6MWT. A multiple stepwise linear regression analysis was used to generate the regression model.

RESULTS

The 6MWT distance had strong positive correlations with age, arm span, height, and weight (p<0.001). There was also a very strong correlation between arm span and height (p<0.001). Age and arm span were found as significant predictors in the first regression model. These two variables explained 60.2% of the variance in the 6MWT distance. Age and height were also found as significant predictors, explaining 60.5% of the variance in the 6MWT distance. The two following formula were obtained to predict the 6MWT distance: (-23.09+(31.12×Age)+(2.39×Arm span)) or (-80.0+(28.98×Age)+(2.92×Height)).

CONCLUSIONS

The results suggest that the combination of arm span (or height) and age are strong predictors of the 6MWT distance in healthy children.

Lung transplant referrals for individuals with cystic fibrosis: A pediatric perspective on the cystic fibrosis foundation consensus guidelines

Lung transplant referral guidelines for individuals with cystic fibrosis (CF) were published recently. Most of the recommendations focus on the specific indications and barriers to transplantation in adults with CF. Although the number of children with CF and end-stage lung disease continues to decrease, the specific issues related to pediatric patients merit further elucidation. We address each recommendation from the recent publication with a pediatric perspective. Furthermore, we note some significant differences between the practice and policy related to lung transplantation between Canada and the United States.

Does Ramadan Observance Affect Cardiorespiratory Capacity of Healthy Boys?

Studies raising the issue of the effects of Ramadan observance (RO) on boys' 6-min walk test (6MWT) data are rare. The studies, which did not include control groups of non-fasters, presented contradictory results. This study aimed to compare the 6MWT data (6-min walk distance [6MWD; m, %predicted], heart rate [HR; bpm, % of maximal predicted HR]), oxy-hemoglobin saturation (Oxy-sat; %), systolic and diastolic blood pressures (SBP and DBP, respectively; mmHg) determined at rest (_Rest and at the end _End of the test) of a group of 22 healthy fasting boys (age: 12 to 15 years) with an age-matched non-fasting group (n = 10). The 6MWTs were performed during three experimental conditions (ECs): Pre-Ramadan, Mid-Ramadan, and Post-Ramadan. The two groups' 6MWT data for each EC were compared, and repeated factorial analysis of variance (2 groups vs. 3 ECs) was performed. Both groups had similar values of 6MWD (m, %predicted), HR_Rest or HR_End (bpm, % of maximal predicted HR), Oxy-sat_Rest, Oxy-sat_End, SBP_Rest, and DBP_Rest during the three ECs. Compared to the non-fasting group, the fasting group had significantly higher SBP_End (121 ± 10 vs. 130 ± 11) and DBP_End (72 ± 6 vs. 78 ± 7) determined during the Mid-Ramadan EC. No significant interactive effects of the groups (2) vs. ECs (3) was found for the 6MWD (%predicted; p = .809), HR_Rest (%, p = .555), HR_End (%, p = .964), Oxy-sat_Rest (p = .336), Oxy-sat_End (p = .389), SBP_Rest (p = .708), SBP_End (p = .548), DBP_Rest (p = .277), and DBP_End (p = .096). To conclude, in boys, RO does not impact the 6MWD, HR, or Oxy-sat, but it has minimal impact on the SBP_End and DBP_End.

Randomized controlled trial of N-acetylcysteine therapy for RYR1-related myopathies

Objective

To investigate the efficacy of N-acetylcysteine (NAC) for decreasing elevated oxidative stress and increasing physical endurance in individuals with ryanodine receptor 1-related myopathies (RYR1-RM).

Methods

In this 6-month natural history assessment (n = 37) followed by a randomized, double-blinded, placebo-controlled trial, 33 eligible participants were block-randomized (1:1) to receive NAC (n = 16) or placebo (n = 17), orally for 6 months (adult dose 2,700 mg/d; pediatric dose 30 mg/kg/d). The primary endpoint was urine 15-F2t isoprostane concentration and the clinically meaningful co-primary endpoint was 6-minute walk test (6MWT) distance.

Results

When compared to the general population, participants had elevated baseline 15-F2t isoprostane concentrations and most had a decreased 6MWT distance (mean ± SD 3.2 ± 1.5 vs 1.1 ± 1.7 ng/mg creatinine and 468 ± 134 vs 600 ± 58 m, respectively, both p < 0.001). 15-F2t isoprostane concentration and 6MWT distance did not change over the 6-month natural history assessment (p = 0.98 and p = 0.61, respectively). NAC treatment did not improve 15-F2t isoprostane concentration (least squares means difference 0.1 [95% confidence interval [CI] −1.4 to 1.6] ng/mg creatinine, p = 0.88) or 6MWT distance (least squares means difference 24 [95% CI −5.5 to 53.4] m, p = 0.11). NAC was safe and well-tolerated at the doses administered in this study.

Conclusion

In ambulatory RYR1-RM–affected individuals, we observed stable disease course, and corroborated preclinical reports of elevated oxidative stress and decreased physical endurance. NAC treatment did not decrease elevated oxidative stress, as measured by 15-F2t isoprostane.

Classification of evidence

This study provides Class I evidence that, for people with RYR1-RM, treatment with oral NAC does not decrease oxidative stress as measured by 15-F2t isoprostane.

Clinicaltrials.gov identifier

NCT02362425.

Determinants of Work in the Six-Minute Walk Test in School-Age Children

Abstract Introduction: The Six-Minute Walk Test (6MWT) is widely used to assess functional capacity in children. The measure of work during 6MWT can add important information to the 6MWT assessment in this population as it relates to walking efficiency. Objective: To verify the determinants of work during the Six-Minute Walk Test (6MWTwork) in school-aged children. Method: This is a cross-sectional and exploratory study that included healthy children recruited from the public and private schools of the cities of Belo Horizonte and Uberlândia, Brazil. The inclusion criteria were: children aged 7 to 12 years without diagnosis of chronic cardiorespiratory disease, cognitive, behavioral disorder or physical function impairment (information obtained through self-report of those responsible for children). Exclusion criteria were children who refused to perform the 6MWT; who did not understand the 6MWT or who did not answer the test commands. Three hundred and nineteen school-aged children were included in the study. Correlation analyses and multiple linear regression analysis were used to identify the variables associated with the 6MWTwork. Results: Age, height, nutritional status, physical activity and heart rate showed significant correlation with 6MWTwork (p <0.001) and explained 87% of its variation (p = 0.0001). Conclusion: Age, height, nutritional status and heart rate variation are determinants of 6MWTwork that is able to evaluate functional capacity of school-aged children.

Reference values and prediction equation for the 6-minute walk test in healthy children aged 6–12 years old

Background/aim

The 6-minute walk test (6MWT) is the most commonly used and well-established test to measure functional exercise capacity in research and clinical settings. Country-specific reference values are important to interpret the results of 6MWT. However, no reference values have been reported for healthy Turkish children aged between 6 and 12 years old. The aim of this study was to determine normal reference values for the 6MWT test of healthy Turkish children aged between 6 and 12 years old.

Materials and methods

Two hundred and sixty-two healthy children aged between 6 and 12 years old were included in this cross-sectional study. Measures included height, weight, body mass index (BMI), leg length, and 6MWT distance (6MWD).

Results

The mean 6MWD was 572.58 (SD = 117.72) m. There were significant correlations between 6MWD and age (r = 0.764, P < 0.001), height (r = 0.742, P < 0.001), weight (r = 0.605, P < 0.001), BMI (r = 0.234, P < 0.001), and lower extremity length (r = 0.708, P < 0.001). In the stepwise multiple linear regression model, age and height explained about 60% of the variability of the 6MWT distance for the total sample.

Conclusion

Reference values and prediction equation for the 6MWT in healthy Turkish children aged 6–12 years old have been reported for the first time in this study. Researchers and clinicians can use them to interpret the effectiveness of a treatment and/or to compare the results of disabled children with healthy ones.

Effect of whole body vibration training on bone mineral density and functional capacity in children with thalassemia

Purpose: To investigate the effectiveness of whole body vibration (WBV) on bone mineral density (BMD) and functional capacity in children with β-thalassemia major. Methods: Thirty-nine children (23 boys and 16 girls) with β-thalassemia major, with ages ranging from 6 to 10 years, participated in a randomized controlled trial. They were selected and randomly divided, using computer-generated random numbers into two groups. The control group (n = 20) received the medical treatment and the physical therapy program whereas the study group (n = 19) received the same program as the control group in addition to WBV training (25-30 Hz, 2 mm amplitude, 10 repetitions (30-60 s) with 1 min rest, 15-20 min/day, 3 days/week/24 weeks). Bone mineral density and functional capacity were assessed before and after 24 weeks. Results: Both groups showed a significant increase in BMD and functional capacity after treatment compared with that before treatment (P ˂ 0.05). However, children in the study group demonstrated a significant increase in the functional capacity and the BMD of the lumbar spine, femoral neck and total body compared with that of the control group (P > .01). Conclusions: Whole body vibration may be an effective modality in improving BMD and functional capacity in children with β-thalassemia major.

Developmental Trajectories and Reference Percentiles for the 6-Minute Walk Test for Children With Cerebral Palsy

PURPOSE

The purposes of this study were to document longitudinal developmental trajectories in 6-minute walk test (6MWT) distances and to develop age-specific reference percentiles for children across different Gross Motor Function Classification System (GMFCS) levels.

METHODS

A TOTAL OF: 456 children with cerebral palsy ages 3 to 12 years of, GMFCS levels I to III participated. Children's motor function was classified on the GMFCS, and children completed the 6MWT 2 to 5 times in 2 years.

RESULTS

Longitudinal developmental trajectories support that 6MWT distances increase with age followed by a tapering, as children approach their functional limit relative to their GMFCS level. Reference percentile graphs were created to monitor change over time.

CONCLUSIONS

The 6MWT longitudinal developmental trajectories, reference percentiles, and interpretation of percentile change should assist collaborative and proactive intervention planning relative to functional walking capacity for children with cerebral palsy.

Effects of Structured Exercise Training in Children and Adolescents With Juvenile Idiopathic Arthritis

PURPOSE

To examine safety and efficacy of exercise training (ET) for juvenile idiopathic arthritis (JIA) to improve physical fitness, pain, functional capability, and quality of life.

METHODS

Ovid Medline, PubMed, CINAHL, PEDro, and Web of Science were searched from 1995 to April 2018 to find English-language articles examining effects of ET in JIA, ages 4 to 21 years. Quality of evidence/strength of clinical recommendations were assessed using the Cochrane GRADE (Grading of Recommendations, Assessment, Development and Evaluation) system. Results were reported using the 2009 Preferred Reporting Items for Systematic Reviews and meta-Analyses (PRISMA) checklist for health care interventions.

RESULTS

Nine papers met inclusion criteria. A total of 457 individuals with JIA, ages 4 to 19.9 years, received ET or alternate activity, wait-list, or no intervention. Moderate-quality evidence supports Stott Pilates and underwater knee-resistance exercise. No adverse effects of ET were reported.

CONCLUSIONS

Moderate-quality evidence exists for ET (30-50 minutes, 2-3 times/week, 12-24 weeks) to decrease pain, improve range of motion, knee strength, functional capability, and quality of life in JIA.

IMPULSE OSCILLOMETRY AND SPIROMETRY IN SCHOOLERS SUBMITTED TO THE SIX-MINUTE WALK TEST

OBJECTIVE

To verify repercussions of submaximal exercise testing on respiratory mechanics and pulmonary function in schoolchildren.

METHODS

Cross-sectional study, with children aged 7 to 14 years, who had their respiratory mechanics assessed by impulse oscillometry (IOS), and pulmonary function by spirometry. They performed the six-minute walk test (6MWT), as per the standards by the American Thoracic Society. The 6MWT was performed twice with a 30-minute interval. IOS and spirometry were performed before the first 6MWT (Pre-6MWT) and immediately after the first (Post-6MWT1) and second walking tests (Post-6MWT2). The results in these three phases were compared by analysis of variance for repeated measures (post-hoc Bonferroni test) or by the Friedman's test, with p≤0.05 considered significant.

RESULTS

Twenty-one subjects participated in the study: 53% were males and mean age was 10.9±2.3 years. There were differences between total resistance (R5) and central airway resistance (R20) at the three phases of assessment (p=0.025 and p=0.041, respectively). Post-hoc analysis indicated increase in R5 when Pre-6MWT and Post-6MWT1 were compared (R5=0.540±0.100 versus 0.590±0.150 kPa/L/s, p=0.013; and R20=0.440±0.800 versus 0.470±0.100 kPa/L/s, p=0.038). Forced expiratory flow 25-75% (FEF25-75%) changed over time (p=0.003).

CONCLUSIONS

Repercussions were: increase in central and total airway resistance and reduction of FEF25-75% after 6MWT in schoolchildren, suggesting that greater attention should be given to submaximal tests in children with predisposition to airways alterations.

Six minute walk distance and reference values in healthy Italian children: A cross-sectional study

The 6-minute walking test (6MWT) is a simple assessment tool to evaluate exercise capacity. The result of the test is the distance that a subject can walk at a constant and normal pace within 6 minutes (6MWD) and reflects the aerobic/fitness performance related to walking function. Use of 6MWT has been relevant to assess exercise tolerance either in healthy children or in patients with, heart, lung and metabolic diseases. Our aim was to find 6MWT reference values in healthy Italian children. The 6MWT was performed in 5614 children aged 6–11 years recruited from primary Italian schools. Age related reference percentiles of the covered distance were gender-modeled. A linear and quadratic regression model was used to predict 6MWT performance. Males walked longer distances than females, respectively 598.8±83.9 m vs 592.1±77.6 m (p = 0.0016). According to the regression analysis, 6MWD was positively related to age, gender and height, while it was negatively related to body weight [(6MWD = -160.16 + 93.35× age (years) -4.05× age²(years) +7.34× gender (m) +2.12× weight (kg) −2.50× height (cm)]. Reference values were established for the 6MWT in healthy children. The age related 6MWD percentiles provided a useful tool in the assessment of capacity in 6–11 year children, in fact they may be helpful to evaluate the effect of a given treatment or rehabilitation program and represent a feasible measure as to prevention within the primary school context. It was found a substantial difference from other countries for 6mwd values. In our study, factors such as age, weight and height were relevant for the prediction of 6MWD, similarly to other studies. Therefore, these variables should be taken into account in context of exercise performance.

Thirty-Second Walk Test: Expansion of Normative Data

PURPOSE

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.

METHODS

Five physical therapists administered the 30sWT on 1223 children developing typically (boys = 517, girls = 706) from 20 urban schools.

RESULTS

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.

CONCLUSION

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.

Do pedometers with or without education on exercise increase functional walking capacity and physical activity level in adolescents with juvenile idiopathic arthritis?

To evaluate the impact of pedometer use on the physical activity (PA) and functional walking capacity (FWC) of adolescents with juvenile idiopathic arthritis (JIA) and lower extremity (LE) involvement. Twenty-seven adolescents, aged 11-19 years with JIA and LE involvement, participated in the three-phase pedometer study that introduced the use of a pedometer and an education seminar at 6 weeks. Measurements were taken at the baseline first visit and at weeks 6, 12, and 20. The primary outcome measure was the 6-minute walk test (6MWT). Thirteen completed the study. Six-minute walk distance (6MWD) significantly increased from baseline (458.0 ± 70.8 m) to the end of phase 1 (501.4 ± 59.8 m) (p = 0.035), prior to receiving the pedometer; and from baseline to the end of study (p = 0.0037). No significant changes in 6MWD were found between weeks 6 and 12 (intervention) (p = 0.77) or between weeks 12 and 20 (follow through phase) (p = 0.27). In adolescents with LE JIA, consistent guidance and support by rheumatology professionals appears to positively influence PA and measures of FWC as seen through improved 6MWD. There was insufficient evidence to show that pedometers further increased FWC or PA.

Use of Pulmonary Hypertension Medications in Patients with Tetralogy of Fallot with Pulmonary Atresia and Multiple Aortopulmonary Collaterals

Tetralogy of Fallot (TOF) with pulmonary atresia (PA) and multiple aortopulmonary collaterals (MAPCAs) is a rare and severe form of congenital heart disease with poor prognosis. Aortopulmonary collaterals expose pulmonary arterioles to systemic pressure resulting in pulmonary hypertension (PH). To date, reports regarding the role of PH medications in this population are sparse. The objective of this study was to assess the effect of PH medications in patients with TOF, PA and MAPCAs or similar anatomy, with emphasis on symptoms, echocardiography and invasive hemodynamics. A retrospective review was performed for patients at a single tertiary care pediatric center. Twelve of 66 patients were treated with PH medications (18 %), and eight of these patients had adequate follow-up for further analysis. Median age at last follow-up was 6 years (range 1.4-21 years). Median length of therapy with PH medication was 4 years (range 0.3-17 years). PH medications included sildenafil, bosentan, ambrisentan, inhaled treprostinil and prostacyclin infusion. PH therapy was associated with improvement in symptoms in all patients and improvement in PH by hemodynamic measures in the majority of patients. All patients underwent at least one cardiac intervention by catheterization or surgery while taking PH medication. Two patients died from non-PH-related causes. The remaining six patients are alive and remain on PH medication. This review indicates that PH medications are well tolerated by this patient group and provide symptomatic improvement. Further studies are required to determine whether PH medications provide long-term survival benefit for patients with complex congenital heart disease.

Timed Up and Go: Reference Data for Children Who Are School Age

PURPOSE

To collect normative data for the Timed Up and Go (TUG) on a large, diverse sample of urban school children who are typically developing, accounting for age, sex, and body mass index.

METHODS

Physical therapists administered the TUG with natural walking speeds on 1481 children (M = 635, F = 846), ages 5 to 13 years representing 29.60% whites, 24.2% Asian/Pacific Islanders, 19.7% Latino/Hispanics, 16.3% African Americans, 1.40% Native American/Alaskans, and 8.80% other.

RESULTS

Average TUG speeds ranged from 6.20 to 7.12 seconds across all ages, with speeds decreasing from 5 to 9 years and increasing from 9 to 13 years. Differences between 8-, 9-, and 11-year-old males and females and across age groups did not exceed a clinically important threshold. Body mass index was not consistently correlated with TUG speed.

CONCLUSION

This study provides reference data on the TUG. These data should complement clinical observations and additional tests and measures to determine whether a student is functioning slower than age-matched peers.

C-Leg® improves function and quality of life in an adolescent traumatic trans-femoral amputee: a case study

BACKGROUND AND AIMS

(1) To demonstrate that a 13-year-old male can be successfully fitted with a C-Leg® microprocessor-controlled knee. (2) To use validated outcome measurement tools to assess change in mobility, physical function, fatigue and quality of life after fitting.

CASE DESCRIPTION AND METHODS

A 13-year-old unilateral traumatic trans-femoral amputee was studied pre-C-Leg fitting and 2 weeks and 10 months post C-Leg fitting.

FINDINGS AND OUTCOMES

The 6-Minute Walk Test improved by 33% from 360 to 480 m. PedsQL™ Multidimensional Fatigue Scale improved by 32% from 68 to 90, and PedsQL™ Quality of Life Scale improved 14 points, with minimal clinically important difference of 4.36 points.

CONCLUSION

In this case, the provision of a microprocessor-controlled knee in the context of a new prosthesis with new socket system produced improvements for the patient in walking speed, fatigue and quality of life.

CLINICAL RELEVANCE

This case report shows that n = 1 methodology can be used to demonstrate clinical improvement in an adolescent subject when using an intervention (C-Leg) which is not supported in this age group by published evidence.

Effects of Ramadan on physical capacities of North African boys fasting for the first time

INTRODUCTION

Most of the literature related to the effects of Ramadan fasting on physical performance has focused on adults, and only three studies have examined its impact on children's physical performance.

AIMS

To examine the effects of Ramadan fasting on first-time fasting boys' performance in short-term explosive exercises [vertical and horizontal jump tests (VJT and HJT), 20-m and 30-m sprints and medicine-ball throw (MBT)], as well as in sub-maximal endurance [6-min walking distance (6MWD) measured during the 6-min walk test (6MWT)].

METHODS

Eighteen Tunisian boys [mean±standard deviation (SD) of age and body mass (BM): 11.9±0.8 y and 55.4±18.2 kg, respectively] were included. The experimental design comprised four testing phases: 2-weeks before Ramadan (BR), the end of the second week (R2) and the fourth week (R4) of Ramadan, and 10-12 days after the end of Ramadan (AR). At each phase, boys performed two test sessions in the afternoon (15:00-17:00 h) interrupted by 48 h of recovery (first test session: BM, VJT, HJT, and 20-m and 30-m sprint tests; second session: MBT and 6MWT). The study was conducted during the summer of 2012 from July 5 to August 29.

RESULTS

6MWDs (m) were significantly shorter during R2 (652±101) and R4 (595±123) compared to BR (697±86) and came back to baseline values AR. BM (kg) mean±SD did not significantly change during R2 (52±15) and during R4 (53±15) compared to BR (55±17), and short-term explosive performances were unchanged throughout the study.

CONCLUSION

In non-athletic children, first-ever Ramadan fasting impairs sub-maximal aerobic capacity but has no effect on BM or short-term explosive performance.

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

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.

Six-minute walk test: reference values and prediction equation in healthy boys aged 5 to 12 years

OBJECTIVE

This study aimed to (1) generate normative data in healthy boys aged 5-12 years for the six-minute walk test (6MWT), an outcome measure currently used in clinical trials in Duchenne muscular dystrophy (DMD), (2) to describe the relation with anthropometric variables and myometry, and (3) to compare our data with published equations.

METHODS

The 6MWT was conducted in 442 boys according to a standardized protocol, as currently used in clinical trials in DMD. Maximal voluntary isometric contractions for knee flexion and extension were recorded with a hand-held myometer.

RESULTS

The 6MWD increased significantly with age, from 478.0 ± 44.1 m at age 5, to 650.0 ± 76.8 m at age 12, with the steepest increase between 5 and 8 years. Age- and height related percentile curves of the 6MWD were developed. Correlations with anthropometric variables were fair to good (age r = 0.60, height r = 0.57, weight r = 0.44). Myometric variables (knee flexors and extensors) showed correlations of 0.46 and 0.50 respectively. When dividing into two age categories (5-8 years, 9-12 years), these magnitudes of correlations only applied to the younger age group. Additionally, predicted values were calculated according to available reference equations (Geiger and Ben Saad), indicating an overestimation by those equations. Finally, the Geiger equation was refitted to our population.

CONCLUSION

The percentile curves according to age and height provide a useful tool in the assessment of ambulatory capacity in boys aged 5 to 12 years. Significant correlations with anthropometric variables and myometry were only found in the 5-8 years age group. The Geiger prediction equation, currently used to assess ambulatory capacity in DMD was refitted to obtain a more accurate prediction model based on a large sample with a homogenous distribution across the age categories 5 to 12 years and applying the methodology as currently used in clinical trials in DMD.

Six-minute walk test in healthy children: is the leg length important?

RATIONALE

Measures as height, age, and weight influence the six-minute walk test (6MWT). It was shown that children's true leg length (TLL) influence the 6MWT distance but so far it has never been evaluated how much this variable could predict the distance walked related to height. Our hypothesis is that there should not have any significant difference between models including height or TLL.

OBJECTIVE

To establish and to compare the predicted walked distance of healthy children in the 6MWT by two distinct models, one including TLL and other including height.

METHODS

Observational cross sectional study. A total of 161 healthy children (84 girls, 52.2%), 6-13 years old from three local primary and secondary schools. Two 6MWT were performed following ATS guidelines. Weight, height, and TLL were measured. The longer walked distance was selected for statistical analysis.

RESULTS

Anthropometric data were similar for both genders into each group of age. Mean (±SD) walked distances in whole group were: boys 704.4 m (77.7); girls 681.6 m (67.9; P = 0.049). In the univariate regression to predict the distance walked, the adjusted coefficients to TLL and height were in boys: 0.46 and 0.39; and in girls: 0.35 and 0.29, respectively. After adjusting for age and weight, the residuals of the two equations were not significantly different (P = 0.998).

CONCLUSION

The model including TLL to predict the walked distance by healthy children explained more of the variation on the walked distance in the 6MWT than the model using the height but without significant difference between the models.

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

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.

Six-minute walking test in children

IMPLICATIONS FOR REHABILITATION

Six-minute walking test. The six-minute walking test is safe and widely performed in the world because of its easy implementation and low cost. Many countries have established normal values to the six-minute walking test in healthy children. However, the applicability of this test also gains popularity among children with other disease conditions.

Test-retest reliability and developmental evolution of the 6-min walk test in Caucasian boys aged 5-12 years

The 6-min walk test (6MWT) assesses functional capacity and has been used as outcome measure in therapeutic studies in childhood neuromuscular disorders. The objectives were to evaluate test-retest reliability of the 6MWT and to generate normative data for healthy boys aged 5-12 years. Ninety boys (mean age 8 years 10 months) were recruited over four age subcategories (5-6, 7-8, 9-10, 11-12 years). Mean 6MWT distance and velocity (±standard deviation) for the total group were 555.5±93 m and 92.6±16.6 m/min. The 6MWT distance increased significantly with age. Test-retest reliability (mean interval 12 days) was very high for the total group (ICC>0.95) and for all age subcategories (ICC>0.80) a moderately high reliability (ICC>0.75) was found from 3 min onwards for each age subcategory. There was a mean difference of 5.2 m between test and retest without systematic bias. The standard error of measurement and smallest detectable difference were 20.7 and 57.4 m, respectively. These findings demonstrate the reliability of the 6MWT in young children, underscore its evolution with age, and indicate that a shorter version of the test is also reliable.

Percent-predicted 6-minute walk distance in duchenne muscular dystrophy to account for maturational influences

We recently described a modified version of the 6-minute walk test (6MWT) for Duchenne muscular dystrophy (DMD) based partly on the American Thoracic Society (ATS) guidelines. This measure has shown reliability, validity and utility as a primary outcome measure in DMD clinical trials. Because loss of muscle function in DMD occurs against the background of normal childhood growth and development, younger children with DMD can show increase in distance walked during 6MWT over ~1 year despite progressive muscular impairment. In this study, we compare 6-minute walk distance (6MWD) data from DMD boys (n=17) and typically developing control subjects (n=22) to existing normative data from age- and sex-matched children and adolescents. An age- and height-based equation fitted to normative data by Geiger and colleagues was used to convert 6MWD to a percent-predicted (%-predicted) value in boys with DMD. Analysis of %-predicted 6MWD data represents a method to account for normal growth and development, and shows that gains in function at early ages represents stable rather than improving abilities in boys with DMD. Boys with DMD from 4-7 years of age maintain a stable 6MWD approximately 80% of that of typically developing peers, with the deficit progressing at a variable rate thereafter.