Reference Equation for the Incremental Shuttle Walk Test in Children and Adolescents.

OBJECTIVE: To determine a prediction equation for distance walked of incremental shuttle walk test (ISWT) and test its reliability in children and adolescents. STUDY DESIGN: Cross-sectional study, which included 108 healthy volunteers between 6 and 18 years old. Those who had an abnormal spirometry or had a history of chronic disease were excluded. Two ISWT were performed. Heart rate and peripheral capillary oxygen saturation (SpO2) were continuously measured during the test. Dyspnea and lower limb fatigue were assessed by Borg scale before and after the tests. RESULTS: Boys walked longer distances compared with girls (1066.4 ± 254.1 m vs 889.7 ± 159.6 m, respectively, P < .0001). Except for dyspnea, there were no significant differences in the other outcomes measured (heart rate, lower limb fatigue, SpO2, and distance walked) at the peak of the two ISWT. The variables included in the predicted equation were age, body mass index, and sex. The predicted equation is: ISWTpred = 845.559 + (sex * 193.265) + (age * 47.850) - (body mass index * 26.179). The distance walked had an excellent reliability between the two ISWT, 0.98 (95% CI 0.97-0.99). The Bland-Altman plot shows agreement between tests (range from -40 to 45 m). CONCLUSIONS: We established a prediction equation for ISWT. It can be used as a reference to evaluate exercise capacity for children and adolescents. ISWT has excellent repeatability and it is a maximal-effort field test for this age group.

Effects of a pulmonary rehabilitation program on physical capacity, peripheral muscle function and inflammatory markers in asthmatic children and adolescents: study protocol for a randomized controlled trial.

BACKGROUND: Individuals with chronic lung disease are more susceptible to present reduction in exercise tolerance and muscles strength not only due to pulmonary limitations but also due systemic repercussions of the pulmonary disease. The aim of this study is to assess the physical capacity, peripheral muscle function, physical activity in daily life, and the inflammatory markers in children and adolescents with asthma after pulmonary rehabilitation program. METHOD: This is a study protocol of randomized controlled trial in asthmatic patients between 6 to 18 years old. The assessments will be conducted in three different days and will be performed at the beginning and at the end of the protocol. First visit: quality of life questionnaire, asthma control questionnaire, pre- and post-bronchodilator spirometry (400 µcg salbutamol), inflammatory assessment (blood collection), and cardiopulmonary exercise test on a cycle ergometer to determine aerobic capacity. Second visit: assessment of strength and endurance of the quadriceps femoris and biceps brachii muscles with concomitant electromyography to assess peripheral muscle strength. Third visit: incremental shuttle walk test (ISWT) and accelerometer to evaluate functional capacity and physical activity in daily life during 7 days. Then, the volunteers will be randomized to receive pulmonary rehabilitation program (intervention group) or chest physiotherapy + stretching exercises (control group). Both groups will have a supervised session, twice a week, each session will have 60 minutes duration, with minimum interval of 24 hours, for a period of 8 weeks. Intervention group: aerobic training (35 minutes) intensity between 60 to 80 % of the maximum workload of cardiopulmonary exercise testing or of ISWT; strength muscle training will be applied to the quadriceps femoris, biceps brachii and deltoid muscles (intensity: 40 to 70 % of maximal repetition, 3 x 8 repetition); finally the oral high-frequency oscillation device (Flutter®) will be used for 5 minutes. The control group: oral high-frequency oscillation device (Flutter®) for 10 minutes followed by the stretching of upper and lower limbs for 40 minutes. It is expected to observe the improvement in aerobic capacity, physical activity in daily life, muscle strength and quality of life of patients in the intervention group, and reduction in inflammatory markers. CLINICAL TRIAL NUMBER: NCT02383069. Data of registration: 03/03/2015.

Reference Equation for Respiratory Pressures in Pediatric Population: A Multicenter Study.

Previous studies have proposed only one prediction equation for respiratory muscle strength without taking into consideration differences between ages in pediatric population. In addition, those researches were single-center studies. The objective of this study was to establish reference equations for maximal inspiratory pressure (PImax) and maximal expiratory pressure (PEmax) in children and teenagers. In a multicenter study, 450 healthy volunteers were evaluated (aged 6-18yrs). There were included volunteers with normal lung function. We excluded volunteers who could not perform the tests; participated in physical activity more than twice a week; were born prematurely; smokers; chronic respiratory, cardiologic, and/or neurologic diseases; had acute respiratory disease during the prior three weeks. The volunteers were divided into two groups: Group 6-11 (6-11yrs) and Group 12-18 (12-18yrs). PImax and PEmax were measured according to statement. The mean PImax value was 85.6 (95%IC 83.6-87.6 cmH2O), and PEmax 84.6 (95%IC 85.5-86.2 cmH2O). The prediction equations for PImax and PEmax for Group 6-11 were 37.458-0.559 + (age * 3.253) + (BMI * 0.843) + (age * gender * 0.985); and 38.556 + 15.892 + (age * 3.023) + (BMI * 0.579) + (age * gender * 0.881), respectively (R2 = 0.34 and 0.31, P<0.001). The equations for Group 12-18 were 92.472 + (gender * 9.894) + 7.103, (R2 = 0.27, P = 0.006) for PImax; and 68.113 + (gender * 17.022) + 6.46 + (BMI * 0.927), (R2 = 0.34, P<0.0001) for PEmax. This multicenter study determined the respiratory muscle strength prediction equations for children and teenagers.

Chest wall mobility is related to respiratory muscle strength and lung volumes in healthy subjects.

BACKGROUND: Chest wall mobility is often measured in clinical practice, but the correlations between chest wall mobility and respiratory muscle strength and lung volumes are unknown. We investigate the associations between chest wall mobility, axillary and thoracic cirtometry values, respiratory muscle strength (maximum inspiratory pressure and maximum expiratory pressure), and lung volumes (expiratory reserve volume, FEV(1), inspiratory capacity, FEV(1)/FVC), and the determinants of chest mobility in healthy subjects. METHODS: In 64 healthy subjects we measured inspiratory capacity, FVC, FEV(1), expiratory reserve volume, maximum inspiratory pressure, and maximum expiratory pressure, and chest wall mobility via axillary and thoracic cirtometry. We used linear regression to evaluate the influence of the measured variables on chest wall mobility. RESULTS: The subjects' mean ± SD values were: age 24 ± 3 years, axillary cirtometry 6.3 ± 2.0 cm, thoracic cirtometry 7.5 ± 2.3 cm; maximum inspiratory pressure 90.4 ± 10.6% of predicted, maximum expiratory pressure 92.8 ± 13.5% of predicted, inspiratory capacity 99.7 ± 8.6% of predicted, FVC 101.9 ± 10.6% of predicted, FEV(1) 98.2 ± 10.3% of predicted, expiratory reserve volume 90.9 ± 19.9% of predicted. There were significant correlations between axillary cirtometry and FVC (r = 0.32), FEV(1) (r = 0.30), maximum inspiratory pressure (r = 0.48), maximum expiratory pressure (r = 0.25), and inspiratory capacity (r = 0.24), and between thoracic cirtometry and FVC (r = 0.50), FEV(1) (r = 0.48), maximum inspiratory pressure (r = 0.46), maximum expiratory pressure (r = 0.37), inspiratory capacity (r = 0.39), and expiratory reserve volume (r = 0.47). In multiple regression analysis the variable that best explained the axillary cirtometry variation was maximum inspiratory pressure (R(2) 0.23), and for thoracic cirtometry it was FVC and maximum inspiratory pressure (R(2) 0.32). CONCLUSIONS: Chest mobility in healthy subjects is related to respiratory muscle strength and lung function; the higher the axillary cirtometry and thoracic cirtometry values, the greater the maximum inspiratory pressure, maximum expiratory pressure, and lung volumes in healthy subjects.

Incremental shuttle walk test performed in a hallway and on a treadmill: are they interchangeable? / Shuttle walk teste incremental realizado no corredor e na esteira: eles são intercambiáveis? / La prueba incremental Shuttle walk realizada en el pasillo y la cinta caminadora: ¿son intercambiables?

ABSTRACT The performances of healthy individuals in an incremental shuttle walking test performed in a hallway (ISWT-H) and on a treadmill (ISWT-T) were compared to assess their physiological responses during aerobic training sessions with the speeds estimated from both tests. This was a cross-sectional study with 55 healthy subjects, who were randomized to perform the ISWT tests with 24 hours between them. Training sessions were held using a treadmill at 75% of the speeds obtained from the ISWT-H and ISWT-T. Measurements included walking distance, oxygen uptake (VO2), carbon dioxide (VCO2) production, heart rate (HR), and ventilation (VE). There was a significant difference between walking distances (ISWT-T: 823.9±165.2 m and ISWT-H:685.4±141.4 m), but similar physiological responses for VO2 (28.6±6.6 vs. 29.0±7.3 ml-1.kg-1.min-1), VCO2 (1.9±0.7 vs. 1.9±0.5 1), HR (158.3±17.8 vs. 158.6±17.7 bpm), and VE (41.5±10.4 vs. 43.7±12.9 1). The estimated speeds were different for the training sessions (5.5±0.5 km/h and 4.9±0.3 km/h), as well as the VO2, VCO2, VE, and HR. It was concluded that in healthy young adults, ISWTs carried out in a hallway and on a treadmill are not interchangeable. Since the ISWT-H was determined to have lower speed, the training intensity based on this test may underestimate a patient's responses to aerobic training.

RESUMO Comparou-se o desempenho no shuttle walk teste incremental realizado no corredor (SWTI-C) e na esteira (SWTI-E) em indivíduos saudáveis e comparar as respostas fisiológicas durante as sessões de treinamento aeróbio com as velocidades estimadas em ambos os testes. Trata-se de um estudo transversal com cinquenta e cinco participantes saudáveis. Os participantes foram randomizados para realizar os testes com 24 horas de intervalo. As sessões de treinamento foram realizadas na esteira com 75% da velocidade obtida no SWTI-C e no SWTI-E. As avaliações incluíram a distância da caminhada, consumo de oxigênio (VO2), produção de dióxido de carbono (VCO2), frequência cardíaca (FC) e ventilação (VE). Houve uma diferença significante entre as distâncias caminhadas (SWTI-E: 823,9 ± 165,2 m e SWTI-C: 685,4 ± 141,4 m), mas respostas fisiológicas semelhantes para o VO2 (28,6 ± 6,6 vs. 29,0 ± 7,3 ml-1.kg-1.min-1), VCO2 (1,9 ± 0,7 vs. 1,9 ± 0,5 1), HR (158,3 ± 17,8 vs. 158,6 ± 17,7 bpm) e VE (41,5 ± 10,4 vs. 43,7 ± 12,9 1). As velocidades estimadas foram diferentes para as sessões de treinamento (5,5 ± 0,5xkm/h e 4,9 ± 0,3 km/h), assim como o VO2, VCO2, VE e FC. Concluiu-se que em adultos jovens saudáveis, SWTI realizados no corredor e na esteira não são intercambiáveis. Uma vez que o SWTI-E determinou uma menor velocidade, a intensidade do treinamento baseada neste teste pode subestimar as respostas de um paciente ao treinamento aeróbio.

RESUMEN Se trata de una comparación del rendimiento en la prueba incremental shuttle walk llevado a cabo en el pasillo (SWPI-P) y en la cinta caminadora (SWPC) entre individuos sanos, para evaluar las respuestas fisiológicas durante las sesiones de entrenamiento aeróbico con velocidades estimadas en ambas pruebas. Estudio transversal con 55 individuos sanos. A los participantes se les eligieron al azar para realizar las pruebas con intervalo de 24 horas. Se llevaron a cabo sesiones de entrenamiento en la cinta caminadora con el 75 % de la velocidad obtenida en SWPI-P y en SWPC. Se incluyen entre las evaluaciones la distancia de la caminata, el consumo de oxígeno (VO2), la producción de dióxido de carbono (VCO2), la frecuencia cardiaca (FC) y la ventilación (VE). Hubo una diferencia significativa entre las distancias recorridas (SWPC: 823,9 ± 165,2 m y SWPI-P: 685,4 ± 141,4 m), pero similares a las respuestas fisiológicas del VO2 (28,6 ± 6,6 vs. 29,0 ± 7,3 ml-1.kg-1. min-1), VCO2 (1,9 ± 0,7 vs. ± 1,9 0,5 1), HR (158,3 ± 17,8 vs. 158,6 ± 17,7 bpm) y VE (41,5 ± 10,4 vs. 43,7 ± 12,9 1). Las velocidades estimadas fueron diferentes en las sesiones de entrenamiento (5,5 ± 0,5 km/h y 4,9 ± 0,3 km/h), así como VO2, VCO2, VE y FC. Se concluyó que, en los adultos jóvenes sanos, la SWPI llevada a cabo en el pasillo y en la cinta caminadora no pueden ser intercambiables. Dado que la SWPC determinó una menor velocidad, la intensidad de entrenamiento de esta prueba puede subestimar las respuestas de un paciente en el entrenamiento aeróbico.