Predictive models for the six-minute walk test considering the walking course and physical activity level.

BACKGROUND: In recent decades, space limitations in the clinical environment have forced health professionals to administer the six-minute walk test (6MWT) using a 20-m or even a 10-m course. However, course length and physical activity level (PAL) affect the test outcomes. AIM: To develop a reference equation for the 6MWT that takes into account the effects of course length and PAL on the walking distance. DESIGN: Cross-sectional study. SETTING: Federal University of the State of Rio de Janeiro. POPULATION: Two hundred fifteen healthy adults. METHODS: All subjects performed the 6MWT on 10-, 20- and 30-m courses. Eight regression models were constructed considering the association between the six-minute walking distance (6MWD) and heart rate, perceived effort (scores from the Borg's Perceived Exertion Scale-BPES), PAL (classification according to the International Physical Activity Questionnaire, IPAQ), as well as anthropometric and demographic variables. The models were analyzed for the coefficients of determination (R2) and statistical significance at P<0.05. RESULTS: A nonlinear increase in the means of the 6MWDs obtained using the three course lengths was observed (591±70, 652±79 and 678±85 m for course lengths of 10, 20 and 30 m, respectively, with P<0.001). The 6MWD correlated positively with the following variables: sex (r=0.20), body height (r=0.30), IPAQ classification (r=0.14), ΔBPES rating (r=0.25) and Δheart rate (HR, r=0.23), with P<0.001 for all. In contrast, the 6MWD correlated negatively with age (r=-0.23) and Body Mass Index (BMI, r=-0.18), with P<0.001 for both. The regression model with the highest coefficient of determination (adjusted R2=0.36) included the following variables: sex, age, BMI, course length (CL), BPES, HR, and IPAQ. CONCLUSIONS: The length of the course strongly impacts individual performance on the 6MWT in a predominantly young adult population. Furthermore, IPAQ-assessed PAL is an important independent predictor of 6MWD. CLINICAL REHABILITATION IMPACT: The incorporation of course length in the prediction of 6MWD allows the use of a prediction equation that includes the effects of different course sizes. PAL should be used in the prediction of 6MWD.

Relationship between body balance, lung function, nutritional status and functional capacity in adults with cystic fibrosis

BACKGROUND: Cystic fibrosis (CF) is a hereditary condition in which lung disease affects all patients. In addition to pulmonary involvement, the multisystemic components of CF cause significant physical limitations. However, the impact of lung function on balance control in CF has not been studied. OBJECTIVE: To assess body balance in adults with CF and to test its possible associations with lung function, nutritional status, and functional capacity. METHOD: This was a cross-sectional study in which 14 adults with CF underwent pulmonary function testing (spirometry, body plethysmography, and carbon monoxide diffusing capacity (DLco), respiratory muscle strength, 6-min walking distance (6MWD), Berg balance scale (BBS), nutritional analysis (body mass index and bioelectrical impedance), and stabilometry. Body balance was quantified using stabilometry; all participants performed the following two trials: opened base, eyes open (OBEO); closed base, eyes closed (CBEC). RESULTS: In stabilometry, the median for the lateral range and anterior-posterior range in the CBEC trial was 0.10 (0.08-0.11) and 0.13 (0.11-0.22), respectively (p<0.05). The maximal inspiratory pressure (MIP) correlated inversely with the lateral standard deviation (ρ=–0.61; p<0.05) as the DLco correlated positively with the anterior-posterior range (ρ=0.54; p<0.05). There were significant relationships between body composition indexes and almost all stabilometric variables measured. There were no relationships of the BBS and 6MWD with the stabilometric variables. CONCLUSIONS: In adults with CF, imbalance occurs mainly in the anterior-posterior direction and is especially associated with body composition. .

Relationship between body balance, lung function, nutritional status and functional capacity in adults with cystic fibrosis.

BACKGROUND: Cystic fibrosis (CF) is a hereditary condition in which lung disease affects all patients. In addition to pulmonary involvement, the multisystemic components of CF cause significant physical limitations. However, the impact of lung function on balance control in CF has not been studied. OBJECTIVE: To assess body balance in adults with CF and to test its possible associations with lung function, nutritional status, and functional capacity. METHOD: This was a cross-sectional study in which 14 adults with CF underwent pulmonary function testing (spirometry, body plethysmography, and carbon monoxide diffusing capacity (DLco), respiratory muscle strength, 6-min walking distance (6MWD), Berg balance scale (BBS), nutritional analysis (body mass index and bioelectrical impedance), and stabilometry. Body balance was quantified using stabilometry; all participants performed the following two trials: opened base, eyes open (OBEO); closed base, eyes closed (CBEC). RESULTS: In stabilometry, the median for the lateral range and anterior-posterior range in the CBEC trial was 0.10 (0.08-0.11) and 0.13 (0.11-0.22), respectively (p<0.05). The maximal inspiratory pressure (MIP) correlated inversely with the lateral standard deviation (ρ=-0.61; p<0.05) as the DLco correlated positively with the anterior-posterior range (ρ=0.54; p<0.05). There were significant relationships between body composition indexes and almost all stabilometric variables measured. There were no relationships of the BBS and 6MWD with the stabilometric variables. CONCLUSIONS: In adults with CF, imbalance occurs mainly in the anterior-posterior direction and is especially associated with body composition.