title: The influence of lung function and muscular strength on the functional capacity of chronic obstructive pulmonary disease patients.
abstract: OBJECTIVE
  To determine which variable (forced expiratory volume in 1 second (FEV1), partial pressure of oxygen in arterial blood (PaO2), nocturnal hypoxaemia and muscular strength of femoral quadriceps) can predict the distance walked in the six-minute walk test (6MWT) by COPD patients.
  
  
  METHODS
  A cross-sectional and observational study of thirty patients referred to a pulmonary rehabilitation programme at a university hospital. Lung function was evaluated by spirometry, arterial blood gas analysis and nocturnal oximetry. Muscle function was evaluated by quadriceps strength and functional capacity by the 6MWT.
  
  
  RESULTS
  Bivariate regression analysis showed that quadriceps strength, was the only variable to correlate significantly with the distance walked in the 6MWT (p=0.002), accounting for 38% of the 6MWT variance. The statistical relationship established for these variables was 1kg of quadriceps strength equalled 5.9 metres walked in the 6MWT.
  
  
  CONCLUSIONS
  Our results showed the importance of lower limb muscle strength in submaximal exercise testing. We conclude that femoral quadriceps muscle strength is the only one of the variables studied which can predict the distance COPD patients walk in the 6MWT.
authors.affiliation: Mestre em Ciências da Saúde / MSC, Health Sciences.
authors.forename: Sérgio
authors.initials: S
authors.lastname: Leite Rodrigues
authors.forename: César Augusto
authors.initials: CA
authors.lastname: Melo E Silva
authors.forename: Tereza
authors.initials: T
authors.lastname: Lima
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: de Assis Viegas
authors.forename: Marcelo
authors.initials: M
authors.lastname: Palmeira Rodrigues
authors.forename: Fernanda
authors.initials: F
authors.lastname: Almeida Ribeiro
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D000860:Hypoxia / Q000209:etiology; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D010100:Oxygen / Q000097:blood; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood / Q000150:complications / Q000503:physiopathology*
chemical_list: D010100:Oxygen