title: Treadmill versus shuttle walk tests of walking ability in intermittent claudication.
abstract: OBJECTIVE
  To compare treadmill and shuttle walk tests for assessing functional capacity in patients with intermittent claudication, with respect to test-retest reliability, cardiovascular responses, and patient preferences.
  
  
  METHODS
  Patients with stable intermittent claudication (N = 55, ages 52-85 yr, median age 68 yr) were recruited from the Sheffield Vascular Institute at the Northern General Hospital, Sheffield, UK. Each patient performed an incremental shuttle walk test, a constant-pace shuttle walk test, and a standardized treadmill test (3.2 km x h(-1), 12% gradient), each on three occasions. The incremental shuttle walk began at 3 km x h(-1) and increased by 0.5 km x h(-1) every minute, whereas the constant-pace shuttle walk was performed at the fixed pace of 4 km x h(-1). Claudication distance (CD), maximum walking distance (MWD), heart rate (HR), and blood pressure were assessed in each testing session. The patients also completed a test preference questionnaire.
  
  
  RESULTS
  CD and MWD for both shuttle walks were greater than the corresponding walking distances achieved in the treadmill test (P < 0.001). Average coefficients of variation for repeated incremental shuttle walk, constant-pace shuttle walk, and treadmill tests were 15.9%, 21.1%, and 18.7%, respectively, for MWD, corresponding to average intraclass correlation coefficients of 0.87, 0.82, and 0.87. Treadmill walking evoked greater increases in HR and blood pressure (P < 0.001), and fewer patients expressed a preference for it (24 vs 43% for shuttle walking).
  
  
  CONCLUSIONS
  These findings indicated that shuttle walk testing exhibits similar test-retest reliability as treadmill testing, but that it evoked a lower level of cardiovascular stress and is preferred to treadmill testing by a large proportion of patients.
authors.affiliation: The Centre for Sport and Exercise Science, Sheffield Hallam University, Sheffield, UK.
authors.forename: Irena
authors.initials: I
authors.lastname: Zwierska
authors.forename: Shah
authors.initials: S
authors.lastname: Nawaz
authors.forename: Richard D
authors.initials: RD
authors.lastname: Walker
authors.forename: Richard F M
authors.initials: RF
authors.lastname: Wood
authors.forename: A Graham
authors.initials: AG
authors.lastname: Pockley
authors.forename: John M
authors.initials: JM
authors.lastname: Saxton
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006339:Heart Rate; D006801:Humans; D007383:Intermittent Claudication / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D015203:Reproducibility of Results; D013312:Stress, Physiological / Q000503:physiopathology; D013647:Task Performance and Analysis; D016138:Walking