ABSTRACT
Validity and test-retest liability of the 12-minute distance (12MD) walk, a measure of functional status, were examined in patients with chronic obstructive pulmonary disease. Four tests were administered at weekly intervals. Performance increased (p < .01) over the first three tests. Test-retest reliability was r34 = .98 (df = 46) for tests 3 and 4. The 12MD walk correlated with the Sickness Impact Profile, Physical Dimension (r = -.45); forced expiratory volume in 1 second % predicted ( r = .40); maximal inspiratory pressure (PImax) (r = .52); and exercise-related breathlessness (r = -.49). Exercise-related breathlessness and PImax accounted for 42% of the variance. The validity and reliability of the 12MD walk were supported.
Subject(s)
Lung Diseases, Obstructive/physiopathology , Walking , Aged , Dyspnea/etiology , Female , Humans , Lung Diseases, Obstructive/diagnosis , Male , Middle Aged , Physical Exertion , Reproducibility of Results , Respiratory Function Tests , Time FactorsABSTRACT
Gender-related effects and two measures of muscularity, handgrip strength and fat-free mass (FFM), were examined to determine their relationship to respiratory muscle strength. Subjects were 101 healthy older adults. In 75 subjects, the magnitude of learning effect was examined over four weekly sessions. Maximal inspiratory pressure (PImax) was lower with increasing age in women, and maximal expiratory pressure (PEmax) was lower with increasing age in both genders. The PEmax correlated with handgrip strength and FFM in men only. Performance of PImax plateaued by the third visit in both men and women. Performance of PEmax plateaued by the third measure in women and was unchanged across four measurements for men.
Subject(s)
Body Mass Index , Hand Strength , Maximal Voluntary Ventilation , Muscle Weakness/diagnosis , Respiratory Muscles/physiology , Aged , Aging/physiology , Effect Modifier, Epidemiologic , Female , Humans , Learning , Male , Middle Aged , Sex CharacteristicsABSTRACT
The effects of 6 months of muscle training with an inspiratory pressure load equal to 30% of the maximal inspiratory pressure (PImax) was compared with sham training with a light inspiratory pressure load. In this double-blind randomly assigned study, 67 patients with chronic obstructive pulmonary disease were followed for 6 months. Both groups demonstrated improvements in performance of PImax, respiratory muscle endurance time for breathing against an inspiratory pressure load equal to 66% of PImax, 12-minute distance walk, and dyspnea. The treatment group did not demonstrate significant effects beyond those observed in the control group. Improvements in performance were related to improved coordination of the inspiratory muscles and desensitization to dyspnea.
Subject(s)
Breathing Exercises , Lung Diseases, Obstructive/rehabilitation , Respiratory Muscles , Activities of Daily Living , Double-Blind Method , Dyspnea/etiology , Dyspnea/prevention & control , Female , Follow-Up Studies , Humans , Inspiratory Capacity , Lung Diseases, Obstructive/complications , Lung Diseases, Obstructive/physiopathology , Male , Maximal Voluntary Ventilation , Middle Aged , Patient Satisfaction , Physical Endurance , PressureABSTRACT
Reliability of the maximal inspiratory pressure (Pimax) was examined by measuring Pimax once a week for 4 weeks in 91 patients with chronic obstructive pulmonary disease using an aneroid pressure gauge. Five Pimax trials were conducted at each test. From the first to the fourth test, the Pimax increased by a mean of 9 cm H2O (SD = 10). From the third to the fourth test, Pimax increased by a mean of 2 cm H2O and performance appeared to be plateauing. The test-retest reliability coefficient was r = 0.97 for Pimax measured at the third and fourth test session. The 95 percent confidence interval for the absolute difference in Pimax at the third and fourth test was 3 to 5 cm H2O. We conclude that performance of Pimax improves with practice in naive COPD patients and Pimax is reliable when measured with an aneroid gauge by experienced data collectors if patients are given sufficient practice.
