This study investigated the test-retest reliability of several commonly used variables in functional capacity assessment for patients with peripheral arterial disease (PAD), including maximum walking time with tolerable claudication and peak VO2 in a graded treadmill test, and maximal torque in isokinetic ankle plantar flexion at three velocities (30deg/s, 60deg/s, and 90deg/s). Participants were seven PAD patients (6 male and 1 female), as recommended by a vascular surgeon, with age, height and mass of (mean+/-SD) 72.3+/-4.8 years, 168.1+/-4.8cm, and 75.6+/-9.3kg, respectively. They had stable intermittent claudication, resting ankle/brachial index (ABI) of 0.71+/-0.14 and post-exercise ABI of 0.51+/-0.17. The participant undertook two functional capacity assessments separated by three months while maintaining their prescribed medication. The mean values of these variables showed no significant difference between the two testing occasions. Intraclass Correlation Coefficients (ICC) and Technical Error of Measurement (TEM) are showed as below. ICC TEM
Pain-free walking time 0.35~0.58 29%~38%
Peak VO2 0.79~0.93 < 7 %
Isokinetic strength and endurance 0.66~0.91 7%~15%
The wide range of ICC and TEM values might relate the physical conditions of the aged participants as well as the nature of the variables measured.