Speed rather than distance: a novel graded treadmill test to assess claudication

To evaluate a new treadmill test, determining pain threshold speed (PTS) for use in assessment and measuring rehabilitation of patients with intermittent claudication.

Twenty-nine patients with claudication were evaluated, and the ankle-brachial index (ABI) was assessed. PTS was determined with a treadmill protocol based on level walking, low starting speed, and progressive increments at a predetermined distance up to the onset of pain. Repeatability and equivalence with a time-based protocol were verified. PTS was compared to pain-free walking distance, 6-minute walking distance, and ABI.

PTS was measured in all patients (3.6+/-1.1 km/h). Repeatability and equivalence between established tests were demonstrated. PTS showed a significant correlation with pain-free walking distance (r=0.833; P=0.0001), with 6-minute walking distance (r=0.724; P=0.005), and with ABI in the more ischemic limb (r=0.641; P=0.0001).

PTS is a reliable parameter that correlates well with other established measures. It is useful for determining the degree of functional handicap and for designing and guiding rehabilitation protocols.