An incremental test to identify the pain threshold speed in patients with intermittent claudication

The purpose of this study was to develop a test for identifying the speed of onset of claudication, or pain threshold speed (PTS), in 16 patients affected by intermittent claudication. An echo-Doppler examination and the ankle-brachial index (ABI) determination were also performed. Test repeatability was evaluated in 10 patients retested within a few days. All 16 patients underwent the incremental walking test 3 times during a 6-month rehabilitation training program to verify the test's sensitivity in detecting the expected functional modifications. PTS was identified in all patients examined and the test-retest correlation coefficient (R) for PTS was 0.98. During the 6-month rehabilitation period, the ABI rose from 0.43 +/-0.16 to 0.72+/-0.15 for the worst limb and PTS also rose significantly from 3.9+/-1.4 km/h to 6.1+/-1.1 km/h. The average increments of ABI and PTS were significantly correlated. An incremental walking test for the identification of the walking speed at which claudication occurs has been developed. The PTS is a reproducible parameter that can be combined with other test results to establish the severity of the disease and to check any modifications that occur during rehabilitation.