[Muscular ischemic pain. Effect of "training" after repeated performance of an experimental test]

Ischaemic muscle pain is a commonly used experimental stimulus in the evaluation of therapeutic analgesic measures. However, some doubts have recently been cast on the reliability of the results obtained with these methods. In this study, the reproducibility of Pain Threshold and Pain Tolerance time was investigated in 11 subjects who performed a tourniquet test on three occasions. Pain experienced between these two parameters was estimated using a Visual Analogue Scale. A statistically significant increase (p = 0.007) in Pain Tolerance was observed between the first and third tests. A non-linear relationship between perceived intensity of pain and time of painful muscular activity was similarly verified. These results were interpreted as a training effect. Caution on the experimental design of studies sequentially using ischaemic muscle pain methods is therefore recommended.