Standardized intermittent static exercise increases peritendinous blood flow in human leg

Alteration in tendinous and peritendinous blood flow during acid after exer cise is suggested to contribute to the development of Achilles tendon injur y and inflammation. In the present study a method for evaluating the influe nce of standardized workload on peritendinous flow is presented. The radioa ctive isotope xenon-133 was injected just ventrally to the Achilles tendon 5 cm proximal to the tendon's insertion on the calcaneus. The disappearance of Xe-133 was used to determine blood flow during intermittent static exer cise of the calf muscle (1.5 s exercise/1.5 s rest) for 30 min at a workloa d equivalent to individual body weight (1 BW) in six healthy volunteers aro und both Achilles tendons (n = 12). During intermittent static exercise, bl ood flow was increased from 1.8 +/- 0.3 mi 100 g tissue(-1) min(-1) (mean v alue and SEM) (rest) to 6.1 +/- 1.3 ml 100 g tissue(-1) min(-1) (exercise) (P < 0.05). The exercise induced an average increase in blood flow (3.4-fol d) equivalent to results previously obtained during regular dynamic heel ra ises (P < 0.05). It is concluded that the method is well suited to study th e influence of standardized workload on the physiology and pathophysiology of the tissue around the Achilles tendon in humans.