The influence of external compression on muscle blood flow during exercise

Abstract

Intramuscular pressures and muscle blood flow were measured in the anterior tibial muscle during dynamic concentric exercise in 14 subjects. Pressures were recorded by the microcapillary infusion method and muscle blood flow by the 133-Xenon clearance tech nique. Muscle blood flow during constant exercise de creased from 34.5 (SD = 10.3) to 10.6 (SD = 4.9) ml/ 100 g/min (P < 0.001 ) when muscle relaxation pressure was increased from 13.5 (SD = 2.7) to 39.9 (SD = 9.0) mm Hg by external compression. Muscle relaxation pressure during exercise is the intramuscular pressure between contractions. External compression of the lower limb during exercise impedes muscle blood flow by increasing muscle relaxation pressure. The experi mental model seems suitable to study the influence of external compression by knee braces on intramuscular pressure during exercise.