Measurement of exercise-induced muscular hyperaemia with colour duplex ultrasonography

Muscular activity results in increased muscular perfusion. Only few publications have shown colour duplex ultrasonography to be useful in measuring vascularisation of the muscle tissue quantitatively.

Purpose of the present study was to answer whether exercise-induced muscular hyperaemia can be depicted by means of colour duplex ultrasonography and check the time course of this hyperaemia.

Twenty-five healthy males, aged 18 to 60 years, were examined. The dominant arm was strained isometrically randomly over 15, 30, and 60s with 10%, 20%, 30%, 40%, and 50% of the maximum voluntary contraction (MVC). Thereafter ultrasonography was performed at the maximum diameter of the elbow flexors in 15s intervals, until the pre-recorded perfusion parameters in the resting muscle were achieved again.

In the resting muscle, only a few vessels were sonographically visible. Under exercise, an exponential correlation was calculated between the strain intensity and the time period until perfusion reached the level of the resting muscle again (r >0.90). Furthermore, the duration of exercise closely correlated with the time until the pre-exercise level was achieved again (r >0.96, except 10% MVC: r=0.57). In conclusion, colour duplex ultrasonography is an adequate and valid method for the quantitive measurement of muscular hyperaemia in healthy muscle tissue. This is of special interest for sport medicine as well as occupational physiological investigations.