Intramuscular pressure was measured with transducer-tipped catheters
that had been inserted into the anterior and deep posterior compartments of
the leg in seven healthy adults. Intramuscular pressure increased three to
sevenfold (depending on the position of the ankle) in both compartments
after the application of a plaster cast from the proximal part of the thigh
to the malleoli. While the cast was in place, the baseline intramuscular
pressure was elevated by the inflation of a tourniquet, which was located
on the proximal part of the thigh, to a pressure of sixty millimeters of
mercury (8.00 kilopascals). The intramuscular pressure in both the anterior
and the deep posterior compartments was found to be lowest when the ankle
joint was between the neutral and the resting positions (between 0 and 37
degrees of flexion). After the cast was bivalved and the opening on each
side was spread approximately one-half centimeter, there was a significant
decrease in intramuscular pressure of 47 per cent in the anterior
compartment and of 33 per cent in the deep posterior compartment (p <
0.05 for both).