With the elbow flexed, compression of the human biceps brachii has bee
n found to reduce twitch torque, with an approximately linear relation
ship being observed between the loss of torque and the applied pressur
e (up to 45 kPa). The decline in torque could no longer be demonstrate
d when the biceps muscle was stretched, by extending the elbow from a
flexed position. The loss of torque in the flexed position appeared to
be due to an inability of muscle sarcomeres to bulge sufficiently to
take up the series elasticity at the fiber ends. (C) 1997 John Wiley &
Sons, Inc.