  Nerves are frequently stretched during movement. We investigate here the
effect of stretch on nerve excitability within the framework of the soliton
theory. This thermodynamic theory for nerve pulse propagation relies on the
presence of a melting transition in the nerve membrane. In this transition, the
area of the nerve membrane and the nerve thickness change. It depends on
thermodynamic variables including temperature, the chemical potentials of
anesthetics and on hydrostatic pressure. A further variable relevant for
movement science is the the stretching of nerves, i.e., a tension in the nerve
caused by muscle contraction, the bending of joints and the pulling on
extremities. We show here that the soliton theory predicts a decrease in nerve
excitability upon stretching. This becomes evident in a reduction of the
amplitude of compound action potentials and in the suppression of reflexes. We
compare these predictions with medical findings.
