Instrumented forceps for measurement of nerve compression forces.

Compression (or crushing) is used to induce nerve injury in test rats to study nerve degeneration and regeneration. The compression forces could be applied using a variety of techniques developed by several investigators. The lack of precise control of the applied compression may be the source of significant variations among observations. In this study, a Mosquito and dressing forceps were used. The Mosquito forceps was calibrated to determine the tip load corresponding to the clamping position. The dressing forceps was modified, instrumented with strain gauges and calibrated to directly measure the force applied at its tip. These two forceps were used to induce known and controlled nerve compression in 75 male Wistar rats (280-300g). The applied forces were of the order of 40N and 20N, for the Mosquito and dressing forceps, respectively.