The biomechanical properties of peripheral nerves still are not completely understood or quantified. This is partly because of the nonhomogeneous nature of nerves and the variation in the proportions of the components of different nerves. The recognition and quantification of the in-situ stress and the viscoelastic behavior of nerves have been important stepping stones in understanding their mechanical behavior. The effects of stretch and compression on the vascular supply and conduction properties of normal animal nerves have been well studied. Similar studies in injured nerves will provide invaluable information for understanding the mechanics of nerve function and the prevention of stretch- and compression-related trauma.