In recent years, some taxonomic controversy has occurred over the genus of North American rat snakes. Based on mitochondrial DNA, Utiger et al. (2002) showed that North American rat snakes of the genus Elaphe, along with closely related genera such as Pituophis and Lampropeltis, form a monophyletic group separate from Old World members of the genus.
A pinched nerve is a type of injury or damage to a nerve or a group of nerves. The injury can result from compression, constriction, or stretching. A pinched nerve can lead to other conditions and cause temporary or permanent damage depending on the extent of the injury. pinched nerve is a type of injury or damage to a nerve or a group of nerves. The injury can result from compression, constriction, or stretching. A pinched nerve can lead to other conditions and cause temporary or permanent damage depending on the extent of the injury.
When an individual has a pinched nerve in the lower back, for example, symptoms of pain will usually radiate down the leg. A pinched nerve in the neck can cause pain to travel from the neck, through the shoulders, down the arms and into the hands. Muscle spasms in the back commonly coincide with pinched nerves and can cause weakness in the arms or legs. The two most common pinched nerves in the lower back are L5 (lumbar 5) and S1 (sacral 1).