What describes the effect of an injury at the level between T2 and T4?

An injury at the level between T2 and T4 involves the thoracic spine, which can impact the autonomic and sensory functions of the body. Specifically, this level of injury often leads to the loss of sensation below the nipple level due to the way spinal nerves are organized and function. The T4 level corresponds with the area of innervation for the nipple; thus, an injury at or above this level can eliminate sensation in areas below the nipple, affecting the abdominal region and lower extremities.

Injuries at this specific level can also lead to other issues. For instance, while arm movement might be preserved due to the innervation coming from higher cervical levels, there can still be significant dysfunction in other regions due to the loss of lower thoracic innervation. This helps to contextualize why loss of sensation below the nipples is the primary consequence of such an injury.