Which of the following statements is true regarding the intercostal nerves?

The statement that intercostal nerves have anterior and posterior branches that serve different functions is accurate because intercostal nerves arise from the thoracic spinal nerves and branch out to innervate various structures in the thoracic region. The anterior branches primarily serve motor functions to the intercostal muscles, which are essential for respiration, as well as providing sensory innervation to the skin and parietal pleura of the thorax. The posterior branches of the intercostal nerves typically supply the muscles and skin of the back, showcasing the complexity and dual functionality of these nerves. This division of labor is essential for the proper functioning of both movement and sensation in the thoracic region.

In contrast, the other options do not accurately represent the role of intercostal nerves. They are not limited to motor innervation, nor do they lack sensory functions, as they do innervate the skin. Additionally, intercostal nerves have no role in leg movement, as their primary focus is on the thoracic region.