ABSTRACT
The lower limb is connected to the abdomen anteriorly by the inguinal ligament. Posteriorly, the gluteal region of the lower limb is demarcated from the lumbar region by the iliac crest. Below the inguinal ligament and gluteal fold, the lower limb can be divided into the thigh, knee, leg, ankle, and foot. A thigh has four compartments: anterior, lateral, posterior, and medial. The knee is a joint, the configuration of which is the patella anteriorly and the popliteal fossa posteriorly. The leg has three compartments: anterior, lateral, and posterior. The ankle joint has two bony prominences, the medial malleolus of the tibia and the lateral malleolus of the fibula. A foot has two surfaces, dorsal and plantar. In spite of so many regions, compartments, and surfaces, nerve supplies to the lower limb can be simplified into two plexuses, the lumbar and the sacral. Branches from the lumbar plexus innervate the inguinal region, the anterior and medial compartments of the thigh, the patella of the knee, and the skin that covers the medial surface of the leg. Branches from the sacral plexus take care of all other regions of the lower limb, including the gluteal, lateral and posterior compartments of the thigh, popliteal fossa, lateral and posterior compartments of the leg, and the entire foot. Thus, the quintessential point of this chapter is to become acquainted with the organization and distribution of the lumbar and sacral spinal nerve plexus. All acupoints that we need to know that appear in the lower limb are attributed to nerve branches of these two plexuses.
