| Posterior compartment of leg | |
|---|---|
 Diagram of leg compartments | |
Dissection video of posterior compartment of leg (6 min 39 sec) | |
| Details | |
| Artery | Posterior tibial artery |
| Nerve | Tibial nerve |
| Identifiers | |
| Latin | compartimentum cruris posterius |
| TA98 | A04.7.01.006 |
| TA2 | 2654 |
| FMA | 45167 |
| Anatomical terminology | |
The posterior compartment of the leg is one of the fascial compartments of the leg and is divided further into deep and superficial compartments.
| Image | Muscle | Origin | Insertion | Innervation | Main Action ! |
|---|---|---|---|---|---|
 | Gastrocnemius | Lateral head: lateral aspect of lateral condyle of femur Medial head: popliteal surface of femur; superior to medial condyle | Posterior surface of calcaneus via calcaneal tendon | Tibial nerve (S1, S2) | Plantarflexes ankle when knee is extended; raises heel during walking; flexes leg at knee joint |
 | Plantaris | Inferior end of lateral supracondylar line of femur; oblique popliteal ligament | Weakly assists gastrocnemius in plantarflexing ankle | ||
 | Soleus | Posterior aspect of head and superior quarter of posterior surface of fibula; soleal line and middle third of medial border of tibia; and tendinous arch extending between the bony attachments | Plantarflexes ankle independent of position of knee; steadies leg on foot |
| Image | Muscle | Origin | Insertion | Innervation | Main Action |
|---|---|---|---|---|---|
 | Flexor hallucis longus muscle | Inferior two-thirds of posterior surface of fibula; inferior part of interosseous membrane | Base of distal phalanx of big toe (hallux) | Tibial nerve (S1, S2) | Flexes big toe at all joints; weakly plantarflexes ankle; supports medial longitudinal arch of foot |
 | Tibialis posterior muscle | Interosseous membrane; posterior surface of tibia inferior to soleal line; posterior surface of fibula | Tuberosity of navicular, cuneiform, cuboid, and sustentaculum tali of calcaneus; bases of 2nd, 3rd, and 4th metatarsals | Tibial nerve (L4, L5) | Plantarflexes ankle; inverts foot |
 | Flexor digitorum longus muscle | Medial part of posterior surface of tibia; by a broad tendon to fibula | Bases of distal phalanges of lateral four digits | Tibial nerve (S1, S2) | Flexes lateral four digits; plantarflexes ankle; supports longitudinal arches of foot |
 | Popliteus muscle | Lateral surface of lateral condyle of femur and lateral meniscus | Animation. Posterior surface of tibia, superior to soleal line | Tibial nerve (L4, L5, S1) | Weakly flexes knee and unlocks it by rotating femur 5 deg on fixed tibia; medially rotates tibia of unplanted limb |
The posterior compartment of the leg is supplied by the tibial nerve.
The brachioradialis is a muscle of the forearm that flexes the forearm at the elbow. It is also capable of both pronation and supination, depending on the position of the forearm. It is attached to the distal styloid process of the radius by way of the brachioradialis tendon, and to the lateral supracondylar ridge of the humerus.
The sciatic nerve, also called the ischiadic nerve, is a large nerve in humans and other vertebrate animals which is the largest branch of the sacral plexus and runs alongside the hip joint and down the lower limb. It is the longest and widest single nerve in the human body, going from the top of the leg to the foot on the posterior aspect. The sciatic nerve has no cutaneous branches for the thigh. This nerve provides the connection to the nervous system for the skin of the lateral leg and the whole foot, the muscles of the back of the thigh, and those of the leg and foot. It is derived from spinal nerves L4 to S3. It contains fibers from both the anterior and posterior divisions of the lumbosacral plexus.
The sartorius muscle is the longest muscle in the human body. It is a long, thin, superficial muscle that runs down the length of the thigh in the anterior compartment.
The ankle, the talocrural region or the jumping bone (informal) is the area where the foot and the leg meet. The ankle includes three joints: the ankle joint proper or talocrural joint, the subtalar joint, and the inferior tibiofibular joint. The movements produced at this joint are dorsiflexion and plantarflexion of the foot. In common usage, the term ankle refers exclusively to the ankle region. In medical terminology, "ankle" can refer broadly to the region or specifically to the talocrural joint.
In human anatomy, the groin, also known as the inguinal region or iliac region, is the junctional area between the torso and the thigh. The groin is at the front of the body on either side of the pubic tubercle, where the lower part of the abdominal wall meets the thigh. A fold or crease is formed at this junction known as the inguinal groove, or crease. This is also the area of the medial compartment of the thigh that contains attachments of the adductor muscles of the hip or the groin muscles. The groin is the common site for a hernia.
The popliteal vein is a vein of the lower limb. It is formed from the anterior tibial vein and the posterior tibial vein. It travels medial to the popliteal artery, and becomes the femoral vein. It drains blood from the leg. It can be assessed using medical ultrasound. It can be affected by popliteal vein entrapment.
In humans and some other mammals, the soleus is a powerful muscle in the back part of the lower leg. It runs from just below the knee to the heel and is involved in standing and walking. It is closely connected to the gastrocnemius muscle, and some anatomists consider this combination to be a single muscle, the triceps surae. Its name is derived from the Latin word "solea", meaning "sandal".
The gastrocnemius muscle is a superficial two-headed muscle that is in the back part of the lower leg of humans. It is located superficial to the soleus in the posterior (back) compartment of the leg. It runs from its two heads just above the knee to the heel, extending across a total of three joints.
The popliteus muscle in the leg is used for unlocking the knees when walking, by laterally rotating the femur on the tibia during the closed chain portion of the gait cycle. In open chain movements, the popliteus muscle medially rotates the tibia on the femur. It is also used when sitting down and standing up. It is the only muscle in the posterior (back) compartment of the lower leg that acts just on the knee and not on the ankle. The gastrocnemius muscle acts on both joints.
The plantaris is one of the superficial muscles of the superficial posterior compartment of the leg, one of the fascial compartments of the leg.
The deep fibular nerve begins at the bifurcation of the common fibular nerve between the fibula and upper part of the fibularis longus, passes infero-medially, deep to the extensor digitorum longus, to the anterior surface of the interosseous membrane, and comes into relation with the anterior tibial artery above the middle of the leg; it then descends with the artery to the front of the ankle-joint, where it divides into a lateral and a medial terminal branch.
The popliteal fossa is a shallow depression located at the back of the knee joint. The bones of the popliteal fossa are the femur and the tibia. Like other flexion surfaces of large joints, it is an area where blood vessels and nerves pass relatively superficially, and with an increased number of lymph nodes.
The posterior cutaneous nerve of the thigh is a sensory nerve of the thigh. It is a branch of the sacral plexus. It supplies the skin of the posterior surface of the thigh, leg, buttock, and also the perineum.
The fibularis muscles are a group of muscles in the lower leg.
The prevertebral fascia is the layer of deep cervical fascia that surrounds the vertebral column. It is the deepest layer of deep cervical fascia.
The anterior compartment of the forearm contains the following muscles:
The anterior compartment of the leg is a fascial compartment of the lower leg. It contains muscles that produce dorsiflexion and participate in inversion and eversion of the foot, as well as vascular and nervous elements, including the anterior tibial artery and veins and the deep fibular nerve.
The lateral compartment of the leg is a fascial compartment of the lower leg. It contains muscles which make eversion and plantarflexion of the foot.
A neurovascular bundle is a structure that binds nerves and veins with connective tissue so that they travel in tandem through the body.
In anatomy, the fibular artery, also known as the peroneal artery, supplies blood to the lateral compartment of the leg. It arises from the tibial-fibular trunk.
