Posterior compartment of leg explained

Posterior compartment of leg
Latin:	compartimentum cruris posterius
Artery:	Posterior tibial artery
Nerve:	Tibial nerve

The posterior compartment of the leg is one of the fascial compartments of the leg and is divided further into deep and superficial compartments.

Structure

Muscles

Superficial posterior compartment

Image	Muscle	Origin	Insertion	Innervation	Main Action !
		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
		Inferior end of lateral supracondylar line of femur; oblique popliteal ligament	Weakly assists gastrocnemius in plantarflexing ankle
		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

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Deep posterior compartment

Image	Muscle	Origin	Insertion	Innervation	Main Action
		Inferior two-thirds of posterior surface of fibula; inferior part of interosseous membrane	Base of distal phalanx of big toe (hallux)		Flexes big toe at all joints; weakly plantarflexes ankle; supports medial longitudinal arch of foot
		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		Plantarflexes ankle; inverts foot
		Medial part of posterior surface of tibia; by a broad tendon to fibula	Bases of distal phalanges of lateral four digits		Flexes lateral four digits; plantarflexes ankle; supports longitudinal arches of foot
		Lateral surface of lateral condyle of femur and lateral meniscus	Animation. Posterior surface of tibia, superior to soleal line		Weakly flexes knee and unlocks it by rotating femur 5 deg on fixed tibia; medially rotates tibia of unplanted limb

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Blood supply

Posterior tibial artery

Innervation

The posterior compartment of the leg is supplied by the tibial nerve.

Function

It contains the plantar flexors:

External links

Diagram at patientcareonline.com

Notes and References

Moore, Dally and Agur (2014). Moore Clinically-Oriented Anatomy, Table 5.13.I, p 597.
Moore, Dally, and Agur (2014). Moore Clinically-Oriented Anatomy, Table 5.13.II, p 598.
Web site: Muscle Database - sorted by muscle location . 2014-05-10 . 2012-10-18 . https://web.archive.org/web/20121018122315/https://www.msu.edu/user/vosskurt/Miscellaneous%20pages/musloc.htm . dead .