Plantaris muscle

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Plantaris muscle
The mucous sheaths of the tendons around the ankle. Medial aspect. (Plantaris labeled at bottom right.)
Latin	musculus plantaris
Gray's	subject #129 483
Origin	Lateral supracondylar ridge of femur above lateral head of gastrocnemius
Insertion	Tendo calcaneus (medial side, deep to gastrocnemius tendon)
Artery:	sural arteries
Nerve:	tibial nerve
Action:	Plantar flexes foot and flexes knee
Antagonist:	Tibialis anterior muscle
Dorlands /Elsevier	m_22/12550213

Plantaris is a vestigial structure and one of the superficial muscles of the posterior crural compartment of the leg.

It is innervated by the tibial nerve (S1, S2).

Contents 1 Origin and insertion 2 Functions 3 Additional images 4 References 5 External links

[edit] Origin and insertion

It arises from the inferior part of the lateral supracondylar line of the femur at a position slightly superior to the origin of the lateral head of gastrocnemius.

Also, it may arise from the oblique popliteal ligament.

Passing inferomedially posterior to the knee joint, it becomes tendinous while passing distally to insert into the tendo calcaneus, or occasionally separately inserting into the medial side of the calcaneus.

[edit] Functions

Plantaris acts to weakly:

• plantarflex the ankle joint
• flex the knee joint

Plantaris may also provide proprioceptive feedback information to the central nervous system regarding the position of the foot. The unusually high density of proprioceptive receptor end organs supports this notion.

Its motor function is so minimal that its long tendon can readily be harvested for reconstruction elsewhere with little functional deficit. "Often mistaken for a nerve by freshman medical students, the muscle was useful to other primates for grasping with their feet. It has disappeared altogether in 9 percent of the population." ^[1]

[edit] Additional images

Right femur. Posterior surface.

Muscles of the back of the leg. Superficial layer.

Cross-section through middle of leg.

[edit] References

[edit] External links

• LUC plnt
• SUNY Labs 15:st-0412
• -1274675120 at GPnotebook
• plantaris+%28muscle%29 at eMedicine Dictionary
• PTCentral

v • d • e List of muscles of lower limbs ILIAC Region / ILIOPSOAS psoas major/psoas minor - iliacus BUTTOCKS gluteals: (maximus, medius, minimus) - tensor fasciae latae lateral rotator group: piriformis - inferior gemellus - obturator internus - superior gemellus - quadratus femoris THIGH anterior compartment: sartorius - quadriceps (rectus femoris, vastus lateralis, vastus intermedius, vastus medialis) - articularis genu posterior compartment/hamstring: biceps femoris - semitendinosus - semimembranosus medial compartment: pectineus - obturator externus - gracilis - adductor (longus, brevis, magnus) LEG anterior compartment: tibialis anterior - extensor hallucis longus - extensor digitorum longus - peroneus tertius posterior compartment: superficial - calf/triceps surae (gastrocnemius, soleus) - plantaris posterior compartment: deep - tarsal tunnel (flexor hallucis longus, flexor digitorum longus, tibialis posterior) - popliteus lateral compartment: peroneus muscles (longus, brevis) FOOT dorsal - extensor hallucis brevis - extensor digitorum brevis plantar - 1st layer (abductor hallucis, flexor digitorum brevis, abductor digiti minimi) plantar - 2nd layer (quadratus plantae, lumbrical muscle) plantar - 3rd layer (flexor hallucis brevis, adductor hallucis, flexor digiti minimi brevis) plantar - 4th layer (dorsal interossei, plantar interossei)