Plantaris muscle

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Plantaris muscle
Muscles of the back of the leg. Superficial layer.
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)
Blood:
Nerve:	tibial nerve
Action:	Plantar flexes foot and flexes knee
Dorlands/Elsevier	m_22/12550213

Plantaris is claimed by some to be a vestigial structure and one of the superficial muscles of the posterior crural compartment of the leg. 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.

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

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 is useful to other primates for grasping with their feet. It has disappeared altogether in 9 percent of the population." [1]

[edit] Additional images

The mucous sheaths of the tendons around the ankle. Medial aspect.

[edit] External links

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

Muscles of the Head — Neck — Trunk — Upper limb — Lower limb— LIST OF ALL MUSCLES

ILIAC REGION/HIP FLEXORS: psoas major | psoas minor | iliacus | (Gray's s127) THIGH: anterior femoral | sartorius | quadriceps (rectus femoris, vastus lateralis, vastus intermedius, vastus medialis) | articularis genu medial femoral/adductor | gracilis | pectineus | adductor brevis | adductor longus | adductor magnus gluteal region | gluteals (maximus, medius, minimus) | tensor fasciae latae lateral rotator group | piriformis | obturator externus | obturator internus | inferior gemellus | superior gemellus | quadratus femoris posterior femoral/hamstring | biceps femoris | semitendinosus, semimembranosus | (Gray's s128) LEG: anterior crural | tibialis anterior | extensor hallucis longus | extensor digitorum longus | fibularis tertius superficial posterior crural | calf (gastrocnemius, soleus) | plantaris deep posterior crural | popliteus | flexor hallucis longus | flexor digitorum longus | tibialis posterior lateral crural | fibularis longus | fibularis brevis | (Gray's s129) FOOT: dorsal | extensor digitorum brevis | extensor hallucis brevis plantar first layer | abductor hallucis | flexor digitorum brevis | abductor digiti minimi plantar second layer | quadratus plantae | lumbrical muscle plantar third layer | flexor hallucis brevis | adductor hallucis | flexor digiti minimi brevis plantar fourth layer | dorsal interossei | plantar interossei | (Gray's s131)