Lower Extremity Pictures

Planes of Body

Plantaris

Origin Inferior aspect of lateral supracondylar line of distal femur

Insertion Middle 1/3 of the posterior calcaneal surface, just medial to Achilles tendon

Action:Plantar flexor of ankle; also flexes knee

Innervation Tibial nerve (L5, S1, S2) (L5, S1, S2)

Arterial Supply Sural arteries

Flexor Digitorum Longus (Deep Group)

Origin: Posterior surface of tibia distal to popliteal line

Insertion: Splits into four slips after passing through medial intermuscular septum of plantar surface of foot; these slips then insert on plantar surface of bases of 2nd - 5th distal phalanges

Action: Flexes toes 2 - 5; also helps in plantar flexion of ankle

Innervation: Tibial nerve (S2, S3) (S2, S3)

Arterial Supply: Muscular branch of posterior tibial artery

Posterior Tibialis

Origin: Posterior aspect of interosseous membrane, superior 2/3 of medial posterior surface of fibula, superior aspect of posterior surface of tibia, and from intermuscular septum between muscles of posterior compartment and deep transverse septum

Insertion: Splits into two slips after passing inferior to plantar calcaneonavicular ligament; superficial slip inserts on the tuberosity of the navicular bone and sometimes medial cuneiform; deeper slip divides again into slips inserting on plantar surfaces of metatarsals 2 - 4 and second cuneiform

Action: Principal invertor of foot; also adducts foot, plantar flexes ankle, and helps to supinate the foot

Innervation: Tibial nerve (L4, L5) (L4, L5)

Arterial Supply: Muscular branches of sural, peroneal and posterior tibial arteries

Popliteus

Origin: Anterior part of the popliteal groove on lateral surface of lateral femoral condyle

Insertion: Posterior surface of tibia in a fan-like fashion, just superior to the popliteal line

Action: Rotates knee medially and flexes the leg on the thigh

Innervation: Tibial nerve (L4, L5, S1) (L4, L5, S1)

Arterial Supply: Medial inferior genicular branch of popliteal artery and muscular branch of posterior tibial artery

Gastrocnemeus (Posterior Leg)

Origin: Medial head from posterior nonarticular surface of medial femoral condyle; Lateral head from lateral surface of femoral lateral condyle

Insertion: The two heads unite into a broad aponeurosis which eventually unites with the deep tendon of the soleus to form the Achilles tendon, inserting on the middle 1/3 of the posterior calcaneal surface

Action: Powerful plantar flexor of ankle

Innervation: Tibial nerve (S1, S2) (S1, S2)

Arterial Supply: Each head supplied by a sural branch of the popliteal artery

Soleus (Posterior Leg)

Origin: Posterior aspect of fibular head, upper 1/4 - 1/3 of posterior surface of fibula, middle 1/3 of medial border of tibial shaft, and from posterior surface of a tendinous arch spanning the two sites of bone origin

Insertion: Eventually unites with the gastrocnemius aponeurosis to form the Achilles tendon, inserting on the middle 1/3 of the posterior calcaneal surface

Action: Powerful plantar flexor of ankle

Innervation: Tibial nerve (S1, S2) (S1, S2)

Arterial Supply: Posterior tibial, peroneal, and sural arteries

Flexor Hallucis Longus

Origin: Inferior 2/3 of posterior surface of fibula, lower part of interosseous membrane

Insertion: Plantar surface of base of distal phalanx of great toe

Action: Flexes great toe, helps to supinate ankle, and is a very weak plantar flexor of ankle

Innervation: Tibial nerve (S2, S3) (S2, S3)

Arterial Supply: Muscular branch of peroneal and posterior tibial artery

Flexor Digitorum Longus
Origin: Posterior surface of tibia distal to popliteal line

Insertion: Splits into four slips after passing through medial intermuscular septum of plantar surface of foot; these slips then insert on plantar surface of bases of 2nd - 5th distal phalanges

Action: Flexes toes 2 - 5; also helps in plantar flexion of ankle

Innervation: Tibial nerve (S2, S3) (S2, S3)

Arterial Supply: Muscular branch of posterior tibial artery

Tibialis Anterior (Anterior Leg)

Origin: Lateral condyle of tibia, proximal 1/2 - 2/3 or lateral surface of tibial shaft, interosseous membrane, and the deep surface of the fascia curries

Insertion: Medial and plantar surfaces of 1st cuneiform and on base of first metatarsal

Action: Dorsiflexor of ankle and invertor of foot

Innervation: Deep peroneal nerve (L4, L5, S1) (L4, L5, S1)

Arterial Supply: Anterior tibial artery

Extensor Hallucis Longus

Origin: Anterior surface of the fibula and the adjacent interosseous membrane

Insertion: Base and dorsal center of distal phalanx of great toe

Action: Extends great toe and dorsiflexes ankle

Innervation: Deep peroneal nerve (L4, L5, S1) (L4, L5, S1)

Arterial Supply: Anterior tibial artery

Extensor Digitorum Longus

Origin: Lateral condyle of fibula, upper 2/3 - 3/4 of medial fibular shaft surface, upper part of interosseous membrane, fascia cruris, and anterior intermuscular septum

Insertion: Splits into 4 tendon slips after inferior extensor retinaculum, each of which insert on dorsum of middle and distal phalanges as part of extensor expansion complex

Action: Extend toes 2 - 5 and dorsiflexes ankle

Innervation: Deep peroneal nerve (L4, L5, S1) (L4, L5, S1)

Arterial Supply: Anterior tibial artery