Makindo Medical Notes

Adductor Minimus

Origin: Lower portion of the inferior pubic ramus

Insertion: Gluteal ridge and upper part of the linea aspera of the femur

Action: Adducts and laterally rotates the femur

Innervation: Posterior division of the obturator nerve

Artery: Obturator a., medial femoral circumflex a., deep femoral a.

Notes: Adductor minimus is the uppermost fibers of the adductor magnus

Articularis Genu

Origin: Anterior surface of the femur above the patellar surface

Insertion: Articular capsule of the knee

Action: Elevates the articular capsule of the knee joint

Innervation: Femoral nerve

Artery: Descending genicular a.

Notes: Articularis genu is formed by muscle fascicles deep to the vastus intermedius muscle

Biceps Femoris

Origin: Long head: ischial tuberosity; Short head: lateral lip of the linea aspera

Insertion: Head of fibula and lateral condyle of the tibia

Action: Extends the thigh, flexes the leg

Innervation: Long head: tibial nerve; Short head: common fibular (peroneal) nerve

Artery: Perforating branches of the deep femoral a.

Notes: One of the "hamstring" muscles

Dorsal Interosseous (Foot)

Origin: Shafts of adjacent metatarsal bones

Insertion: Bases of the proximal phalanges for digit 2 (both sides) & digits 3,4 (lateral side)

Action: Abducts digits 2-4 (moves these digits away from midline); flexes the metatarsophalangeal joints and extends the interphalangeal joints

Innervation: Deep branch of the lateral plantar nerve

Artery: Dorsal metatarsal aa.

Notes: Four in number; remember DAB (Dorsal interossei ABduct) and PAD (Plantar interossei ADduct)

Extensor Digitorum Brevis

Origin: Superolateral surface of the calcaneus

Insertion: Extensor expansion of toes 1-4

Action: Extends toes 1-4

Innervation: Deep fibular (peroneal) nerve

Artery: Dorsalis pedis a.

Notes: The part of the extensor digitorum brevis that goes to the great toe is called the extensor hallucis brevis

Extensor Digitorum Longus

Origin: Lateral condyle of the tibia, anterior surface of the fibula, lateral portion of the interosseous membrane

Insertion: Dorsum of the lateral 4 toes via extensor expansions

Action: Extends the metatarsophalangeal, proximal interphalangeal, and distal interphalangeal joints of the lateral 4 toes

Innervation: Deep fibular (peroneal) nerve

Artery: Anterior tibial a.

Notes: One of the muscles involved in anterior compartment syndrome

Extensor Hallucis Brevis

Origin: Superolateral surface of the calcaneus

Insertion: Dorsum of the base of the proximal phalanx of the great toe

Action: Extends the great toe

Innervation: Deep fibular (peroneal) nerve

Artery: Dorsalis pedis a.

Notes: Usually considered to be the medial-most part of the extensor digitorum brevis

Extensor Hallucis Longus

Origin: Middle half of the anterior surface of the fibula and the interosseous membrane

Insertion: Base of the distal phalanx of the great toe

Action: Extends the metatarsophalangeal and interphalangeal joints of the great toe

Innervation: Deep fibular (peroneal) nerve

Artery: Anterior tibial a.

Notes: One of the muscles involved in anterior compartment syndrome

Fibularis (Peroneus) Brevis

Origin: Lower one third of the lateral surface of the fibula

Insertion: Tuberosity of the base of the 5th metatarsal

Action: Extends (plantar flexes) and everts the foot

Innervation: Superficial fibular (peroneal) nerve

Artery: Fibular (peroneal) a.

Notes: Stress fracture of the base of the 5th metatarsal bone is a common runner's injury

Fibularis (Peroneus) Longus

Origin: Upper two-thirds of the lateral surface of the fibula

Insertion: After crossing the plantar surface of the foot deep to the intrinsic muscles, it inserts on the medial cuneiform and the base of the 1st metatarsal bone

Action: Extends (plantar flexes) and everts the foot

Innervation: Superficial fibular (peroneal) nerve

Artery: Fibular (peroneal) a.

Notes: Fibularis longus lies superficial to the fibularis brevis in the lateral compartment of the leg

Fibularis (Peroneus) Tertius

Origin: Distal part of the anterior surface of the fibula

Insertion: Dorsum of the shaft of the 5th metatarsal bone

Action: Everts the foot

Innervation: Deep fibular (peroneal) nerve

Artery: Anterior tibial a.

Notes: Fibularis tertius is in the anterior compartment of the leg, not the lateral compartment

Flexor Digiti Minimi Brevis (Foot)

Origin: Base of 5th metatarsal bone

Insertion: Lateral side of base of proximal phalanx of 5th digit

Action: Flexes the metatarsophalangeal joint of the 5th digit

Innervation: Lateral plantar nerve

Artery: Lateral plantar a.

Flexor Digitorum Brevis

Origin: Tuberosity of the calcaneus, plantar aponeurosis, intermuscular septa

Insertion: Base of the middle phalanx of digits 2-5 after splitting to allow passage of the flexor digitorum longus tendons

Action: Flexes the metatarsophalangeal and proximal interphalangeal joints of digits 2-5

Innervation: Medial plantar nerve

Artery: Medial and lateral plantar aa.

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