Muscles of posterior group of thigh

Muscles of posterior group of thigh

Muscle	Origin	insertion	nerve	action	comment
Posterior: Hamstrings
Semitendinosus	Ischial tuberosity	Proximal medial tibia(pes anserinus)	Sciatic(tibial)	Extend thigh, flex leg	Tendon used in ligament reconstruction(ACL)
Semimembranosus	Ischial tuberosity	Posterior medial tibial condyle	Sciatic(tibial)	Extend thigh, flex leg	A border in medial approach
Biceps femoris: long head	Ischial tuberosity	Head of fibula	Sciatic(tibial)	Extend thigh, flex leg	Can avulse front origin(avulsion fx)
Biceps femoris: short head	Linea aspera, supracondylar line	Fibula, lateral tibia	Sciatic(peroneal)	Extend thigh, flex leg	Share tendon insertion with long head

Ref) Netter’s concise orthopaedic anatomy P268

Muscles of medial group of thigh

Muscles of medial group of thigh

Muscle	Origin	insertion	nerve	action	comment
Obturator externus	Ischiopubic rami, obturator memb	Piriformis fossa	Obturator	ER thigh	Insetion at start point of IM nail
Hip adductors
Adductor longus	Body of pubis(inferior)	Linea aspera(mid 1/3)	Obturator	Adducts thigh	Tendon can ossify
Adductor brevis	Body and inferior pubic ramus	Pectineal line, linea aspera	Obturator	Adducts thigh	Deep to pectineus
Adductor magnus	1.     Pubic ramus 2.     Ischial tub.	Linea aspera, add. tubercle	1.     Obturator 2.     sciatic	Adducts & flex/extend thigh	Muscle has two sepatate parts
Gracilis	Body and inferior pubic ramus	Prox. Med. Tibia(pes anserinus)	Obturator	Adduct thigh, flex/IR leg	Used in ligament reconstruction
Hip Flexors
Pectineus	Pectineal line of pubis	Pectineal line of femur	Femoral	Flex and adducts thigh	Part of femoral triangle floor

Ref) Netter’s concise orthopaedic anatomy P267

Muscles of anterior part of thigh

Muscles of anterior part of thigh

Muscle	Origin	insertion	nerve	action	comment
Articularis genus	Distal anterior femoral shaft	Synovial capsule	Femoral	Pulls capsule superiorly in extension	May join with vastus intermedialis
Sartorius	ASIS	Prox .med. tibia (pes anserinus)	Femoral	Flex, ER hip	Can avulse from ASIS (avulsion fracture)
Quadriceps
Rectus femoris	1.     AIIS 2.     Sup. Acetab. rim	Patella/tibial tubercle	Femoral	Flex thigh, extend leg	Can avulse from AIIS (avulsion fracture)
Vastus lateralis	Gtr, Trochanter, lat. Linea aspera	Lateral patella/ tibia tubercle	Femoral	Extend leg	Oblique fibers can affect Q angle
Vastus intermedius	Proximal femoral shaft	Patella/tibial tubercle	Femoral	Extend leg	Covers articularis genu
Vastus medialis	Intertrochant. line, med. linea aspera	Medial patella/tibia tubercle	Femoral	Extend leg	Weak in many patellofemoral disorders

Ref) Netter’s concise orthopaedic anatomy P266

Muscles of Deep posterior compartment of lower leg

Muscles of Deep posterior compartment of lower leg

Muscle	Origin	insertion	nerve	action	comment
Popliteus	Lateral femoral condyle(anterior and distal to LCL)	Proximal posterior tibia	Tibial	IR tibia/knee(during” swing” phase)	Origin is intraarticular Primary restraint to ER of knee
Flexor hallucis longus(FHL)	Posterior fibula	Base of distal phalanx of great toe	Tibial	Plantar flex great toe	Test S1 motor function
Flexor digitorum longus(FDL)	Posterior tibia	Base of distal phalanx of 4 toe	Tibial	Plantar flex 4 toe	At ankle, tendon is just anterior to tibial artery
Tibialis posterior(TP)	Posterior tibia, fibula, interosseous membrane	Plantar navicular cuneiforms, MT base	Tibial	Plantar flex and invert foot(in ”heel off” phase)	Tendon rupture/degen, can cause acquired flot foot

Ref) Netter’s concise orthopaedic anatomy P319

Muscles of superficial posterior compartment of lower leg

Muscles of superficial posterior compartment of lower leg

Muscle	Origin	insertion	nerve	action	comment
Gastrocnemius	Lateral and medial femoral condyles	Calcaneus(Via Achilles tendon)	Tibial	Plantar flex foot	Test S1 motor function; two heads, fabella is in tendon of lateral head
Soleus	Posterior fibulr head/soleal line of tibia	Calcaneus(Via Achilles tendon)	Tibial	Plantar flex foot	Fuses to gastrocnemius at Achilles tendon
Plantaris	Lateral femoral supracondylar line	Calcaneus	Tibial	Plantar flex foot	Long tendon can boe harvested for tendon reconstruction

Ref) Netter’s concise orthopaedic anatomy P318

Muscles of Lateral compartment of lower leg

Muscles of Lateral compartment of lower leg

Muscle	Origin	insertion	nerve	action	comment
Peroneus longus	Proximal lateral fibula	Plantar medial cuneiform, 1st metatarsal base	Superficial peroneal	Plantar flex foot(1st ray)	Test S1 motor function; runs under the foot
Peroneus brevis	Distal lateral fibula	Base of 5th metatarsal	Superficial peroneal	Evert foot	Can cause avulsion fx at base of 5th MT; has most distal muscle belly

Ref) Netter’s concise orthopaedic anatomy P317