Thigh Muscles

thick thighs save lives

Overview of the Thigh

Anterior (flexor) Compartment

• sartorius

• quadriceps femoris

  • rectus femoris

  • vastus lateralis

  • vastus intermedius

  • vastus medialis

Medial (Adductor) Compartment

• pectineus

• adductor longus

• adductor brevis

• adductor magnus

• adductor minimus

• gracilis

• obturator externis

Posterior (Extensor) Compartment

• biceps femoris

• semimembranosus

• semitendinosus

sartorius

• the longest muscle in the human body

• part of the anterior compartment along with quadriceps femoris

• has an oblique course; arising from the anterior superior iliac spine, crossing to the medial side of the thigh, and inserting on the medial side of the proximal tibia

• flexes, abducts, and externally rotates the thigh, internally rotates the leg

origin → anterior superior iliac spine (ASIS)

insertion → proximal end of tibia below medial condyle (via pes anserinus)

action → thigh flexion, abduction, and external rotation at the hip joint; leg flexion and internal rotation at the knee joint

innervation → femoral nerve (L2-L3)

blood supply → proximal third: branches of femoral artery, deep femoral artery, artery of quadriceps, lateral circumflex femoral artery

→ middle third: branches of femoral artery

→ distal third: branches of femoral and descending genicular arteries

quadriceps femoris

• the strongest muscle of the human body

• consists of 4 individual muscles:

  • rectus femoris

  • vastus medialis

  • vastus intermedius

  • vastus lateralis

• out of the 4, only rectus femoris crosses both the hip and knee joints, the others only cross the knee joint

• they vary in origin but all 4 share a common quadriceps femoris tendon which inserts into the patella

• extends the leg at the knee joint and flexes the thigh at the hip joint

rectus femoris

origin → anterior inferior iliac spine, supraacetebular groove

insertion → tibial tuberosity via patellar ligament, patella

action → thigh flexion at the hip joint, leg extension at the knee joint

innervation → femoral nerve (L2-L4)

blood supply → femoral, lateral femoral circumflex, superficial circumflex iliac arteries

vastus lateralis

origin → intertrochanteric line, greater trochanter, gluteal tuberosity, linea aspera of femur

insertion → tibial tuberosity via patellar ligament, patella, lateral condyle of tibia

action → leg extension at the knee joint

innervation → femoral nerve (L2-L4)

blood supply → lateral circumflex and deep femoral arteries; artery to quadriceps

vastus intermedius

origin → anterior surface of femoral shaft

insertion → tibial tuberosity via patellar ligament, patella

action → leg extension at the knee joint

innervation → femoral nerve (L2-L4)

blood supply → artery to quadriceps, deep femoral arteries

vastus medialis

origin → intertrochanteric line, pectineal line of femur, linea aspera, medial supracondylar line of femur

insertion → tibial tuberosity via patellar ligament, patella, medial condyle of tibia

action → leg extension at the knee joint

innervation → femoral nerve (L2-L4)

blood supply → femoral, deep femoral, descending genicular arteries

pectineus

• a flat muscle found in the superomedial part of the anterior thigh

• typically classified as a muscle of the adductor compartment

• adducts, flexes, externally rotates, internally rotates the thigh at the hip joint and stabilizes the pelvis and balances the trunk on the lower extremity during walking

origin → superior pubic ramus (pectineal line of pubis)

insertion → pectineal line of femur, linea aspera of femur

action → thigh flexion, adduction, external rotation, internal rotation at the hip joint; pelvis stabilization

innervation → femoral nerve & obturator nerve (L2, L3)

blood supply → medial femoral circumflex artery, obturator artery

adductor longus

• a long, fan shaped muscle in the medial aspect of the thigh

• adducts the thigh at the hip joint

origin → body of pubis, inferior to pubic crest and lateral to pubic symphysis

insertion → middle third of linea aspera of femur (medial lip)

action → thigh flexion, adduction, external rotation at the hip joint; pelvis stabilization

innervation → obturator nerve (L2-L4)

blood supply → deep femoral artery, obturator artery

adductor brevis

• a flat, triangular muscle running from the pubis to the medial aspect of they femur

• produces thigh adduction and participates in flexion, internal rotation of the thigh and pelvis stabilization when standing or walking

• a weak adductor, as it is the shortest muscle in the adductor group

origin → anterior body of pubis, pubic ramus

insertion → linea aspera of femur (medial lip)

action → thigh flexion, adduction, external rotation at the hip joint; pelvis stabilization

innervation → obuturator nerve (L2-L4)

blood supply → arteria profunda femoris

adductor magnus

• a large, triangular adductor with its apex situated on the hip bone and its base on the linea aspera of the femur

• situated in both the posterior and medial compartments of the thigh but is classified as an adductor

• the largest and strongest in the adductor compartment

• forms the adductor hiatus, which transmits the femoral artery and vein to the popliteal fossa

• contains 4-5 oseo-aponeurotic openings as passage for perforating branches of the deep femoral artery

• divided into 2 parts: adductor part and ischiocondylar part

  • adductor part acts as an adductor, the ischiocondylar part is part of the posterior compartment

origin → adductor part: inferior pubic ramus, ischial ramus

→ ischiocondylar part: ischial tuberosity

insertion → adductor part: gluteal tuberosity, linea aspera (medial lip), medial supracondylar line

→ ischiocondylar part: adductor tubercle of femur

action → adductor part: thigh flexion, adduction, external rotation at the hip joint

→ ischiocondylar part: thigh extension, internal rotation at the hip joint

innervation → adductor part: obturator nerve (L2-L4), ischiocondylar part: tibial division of sciatic nerve (L4)

→ mnemonic: African Mouse Sneaks Out (refers to Adductor Magnus Sciatic Obturator)

blood supply → deep femoral artery; femoral, popliteal, genicular arteries

adductor minimus

• the uppermost portion of the adductor magnus

origin → inferior ramus of pubic bone

insertion → medial lip of linea aspera

action → adductos the thigh at the hip joint, assists in external rotation of thigh at hip joint

innervation → posterior division of obturator nerve (L2-L4)

blood supply → medial circumflex femoral artery, first perforating branch of deep femoral artery (profunda femoris)

gracilis

• a long, slender muscle, the most superficial muscle in the adductor compartment

• the weakest adductor, but the only adductor that crosses and acts on both the hip and knee

• extends from the coxal bone to the tibia

origin → anterior body of pubis, inferior pubic ramus, ischial ramus

insertion → medial surface of proximal tibia via pes anserinus

action → thigh flexion and adduction at the hip joint, leg flexion and internal rotation at the knee joint

innervation → obturator nerve (L2-L3)

blood supply → deep femoral artery (via artery to the adductors)

obtutator externus

• a flat, triangular, paired muscle of the gluteal region found on the anterior aspect of the obturator foramen, attached to the obturator membrane and the adjacent margin of the obturator foramen

• externally rotates the femur when the hip is extended

• abducts the thigh when the hip is flexed

** anatomiclly locate in the adductor compartment, but functionally considered a deep gluteal lateral rotator

origin → anterior surface of obturator membrane, bony boundaries of obturator foramen

insertion → trochanteric fossa of femur

action → thigh external rotation and thigh abduction (from a flexed hip) at the hip joint; stabilizes the head of the femur in the acetabulum

innervation → obturator nerve (L3, L4)

blood supply → obturator and medial circumflex femoral arteries

biceps femoris

• a long muscle of the posterior compartment, makes up the hamstrings along with semimembranosis and semitendinosus

• runs from the ischial tuberosity to the proximal part of the fibula, crossing two joint (hip and knee)

• flexes and externally rotates at the knee joint, extends and externally rotates at the hip

• consists of a long and short head

origin → long head: inferomedial impression of the ischial tuberosity, sacrotuberous ligament

→ short head: linea aspera of femur (lateral lip), lateral supracondular line of femur

insertion → lateral aspect of head of femur

action → thigh extension and external rotation at the hip joint; leg flexion and external rotation at the knee joint; stabilizes pelvis

innervation → long head: tibial division of sciatic nerve (L5-S2)

→ short head: common fibular division of sciatic nerve (L5-S2)

blood supply → inferior gluteal artery, perforating arteries, popliteal artery

semimembranosis

• part of the hamstring group

• crosses both hip and knee joints

• part of the hip extensor group with the other 2 hamstring muscles plus glute max

• occupies the medial aspect of the posterior thigh

origin → superolateral impression of ischial tuberosity

insertion → medial condyle of tibia

action → thigh extension and internal rotation at the hip joint; flexion and internal rotation of the leg at the knee joint; stabilizes pelvis

innervation → tibial division of sciatic nerve (L5-S2)

blood supply → perforating branches of femoral and popliteal arteries

semitendinosus

• a fusiform muscle of the posterior compartment of the thigh, part of the hamstring group

• a prime mover that extends and internally rotates the thigh, flexes and internally rotates the leg

• crosses both hip and knee joints

origin → posteromedial impression of ischial tuberosity

insertion → proximal end of tibia below medial condyle (via pes anserinus)

action → thigh extension and internal rotation at the hip joint; leg flexion and internal rotation at the knee joint; pelvis stabilization

innervation → tibial division of sciatic nerve (L5, S2)

blood supply → first perforating branch of femoral artery (profunda femoris), medial femoral circumflex artery, inferior gluteal artery, inferior medial geniculate artery