lower extremity Muscles: Human Anatomy

Anterior View

Muscles

Name: Tensor fascia latae

Description: Helps keep knee extended during upright posture. Keeps pelvis level when opposite leg is raised

O: Anterior external lip of iliac crest and the ASIS

I: IT band which attaches to lateral condyle of the tibia

A: Assists in ABduction and medial rotation of the thigh

N: Superior Gluteal nerve

Anterior view

Muscles

Name: Sartorius

Description: Part of thigh. Most superficial muscle of ant. thigh. Seatbelt. Not affected by position of knee

O: ASIS

I: Pes anserine

A: main action is hip flexion; can produce ABduction and external rotation

N: Femoral Nerve

Anterior View

Muscles

Name: Rectus femoris

Description: Power as a hip flexor. Only portion of the quad that passes the hip and the knee. Optimal length for hip flexor is when knee is flexed

O: AIIS

I: Common tendon to tibial tuberosity

A: assists illiopsoas in hip flexion and extends the knee with the quad.

N: Femoral Nerve

Anterior view

Muscles

Name: vastus lateralis

Description:

O: Greater trochanter and lateral lip of linea aspera

I: Common tendon to tibial tuberosity

A: extends knee

N: femoral nerve

Anterior view

Muscles

Name: vastus medialis

Description:

O: Medial lip of linea aspera

I: Common tendon to tibial tuberosity

A: extends knee

N: femoral nerve

Anterior view

Muscles

Name: vastus Intermedius

Description:

O: anterior and lateral surface of the femur

I: Common tendon to tibial tuberosity

A: extends knee

N: femoral nerve

Anterior view

Muscles

Name: Illiacus part of the iliopsoas

Description:

O: Iliac fossa, illiac crest, ala of sacrum

I: lesser trochanter of the femur

A: hip flexion

N: femoral nerve

Anterior view

Muscles

Name: Psoas Major part of the iliopsoas

Description:

O: Transverse processes of lumbar vertebrae T12-L-5

I: lesser trochanter of the femur

A: hip flexion for lateral rotation

N: Anterior rami of the lumbar nerves L1, L2, L3

Anterior view

Muscles

Name: Pectineus

Description:

O: Superior ramus of pubis

I: Pectineal line of femur inferior to lesser trochanter

A: adduction and flexion in the thigh> Assists with medial rotation

N: femoral nerve

Anterior view

Muscles

Name: Adductor Longus

Description:

O: Body of pubis inferior to crest

I: Middle third of linea aspera

A: Adduction and flexion in the thigh. Assists with medial rotation

N: Obturator Nerve

Anterior view

Muscles

Name: Adductor brevis

Description:

O: Body and inferior ramus of pubis

I: Pectineal line of femur, proximal linea aspera

A: Adduction and flexion in the thigh. Assists with medial rotation

N: Obturator Nerve

Anterior view

Muscles

Name: Adductor magnus

Description:

O: Inferior ramus of pubis nad ramus of ischium

I: Adductor part: Gluteal tuberosity, linea aspera, and medial supracondylar line.

Hamstring part: Adductor tubercle

A: Adduction and flexion in the thigh. Assists with medial rotation

N: Adductor part: Obturator Nerve

Hamstring part: tibial portion of the Sciatic Nerve

Anterior view

Muscles

Name: Gracilis

Description:

O: Body and inferior ramus of pubis

I: Pes Anserine

A: Adduction and flexion in the thigh. Assists with medial rotation

N: Adductor part: Obturator Nerve

Posterior view

Muscles

Name: Gluteus maximus

Description:

O: Posterior ilium and sacrum and associated ligaments

I: Superior fibers insert into ITB inferior fibers into gluteal tuberosity on the femur

A: Hip extension, external rotation

N: inferior gluteal nerve

Posterior view

Muscles

Name: Gluteus medius

Description:

O: external surface of ilium

I: Greater trochanter of femur

A: hip abduction

N: Superior gluteal nerve

Posterior view

Muscles

Name: Gluteus minimus

Description:

O: external surface of ilium

I: Greater trochanter of femur

A: hip abduction

N: Superior gluteal nerve

Posterior view

Muscles

Name: Piriformis

Description:

O: Anterior sacrum

I: Greater trochanter of femur

A: Laterally rotates extended thigh, abducts a flexed thigh

N: Nerve to Piriformis

Posterior view

Muscles

Name: Superior gemellus

Description:

O: ischial spine

I: Greater trochanter of femur

A: Laterally rotates thigh, abducts thigh when flexed

N: Nerve to Obturator internus

Posterior view

Muscles

Name: Inferior gemellus

Description:

O: ischial tuberosity

I: Greater trochanter of femur

A: Laterally rotates thigh

N: Nerve to Quadratus Femoris

Posterior view

Muscles

Name: Obturator internus

Description:

O: Posterior margins of obturator foramen, obturator membrane

I: Greater trochanter of femur

A: Laterally rotates thigh, abducts thigh when flexed

N: Nerve to obturator internus

Posterior view

Muscles

Name: Quadratus femoris

Description:

O: Lateral aspect of ischial tuberosity

I: Greater trochanter of femur

A: Laterally rotates thigh

N: Nerve to Quadratus Femoris

Posterior view

Muscles

Name: Biceps femoris Long and short head

Description:

O: Long head- ischial tuberosity

O: Short head-lateral linea aspera

I: fibular head

A: flexes knee and extends hip

N: Long head- tibial nerve

N: Short head-comon peroneal

Posterior view

Muscles

Name: Semitendinosus

Description:

O: ischial tuberosity

I: pes anserine

A: flexes knee and extends hip

N: sciatic nerve

Posterior view

Muscles

Name: Semimembranosus

Description:

O: ischial tuberosity

I: Medial condyle of the tibia

A: flexes knee and extends hip

N: sciatic nerve

Posterior view

Muscles

Name: adductor magnus

Description:

O: ischial tuberosity

I: Medial condyle of the tibia

A: flexes knee and extends hip

N: sciatic nerve

Transverse view

Name: Pes Anserine

Descripton: Attatchment site for semitendinosus, sartorius and gracilis

Posterior view

Muscles

Name: Popliteus

Description:

O: Anterior lateral condyle of femur

I: posterior surface of tibia near soleal line

A: internal rotation of knee joing, unlocks extended knee, weak knee flexor

N: tibial nerve

Posterior view

Muscles

Name: Gastrocnemius

Description:

O: Posterior parts of medial and lateral femoral condyles

I: achilles tendon

A: Primary ankle plantarflexor, secndary knee flexor

N: tibial nerve

Posterior view

Muscles

Name: Plantaris

Description:

O: distal end of lateral supracondylar line

I: posterior calcaneus

A: works with gastrocnemius to plantarflex the ankle and assist in flexion of the knee

N: tibial nerve

Posterior view

Muscles

Name: Soleus

Description:

O: Posterior surfaces of the head of the fibula and soleal line

I: posterior calcaneus

A: Plantarflexor of ankle

N: tibial nerve

Posterior view

Muscles

Name: Calcaneal (achilles) tendon

Description:

O: Posterior surfaces of the head of the fibula and soleal line

I: posterior calcaneus

A: Plantarflexor of ankle

N: tibial nerve

Posterior view

Muscles

Name: Flexor hallucis longus

Description:

O: Posterior surface of distal 2/3 of fibula and interosseus membrane

I: Base of distal phalanx of great toe (plantar surface)

A: flexes the great toe

N: tibial nerve

Posterior view

Muscles

Name: Flexor digitorum longus

Description:

O: Middle 3/5 of posterior surface of body of tibia

I: Base of distal phalanges of digits 2-5

A: Flexes proximal and distal interphalangeal and metatarsophalangeal joints of digits 2-5, assists with plantarflexion

N: tibial nerve

Posterior view

Muscles

Name: Tibialis posterior

Description:

O: Most of interosseus membrane, lateral portion of posteiror surface of tibia, proximal 2/3 of medial surface of fibula

I: Navicular tuberosity, cunieforms, cuboid and the bases of the 2-4 metatarsals

A: plantarflexes and inverts the ankle

N: tibial nerve

sagittal View

Muscles

Name: Peroneus Longus

Description:

O: Head and proximal 2/3 of lateral surface of fibula

I: Lateral side of the base of 1st metatarsal and of medial cuneiform

A: everts foot, assists in plantarflexion, depresses 1st metatarsal

N: superficial peroneal

sagittal View

Muscles

Name: Peroneus Brevis

Description:

O:distal 2/3 of the lateral surface of the fibula

I: Tuberosity of the 5th metatarsal

A: Everts foot and assists in plantarflexion

N: Superficial peroneal

Anterior view

Muscles

Name: Tibialis anterior

Description:

O: Lateral condyle and proximal ½ of lateral surface of tibia

I: medial and plantar surface of medial cuneiform and base of 1st metatarsal

A: Dorsiflexes and inverts the ankle

N: Deep peroneal

Anterior view

Muscles

Name: Extensor digitorum longus

Description:

O: Lateral condyle of tibia, proximal ¾ of anterior surface of the body of fibula and the interosseus membrane

I: by four tendons to the digits 2-5 attached to base of middle and distal phalanges

A: Extends metatarsophalangeal joins and assists extending the interphalangeal joints of digits 2-5, dorsiflexes the ankle

N: Deep peroneal

Anterior view

Muscles

Name: peroneus tertius

Description:

O: Distal 1/3 of anterior surface of the fibula

I: dorsal surface, base of the 5th Metatarsal

A: elevates the base of the 5t metatarsal, dorsiflexes and everts the foot

N: Deep peroneal

Anterior view

Muscles

Name: Extensor hallucis longus

Description:

O: Middle two quarters of the anterior surface of the fibula

I: base of the distal phalanx of the great toe

A: extends the metatarsalphalangeal and interphalangeal joints of the great toe

N: Deep peroneal

transverse superior view

Muscles

Name: Extensor digitorum longus

Description:

O: Lateral condyle of tibia, proximal ¾ of anterior surface of the body of fibula and the interosseous membrane

I: By four tendons to the digits 2-5 attached to base of middle and distal phalanges

A: extends the metatarsophalangeal joints and assists in extending the interphalangeal joints of digits 2-5, dorsiflexes the ankle

N: Deep peroneal

anterior view

Name: inguinal ligament

Description: attaches to anterior superior iliac spine (ASIS) of the pelvis to the pubic tubercle of the pubic bone