Lab 6: Lower Limb & Axial Muscles

epaxial muscles

The muscles located posterior to the spinal cord.

hypaxial muscles

The muscles that are located anterior to the spinal cord.

strap muscles

AKA infrahyoid muscles. The move the hyoid and larynx during swallowing movements. Ventral muscles of the neck.

longus coli & longus capitis

Flex the cervical vertebrae & head. They lie on the anterior surface of the cervical and upper thoracic vertebrae, posterior to the esophagus & trachea. Prevertebral muscles of the neck.

scalene muscles

Extend to the first 2 ribs & stabilize the thoracic cage during forced breathing. They also laterally flex the neck. Lateral muscles of the neck.

intercostal muscles

Includes the transversus thoracis muscles, internal intercostals, & external intercostals. Lateral muscles of the thorax.

serratus posterior

Assist in ventilating the lungs. Lateral muscles of the thorax.

rectus abdominis

Large ventral muscle of the abdomen that flexes the vertebral column, as when doing sit-ups.

psoas major

Lies along the ventral surface of the lumbar vertebrae. Extends past the hip to the femur, where it moves the hip joint. A prevertebral muscle of the abdomen.

transversus abdominis, internal oblique, & external oblique

Lateral muscles of the abdomen that help twist your lower trunk and compress its contents to build intra-abdominal pressure (as when sneezing, coughing, defacating, etc.).

transversospinalis group

Lies just lateral to the spinous processes of vertebrae. These muscles span 2 vertebrae and mostly rotate the spine and maintain posture. These are the deep epaxial muscles.

erector spinae group

These are the more superficial epaxial muscles. They consist of muscles spanning several vertebrae and are major extensors of the spinal column.

iliotibial (IT) tract

A tough region of the deep fascia surrounding the thigh.

gluteus maximus

O: iliac crest & sacrum

I: posterior femur & IT tract

Action: extension of the femur (hip)

tensor fascia lata

O: iliac crest

I: IT tract

Action: flexor of the femur (hip)

iliacus

O: iliac crest and fossa

I: lesser trochanter

Action: flexion of the femur (hip)

psoas major

O: anterior lumbar vertebrae

I: lesser trochanter

Action: flexion of the femur (hip)

deep hip rotators

O: sacrum & posterior pelvis

I: greater trochanter

Action: lateral rotation of the femur (hip)

gluteus medius

O: lateral ilium

I: greater trochanter

Action: abduction & medial rotation of femur (hip)

adductors magnus

O: inferior ramus of pubis

I: posterior medial femur

Action: adduction of the femur (hip)

adductors longus

O: inferior ramus of pubis

I: posterior medial femur

Action: adduction of the femur (hip)

adductors brevis

O: inferior ramus of pubis

I: posterior medial femur

Action: adduction of the femur (hip)

gracilis

O: inferior ramus of pubis

I: medial tibia

Action: adduction of the femur (hip)

pectineus

O: pectineal line

I: posterior medial femur

Action: adduction of the femur (hip)

semimembranosus

O: ischial tuberosity

I: medial tibia

Action: flexion of leg (knee)

semitendinosus

O: ischial tuberosity

I: medial tibia

Action: flexion of leg (knee)

biceps femoris

O: ischial tuberosity, posterior femur

I: fibular head

Action: flexion of leg (knee)

popliteus

O: posterior tibia

I: proximal lateral femur

Action: rotation of knee joint

sartorius

O: anterior superior iliac spine

I: tibial tuberosity

Action: extension of leg (knee)

rectus femoris

O: ilium

I: tibial tuberosity

Action: extension of leg (knee)

vastus intermedius

O: anterior femur

I: tibial tuberosity

Action: extension of leg (knee)

vastus medialis

O: anterior femur

I: tibial tuberosity

Action: extension of leg (knee)

vastus lateralis

O: anterior femur

I: tibial tuberosity

Action: extension of leg (knee)

gastrocnemius

O: femur

I: calcaneus

Action: plantarflexion

soleus

O: fibular head

I: calcaneus

Action: plantarflexion

plantaris

O: femur

I: calcaneus

Action: plantarflexion

tibialis posterior

O: posterior interosseous membrane

I: plantar surface of tarsals/metatarsals

Action: inversion of foot

flexor digitorum longus

O: posterior interosseous membrane

I: plantar surface of phalanges

Action: flexion of digits (2-5)

flexor hallucis longus

O: posterior interosseous membrane

I: plantar surface of phalanges

Action: flexion of hallux

tibialis anterior

O: anterior interosseous membrane

I: plantar surface of tarsals

Action: dorsiflexion of foot

extensor digitorum longus

O: anterior interosseous membrane

I: dorsal surface of phalanges

Action: extension of digits (2-5)

extensor hallucis longus

O: anterior interosseious membrane

I: dorsal surface of phalanges

Action: extension of hallux

fibularis muscles (longus, brevis)

O: fibula

I: plantar surface of tarsals

Action: eversion of foot