anterior view

extensor digitorum brevis

Muscle that allows the big toe to extend and reinforces the action of the long extensor (extension of certain toes).

peroneus longus

Muscle attached to the fibula enabling the foot to extend and to draw away from the median axis of the body; it also supports the plantar arch.

anterior tibialis

Thick muscle enabling the foot to flex on the leg and to draw near the median axis of the body; the posterior tibial allows the foot to extend.

vastus medialis

Large deep inner-thigh muscle mainly enabling the knee to extend; it also stabilizes the knee.

rectus femoris

Powerful muscle enabling the knee to extend and the thigh to flex on the pelvis.

sartorius

Long narrow ribbon-shaped muscle enabling the thigh to flex and to rotate outwardly (outside the median axis); it also allows the leg to flex.

adductor longus

Long muscle enabling the thigh to draw near the median axis of the body; it also allows it to rotate outwardly (outside the median axis) and to flex.

tensor of fascia lata

Thick muscle especially enabling the leg to stretch and the thigh to flex and draw away from the median axis of the body; it also stabilizes the hip and the knee.

brachioradialis

Muscle mainly enabling the forearm to flex on the arm.

rectus abdominis

Flat muscle enabling the trunk to flex frontward; it protects and enables compression of the internal organs, and aids in expiration.

external oblique

Large thin muscle enabling the trunk to flex and to rotate on the pelvis and the internal organs to compress; it also aids in expiration.

deltoid

Thick triangular muscle drawing the arm away from the median axis of the body and directing it toward the front and back until it is horizontal.

masseter

Masticator muscle enabling the lower jaw to move.

orbicularis of eye

Large slender circular muscle surrounding the eye socket; it allows the eyelids to close.

plantar interosseous

Lower muscle of the foot enabling the three last toes to draw near the median axis of the foot; it also allows their first phalanx to flex.

extensor digitorum longus

Long muscle allowing all the toes, except the big toe, to extend; it also helps the foot to flex on the leg.

soleus

Thick muscle enabling the foot to extend, the heel to lift off the ground and the body to rise; it is a major muscle involved in walking, running and jumping.

gastrocnemius

Large thick muscle forming the curve of the calf and allowing the foot to extend; it also helps the knee to extend.

vastus lateralis

Large outer thigh muscle mainly allowing the knee to extend; it also stabilizes the knee.

ulnar flexor of wrist

Muscle enabling the hand to flex and to draw near the median axis of the body.

short palmaris

Muscle mainly enabling the hand to flex.

long palmaris

Muscle enabling various hand movements, including flexing it and drawing it away from the median axis of the body; it also helps to stabilize the wrist.

pronator teres

Short round muscle enabling the forearm to flex on the arm and to rotate inwardly, turning the palm of the hand toward the back.

brachialis

Powerful muscle enabling the forearm to flex on the arm.

biceps of arm

Muscle allowing the forearm to flex and to rotate outwardly (palm of the hand toward the front); the biceps contracts while the triceps relaxes.

pectoralis major

Flat muscle enabling various arm movements, such as drawing it near the median axis of the body and rotating it inwardly (toward the median axis); it also aids in inhalation.

trapezius

Large flat triangular muscle enabling many shoulder movements; it also helps to extend the head.

sternocleidomastoid

Powerful muscle enabling the head to flex, to tilt sideways and to rotate.

frontalis

Muscle that creases the skin of the forehead, raises the eyebrows and pulls the scalp forward.