Notes

NECK
Sternocleidomastoid muscle- located on both sides of the neck, acts to flex the neck and raise the sternum to assist in forced inhalation. It also bends the neck to the ipsilateral side and rotates the neck contralaterally.
Anterior and middle scalene muscles- located at the sides of the neck that act ipsilaterally to rotate the neck, as well as to elevate the first rib.
Splenius capitis and splenius cervicis- located in the back of the neck, work to rotate the head.
BACK
Erector spinae muscles- extend the back (bend it backward) and side bend the back.
Semispinalis dorsi and semispinalis capitis muscles- also extend the back.
Quadratus lumborum muscle- located in the lower back, side bends the lumbar spine and aids in the inspiration of air through its stabilizing affects at its insertion at the 12th rib (the last of the floating ribs).
Trapezius muscle- elevates the scapula (shoulder blade), which runs from the back of the neck to the middle of the back, by the rhomboid major and rhomboid minor muscles in the upper back.
Levator scapulae muscle- runs along the side and back of the neck.
SHOULDER
Deltoid muscle in the uppermost extent of the arm, Pectoralis major muscle in the chest, Coracobrachialis muscle on the inside of the upper arm, and the Biceps brachii muscles on the front of the upper arm- combined actions of these muscle systems make shoulder flexion possible.
Triceps- as the name suggests, consists of three heads that originate from different surfaces but share the same insertion at the olecranon process of the ulna (a bone in the forearm); the three heads together act to extend the elbow.
Pectoralis major, Latissimus dorsi, Teres major, Triceps, and Coracobrachialis- makes adduction and abduction, the act of serving to lower the arm toward and lift the arm away from the body, possible.
Supraspinatus- a muscle that runs along the scapula in the back, along with Deltoid, are the two main abductors of the shoulder.
Subscapularis muscles- is a deep muscle situated on the anterior, or front-facing, surface of the scapula, achieving movement like reaching into back pocket.
ARM
Biceps brachii- primary muscles involved in forearm flexion.
Brachialis- situated beneath the biceps brachii in the upper arm, one of the primary muscles involved in forearm flexion.
Brachioradialis- the origin of which is on the humerus, one of the primary muscles involved in forearm flexion.
Coracobrachialis- provided minor contributions to forearm flexion.
Pronator teres, Flexor carpi radialis, Flexor digitorum superficialis, Palmaris longus, Flexor carpi ulnaris- flexor muscles situated in the anterior compartment of the forearm (the palm side of the forearm; also known as the flexor compartment)
Triceps brachii- responsible for extension of the forearm increases the angle at the elbow, moving the hand away from the shoulder.
WRIST
Flexor carpi radialis, Flexor carpi ulnaris, Flexor digitorum superficialis,
Flexor digitorum profundus, and the Flexor pollicis longus- carries wrist flexion, or the movement of the wrist that draws the palm of the hand downward.
Extensor carpi radialis longus and the Extensor carpi radialis brevis- muscles responsible for wrist extension, that by contrast, shortens the angle at the back of the wrist. It also abducts the hand at the wrist (move the hand in the direction of the thumb, or first digit)
Extensor digitorum- also extends the index to little finger (the second to fifth digits)
Extensor digiti minimi- which also extends the little finger and adducts the hand (moves the hand in the direction of the little finger)
Extensor carpi ulnaris- which also adducts the hand.
Supinator muscle- in the posterior compartment acts to supinate the forearm for wrist supination. The biceps brachii also adds to supination.
Pronator quadratus and Pronator teres- a deep muscle in the anterior compartment pronates the forearm. Pronation is the opposing action, in which the wrist is rotated so that the palm is facing down.
ABDOMEN
Rectus abdominis- has vertically running muscle fibres that flex the trunk and stabilize the pelvis. To either side of the rectus abdominis are the other three layers of abdominal muscles.
Transversus abdominis- deepest layer; has fibres that run perpendicular to the rectus abdominus; it also acts to compress and support the abdomen and provides static core stabilization.
Internal oblique layers- run upward and forward from the sides of the abdomen, and the
External oblique layers- form the outermost muscle layers of the abdomen, run downward and forward. The internal oblique layers act in conjunction with the external oblique on the opposite side of the body to flex and rotate the trunk toward the side of the contracting internal oblique (“same-side rotator”).
UPPER LEG
Quadriceps femoris- increases the angle of the knee, bringing the lower leg into a straight position, accomplishing the extension of the knee. It groups including the Vastus medius, Vastus lateralis, Vastus intermedius, and Rectus femoris.
Sartorius- provided minor contribution to knee extension.
Hamstring muscles- are situated in the back of the thigh and include the Biceps femoris, Semitendinosus, and Semimembranosus; perform knee flexion, or the bending of the knee from the straight position.
Gastrocnemius muscle- in the back of the calf and by several small muscles that cross the knee joint posteriorly; provided minor contributions to knee flexion.
LOWER LEG

Tibialis anterior- inverts the foot (tilts the foot toward the midline), stabilizes the foot when striking the ground, and locks the ankle when kicking; accomplished dorsiflexion, or the ankle flexion in the direction of the dorsum, or anterior surface of the foot (the surface of the foot viewed from above).
Peroneus tertius (fibularis tertius)- participates to a limited extent in dorsiflexion and eversion of the foot (tilting of the foot away from the midline).
Extensor hallucis longus- primarily acts in big toe (hallux) dorsiflexion, but it also acts to dorsiflex, as well as weakly invert, the ankle.
Plantarflexion refers to flexion of the ankle in the direction of the sole of the foot. That is most easily demonstrated by having a person stand on his or her toes. The majority of ankle plantarflexion is performed by the
Large calf musculature- demonstrates ankle plantarflexion, including the gastrocnemius and the soleus, which lies just behind the gastrocnemius. It is generally accepted that those are two distinct muscles; however, there is some debate as to whether the gastrocnemius and the soleus are two parts of the same muscle.
Flexor hallucis longus- contributes to ankle flexion but is involved primarily in big toe flexion
Flexor digitorum longus- flexes the second to fifth toes; the peroneus longus, which flexes the ankle and everts the foot
Peroneus brevis- involved in plantarflexion and eversion of the foot.