Muscle Action

Frontalis

Draws scalp forward, Raises eyebrows, Wrinkles forehead horizontally

Occipitalis

Retracts scalp

Temporalis

Elevates and retracts mandible at jaw

Orbicularis oris

Compresses and purses lips (Kiss Muscle)

Orbicularis Oculi 

Closes Eye

Zygomaticus Minor

Raises upper lip, exposing upper teeth

Zygomaticus Major

Pulls corner of mouth superiorly(smile muscle)

Buccinator

Presses cheeks against molar teeth, holds food between teeth during chewing

Masseter

closes jaw, elevates mandible at jaw

Platysma

Pulls lower lip inferiorly, tenses skin of neck, aids in depressing mandible 

Sternocleidomastoid

One Side: Laterally flexes & rotates head to opposite side of contracting muscle 

Both Sides: Flexes cervical portion of vertebral column 

Pectoralis Major

Flexes, extends, adducts, & medially rotates arm at shoulder joint 

Pectoralis Minor

Abducts/protracts and depresses scapula

Splenius Capitis

One Side: Rotates head to same side of contracting muscle 

Both Sides:Extend head and neck 

Splenius Cervicis

One Side: Rotates head to same side of contracting muscle 

Both Sides: Extend head and neck 

Trapezius

Adducts scapula, Depresses Scapula

Adducts and upwardly rotates scapula; elevates clavicle; extends head

Serratus Anterior

Abduct/protracts & stabilizes scapula

Latissimus Dorsi

Extends,Adducts, & medially rotates arm at shoulder joint

Levator Scapulae

Elevates scapula

Rhomboid Major

Stabilizes, elevates, & Adducts/protracts scapula; downwardly rotates scapula

Rhomboid Minor

Stabilizes, elevates, & Adducts/protracts scapula; downwardly rotates scapula

Supraspinatus

Abducts Arm at shoulder

Infraspinatus

Laterally rotates arm at shoulder joint

Subscapularis 

Medially rotates arm at shoulder joint 

Teres Minor

Laterally rotates & weakly adducts arm at shoulder joint

Teres Major

Extends,Adducts, & medially rotates arm at shoulder joint

Deltoid

Abducts, flexes, & extends arm at shoulder joint. Anterior fibers medially rotate arm at shoulder joint. Posterior fibers laterally rotate arm at shoulder joint.

Triceps brachii

Extend forearm at elbow joint

Triceps Brachii Medial Head 

Extend forearm at elbow joint

Triceps Brachii Lateral Head

Extend forearm at elbow joint

Triceps Brachii Long head

Assists in extension of arm at shoulder joint

Extend forearm at elbow joint

Biceps Brachii 

Flexes forearm at elbow joint, Supinates forearm at radioulnar joint

Biceps Brachii Long Head 

Flexes arm at shoulder joint, Flexes forearm at elbow joint, Supinates forearm at radioulnar joint

Biceps Brachii Short Head

Flexes forearm at elbow joint, Supinates forearm at radioulnar joint

Coracobrachialis

Adducts & flexes arm at shoulder joint

Brachialis

Flexes forearm at elbow joint

Brachioradialis

Flexes forearm at elbow joint

Pronator Teres

Pronates the forearm at radioulnar joint

Flexor Carpi Radialis

Flexes & abducts hand at wrist joint

Palmaris Longus

Weakly flexes had at wrist joint & tenses fascia of palm

Flexor Carpi Ulnaris

Flexes and adducts hand at wrist joint 

Flexor digitorum superficialis

Flexes hand at wrist joint & flexes middle phalanx of each finger at 2nd -5th MP & PIP joints

Flexor Digitorum profundus

Flexes hand at wrist joint; flexes distal & middle phalanges of each finger at 2nd -5th MP, PIP & DIP joints

Flexor Pollicis Longus

Flexes distal phalanx of thumb at IP joint

Flexor Retinaculum

Fibrous band of connective tissue that covers the palmar surface of the carpal bones

Extensor Carpi Radialis Longus 

Extends and abducts hand at wrist joint

Extensor Carpi Radialis Brevis 

Extends and abducts hand at wrist joint

Extensor Digitorum

Extends hand at wrist joint, Extends distal & middle phalanges at 2nd-5th MP,PIP,DIP joints

Extensor Carpi Ulnaris

Extends and adducts hand at wrist joint

Abductor pollicis longus

Abducts and extends thumb joint between carpals and metacarpals, weakly extends hand at wrist joint

Extensor Pollicis Brevis

Weakly extends hand at wrist joint, Extends thumb at MP joint

Extensor Pollicis longus

Weakly extends hand at wrist joint, extends thumb at MP & IP joints

Supinator

Supinates forearm at radioulnar joint

Extensor Retinaculum

Fibrous band of connective tissue that covers the dorsal surface of the carpal bones

Quadratus Lumborum

One Side: laterally flexes lumbar portion of vertebral column,

Both Sides: extend lumbar portion of vertebral column

Iliocostalis Group (lateral)

 One Side: laterally flexes vertebral column to the same side as the contracting muscle

Both Sides: extend vertebral column

Longissimus Group(Intermediate)

One Side: laterally flexes vertebral column to the same side as the contracting muscle

Both Sides: extend vertebral column

Spinalis Group (Medial)

One Side: laterally flexes vertebral column to the same side as the contracting muscle

Both Sides: extend vertebral column

External Intercostals

Elevate ribs during normal inspiration

Internal Intercostals

Depressed ribs during forced exhalation

Diaphragm

Extends the thoracic cavity during normal inspiration

External Oblique

Both sides: compress abdominal wall and flex vertebral column

One Side: laterally flexes vertebral column and rotates torso to opposite side

Internal Oblique

Both sides: compress abdominal wall and flex vertebral column

One Side: laterally flexes vertebral column and rotates torso to opposite side

Transversus Abdominis

Both sides: compress abdominal wall and flex vertebral column

One Side: laterally flexes vertebral column and rotates torso to opposite side

Rectus Abdominis

Compresses abdominal wall and flexes vertebral column

Inguinal Ligament

Formed by the aponeurosis of the external oblique; contains tissues coursing from the trunk to the lower limb

Linea Alba

Connective tissue connecting left and right rectus abdominis muscles

Rectus Femoris

flexes thigh at hip joint, extends leg at knee joint

Vastus Lateralis

extends leg at knee joint

Vastus Medialis

Extends leg at knee joint

Vastus Intermedius

Extends leg at knee joint

Sartorius

Flexes abducts and laterally rotates thigh at hip joint, flexes and medially rotates leg at knee joint

Iliacus

Flexes thigh at hip joint

Psoas Major

Flexes thigh at hip joint 

Pectineus

Adduct and weakly flex thigh at hip joint

Adductor Longus

Adduct and weakly flex thigh at hip joint

Adductor Brevis

Adduct and weakly flex thigh at hip joint

Adductor Magnus

 Adducts thigh at hip joint, adductor part of muscle flexes thigh; hamstring part of muscle extends and laterally rotates thigh at hip joint

Gracilis

Weakly adducts and weakly flexes thigh at hip joint, flexes leg at knee joint

Semitendinosus

Extends thigh at hip joint, flexes and medially rotates leg at knee joint

Semimembranosus

Extends thigh at hip joint, flexes and medially rotates leg at knee joint

Biceps Femoris Long Head

Extends thigh at hip joint, flexes leg at knee joint

Biceps Femoris Short head 

Flexes and laterally rotates leg at knee joint

Tensor fasciae latae

abducts, flexes, and medially rotates thigh at hip joint

Gluteus Maximus

Extends and laterally rotates thigh at hip joint

Gluteus Medius

Abduct and medially rotates thigh at hip joint

Gluteus Minimus

Abduct and medially rotates thigh at hip joint

Piriformis

Laterally rotates and abducts thigh at hip joint

Iliotibial band

Thick band of fascia continuous with tensor fasciae latae

Tibialis Anterior

Dorsiflexes & inverts foot at ankle joint

Extensor Hallucis Longus

Dorsiflexes foot at ankle joint; extends hallux

Extensor Digitorum Longus

Dorsiflexes foot at ankle joints, Extends distal and middle phalanges 2-5

Fibularis Longus

Everts & weakly plantar flexes foot at ankle joint

Fibularis Brevis

Everts & weakly plantar flexes foot at ankle joint

Gastrocnemius

Flexes leg at knee joint, plantar flexes foot at ankle joint

Soleus

plantar flexes foot at ankle joint

Tibialis Posterior

plantar flexes & inverts foot at ankle joint

Popliteus

Flexes leg at knee joint, Medially rotates tibia at knee joint

Flexor Digitorum Longus

Plantar flexes foot at ankle joint, Flexes distaland middle phalanges 2-5 at MP,PIP,DIP joints

Flexor Hallucis Longus

Plantar flexes foot at ankle joint, Flexes MP and IP joints of hallux