Muscle | Action | Origin | Insertion |
Sternocleidimastoid | UNILATERALLY: Laterally flexes the head and the neck to the same side / Rotates the head and neck to the opposite sideBILATERALLY: Flexes the neck / assists in inhalation ( elevation of the rib cage) | STERNAL HEAD: Top of the manubriumCLAVICAL HEAD: medial one-third of the clavicle | Mastoid process of the temporal bone / lateral portion of the superior nuchal line of occiput |
Scalenes- Anterior, Middle, Posterior | BILATERALLY: Elevate the ribs during inhalation (all) / Flex the head and neck (anterior)UNILATERALLY: with rib fixed, laterally flex the head and neck to the same side (all) / Rotate head and neck to the opposite side (all) | TRANSVERSE PROCESSES: Anterior scalene- third to sixth cervical vertibrae / Middle scalene- second to seventh cervical vertibrae / Posterior scalene- fifth and sixth cervical vertibrae | ANTERIOR AND MIDDLE: 1st ribPOSTERIOR: 2nd rib |
Biceps brachii | Flexes the elbow / Supinates the forearm / flexes the shoulder | SHORT HEAD: Caracoid process of the scapulaLONG HEAD: Supraglenoid tubercle of scapula | Tuberosity of the radius and aponeurosis of the biceps brachii |
Triceps brachii | ALL HEADS: extend the elbow LONG HEAD: Extends the shoulder (glenohumeral joint) / Adducts the shoulder | LONG HEAD: infraglenoid tubercle of scapulaLATERAL HEAD: posterior surface of proximal half of humerusMEDIAL HEAD: Posterior surface of distal half of humerus | Olecranon process of ulna |
Deltoid | ALL FIBERS: abduct the shoulder (glenohumeral joint)ANTERIOR FIBERS: flex the shoulder/medially rotate the shoulder/Horizontally adduct the shoulderPOSTERIOR FIBERS: Extend the shoulder/Laterally rotate the shoulder/Horizontally abduct the shoulder | Laterally one third of clavicle, acromion and spine of scapula | Deltoid Tuberosity |
Pectoralis major | ALL FIBERS: adducts the shoulder glenohumeral joint)/Medially rotates the shoulder/Assists in elevating the thorax in forced inhalation (if arm is fixed)UPPER FIBERS: flex the shoulder/Horizontally adduct the shoulderLOWER FIBERS: extend the shouder | Medial half of clavicle, sternum, cartilage of ribs first thru sith ribs | Crest of greater tubercle of humerus |
Latissimus dorsi | Extends the shoulder (glenohumeral joint) / Adducts the shoulder / Medially rotates the shoulder | Spineous processes of the last six thoratic vertebrae, last three or four ribs, thoracolumbar aponeurosis and porterior iliac crest | Crest of the lesser tubercle of the humerus |
Supraspinatus | Abducts the shoulder (glenohumeral joint) / stabalizes head of humerus in glenoid cavity | supaspinous fossa of scapula | Greater tubercle of the humerus |
Infraspinatus | Laterally rotates the shoulder (glenohumeral joint) / Adducts the shoulder / Extends the shoulder / Horizontally abducts the shoulder / Stabalizes head of humerus in glenoid cavity | Infraspinous fossa of scapula | Greater tubercle of the humerus |
Teres minor | laterally rotates the shoulder Laterally rotates the shoulder (glenohumeral joint) / Adducts the shoulder / Extends the shoulder / Horizontally abducts the shoulder / Stabalizes head of humerus in glenoid cavity | Superior half of lateral border of scapula | Greater tubercle of humerus |
Subscapularis | Medilally rotates the shoulder (glenohumeral joint) / Stabalize head of humerus in glenoid cavity | Subscapular fossa of the scapula | Lesser tubercle of the humerus |
Levator scapula | UNILATERALLY: Elevates teh scapula / Downwardly rotates the scapula / laterally flex the head and neck / Rotates teh head and neck to the same side BILATERALLY: Extends the head and neck | Transverse process of first through fourth cervical vertebrae | Upper region of medial border and superior angle of scapula |
Trapezius | UPPER-BILATERAL:Extends head & neck UNILATERAL:Laterally flex head and neck to the same side/Rotate head & neck to opposite side/Elevate scapula/Upwardly rotate scapula MIDDLE- Adduct scapula/stabalize scapula LOWER-depress scapula/Upwardly rotate scapula | External occipital protuberance, medial portion of superior nuchal line of occiput, ligamentum nuchae. and spineous processes of C7 through T12 | Lateral one-third of clavicle, acromion and spine of the scapula |
Rhomboids - major and minor | Adducts the scapula (scapulothoracic joint) / elevates the scapula / Downwardly rotates the scapula | MINOR:Spinous processes of C7 and T1 MAJOR: Spinous process of T2 to T5 | MAJOR: Medial border of the scapula between spine of the scapula and inferior angleMINOR: Upper portion of the medial border of the scapula , across from ethe spine of the scapula |
Pectoralis Minor | Depresses the scapula / abducts the scapula / Tilts the scapula anteriorly / Assists in forced inhalation (if scapula is fixed) | third, fourth, and fifth ribs | Coracoid process of the scapula |
Serratus anterior | WITH THE ORIGIN FIXED: Abducts the scapula / Depresses the scapula / holds the medial border of scapula against the rib cageIF SCAPULA IS STABALIZED: may act in forced inhalation | Surfaces of upper eight or nine ribs | Anterior surface of the medial border of the scapula |
Quadriceps group | ALL: Extend the kneeRECTUS FEMORIS: Flexes the hip | RECTUS FEMORIS: Anterior inferior iliac spine (AIIS)VASTUS LATERALIS: lateral lip of linea aspera, gluteal tuberosityVASTUS MEDIALIS: medial lip of linea asperaVASTUS INTERMEDIUS: Anterior and lateral shaft of the femur | Tibial Tuberosity |
Hamstring Group | ALL: flex the knee / Extend the hip / Tilt the pelvis posteriorly BICEPS FEMORIS:Laterally rotates the hip / Laterally rotates the flexed kneeSEMITENDINOSUS AND SEMIMEMBRANOSUS: Medially rotate the hip / Medially rotate the flexed knee | BOTH SEMIS AND LONG HEAD OF BICEPS FEMORIS: Ischial Tuberosity SHORT HEAD OF BICEPS FEMORIS: lateral lip of linea aspera | BICEPS FEMORIS: head of fibulaSEMITENDINOSUS: Proximal medial shaft of the tibia at pes anserinus tendonSEMIMEMBRANOSUS: posterior aspect of medial condyle of tibia |
Gastrocnemius | Flexes the knee / Plantar flexes the ankle | Condyles of femur, posterior surfaces | Calcaneus via calcaneal tendon |
Soleus | Plantar flexes ankle | Soleal line and posterior surface of tibia, proximal, posterior surface of fibula | Calcaneus via calcaneal tendon |
Tibialis Anterior | Inverts the foot / Dorsiflexes the ankle | Proximal lateral surface of tibia, interosseous membrane | Medial uneiform, base of the first metatarsel |