Muscles Of The Apendicular Skeleton

Front 1

Levator scapulae

Back 1

O: Transverse process of first four cervical vertebrae
I: Vertebral border of scapula near superior angle
A: Elevates scapula

Front 2

Pectoralis minor

Back 2

O: Anterior sufaces and superior margin or ribs 3-5 and fascia covering the associated external intercostal muscles
I: Coracoid process of scapula
A: Depresses and protract should; rotates scapula so glenoid cavity moves inferiorly (downward rotation); elevates ribs if scapula is stationary

Front 3

Rhomboid major

Back 3

O: Spinous process of superior thoracic vertebrae
I: Vertebral border of scapula from spine to inferior angle
A: Adducts and performs downward rotation of the scapula

Front 4

Rhomboid minor

Back 4

O: Spinous processes of vertebrae C7-T1
I: Vertebral border of scapula
A: Adducts and performs downward rotation of the scapula

Front 5

Serratus anterior

Back 5

O: Anterior and superior margins of ribs 1-8 or 1-9
I: Anterior surface of vertebral border of scapula
A: Protracts shoulder; rotates scapula so glenoid cavity moves superiorly

Front 6

Trapezius

Back 6

O: Occipital bone, ligamentum nuchae, and spinos processes of thoracic vertebrae
I: Clavicle and scapula (acromion and scapular spine)
A: depends on active region and state of other muscles; may elevate, retract, depress, or rotates scapula upward and/or clavicle; can also extend neck

Front 7

Deltoid

Back 7

O: Clavicle and scapula (acromion and adjacent scapular spine)
I: Deltoid tuberosity of humerus
A (whole muscles): abduction of shoulder
A (ant. part): flexion and medial rotation of humerus
A (post part): extension and lateral rotation of humerus

Front 8

Supraspinatus

Back 8

O: Supraspinous fossa of scapula
I: Greater tubercles of humerus
A: Abducation at shoulder

Front 9

Infraspinatus

Back 9

O: Infraspinous fossa of scapula
I: Greater tubercle of humerus
A: Lateral rotation at shoulder

Front 10

Subscapularis

Back 10

O: Subscapular fossa of scapula
I: Lesser tubercle of humerus
A: Medial rotation at shoulder

Front 11

Teres major

Back 11

O: Inferior angle of scapula
I: Medial lip of intertubercular sulcus of humerus (ant.)
A: Extension and medial rotation at shoulder

Front 12

Teres minor

Back 12

O: Lateral border of scapula
I: Greater tubercle of humerus (post)
A: Lateral rotation and adduction at shoulder

Front 13

Latissimus dorsi

Back 13

O: Spinous process of inferior thoracic and all lumbar vertebrae, ribs 8-12, and thoracolumbar fascia
I: Floor of intertubercular sulcus of the humerus
A: Extension, adduction, and medial rotation at shoulder

Front 14

Pectoralis major

Back 14

O: Cartilages of the ribs 2-6, body of the sternum, and inferior, medial portion of the clavicle
I: Crests of greater tubercle and lateral lip of intertubercular sulcus of humerus
A: Flexion, adduction, and medial rotation at should

Front 15

Biceps brachii

Back 15

O: Short head from the coracoid process; long head from the supraglenoid tubercle (both on the scapula)
I: Radial tuberosity
A: Flexion at elbow and shoulder; supination

Front 16

Brachialis

Back 16

O: Anterior, distal surface of the humerus
I: Ulnar tuberosity
A: Flexion at elbow

Front 17

Triceps brachii

Back 17

O: lateral head at superior, lateral margin of humerus; long head at infraglenoid tubercle of scapula; medial head at posterior surface of humerus, inferior to radial groove
I: Olecranon of ulna
A: Extension at elbow (plus adduction at should w/long head)

Front 18

Pronator quadratus

Back 18

O: Anterior and media surfaces of distal ulna
I: Anterolateral surface of distal portion of radius
A: Pronates forearm and hand by medial rotation of radius at radioulnar joints