11. Upper Extremity Muscles Flashcards
Muscles that act on the scapula
Trapezius, Rhomboids, Levator scapulae, Pectoralis minor, and Serratus anterior
OIA of trapezius
Origin: external occipital protuberance, and
spinous processes of vertebrae
Insertion: scapular spine, acromion, and distal
clavicle
Action: elevates, depresses, adducts scapula
OIA of rhomboids
Origin: spinous processes of vertebrae
Insertion: medial border of scapula
Action: adducts scapula
OIA of levator scapulae
Origin: transverse processes of cervical vertebrae
Insertion: superior angle of scapula
Action: elevate scapula
OIA of pectoralis minor
Origin: ribs 3-5
Insertion: coracoid process of
scapula
Action: abducts and depress
scapula
OIA of serratus anterior
Origin: ribs 1-8
Insertion: medial border of
scapula
Action: abduct scapula
Muscles that act on the arm
Flexors: Pectoralis major and Coracobrachialis
Extensors: Latissimus dorsi and Teres major
Abductor: Deltoid (& Supraspinatus)
Rotator cuff (“SITS”): Supraspinatus, Infraspinatus, Teres minor, and Subscapularis
OIA of Pectoralis major
Origin: sternum and clavicle
Insertion: greater tubercle of humerus
Action: flex, adduct arm at shoulder
OIA of Coracobrachialis
Origin: coracoid process of scapula
Insertion: proximal humerus
Action: flex and adduct arm at
shoulder
OIA of latissimus dorsi
Origin: spinous processes of thoracic and
lumbar vertebrae and posterior iliac crest
Insertion: lesser tubercle of humerus
Action: extend, adduct arm at shoulder
OIA of Teres major
Origin: inferior angle of the scapula
Insertion: lesser tubercle of humerus
Action: extend, adduct arm at shoulder
OIA of deltoid
Origin: scapular spine, acromion, clavicle
Insertion: deltoid tuberosity of humerus
Action: abduct, flex, extend arm at shoulder
Rotator cuff muscles
4 muscles: supraspinatus, infraspinatus, teres minor, and subscapularis
OIA of Rotator cuff muscles
Origin:
• Supraspinatus: supraspinous fossa of scapula
• Infraspinatus: infraspinous fossa of scapula
• Teres minor: lateral border of scapula
Insertion: greater tubercle of humerus
Action:
• Supraspinatus- abduct arm at shoulder
• Infraspinatus & teres minor: laterally rotate arm
at shoulder
OIA of subscapularis
Origin: subscapular fossa of scapula
Insertion: lesser tubercle of humerus
Action: medially rotate arm at shoulder
Muscles that act on the forearm
Anterior compartment (of arm)
• Biceps brachii
• Brachialis
• Brachioradialis (in forearm, mostly)
Posterior compartment (of arm)
• Triceps brachii
Rotators (in forearm)
• Pronator teres
• Pronator quadratus
• Supinator
OIA of biceps brachii
Origin:
• Long head: superior glenoid tubercle
• Short head: coracoid process of scapula
Insertion: radial tuberosity of radius
• Note: this muscle spans two joints
Action: flex forearm at elbow and supinate; flex arm at shoulder
OIA of brachialis
Origin: distal humerus
Insertion: coronoid process of ulna
Action: flex forearm at elbow
OIA of brachioradialis
Origin: distal lateral humerus
Insertion: styloid process of radius
Action: flex forearm at elbow
OIA of triceps brachii
Origin:
• Lateral head: lateral surface of humerus
• Long head: infraglenoid tubercle of scapula
• Medial head: posterior surface of humerus
Insertion: olecranon process of ulna
• Note: this muscle spans two joints
Action: extend forearm at elbow; extend arm at shoulder
OIA of Pronators (anterior comp.)
Origin: ulna
Insertion: radius
Action: pronates forearm
OIA of Supinator (posterior comp.)
Origin: proximal ulna
Insertion: proximal radius
Action: supinates forearm
Muscles that act on the hand and fingers
Anterior compartment (flexor)
• Superficial group
• Deep group
Posterior compartment (extensor)
• Superficial group
• Deep group
OIA of forearm flexors (anterior)
Origin:
• Superficial: medial epicondyle of humerus
• Deep: Ulna and radius
Insertion: carpals and phalanges of hand
Action: flex wrist, fingers, & thumb
OIA of forearm extensors (posterior)
Origin:
• Superficial: lateral epicondyle of humerus
• Deep: Ulna and radius
Insertion: carpals and phalanges of the hand
Action: extend wrist, fingers, & thumb; abduct
thumb
Intrinsic muscles of the hand
19 muscles in all
Name of thumb muscles
Thenar
Name of 5th digit (little fingers) muscles
Hypothenar
