UE Muscles Flashcards
(53 cards)
Trapezius
O: (1) Medial part of superior nuchal line, (2) Ligamentum nuchae [an expansion of the supraspinous ligament], (3) Thoracic spinous processes, (4) Supraspinous ligament
I: (1) Lateral part of the clavicle, (2) Acromion, (3) Spine of the scapula
I: Motor from spinal portion of accessory nerve (CN XI)
A: (1) As a whole, rotates scapula upward, (2) Upper trap alone: rotates scapula upward, (3) Middle trap retracts [adducts] scapula, (4) Lower trap depresses and upwardly rotates scapula
NOTE: Most superficial layer of superficial back muscles
Nerve runs on deep side of muscle with superficial branch of transverse cervical artery
Latissimus Dorsi
O: (1) Spinous processes of T7-T12, (2) Lumbar aponeurosis [thoracolumbar fascia], (3) Crest of Ilium, (4) Lower 3-4 ribs, (5) Inferior angle of scapula
I: Floor of bicipital groove of humerus (“Lady between 2 majors”)
I: Thoracodorsal nerve (from brachial plexus)
A: (1) Shoulder extension, (2) Shoulder internal rotation, (3) Shoulder adduction, (4) Can also contribute to scapular depression and retraction [adduction]
NOTE: Most superficial layer of superficial back muscles
Levator Scapulae
O: Transverse processes of C1-C4
I: Vertebral border between spine and superior angle of scapula
I: Dorsal scapular nerve
A: (1) Elevation of scapula, (2) downward rotation of scapula
NOTE: Intermediate layer of superficial back muscles.
Rhomboid Minor
O: Spinous processes of C7 and T1
I: Vertebral border of scapula at base of spine
I: Dorsal scapular nerve
A: (1) Downward rotation of scapula, (2) Retraction [adduction] of scapula, (3) Elevation of scapula
NOTE: Intermediate layer of superficial back muscles
Nerve lies on deep surface with deep branch of transverse cervical artery
Serratus Posterior Superior
O: Spinous processes of C7-T2
I: Upper ribs
I: Intercostal nerves T2-T5 (ventral rami)
A: Assists with lifting ribs in inspiration
NOTE: Deepest layer of superficial back muscles
Rhomboid Major
O: Spinous processes T2-T5
I: Vertebral border of scapula below rhomboid minor to the inferior angle
I: Dorsal scapular nerve
A: (1) Downward rotation of scapula, (2) Retraction [adduction] of scapula, (3) Elevation of scapula
NOTE: Intermediate layer of superficial back muscles
Serratus Posterior Inferior
O: Spinous processes T11-L2
I: Lower ribs
I: Intercostal nerves T9-T12 (ventral rami)
A: Unclear, may hold lower ribs down during inspiration
NOTE: Deepest layer of superficial back muscles
Serratus Anterior
O: Digitations from ribs 1-8
I: (1) Vertebral border on costal surface of scapula, (2) Inferior angle of scapula
I: Long thoracic nerve
A: (1) Scapular protraction [abduction], (2) Rotates scapula [glenoid] upward
NOTE: Scapular winging if serratus anterior denervated. Important in scapulohumeral rhythm
Deltoid
O: (1) Lower margin of scapular spine, (2) Acromion, (3) Lower margin of lateral 1/3 of clavicle
I: Deltoid tuberosity of humerus
I: Axillary nerve
A: (1) Acting as a whole, deltoid stabilizes glenohumeral {GH} joint, (2) Acting individually, Anterior fibers: shoulder flexion and horizontal aDDuction, (3) Middle fibers: shoulder ABduction, (4) Posterior fibers: shoulder extension and horizontal abduction
Subscapularis
O: Costal surface of scapula (subscapular fossa)
I: Lesser tubercle of humerus
I: Upper and lower subscapular nerves
A: (1) Stabilizes GH joint, (2) shoulder internal rotation
NOTE: Rotator cuff muscle
Supraspinatus
O: Supraspinous fossa
I: Superior facet of greater tubercle of humerus
I: Suprascapular nerve
A: (1) Stabilizes GH joint, (2) Shoulder abduction, (3) Depresses humeral head during abduction
NOTE: Rotator cuff muscle
Infraspinatus
O: Infraspinous fossa
I: Middle facet of greater tubercle
I: Suprascapular nerve
A: (1) Stabilizes GH joint, (2) Shoulder external rotation
NOTE: Rotator cuff muscle
Teres Minor
O: Lateral border of scapula, above teres major
I: Lower facet of greater tubercle
I: Axillary nerve
A: (1) Stabilizes joint, (2) Shoulder external rotation
NOTE: Rotator cuff muscle
Teres Major
O: Lower lateral border of scapula, as far as inferior angle
I: Medial lip of bicipital groove (“Lady between two majors”)
I: Lower subscapular nerve
A: (1) Shoulder internal rotation, (2) Shoulder adduction, (3) Shoulder extension
Coracobrachi
O: Coracoid process
I: Middle shaft of humerus
I: Musculocutaneous n.
A: (1) Shoulder Flexion, (2) Shoulder adduction
*Muscle belly pierced by musculocutaneous nerve
Biceps Brachii
O: (1) Short Head: Coracoid process, (2) Long head: supraglenoid tubercle (blends with labrum)**
I: Radial tuberosity (radius)
I: Musculocutaneous n.
A: (1) Elbow flexion, (2) Forearm supination, (3) Shoulder flexion
** Tendinous origin of long head runs in fibrous capsule of GH joint (enclosed in synovial membrane,), travel sin bicipital groove, held down by transverse humeral ligament. Two tendons fuse into one muscle belly. Prior to insertion, gives of bicipital aponeurosis medially which fuses with deep fascia. In 10% a third head can be found arising from humerus.
Brachialis
O: Lower, anterior humerus
I: Coronoid process (of ulna)
I: Musculocutaneous n.
A: Elbow flexor (in both supination and pronation)
*Possibly dual innervation from radial nerve
Triceps Brachii
O: (1) Long head: Infraglenoid tubercle, (2) Short head: posterior humerus above spiral groove, (3) Medial head: posterior humerus below the spiral groove (deep)
I: Olecranon process
I: Radial nerve
A: (1) Elbow extension, (2) Long head can adduct and extend shoudler
*Long head runs anterior to teres minor and posterior to teres major muscles
Long and lateral heads form the superficial part of the muscle
Aconeous
O: Lateral epicondyle of humerus I: (1) Lateral surface of olecranon, (2) Lateral ulna I: Radial nerve A: Elbow extension *Posterior compartment
Pectoralis Major
O: (1) Clavicular head: medial 1/3 of clavicle, (2) Sternal head: sternum, upper 6 costal cartilages, (3) Aponeurosis of external oblique
I: Lateral lip of bicipital groove of humerus (clavicular fibers insert lower part of groove, and sternal fibers insert on the higher part of groove)
I: Medial and lateral pectoral nerves
A: Shoulder adduction, shoulder flexion, shoulder internal rotation
Pectoralis Minor
O: Ribs 2-5 (may vary)
I: Coracoid process of scapula
I: Medial and lateral pectoral nerves
A: Protraction of scapula, Scapular depression
Subclavius
O: First rib
I: Clavicle
I: Nerve to subclavius
A: Elevates first rib
Pronator teres
O: Medial epicondyle (common flexor origin), coranoid process of ulna
I: Mid-radius
I: Median nerve
A: Pronation of forearm, weak flexor of elbow
*Median nerve passes between its two heads!!
Flexor carpi radialis
O: Medial epicondyle
I: Base of 2nd metacarpal
I: Median nerve
A: Wrist flexion, wrist radial deviation (along with extensor carpi radialis longus)