Muscles of the Upper Extremity

Question 1

Pectoralis Major

Answer 1

O: Medial half of clavicle, Manubrium & body of
sternum & cartilages of first 6-7 ribs

I: Crest of greater tubercle of humerus

A: Flexion, medial rotation and horizontal adduction of shoulder.

Scapular Protraction and Depression

Inv: Lateral Pectoral Nerve

Question 2

Pectoralis Minor

Answer 2

O: Ribs 2-5

I: Medial border of the coracoid process

A: Downward Rotation of scapula, Scapular Protraction and Depression

Inv: Medial pectoral

Question 3

Serratus Anterior

Answer 3

O: Ribs 1-8

I: Medial border, costal surface of scapula

A: Upward Rotation of scapula, Scapular Protraction and Depression

Inv: Long Thoracic

Question 4

Trapezius

Answer 4

O: Superior nuchal line and external occipital
protuberance, ligamentum nuchae, spinous processes and supraspinous ligaments of C7 and all thoracic vertebrae

I: Upper part: Lateral one third of the clavicle

Middle part: Acromion and upper lip of the spine of the scapula

Lower part: Spine of the scapula

A:
- Upper fibers- Scapula elevation,
- Middle fibers- Scapula Retraction
- Lower fibers- Scapula Depression
- Upper and lower fibers: Upward
rotation of scapula

Inv: Cranial nerve XI (Spinal accessory nerve)

Question 5

Rhomboids Major and Minor

Answer 5

O: Ligamentum nuchae and spinous processes of C7 to T5

I: Medial border of scapula

A: Adduction, elevation and downward rotation of scapula

Inv: Dorsal Scapular

Question 6

Levator Scapulae

Answer 6

O: Transverse Processes of C1-4

I: Medial border of scapula between superior angle and root of spine

A: Scapular Elevation and Downward Rotation

Inv: Ventral rami of spinal nerves (C3-C4) and the dorsal scapular nerve

Question 7

Sternocleidomastoid (SCM)

Answer 7

O: Manubrium & medial portion of Clavicle

I: Mastoid process of temporal bone

A: U/L: Same side lateral flexion & opposite side rotation of neck

Inv: Spinal Accessory nerve (CN XI)

Question 8

Latissimus Dorsi

Answer 8

O: Spinous processes of 7th through 12th
thoracic vertebrae, through fascia from the lumbar and sacral vertebrae, last three or four ribs and slip from inferior angle of scapula

I: Intertubercular groove of Humerus (Lady Between Two Majors)

A: Medial (Internal) rotation, adduction and extension of shoulder joint

Inv: Thoracodorsal

Question 9

Deltoid

Answer 9

O: Anterior part: lateral end of clavicle
Middle part: acromion
Posterior part: spine of the scapula

I: Deltoid tuberosity of humerus

A:
Lateral: Abduction at shoulder
Anterior fibers: flex the shoulder
Posterior fibers: extend the shoulder

Inv: Axillary

Question 10

Teres Major

Answer 10

O: Inferior angle of scapula

I: Crest of lesser tubercle of
Humerus

A: Shoulder medial rotation, extension, adduction

Inv: Lower subscapular

Question 11

Coracobrachialis

Answer 11

O: Coracoid process of scapula

I: Medial aspect of middle shaft of the humerus

A: Flexion of arm

Inv: Musculocutaneous

Question 12

Subscapularis

Answer 12

O: Subscapular fossa of scapula

I: Lesser tubercle of humerus

A: Medially rotate shoulder, adduction at shoulder

Inv: Upper and lower subscapular nerves

Question 13

Supraspinatus

Answer 13

O: Supraspinatus (Suprascapular) fossa of scapula

I: Upper facet of greater tubercle of humerus

A: Shoulder Abduction up to 15 degrees [First 15 degrees]

Inv: Suprascapular

Question 14

Infraspinatus

Answer 14

O: Infraspinatus (Infrascapular) fossa of scapula

I: Middle facet of greater tubercle of humerus

A: Lateral (External) rotation at shoulder

Inv: Suprascapular

Question 15

Teres Minor

Answer 15

O: Lateral border of scapula

I: Lower facet of greater tubercle of humerus

A: Lateral rotation at shoulder

Inv: Axillary

Question 16

Long Head of Biceps

Answer 16

O: Supraglenoid tubercle of scapula

I: Bicipital tuberosity of the radius

A: Flexion of elbow, supination of forearm, flexion of shoulder

Inv: Musculocutaneous

Question 17

Short Head of Biceps

Answer 17

O: Coracoid process of scapula

I: Bicipital tuberosity of the radius

A: Flexion of elbow, supination of forearm, flexion of shoulder

Inv: Musculocutaneous

Question 18

Brachialis

Answer 18

O: Distal aspect of the anterior surface of the humerus

I: Coronoid process and tuberosity on the proximal ulna

A: Flex elbow

Inv: Musculocutaneous

Question 19

Lateral Head of Triceps

Answer 19

O: Posterior humerus, superior and lateral to the radial groove

I: Olecranon process of ulna

A: Extend elbow and shoulder

I: Radial

Question 20

Long Head of Triceps

Answer 20

O: Infraglenoid tubercle of
scapula

I: Olecranon process of ulna

A: Extend elbow and shoulder

I: Radial

Question 21

Medial Head of Triceps

Answer 21

O: Posterior humerus, inferior and medial to the radial groove

I: Olecranon process of ulna

A: Extend elbow and shoulder

I: Radial

Question 22

Brachioradialis

Answer 22

O: Upper two thirds of the lateral supracondylar ridge of the humerus

I: Near styloid process at the distal radius

A: Elbow Flexion especially in mid-prone position

Inv: Radial

Question 23

Anconeus

Answer 23

O: Posterior side of the lateral epicondyle of the humerus

I: Between the olecranon process and proximal surface of the posterior side of the ulna

A: Weak elbow extensor

Inv: Radial