Humerus and Elbow

Question 1

Coracobrachialis:

O: apex of the coracoid process of scapula

I: medial surface of middle of shaft of humerus

A: flexes and adducts the shoulder joint

N: musculocutaneous nerve (C6, C7)

Answer 1

Muscle Testing - Coracobrachialis

Patient: sitting or supine
Fixation: none
Test: shoulder flexion in lateral rotation, with elbow flexed and forearm supinated
Pressure: against anteromedial surface of the lower ⅓ of the humerus

Question 2

Biceps Brachii:

O: short head: apex of coracoid process of scapula
O: long head: supraglenoid tubercle of the scapula

I: tuberosity of the radius and aponeurosis of biceps brachii

A: flexes the elbow joint, supinates the forearm, flexes the shoulder joint

N: musculocutaneous nerve (C5, C6)

Answer 2

Muscle Testing - Biceps Brachii (with Brachialis):

Patient: supine or sitting
Fixation: examiner places one hand under the elbow to cushion
Test: elbow flexion with forearm in supination
Pressure: against the lower forearm

Question 3

Brachialis:

O: distal ½ of anterior surface of humerus, both medial & lateral intermuscular septa

I: tuberosity and coronoid process of ulna

A: flexes the elbow joint

N: musculocutaneous nerve (C5, C6)

Answer 3

Muscle Testing - Biceps Brachii (with Brachialis):

Patient: supine or sitting
Fixation: examiner places one hand under the elbow to cushion
Test: elbow flexion with forearm in supination
Pressure: against the lower forearm

Question 4

Triceps Brachii:

O: Long head: infraglenoid tubercle of scapula
O: Lateral head: lateral & posterior surface of proximal ½ of body of humerus & lateral intermuscular septum
O: Medial head: distal 2/3 of the medial & posterior surfaces of the humerus below the radial groove & medial intermuscular septum

I: posterior surface of the olecranon process of the ulna & antebrachial fascia

A: extends the elbow joint, long head aids in adduction & extension of shoulder joint

N: radial nerve (C6, C7, C8, T1)

Answer 4

Muscle Testing - Triceps Brachii
(with Anconeus):

Patient: supine
Fixation: shoulder at 90 degrees of flexion with arm supported
Test: extension of the elbow joint
Pressure: against the forearm

Question 5

Pronator Teres:

O: Humeral head: above the medial epicondyle of humerus & the common flexor tendon
O: Ulnar head: medial side of the coronoid process of the ulna

I: middle of the lateral surface of the radius

A: pronates the forearm, assists in flexion at the elbow joint

N: median nerve (C6, C7)

Answer 5

Muscle Testing - Pronator Teres (with Quadratus):

Patient: supine or sitting
Fixation: elbow held against the patient’s side
Test: pronation of the forearm, with elbow partially flexed
Pressure: at lower forearm, above the wrist

Question 6

Flexor Carpi Radialis:

O: common flexor tendon at medial epicondyle of humerus

I: base of the 2nd metacarpal bone and a slip at the base of the 3rd metacarpal bone

A: flexes and abducts the wrist, assists in pronation of the forearm and flexion of the elbow joint

N: median nerve (C6, C7, C8)

Answer 6

Muscle Testing - Flexor Carpi Radialis:

Patient: sitting or supine
Fixation: forearm is slightly less than full supination and rests on table or supported by examiner
Test: flexion of the wrists towards the radial side
Pressure: against the thenar eminence

Question 7

Flexor Carpi Ulnaris:

O: Humeral head: common flexor tendon at medial epicondyle of humerus
O: Ulnar Head: aponeurosis from medial margin of olecranon, proximal 2/3 of posterior border of the ulna

I: pisiform bone, ligaments, hamate bone, and 5th metacarpal bone

A: flexes & adducts the wrist, assists in flexion of the elbow

N: ulnar nerve (C7, C8, T1)

Answer 7

Muscle Testing - Flexor Carpi Ulnaris:

Patient: sitting or supine
Fixation: forearm in full supination and resting on the table or supported by examiner
Test: flexion of the wrist toward the ulnar side
Pressure: against the hypothenar eminence

Question 8

Palmaris Longus:

O: common flexor tendon from medial epicondyle of humerus

I: flexor retinaculum and palmar aponeurosis

A: tenses the palm, flexes the wrist, assists in flexion at the elbow

N: median nerve (C6, C7, C8, T1)

Answer 8

Muscle Testing - Palmaris Longus:

Patient: sitting or supine
Fixation: forearm rests on table in supination
Test: tensing the palmar fascia by strongly cupping the palm of the hand with flexion of the wrist
Pressure: against the thenar and hypothenar eminence

Question 9

Flexor Digitorum Superficialis:

O: Humeral head: common flexor tendon at medial epicondyle of humerus
O: Ulnar head: medial side of the coronoid process
O: Radial head: oblique line of the radiusI: by four tendons into the sides of the middle phalanges of the 2-5 digits

A: Flexes the interphalangeal joints of 2-5 digits, assists in flexion of metacarpophalangeal joint & flexion of wrist

N: median nerve (C7, C8, T1)

Answer 9

Muscle Testing - Flexor Digitorum Superficialis:

Patient: sitting or supine
Fixation: examiner stabilizes the metacarpophalangeal joint, wrist in neutral
Test: flexion of proximal interphalangeal joint with distal interphalangeal joints extended (2-5 only) each finger tested.
Pressure: against the palmar surface of the middle phalanx

Question 10

Flexor Pollicis Longus:

O: anterior surface of body of radius below tuberosity, interosseous membrane, medial border of coronoid process of ulna, medial epicondyle of humerus

I: base of the distal phalanx of the thumb, palmar surface

A: flexes the interphalangeal joint of thumb, flexes metacarpophalangeal and carpometacarpal joints, flexes the wrist

N: median nerve (C6, C7, C8, T1)

Answer 10

Muscle Testing - Flexor Pollicis Longus:

Patient: sitting or supine
Fixation: hand rests on table, examiner stabilizes metacarpal bone and proximal phalanx of the thumb in extension.
Test: flexion of the interphalangeal joint of the thumb
Pressure: against the palmar surface of the distal phalanx

Question 11

Brachioradialis:

O: proximal 2/3 of lateral supracondylar ridge of humerus

I: lateral side of base of styloid process of radius

A: flexes the elbow joint, assists in pronation/supination

N: radial nerve (C5, C6)

Answer 11

Muscle Testing - Brachioradialis:

Patient: supine or sitting
Fixation: examiner places one hand under the elbow to cushion
Test: flexion of the elbow, with forearm in neutral
Pressure: against the lower forearm

Question 12

Extensor Carpi Radialis Longus:

O: distal 1/3 of lateral supracondylar ridge of humerus

I: dorsal surface of base of 2ne metacarpal bone, radial side

A: extends & abducts the wrist, flexes elbow

N: radial nerve (C5, C6, C7, C8)

Answer 12

Muscle Testing - Extensor Carpi Radialis Longus (with Brevis):

Patient: sitting, elbow in 30 degrees of zero extension
Fixation: forearm slightly less than full pronation and resting on table
Test: extension of wrist toward radial side
Pressure: against the dorsum of the hand, along the 2nd and 3rd metacarpal bones

Question 13

Extensor Carpi Radialis Brevis:

O: common extensor tendon at lateral epicondyle of humerus, radial collateral ligament of elbow

I: dorsal surface of base of the 3rd metacarpal bone

A: extends & and aids in abduction the wrist

N: radial nerve (C6, C7, C8)

Answer 13

Muscle Testing - Extensor Carpi Radialis Brevis:

Patient: sitting, elbow fully flexed
Fixation: forearm is slightly less than full pronation and resting on table
Test: extension of wrist towards the radial side
Pressure: against the dorsum of the hand, along the 2nd and 3rd metacarpal bones

Question 14

Extensor Digitorum (communis):

O: common extensor tendon from lateral epicondyle of humerus

I: by four tendons to the 2-5th digits, dividing into 1 medial & 2 lateral bands

A: extends metacarpophalangeal & interphalangeal.

N: radial nerve (C6, C7, C8

Answer 14

Muscle Testing - Extensor Digitorum:

Patient: sitting or supine
Fixation: examiner stabilizes the wrist avoiding full extension
Test: extension of the metacarpophalangeal joints of the 2-5 digits with the interphalangeal joints relaxed
Pressure: against the dorsal surfaces of the proximal phalanges

Question 15

Extensor Digiti Minimi:

O: common extensor tendon of lateral epicondyle of humerus

I: into extensor expansion of little finger with extensor digitorum tendon

A: extends metacarpophalangeal (MCP) joint & interphalangeal (IP) joint of little finger

N: radial nerve (C6, C7, C8)

Answer 15

Question 16

Extensor Carpi Ulnaris:

O: common extensor tendon at lateral epicondyle of humerus, aponeurosis of posterior border of ulna

I: base of the 5th metacarpal bone, ulnar side

A: extends & adducts the wrist

N: radial nerve (C6, C7, C8)

Answer 16

Muscle Testing - Extensor Carpi Ulnaris:

Patient: sitting or supine
Fixation: forearm in full pronation and resting on table
Test: extension of the wrist toward the ulnar side
Pressure: against the dorsum of the hand along the 5th metacarpal bone

Question 17

Anconeus:

O: lateral epicondyle of humerus, posterior surface

I: lateral side of olecranon process & upper ¼ of posterior surface of body of ulna

A: extends the elbow joint

N: radial nerve (C7, C8)
muscle tested with triceps brachii

Answer 17

Question 18

Supinator:

O: lateral epicondyle of humerus, radial collateral ligament of elbow joint, annular ligament of radius & supinator crest of ulna

I: lateral surface of upper 1/3 of body of radius

A: supinates the forearm

N: radial nerve (C5, C6, C7)

Answer 18

Muscle Testing - Supinator (with Biceps):

Patient: supine
Fixation: elbow held against the patient’s side
Test: supination of the forearm with elbow at 90 degrees
Pressure: at the distal end of the forearm above the writs