Cubital Fossa & Anterior Forearm

Question 1

What are the muscles of the anterior compartment of the forearm?

Answer 1

Superficial: flexor carpi ulnaris, palmaris longus, flexor carpi radialis, pronator teres
Intermediate: Flexor digitorum superficialis
Deep: flexor pollicis longus, pronator quadratus, flexor digitorum profundus

Question 2

Identify the joints of the elbow and provide their synovial classification.

Answer 2

Humeroulnar - hinge
Humeroradial - gliding
Proximal Radioulnar - pivot

Question 3

Identify the ligaments of the elbow and forearm.

Answer 3

Radial Collateral Ligament: lateral epicondyle to anular ligament and head of radius (resists varus load)
Ulnar Collateral Ligament: 3 bands (anterior, posterior, transverse) provide stability to medial side of elbow (resists valgus load) - I.e., throwing tommy john
Annular Ligament: wrapping around head of radius; stabilizes radial head

Question 4

Use a drawing to summarize collateral circulation at the elbow.

Answer 4

See drawing

Question 5

Describe the location and function of the bursae at the elbow.

Answer 5

Subcutaneous bursa of medial epicondyle
Subcutaneous bursa of lateral epicondyle
Bursa of anconeus
Bursa at origin of extensor carpi radialis brevis
Olecranon bursae: subtendinous, intratendinous, subcutaneous

Question 6

Describe radial head subluxation and relate anatomical structures.

Answer 6

AKA “nurse maid’s elbow”
Dislocation of radial head from anular ligament (mostly in kids because the radial head is not fully developed)
Distraction force pulls radial head out of anular ligament
Reduction: flex elbow simultaneously with supination (ensure no fracture from FOOSH)

Question 7

Describe olecranon bursitis and relate anatomical structures.

Answer 7

Olecranon Bursitis is seen usually from leaning on the elbow consistently or a poorly fitted sling post-op — inflammation of bursa
Rest is usually suitable for healing but sometimes it can need to be drained

Question 8

Predict what neurovascular structures would be injured based on bone fracture located at the medial epicondyle of the humerus.

Answer 8

Median n., basilic v., brachial a., ulnar n., radial n., median cubital v., median cutaneous n. of forearm

Question 9

Locate the areas of skin associated with a single spinal segment/nerve (dermatome).

Answer 9

C5 - deltoid tuberosity
C6 - thumb 
C7 - index finger
C8 - 5th digit (pinky)
T1 - medial aspect of forearm just below medial condyle

Question 10

Identify structures on the pronator quadratus muscle level.

Answer 10

Kenhub

Question 11

Name the actions and innervations of the flexor carpi radialis muscle.

Answer 11

C6-C8
Attachments: from the medial epicondyle (common flexor origin) to the palmar aspect of the base of the 2nd metacarpal
Actions: flexes and abducts hand at wrist (radial deviation) and may assist in pronation of forearm and flexion of the elbow
Innervation: median n.

Question 12

Name the actions and innervations of the pronator teres muscle

Answer 12

C6-C7
Attachments: from the medial epicondyle and ulnar coronoid process to lateral aspect of radius
Actions: pronates and flexes forearm
Innervation: median n.

Question 13

Name the actions and innervations of the palmaris longs muscle.

Answer 13

C7-C8
Attachments: from the medial epicondyle of the humerus to the palmar aponeurosis
Actions: flexes hand at wrist and tenses palmar fascia
Innervation: median n.

Question 14

Name the actions and innervations of the flexor carpi ulnaris muscle.

Answer 14

C7-T1
Attachments: from the medial epicondyle and proximal ulnar shaft of the humerus to the pisiform
Actions: flexes and abducts hand at wrist (ulnar deviation) and assists in flexion of the elbow
Innervation: ulnar n.

Question 15

Name the actions and innervations of the flexor digitorum superficialis muscle.

Answer 15

C7-T1
Attachments: from the medial epicondyle to the sides of the middle phalanges of digits 2-5
Actions: flexion of digits (metacarpophalangeal and proximal interphalangeal), and hand at wrist
Innervation: median n.

Question 16

Name the actions and innervations of the flexor digitorum profundas muscle.

Answer 16

C7-T1
Attachments: anterior proximal two thirds of the ulna and interosseous membrane to the base of the distal phalanges of digits 2-5
Actions: flexion of digits 2-5 (metacarpophalangeal and distal interphalangeal and proximal interphalangeal) and flexion of hand at wrist
Innervation: median (anterior interosseous nerve, 2nd and 3rd digits) and ulnar (4th and 5th digits) nerves

Question 17

Name the actions and innervations of the flexor pollicis longus muscle.

Answer 17

C7-T1
Attachments: anterior surface of the radius and interosseous membrane to the base of the distal phalanx of the thumb
Actions: flexes thumb (metacarpophalangeal and interphalangeal)
Innervation: median n. (Anterior interosseous n.)

Question 18

Name the actions and innervations of the pronator quadratus muscle.

Answer 18

C8-T1
Attachments: from the anterior surface of the distal ulna to the anterior surface of the distal radius
Actions: pronates the forearm
Innervation: median n. (Anterior interosseous n.)