elbow joints and muscles of the arm

Question 1

label the anterior elbow boney features

Answer 1

1. ulna
2. radius
3. capitulum
4. trochlea
5. head of radius
6. radial tuberosity
7. cornoid process of ulna
8. ulnar tuberosity
9. medial epicondyle of humerus

Question 2

label the posterior elbow boney features

Answer 2

1. olecranon process
2. olecranon fossa

Question 3

is the elbow joint stable?

Answer 3

very stable, lots of boney congruency, does not dislocate easily

Question 4

does the elbow have a natural varus or valgus position? What is the angle called? Which ligament is well developed as a result?

Answer 4

1. natural valgus position
2. carrying angle
3. UCL is very well developed

Question 5

describe the superior radial ulnar joint

Answer 5

head of radius rests against concave notch of the ulna

Question 6

label the ligament and its function

Answer 6

• Annular Ligament
• attaches to the anterior and posterior margins of the radial notch on ulna
• loops around radial head but does not attach
• this allows for radius to stay close to ulna but still move as it needs

Question 7

identify the joint

Answer 7

humero-radial joint

Question 8

identify the ligament, origin, insertion, and motion it limits

Answer 8

• radial collateral ligament (RCL)
• 2 bands
• origin: Lateral epicondyle of humerus
• insertion: annular ligament - posterior band blends into supinator crest
• limits varus

Question 9

identify the ligament, origin, insertion, and what motion it limits

Answer 9

• ulnar or medial collateral ligament (UCL)
• origin: medial epicondyle of humerus
• anterior band inserts: cornoid process
• posterior band inserts: olecranon process
• transverse band: coronoid process to olecranon
• limits valgus force to the elbow

Question 10

identify the muscle, origin, insertion, and movement

Answer 10

• biceps brachi
• origin: 2 heads
  
  • short head: coracoid process
  • long head: supraglenoid tubercle
• 2 insertions: radial tuberosity, biciptial aponeurosis
• movement: flexions of the elbpw, supination of radial ulnar joint

Question 11

identify the muscle that is deep, origin, insertion, and movement

Answer 11

• brachialis
• origin: anterior aspect of humerus in distal half
• insertion: ulnar tuberosity
• flexion of the elbow

Question 12

identify the muscle, origin, insertion, and movement

Answer 12

• triceps brachii
• origin: 3 heads
  
  • long head (1): infraglenoid tubercle
    
    • helps with extension of GH joint, adduction
  • medial head (deep): posterior surface of shaft of humerus
  • lateral head (2): posterior head of shaft of humerus
• insertion: a tendon blending into oelcranon process, radial groove
• movement: extension of elbow