glenohumeral muscles

Question 1

identify the muscles of the rotator cuf - what is the big picture function of the rotator cuff

Answer 1

1. subscapularis
2. supraspinatus
3. infraspinatus
4. teres minor
5. rotator interval

• big picture: enhance joint stabilitly, compress head of humerus into glenoid fossa

Question 2

identify the muscle, origin, insertion and movement

Answer 2

• subscapularis
• origin: subscapular fossa
• insertion: lesser tuberosity
• movement: internal/ medial rotation of GH joint

Question 3

identify muscle 1, origin, insertion, movement

Answer 3

• supraspinatus
• origin: supraspinois fossa
• insertion: superior poart of greater tubercle
• movement: abduction of GH joint

Question 4

identify muscle 2, origin, insertion, movement

Answer 4

• infraspinatus
• origin: infraspinous foss
• insertion: posterior greater tubercle
• movement: lateral/external rotation of GH joint

Question 5

identify muscle 3, origin, insertion, and movement

Answer 5

• teres minor
• origin: lateral boarder of scapula
• insertion: posterior inferior greater tubercle
• movement: lateral/ external roation of GH joint

Question 6

identify the muscle, origin, insertion, and movement

Answer 6

• deltoid
• origin: 3 parts
• all insert on deltoid tuberosity
• all abduct the GH joint

Question 7

what are the 3 deltoid origins and movement

Answer 7

1. (A anterior) origin: inferior lateral third of clavicle. movement: flexion of GH joint, interal/medial rotation of GH joint
2. (middle M) origin: lateral edge of acromion process
3. (spinal P) origin: scapular spine. movement: extension of GH joint, lateral rotation of GH joint

Question 8

label muscle 1, origin, insertion and movement

Answer 8

• pectoralis major
• origin: medial half of clavicle [clavicular fibres are inferior and lateral], length of sternum [horizontal fibres], costal cartilage of ribs 1-6, connective tissue of abdomin [superior fibres]
• insertion: lateral lip of bicipital groove
• movement: adduction, flexion of GH joint, internal/medial rotation of GH joint

Question 9

label muscle 2, origin, insertion, and movement

Answer 9

• coracobrachialis
• origin: tip of choracoid
• insertion: half way down the shaft of humerus, medial side
• movement: adduction, flexion and GH joint

Question 10

label muscle 1, origin, insertion, and movement

Answer 10

• latissumus dorsi
• origin: T7-L5, posterior aspect of iliac crest, distal ribs 10-12
• insertion: biciptial groove
• movement: adduction, extension of GH joint, internal/medial rotation of GH joint

Question 11

label muscle 2, origin, insertion, and movement

Answer 11

• teres major
• origin: distal lateral boarder of scapula
• insertion: medial lip of bicipital groove
• movement: adduction, extension of GH joint, internal/medial rotation of GH joint