Pectoral Girdle

Question 1

What is the 3 joints of the girdle

Answer 1

AC: (acromioclavicular joint) between the clavicle and scapula

SC (sternoclavicular joint) between the clavicle and sternum

Conceptual joint: between the scapula and chest wall.

Question 2

What are the bones in the shoulder girdle

Answer 2

Clavicle and scapula

Question 3

Describe the movements of the pectoral girdle (scapula)

Answer 3

Scapula retraction & protraction

Scapula elevation & depression

Scapula superior & inferior rotation

Question 4

Describe the clavicle anatomy with the joints attached from both superior and inferior view

Answer 4

A sinuous, long bone (medial convexity points anteriorly), largely subcutaneous, forming a strut between the manubrium and the acromial process of the scapula.

Question 5

Describe the scapula anatomy posterior and anterior view

Answer 5

Refer to lecture

Question 6

Describe the SC joint anatomy
What are the four important ligaments of the SC joint

Answer 6

A saddle shaped synovial joint between the medial end of disc (intra-articular disc).

The four important ligaments of the SC joint are the
1. anterior sternoclavicular
2. posterior sternoclavicular
3. interclavicular
4. costoclavicular (the fulcrum for clavicular movements and is the chief stabilizer of the joint).

Question 7

draw/label the SC joint area

Question 8

Describe AC joint anatomy

Answer 8

a synovial joint between the lateral end of the clavicle and the medial border of the acromion.

Inside the AC joint there is a wedge capsule (including the intrinsic acromioclavicular ligament) is strengthened by the strong coracoclavicular ligament (2 components, conoid and trapezoid)

Question 9

Muscles:

Anterior: Axial skeleton to perctoral girdle and axial skeleton to humerus

Posterior: Axial skeleton to perctoral girdle and axial skeleton to humerus

Answer 9

Axial:
Axial skeleton to perctoral girdle:
- Subclavius
-Pectoralis minor
-Serratus anterior

axial skeleton to humerus
- Pectoralis major

Posterior:
Axial skeleton to perctoral girdle
-Trapezius
-Levator scapulae
-Rhomboid minor
-Rhomboid major

axial skeleton to humerus
- Latissimus dorsi

Question 10

Axial skeleton to humerus anterior (pec major orgin, insertion and function)

Answer 10

The Pec Major origin:
Clavucalr head, sternocostal head

Insertion:
Lateral lip of intertubercular groove

Movement:
- adducts the humerus
- internally rotates humerus
- can help protract scapula by pulling on humerus

Question 11

Axial skeleton to pectoral girdle anterior (pec minor and subclavicle orgin, insertion and function)

Answer 11

Pec minor
Insertion: coracoid process of scapula

Orgin: 3-5th rib

Movement:
-depresses scapula
-helps protract scapula

Subclavical
Insertion: Clavicle
Origin: costal cartiliage of 1st rib
Movement:
-“Braces” clavicle
- weak depressor of scapula

Question 12

Axial skeleton to pectoral girdle anterior (serratus anterior orgin, insertion and function)

Answer 12

Origin: ribs 1-8 or 9
InsertionL Medial border of scapula

Movement:
- protracts scapula
- lower fibres help superiorly rotate scapula

Question 13

Axial skeleton to pectoral girdle - posterior: trapezuis orgin, insertion and function

Answer 13

Origin:

Insertion: “anatomical hourseshoe” (Spine of clavicle, scapula, clavicle)

Movement:
-all together = retracts scapula
-superior only = elevates scapula
-middle only = retracts scapula
-lower only = depresses scapula
-sup. & inf. only = superior rotation of scapula

Question 14

Levator scapulae Origin, insertion and function

Rhomboid minor & major Origin, insertion and function

Answer 14

Levator scapulae
Origin: C1-C4
Insertion Scapula
Movement:
- elevates scapula
- helps inferiorly rotate scapula

Rhomboid minor & major
Origin: C7, T1 (minor). T2-T5 (major)
Insertion: scapula
Movement:
-retracts scapula
-elevates scapula
-helps inferiorly rotate scapula

Question 15

Latissimus dorsi Origin, insertion and function

Answer 15

Origin: L1

insertion: Floor of intertubercular groove

function: - adducts the humerus
- internally rotates humerus

Question 16

Name Elevators of the scapula

Answer 16

Trapezuis, Levator scapulae, Rhomboid minor & major

Question 17

Name Depressors of the scapula

Answer 17

Subclavical, Pec minor, lowers fibres of pec major, lower trapezium, lower fibres of serratus anterior, lower fibres of lat dorsi

Question 18

Protractors of the scapula (aka scapula ABduction)

Answer 18

pec minor and major, serratus anterior

Question 19

Retractors of the scapula (aka scapula ADduction)

Answer 19

Rhomboideus minor and major, middles fibres of trapezuis, upper fibres of lat dorsi

Question 20

Inferior rotators of the scapula

Answer 20

Levator scapulae, Rhomboideus major and minor, pec minor and lower pec major, lat dorsi

Question 21

Superior rotators of the scapula

Answer 21

upper and lower part of trapezuis and serratus anterior