Pectoral Girdle Flashcards
What is the 3 joints of the girdle
AC: (acromioclavicular joint) between the clavicle and scapula
SC (sternoclavicular joint) between the clavicle and sternum
Conceptual joint: between the scapula and chest wall.
What are the bones in the shoulder girdle
Clavicle and scapula
Describe the movements of the pectoral girdle (scapula)
Scapula retraction & protraction
Scapula elevation & depression
Scapula superior & inferior rotation
Describe the clavicle anatomy with the joints attached from both superior and inferior view
A sinuous, long bone (medial convexity points anteriorly), largely subcutaneous, forming a strut between the manubrium and the acromial process of the scapula.
Describe the scapula anatomy posterior and anterior view
Refer to lecture
Describe the SC joint anatomy
What are the four important ligaments of the SC joint
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).
draw/label the SC joint area
lecture slide
Describe AC joint anatomy
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)
Muscles:
Anterior: Axial skeleton to perctoral girdle and axial skeleton to humerus
Posterior: Axial skeleton to perctoral girdle and axial skeleton to humerus
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
Axial skeleton to humerus anterior (pec major nerve, orgin, insertion and function)
Nerve:
Lateral and medial pectoral nerve
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
Axial skeleton to pectoral girdle anterior (pec minor and subclavicle nerve, orgin, insertion and function)
Pec minor
Nerve: Medial Pectoral nerve
Insertion: coracoid process of scapula
Orgin: 3-5th rib
Movement:
-depresses scapula
-helps protract scapula
Subclavical
Nerve:C5
Insertion: Clavicle
Origin: costal cartiliage of 1st rib
Movement:
-“Braces” clavicle
- weak depressor of scapula
Axial skeleton to pectoral girdle anterior (serratus anterior nerve, orgin, insertion and function)
Nerve: Long thoracic nerve
Origin: ribs 1-8 or 9
InsertionL Medial border of scapula
Movement:
- protracts scapula
- lower fibres help superiorly rotate scapula
Axial skeleton to pectoral girdle - posterior: trapezuis nerve, orgin, insertion and function
Nerve: Accessory nerve (CN XI)
Origin: Skull to T12
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
Levator scapulae nerve, Origin, insertion and function
Rhomboid minor & major Origin, insertion and function
Levator scapulae
Nerve: Dorsal scapular nerve
Origin: C1-C4
Insertion Superior angle of Scapula
Movement:
- elevates scapula
- helps inferiorly rotate scapula
Rhomboid minor & major
Nerve: Dorsal scapular nerve
Origin: C7, T1 (minor). T2-T5 (major)
Insertion: medial border of scapula
Movement:
-retracts scapula
-elevates scapula
-helps inferiorly rotate scapula
Latissimus dorsi nerve, Origin, insertion and function
Nerve: Thoracodorsal nerve
Origin: Lower thoracic lumbar, sacral spinous process, part of pelvic girdle
insertion: Floor of intertubercular groove
function: - adducts the humerus
- internally rotates humerus
Name Elevators of the scapula
Trapezuis, Levator scapulae, Rhomboid minor & major
Name Depressors of the scapula
Subclavical, Pec minor, lowers fibres of pec major, lower trapezium, lower fibres of serratus anterior, lower fibres of lat dorsi
Protractors of the scapula (aka scapula ABduction)
pec minor and major, serratus anterior
Retractors of the scapula (aka scapula ADduction)
Rhomboideus minor and major, middles fibres of trapezuis, upper fibres of lat dorsi
Inferior rotators of the scapula
Levator scapulae, Rhomboideus major and minor, pec minor and lower pec major, lat dorsi
Superior rotators of the scapula
upper and lower part of trapezuis and serratus anterior
