Shoulder and Arm 1 Flashcards
Which bones constitute the pectoral girdle?
Clavicle and scapula
What kind of joint is the sterno-clavicular joint?
Synovial joint
Which condition results in a very underdeveloped/absent clavicle?
Cleidocranial dysostosis
Which ligaments stabilise the joint between the scapula and the clavicle?
- acromio-clavicular ligament
- trapezoid ligament
- conoid ligament
What kind of joint is the scapulo-thoracic joint?
‘physiological joint’
What are the deep posterior axio-appendicular muscles?
- levator scapulae
- rhomboid minor
- rhomboid major
- serratus anterior
What is the function of the deep posterior axio-appendicular muscles?
elevate, retract and rotate the scapula
What is the function of trapezius?
Elevate, retract and depress the scapula
What is the function of latissimus dorsi?
Extends, adducts and medially rotates the humerus
What are the superficial posterior axio-appendicular muscles?
trapezius
latissimus dorsi
What causes winged scapula?
Paralysis of serratus anterior
What is the function of serratus anterior?
- protracts and rotates the scapula
- holds scapula against thoracic wall
- can assist in respiration
- ‘boxer’s muscle’
What are the anterior axio-appendicular muscles?
Pectoralis major
Serratus anterior
What is the function of pectoralis major?
Adducts, flexes and medially rotates arm
What is Poland’s syndrome?
Absence of pectoralis major1
What are the deep anterior axio-appendicular muscles?
Subclavius
Pectoralis minor
What is scapulo-humeral rhythm?
Some rotation of the shoulder comes from rotation of the scapula on the rib cage
What is the glenoid labrum?
Fibrocartilaginous rim around glenoid cavity (enhances stability)
What is the function of the deltoid muscle?
Anterior: flexion, medial rotation
Middle: Abduction of arm
Posterior: extension, lateral rotation
What is the function of supraspinatus?
Initiates abduction of arm
What is the function of infraspinatus?
Laterally rotates arm
What is the function of teres minor?
Laterally rotates arm
What is the function of teres major?
Medially rotates the arm
What is the function of subscapularis?
Medially rotates arm
What are the rotator cuff muscles?
SITS supraspinatus infraspinatus teres minor subscapularis