Shoulder Girdle - Bones, Joints, and Muscles Flashcards
(35 cards)
What are the 7 landmarks of the proximal end of Humerus?
Important ones you need to get
- Humeral Head*
- Anatomical Neck
- Lesser tuberosity*
- Intertubercular Sulcus* (groove)
- Greater Tuberosity*
- Surgical Neck
- Shaft of Humerus
What does the humeral head articulate with in the shoulder joint?
Glenoid Cavity (Labrum)
What are the ligaments of the Glenoid Cavity (GC)?
Superior GH Ligament:
O = Upper Border of GC I = Upper Aspect of Lesser Tuberosity
Middle GH Ligament:
O = Upper Border of GC I = Anterior of Lesser Tuberosity
Inferior GH Ligament:
O = Both sides of GC (Ant & Post) I = Neck of Humerus
Thickenings in fascia
Coracohumeral Ligament
- Originates on the coracoid process and inserts to the margin of humeral head
What is purpose of ligaments in the Glenoid Cavity?
Significantly, the ligaments are very active in rotational movements.
Neutrally these ligaments are relatively lax and DONT STABILISE THE JOINT
What are the “dynamic ligaments” of the GH joint?
- Subscapularis
- Supraspinatus
- Infraspinatus
- Teres Minor
Why are the rotator muscles considered as “dynamic ligaments” of the GH joint?
They encompassed GH joint and they individually tense to stabilise the joint.
What is the function and name of a significant bursa in the GH joint?
Sub-Acrominal Bursa: Its functions to prevent the acromion process impinging and putting friction onto bicep tendon especially during abduction
What are the insertions and actions of the Supraspinatus?
Originates = Supraspinatus fossa, above spine of scapula Insertion = Runs laterally and under the acromion, inserts to superior aspect of the greater tuberosity. Actions = Abduction
What are the insertions and actions of Infraspinatus?
Originates = Infraspinatus fossa, beneath spine of scapula Insertion = Runs laterally, to insert into the posterior margin of the greater tuberosity of humerus Actions = Lateral rotation
What are the insertions and actions of Teres Minor?
Originates = Lateral border of scapula Insertion = Runs underneath infraspinatus, and inserts to the posterior margin of the greater tuberosity of humerus Actions = Lateral Rotation
What are the insertions and actions of Subscapularis?
Originates = Subscapular fossa Insertion = Runs laterally, inserts into the lesser tuberosity of humerus Actions = Medial Rotation
What are the 5 muscles involved of moving the scapula?
Trapezius Serratus Anterior Rhomboid Minor Rhomboid Major Levator Scapulae
What are the insertions of the Trapezius?
Upper Fibres: Cervical spinous processes, lateral aspect of the Clavicle and Superior Nuchal line of the occiput
Middle Fibres: Lower Cervical and Upper Thoracic spinous processes, and spine of scapula
Lower Fibres: Thoracic spinous process and medial border of scapula
What are the actions of Trapezius?
Upper Fibres: Elevation
Middle Fibres: Retraction
Lower Fibres: Depression
What are the insertions and actions of Serratus Anterior?
Originates = Medial and Inferior Borders of Scapula, anteriorly Insertions = Top 9 shafts of ribs; at the mid-axillary line Actions = Protraction of Shoulder
What movement is produced when serratus anterior and Trapezius are contracting?
The upper and lower fibres of Trapezius and Serratus Anterior cause LATERAL ROTATION of the scapula
What are the insertions of Rhomboid Major/Minor and Levator Scapulae?
Rhomboid Major:
O = Medial Border of Scapula I = Spinous processes T2 - T6
Rhomboid Minor:
O = Medial Border of Scapula I = Spinous processes C7 and T1
Levator Scapulae:
O = Very top of Medial Border of Scapula I = Transverse processes of C1 -C4
What are the actions of the Rhomboids and Levator Scapulae?
Rhomboids - Retraction of Scapula
Levator Scapulae - Elevation
What the deep muscles are the anterior aspect of the shoulder girdle?
Pectoralis Minor
Subclavius
What are the insertions and actions of the deep anterior muscles of the shoulder girdle?
Pectoralis Minor:
O = Coracoid process I = Anterior angle of ribs 3 - 5
Subclavius:
O = Inferior aspect process at the midpoint of the clavicle I = Anterior angle of rib 1
Actions: Protraction of shoulder
What are the 5 muscles of the shoulder girdle that are involved in the glenohumeral joint?
Deltoids (Anterior, Superior and Posterior) Pectoralis Major Latissimus Dorsi Teres Major Coracobrachialis
What are the origins of the 3 deltoid muscles?
Anterior fibres - Anterolateral aspect of the clavicle
Superior (Middle) fibres - Acromion process
Posterior fibres - Spine of Scapula
What are the insertions of the 3 deltoid muscles?
All the fibres of Deltoid insert onto the deltoid tubercle of the humerus
What actions do the separate deltoid fibres perform?
Anterior fibres - Abduction
Superior (Middle) fibres - Horizontal flexion, Medial Rotation
Posterior fibres - Horizontal flexion, Lateral Rotation
ALL FIBRES TOGETHER PERFORM ABDUCTION
