Scapular region Flashcards
Osteology of the scapula:
Osteology of the Proximal Humerus and Articulation with the scapula
Glenohumeral joint type: ?
Unique characteristic: ____ ____ tendon travels through the joint + surrounded by ______ membrane
ball and socket joint; synovial joint;
Unique characteristic: biceps brachii tendon travels through the joint + surrounded by synovial membrane
Ball of the glenohumeral joint
Humeral head
Socket of the glenohumeral joint
concave glenoid fossa
Subacromial bursa location:
inferior to acromion process, coracoacromial ligament and deltoid
Subscapular bursa location:
between the tendon of the subscapularis and the neck of the scapula,
protecting the tendon as it passes by the coracoid process and the neck of the scapula.
Bursa is continuous or not continuous with the GH joint?
Continuous with the cavity of the GH joint
Bursae of the glenohumeral joint:
- Subacromial bursa
- Subscapular bursa
Ligaments of the GH joint (6):
- Coracoacromial ligament
- Coracohumeral ligament
- Superior GH ligament
- Middle GH ligament
- Inferior GH ligament
- Transverse Humeral ligament
Function of GH joints:
Prevent excessive anterior translation of the humeral head.
Acromioclavicular joint: type + location?
Plane type; connects the clavicle + scapula
Sternoclavicular joint: type + location?
Saddle-type synovial joint; functions as a ball & socket to accommodate movements of scapula. Connects scapula + thorax
Glenohumeral Joint: type + location?
ball-and-socket; synovial; connects humeral head + glenoid cavity of scapula
Movements of GH joint?
- Flexion + Extension
- Abduction + Adduction
- Internal Rotation + External Rotation
- Circumduction
Scalpulothoracic Muscles (6): connect thorax + scapula
- Trapezius
- Levator Scapulae
- Rhomboid major + minor
- Pectoralis Minor
- Serratus Anterior
Scalpulohumeral Muscles (6): connects scapula to humerus
- Teres Major
- Deltoid
- Infraspinatus
- Supraspinatus
- Teres Minor
- Subscalpularis
Identify this muscle
Serratus Anterior
Origin:
Insertion:
Action:
Innervation:
Origin: Ribs 1-8 →
Insertion: Anterior border of medial scapula
Action: Protraction & lateral rotation of scapula; holds scapula against thoracic wall
Long thoracic nerve (C5-C7) of ventral rami
Identify this muscle
Teres Major
Teres Major
Origin:
Insertion:
Action:
Innervation:
Origin: Inferior angle of scapula
Insertion: intertubercular sulcus
Action: Adducts + medially rotates humerus
Innervation: lower Subscapular nerve (C5-C6)
Identify this muscle
Deltoid
Origin:
Insertion:
Action:
Innervation:
Origin: Lateral 3rd of clavicle, acromion process, and spine of scapula
Insertion: Deltoid tuberosity
Action: Abduct humerus after first 15°
Flexion and medial rotation, extension
+ lateral rotation
Innervation: Axillary nerve (C5-C6)
Identify this muscle
Infraspinatus
Origin:
Insertion:
Action:
Innervation:
Origin: Infraspinous fossa
Insertion: Greater tubercle
Action: External rotation, tonic contraction stabilizes the GH joint
Innervation: Suprascapular nerve (C5-C6)
Identify this muscle:
Supraspinatus
Origin:
Insertion:
Action:
Innervation:
Origin: Supraspinous fossa
Insertion: Greater tubercle
Action: Initiates abduction (0-15°)
Innervation: Suprascapular nerve (C5-C6)
Identify this muscle
Teres Minor
Origin:
Insertion:
Action:
Innervation:
Origin: Lateral scapula
Insertion: Greater tubercle
Action: External rotation, tonic contraction stabilizes the GH joint
Innervation: Axillary nerve (C5-C6)
Identify this muscle
Subscalpularis
Origin:
Insertion:
Action:
Innervation:
Origin: Subscapular fossa
Insertion: Lesser tubercle
Action: Internal rotation
Innervation: Upper & Lower Subscapular nerves (C5-C6)
Quadrangular space borders:
- Teres minor
- Teres major
- Long head of triceps
- Lateral head triceps
Triangular space:
teres minor, Teres major, Long head of triceps
Triangular interval
Teres major, Long head of triceps, lateral head of triceps
Quadrangular space contents:
Axillary nerve, Posterior humeral circumflex artery
Triangular space contents:
Circumflex scapular artery
Triangular interval contents:
Radial nerve, Deep brachial artery
Follow the anastomosis pathway from the Dorsal scapular artery to the axillary artery. (Hint: Subclavian –> Dorsal Scapular A.)
Subclavian –> Dorsal Scapular A. –> Circumflex Scapular Artery OR Thoracodorsal Artery –> SUBSCAPULAR Artery –> Axillary Artery
Follow the anastomosis pathway from the Suprascapular artery to the Axillary artery. (Hint: Subclavian –> Thyrocervical trunk)
Subclavian –> Thyrocervical trunk –> suprascapular A. –> thoracodorsal A. –> sub scapular A. –> Axillary A.
Cause of shoulder impingement:
Inflammation and calcification of the subacromial
bursa (calcific scapulohumeral bursitis)
Characteristic pain
pain during 50-130 degrees of abduction
Explain what causes the pain associated with shoulder impingement
Tendon of supraspinatus AND
the acromion compresses the subacromial bursa
cause of GH joint anterior dislocation:
cause of GH joint anterior dislocation: Excessive extension and lateral rotation
of the humerus OR forceful blow to the posterior shoulder of an abducted humerus
cause of GH joint anterior dislocation: in simple terms
humeral head is displaced from glenoid cavity
Characteristic of GH joint anterior dislocation:
Damage to axillary nerve and posterior circumflex humeral artery
Shoulder separation cause:
Separation of the acromioclavicular joint as a result of a downward force being applied to the superior part of the acromion
Three types:
- Torn AC ligament
- Torn AC w/ separation
- Torn AC, trapezoid and conoid ligaments w. separation
Is shoulder separation a dislocation of the glenohumeral joint?
Shoulder separation is
NOT a dislocation of
the glenohumeral joint
most common tendon tear associated with rotator cuff tears
supraspinatus most common tendon tear
Characteristic pain of rotator cuff tear
pain when arm is overhead and weakness
How is rotator cuff tear tested for supraspinatus
drop arm test: abduct arm fully, lower arm slowly w. control
After, 90degrees the arm will drop more quickly than the unaffected side
Cause: ___ part of tubercle is torn away d/t a fall onto the ____ OR fall on the hand when arm is ______
Small part of tubercle is torn away d/t a fall onto the acromion OR fall on the hand when arm is abducted
Characteristic: Arm is pulled ____ by muscles still attached (_____)
Arm is pulled medially by muscles still attached (subscapularis)
Cause of axillary nerve injury
May be compressed d/t an anteroinferior shoulder dislocation
Characteristic: Inability to ____ arm to or ____ horizontal (_____ muscle compromised)
Sensory loss on _______ aspect of ____
Inability to abduct arm to or above horizontal (deltoid muscle compromised)
Sensory loss on superolateral aspect of arm
Axillary nerve injury
Nerves of the scapular region: List the (3)
- Axillary nerve (C5-C6)
- Upper sub scapular nerve (C5-C6)
- Lower sub scapular nerve (C5-C6)
