Shoulder And Arm Flashcards
Name the 3 articulations of the scapula
Which is not a true joint? Why?
What does it depend on
- Glenohumeral
- Acromioclavicular
- Scapulothoracic “joint”
- Scapulothoracic, as it has none of the characteristics of a joint
- Depends on integrity of the acromioclavicular and sternoclacicular joint
Are scapula fractures common?
What do they indicate?
Do they require fixation? Why?
No, are uncommon
Indicate severe chest trauma
Doesn’t typically require fixation, as tone of surrounding muscles holds the fragments in place?
What are the the 2 ends of the clavicle
What is the part between the 2 ends called
Sternal End- Manubrium of sternum
Acromial End- Acromion
The shaft
What are the 3 main functions of the clavicle
- Attaches upper limb to trunk
- Protects underlying neurovascular structures supplying the upper limb
- Transmits force from upper limb to axial skeleton
What are the attachments of the Costoclavicular ligament
Inferior aspect of Sternal end of clavicle
Costal cartilage 1
What are the 2 parts of the Coracoclavicular ligament? Which part is more lateral
Where do they attach?
Attach at at the Acromial End of clavicle;
- Conoid ligament attaches to Conoid tubercle
- Trapezoid ligament attaches to Trapezoid line
- Trapezoid ligament is more lateral
What are 2 atypical features of the Acromioclavicular joint?
- Articular surfaces filled with fibrocartilage (Not hyaline cartilage)
- Joint cavity partially divided by an articular disc (A wedge of fibrocartilage)
What are 3 main ligaments that strengthen the Acromioclavicular joint
Intrinsic;
- Acromioclavicular ligament (Superior to joint capsule, which is superior to the articular disc)
Extrinsic;
- Conoid ligament
- Trapezoid ligament
*Both extrinsic are part of the Coracoclavicular ligament
Which muscles act directly on the Acromioclavicular joint?
No muscles act directly
All movement is passive, initiated by movement elsewhere
Describe the strength and mobility of the ONLY attachment of upper limb to axial skeleton?
What kind of cartilage covers the articular surfaces of this joint
Sternoclavicular joint
- Very strong
- Very mobile (Unusually)
Fibrocartilage (Like in the acromioclavicular joint)
What bones make up the shoulder girdle?
What do you call anterior and posterior movement of the girdle
Clavicle and scapula
Anterior: Protraction
Posterior: Retraction
What are the edges of the Intertubuclar sulcus called?
Which muscles attach and where, in relation to each other?
Called lips
A lady between 2 majors
Latissimus Dorsi inserts on the Medial Lip, between Teres major and Pectoralis Major on the Lateral Lip
What are the main neurovascular structures at risk during a fracture to the surgical neck of the humerus
Axillary nerve
Posterior circumflex humeral artery
Describe how the Radial/ Spiral groove runs across the humerus?
What nerve and artery lie in the groove?
Runs diagonally on posterior surface of humerus, at level of deltoid tuberosity
- Radial nerve
- Profunda brachii artery
Name the 3 joints of the shoulder girdle
- Sternoclavicular
- Acromioclavicular
- Glenohumeral
(Scapulothoracic joint, is not a true one)
Explain anatomically, why the Glenohumeral joint is the most mobile in the body
Give 2 reasons
Humeral head is larger than glenoid fossa
Glenoid fossa is shallow
Why is the inferior aspect of the shoulder the weakest part, relative to the superior, anterior and Posterior parts
Inferior part has no rotator cuff muscles providing reinforcement
Name 4 ligaments that provide stability to shoulder joint, preventing dislocation
- Glenohumeral ligaments (Superior, Medial, Inferior)
- Coroclavicular (Conoid, trapezoid)
- Coracohumeral
- Coraco acromial
Where are the Glenohumeral and Coraco-acromial ligaments in relation to the shoulder joint?
What direction of shoulder dislocation do they prevent?
Glenohumeral: Anterior, prevent anterior dislocation
Coraco-acromial: Superior, prevent superior dislocation
Which 2 ligaments act as “tunnels” in the shoulder region
What structures pass through?
- Transverse Humeral Ligament:
- Allows passage of long head of biceps brachii between greater and lesser tubercles - Coraco acromial Ligament:
- “Roof” of sub acromial space, through which supraspinatus tendon passes
Compare the 2 groups of shoulder muscles in terms of insertions and origins
Extrinsic (Deep or superficial):
- Originate from torso
- Insert onto shoulder bones (Clavicle/ scapula/ humerus)
Intrinsic:
- Originate from Scapula and/ or clavicle
- Insert onto humerus
Where are the extrinsic shoulder muscles sited?
Which muscles are in each of the 2 layers
On back of trunk
Superficial;
- Latissimus dorsi
- Trapezius (Most superficial of all back muscles)
Deep (Upper back);
- Levator Scapulae
- Rhomboid major
- Rhomboid minor
How many parts does trapezius have? Name them
Describe the origins and insertions of trapezius
Descending part
Transverse part
Ascending part
Origin- External occipital protuberance, Nuchal ligament, C7-T12 spinous processes
Insertion- Clavicle, Acromion and Spine of scapula
State the innervation of Trapezius
State the actions of the 3 parts of trapezius
Innervation: Accessory nerve (Cranial nerve 9)
Descending part;
- Elevate scapula and rotate it during arm abduction> 90 degrees
Transverse part;
- Retract scapula
Ascending part;
- Pull scapula inferiorly
How do you test trapezius power of a patient
Ask patient to shrug shoulders while attempting to push them back down
Identify the 4 origins of Latissimus Dorsi
Identify the insertion
Spinous process of T6-T12
Iliac crest
Thoracolumbar fascia
Ribs 10,11,12
Insertion: Intertubucular sulcus (Converge into a single tendon)
Identify the Innervation and Actions of Latissimus Dorsi
Innervation: Thoracodorsal nerve
Actions: Arm Extension, Adduction, Medial Rotation
Identify the Origins, Insertion, Innervation and Action of Levator Scapulae
Origin: C1-C4 transverse processes
Insertion: Medial border of scapula, above spine (above rhomboid minor)
Innervation: Dorsal scapular nerve
Action: Elevates scapula
Identify the Origins, Insertion, Innervation and Action of Rhomboid Minor
Origin: C7-T1 spinous processes
Insertion: Medial border of scapula, at level of spine
Innervation: Dorsal scapular nerve
Action: Retracts scapula, rotates medial border so that glenoid fossa is rotated inferiorly
Identify the Origins, Insertion, Innervation and Action of Rhomboid Major
Origin: T2-T5 spinous processes
Insertion: Medial border of scapula, below spine (Below R Minor)
Innervation: Dorsal scapular nerve
Action: Retracts scapula, rotates medial border so that glenoid fossa is rotated inferiorly
What is the combined function of Rhomboid Major and Minor
Return of glenoid fossa to anatomical position after arm abduction> 90 degrees
What are the Intrinsic Shoulders muscles also called?
Name all 6 of them
4 of the muscle are in one category. What is this category?
Scapulohumeral group of muscles
- Deltoid
- Teres Major
Rotator Cuff Muscles; (SITS)
- Teres Minor
- Infraspinatus
- Supraspinatus
- Subscapularis
Identify the Origin, Insertion, Innervation and Actions of Teres Major
Origin: Inferior angle of Infraspinatus fossa
Insertion: (Medial lip of) Intertubucular sulcus
Innervation: Lower subscapular nerve (C5-C7)
Actions: Medial rotation, Adduction, Extension of arm
Compare the paths of Teres Minor and Teres Major in reference to Long Head of Triceps Brachii
Teres Major passes anteriorly to Triceps Long Head
Teres Minor passes posteriorly to Triceps Long Head
What is the collective function of the 4 Rotator Cuff muscles
Their resting tone acts to pull humeral head into the glenoid fosaa
Identify the Origin, Insertion, Innervation and Actions of Supraspinatus
Origin: Supraspinatous fossa
Insertion: Greater tubercle (Above Infraspinatus)
Innervation: Suprascapular nerve (C5, C6)
Action: Arm abduction up to 15 degrees, then assists Deltoid
Identify the Origin, Insertion, Innervation and Actions of Infraspinatus
Origin: Infraspinatous fossa
Insertion: Greater tubercle (Between Supraspinatus and Teres Minor)
Innervation: Suprascapular nerve
Action: Lateral rotation of arm
Identify the Origin, Insertion, Innervation and Actions of Subscapularis
Origin: Subscapular Fossa
Insertion: Lesser tubercle
Innervation: Upper and lower subscapular nerves
Action: Medial rotation of arm
Identify the Origin, Insertion, Innervation and Actions of Teres Minor
Origin: Lateral border of Infraspinatus fossa (Above T Major)
Insertion: Greater tubercle (Below Infraspinatus)
Innervation: Axillary nerve
Action: Lateral rotation
What muscles are in each compartment of the arm
Anterior compartment;
- Biceps brachii
- Brachialis
- Coracobrachialis
Posterior Compartment;
- Triceps brachii
Identify the innervation and blood supply of the Anterior Compartment muscles of the arm
Innervation: Musculocutaenous nerve
Blood supply: Muscular branches of brachial artery
Describe the origins, insertion and actions of Biceps Brachii
Origins;
- Long head from Supraglenoid tubercle
- Short head from Coracoid process
Insertion;
- Radial tuberosity and deep fascia of forearm
Actions;
- Supination
- Arm flexion at elbow joint
- Arm flexion at shoulder joint
Describe the Biceps Tendon Reflex Test
Biceps brachii tendon is stretched briefly by tapping with a hammer
Normally, this causes elbow Flexion
Where may the Long head of Biceps Brachii rupture?
What will a patient hear?
Near its scapular origin
OR
Near its insertion in weight lifters
Will hear a snap whilst lifting
What causes Popeye sign? Describe the sign
Does the cause result in a lot of weakness in arm
Rupture of biceps tendon
A firm lump in lower arm during elbow flexion
Not much weakness after a rupture (Brachialis and Supinator are still intact)
Describe the origin, insertions and action of Brachialis
What are its 2 Innervations
Origin: Distal half of humerus
Insertion: Coronoid process of ulna and ulnar Tuberosity
Action: Elbow Flexion
Innervtions;
- MSC nerve
- Radial nerve (C5, C6 only)
What are the heads of Triceps Brachii?
Which is deeper?
What is the arterial supply to the posterior compartment of the arm?
Medial head lies deeper than Lateral and Long Heads
Profunda Brachii artery
Describe the origins and insertion of Triceps Brachii
Origins;
- Long head: Infraglenoid tubercle
- Lateral head: Humerus shaft, above Radial groove
- Medial Head: Humerus shaft, below Radial groove
Insertion:
- Olecranon of of ulna
State the Innervation and Action of Triceps Brachii
Innervation: Radial nerve
Action: Elbow extension
Stare the 4 borders of the Quadrangular Space
Superior: Teres minor
Inferior: Teres major
Medial: Long head of triceps brachii
Lateral: Surgical neck of humerus
(Axillary nerve and Posterior Circumflex Humeral Artery pass through)
Stare the 3 borders of the Triangular Space
Which nerves and vessels pass through
Superior: Teres minor
Inferior: Teres Major
Lateral: Long head of Triceps Brachii
No nerves pass through
Circumflex Scapular Vessels
Stare the 3 borders of the Triangular Interval
Which nerves and vessels can be seen at the base, as they wind around humerus in the radial groove?
Superior: Teres major
Medial: Long head of Triceps Brachii
Lateral: Humerus shaft OR Lateral head of triceps brachii
- Radial nerve
- Profunda brachii artery
Describe the 2 main Bursae at the shoulder joint
Subacromial bursa;
- Between Supraspinatus and Coraco-acromial ligament, Acromion, Coracoid process and deltoid muscle
Subscapular bursa;
- Between Subscapularis and Neck of Scapula
What is the Subacromial space
Wha are 4 contents in this space
Space between Head of Humerus and Coraco-acromial arch (CA ligament, C process and Acromion)
Subacromial bursa
Joint capsule
Supraspinatus
Long head of Biceps Trachii
What do the insertions of the rotator cuff muscles combine into?
What does this fuse with?
What is the effect?
Combine-> a “Tendinous cuff”
Fuses with the joint capsule, strengthening it
Identify 8 stabilisers of the shoulder joint
Static stabilisers (Stability at rest);
- Congruency of humeral head and glenoid fossa
- Glenoid labrum
- Joint capsule
- Glenohumeral ligaments
- Extracapsular ligaments
- Negative intra-Articular pressure
Dynamic stabilisers (Stability during motion);
- Rotator cuff muscles
- Extrinisc muscles that cross the shoulder joint
Which 3 arteries are involved in the anastomosis around the margin of the scapula
- Subscapular artery (Below spine)
- Suprascapular artery (Above spine)
- Transverse Cervical/ Dorsal Scapular artery (Medial border of scapula)
From which 3 arteries is the shoulder joint’s arterial supply derived?
- Posterior and anterior circumflex humeral arteries
- Suprascapular artery
Which artery provides the main supply to arm and forearm
What happens to this artery immediately distal to Teres Major
Which part of arm does this supply?
Brachial artery, gives off Profunda Brachii (Deep brachial artery)
Profunda Brachii supplies posterior arm
