Upper Limb Flashcards
Pectoral Girdle & Scapular Region
Describe the shape of each end of the clavicle. Which end is enlarged and what is this joint called? Which end is flattened and what is this joint called?
Convex medially (cylindric end) Concave laterally (flat end) Enlarged sternal end- articulates with manubrium; Sternoclavicular joint Flattened acromial end- articulates with acromion process; acromioclavicular joint
The clavicle suspends the scapula at which anatomical feature?
Coracoid process
What is significant about force put on the clavicle?
The clavicle transmits force from the upper limb to the axial skeleton (which is why its frequently fractured)
-Falling on outstretched arm & falling onto outside shoulder
What is the function of the clavicle in relation to the scapula?
It allows the scapula to “glide” on the thoracic wall
scapulothoracic joint
What are the six movements the scapulothoracic joint perform?
Elevation/depression
Protraction/Retraction
Upward/Downward rotation
What is the single articulation between the pectoral girdle and axial skeleton?
Sternoclavicular joint
How would you describe the pectoral girdle? How is this different than the pelvic girdle?
Incomplete ring (open posteriorly); pelvic girdle is a complete ring Pectoral girdle is therefore less stable/more prone to dislocation but more mobile
What does the coracoclavicular ligament connect?
It connects the coracoid process of the scapula with the clavicle
What are the three borders of the scapula?
Medial, lateral, and superior
What does the superior transverse scapular ligament attach to the body and what does it create?
It is attached to the base of the coracoid process and medial end of scapular notch
It converts the suprascapular notch into a foramen
What are the three angles of the scapula?
Superior, lateral and inferior
What two posterior scapular regions are divided by the scapular spine?
Supraspinous fossa
Infraspinous fossa
The acromion and clavicle form what joint? Which two directions does the acromion project in?
Acromioclavicular joint
Projects anteriorly and laterally
What is the anterior scapula surface called?
subscapular fossa
What ligament joins the clavicle and coracoid process?What side of the scapula can you see this ligament?
What is the purpose/function of this ligament?
Coracoclavicular ligament
Anterior
Center of balance/suspending device
What is the function of the glenoid fossa and what directional surface is it found on?
It is the “socket” for much larger humeral head
Lateral surface
Where do the intrinsic shoulder muscles originate and insert? What do these muscles move?
Appendicular skeleton
Upper limb and humerus
What are the two muscles and group of muscles that act on the glenohumoral (shoulder) joint/intrinsic back muscles?
1) . Deltoid
2) . Teres Major
3) . Rotator Cuff group
What four muscles make up the rotator cuff group?
Supraspinatus Infraspinatous Teres Minor Subscapularis **can really be 3-6 muscles
What are the three portions of the deltoid muscle?
anterior, middle, and posterior
What is the origin and insertion of the deltoid?
O: lateral third clavicle (anterior portion), acromion (middle portion), and lateral scapular spine (lateral portion)
I: deltoid tuberosity (lateral aspect of humerus)
What are the three movements of the deltoid muscle?
Abducts arm after 15 degrees (supraspinatus abducts first 15 degrees)
Anterior portion flexes
Posterior portion extends
What nerve innervates the deltoid and what plexus is this a part of?
Axillary nerve (C5, C6) Terminal branch of brachial plexus
What boundary of the axilla does the teres major form?
Posterior lateral boundary
What is the origin and insertion of the teres major?
O: posterior surface of inferior scapular angle (close to superior border of latissimus dorsi)
I: Intertubercular groove of humerus (posteromedial to lat)
What are the two movements of the teres major?
Adducts & medially (interiorly) rotates humerus (like screwball)
What nerve is the teres major innervated by and what plexus is it a part of ?
Lower subscapular nerve (C5, C6); collateral branch of brachial plexus
What shaped muscle is the teres muscle?
cylindrical
What muscles correspond to the anterior, posterior, and superior portions of the rotator cuff?
Anterior- subscapularis
Posterior- Infraspinatus and Teres minor
Superior- Supraspinatus
Lack inferior support
What is the origin and insertion of the supraspinatus muscle?
O: supraspinous fossa
I: Greater tubercle (superior portion)
What movement does the supraspinatus perform?
First 15 degrees of arm abduction (helps out deltoid)
What nerve innervates the supraspinatus muscle and what plexus is it a part of?
Suprascapular nerve (C4-C6) Collateral branch of brachial plexus
What anatomical feature does the supraspinatus muscle pass under?
coracoacromial ligament on top of scapula
What artery supplies the supraspinatus?
Suprascapular artery
What is the origin and insertion of the infraspinatus muscle?
O: infraspinous fossa of scapula
I: greater tubercle of humerus (posterior portion)
What movement does the infraspinatus perform?
Laterally rotates arm (curve ball movement)
What nerve innervates the infraspinatus and what plexus is it a part of?
Innervated by suprascapular nerve (C5, C6)
Collateral branch of brachial plexus
What artery supplies the infraspinatus?
Suprascapular artery
What does the suprascapular artery pass over and what does it pass deep to?
Over superior transverse scapular ligament
Passes deep to acromion (to enter infraspinatus fossa)
What does the suprascapular artery form with intercostal arteries?
Scapular anastomosis (anastomosis joins branches of other arteries together)
What does the suprascapular nerve pass under and pass deep to?
It goes under superior transverse scapular ligament, deep to acromion
Where does the suprascapular nerve originate?
superior trunk of brachial plexus
What two muscles does the suprascapular nerve innervate?
supraspinatus and infraspinatus
What is the origin and insertion of the teres minor?
O: Lateral border of scapula (mid portion)
I: greater tubercle of humerus (posterior portion)
What movement does the teres minor provide?
Lateral rotation of humerus
What nerve is the teres minor innervated by and what plexus is it a part of?
Innervated by axillary nerve (C5, C6); terminal branch of the brachial plexus
What is the origin and insertion of the subscapularis?
O: anterior surface of scapula
I: lesser tubercle of humerus (only rotator cuff muscle that inserts on lesser tubercle)
What does the subscapularis form a portion of?
Posterior wall of axilla
What movement does the subscapularis perform?
medially rotates arm (screw ball movement)
What nerve innervates the subscapularis and what plexus is it a part of?
Upper & lower subscapular nerves (C5-7); collateral branches of brachial plexus
What muscles make up the superior, lateral, inferior, and medial borders of the quadrangular space?
Superior- inferior border of teres minor
Lateral: surgical neck of humerus
Inferior: Superior border of teres major
Medial: lateral border of long head of triceps brachii
What nerve and artery run through the quadrangular space?
Axillary nerve and posterior circumflex humeral artery
What muscles make up the superior, lateral, and inferior portions of the Triangular space?
Superior: inferior border of teres minor
Lateral: medial border of long head of triceps brachii
Inferior: superior border of teres major
What artery passes through the triangular space?
Circumflex scapular artery (branch of subscapular)
What does the long head of triceps separate? Where does it originate? What is it anterior and posterior to?
Separates quadrangular and triangular spaces
Originates at inferior glenoid tubercle/inferior lip of glenoid fossa
It is anterior to teres minor and posterior to teres major
What muscles make up the superior, medial, and lateral borders of the triangular interval?
Superior- inferior border of teres major
Medial- lateral border of long head of triceps brachii
Lateral- medial border of lateral head of triceps brachii
What nerve and artery run through the triangular interval?
Radial nerve & profunda brachii artery (both course in radial/spiral groove)
What muscles and nerve make up the anterior compartment of the posterior arm?
Flexors of forearm & arm
Musculocutaneous nerve
What muscles and nerve make up the posterior compartment of the posterior arm?
Extensors of forearm
Radial nerve
What two compartments does the deep fascia of the posterior arm divide into?
Anterior & posterior
What is the origin and insertion of the triceps brachii?
O: inferior lip of glenoid fossa (long head), posterior humerus, above radial groove (lateral head), posterior humerus, below radial groove (medial head)
I: olecranon process of ulna
What are the three heads of the triceps brachii?
Long, lateral & medial
What movements does the triceps brachii perform?
Extends forearm; long head also extends and abducts arm
Which triceps brachii head is least active? Most active? Strongest?
Least active- long head
Most active- medial head
Lateral head- strongest, only used against resistance
What nerve is the triceps brachii innervated by?
Radial nerve (C6-C8)
What muscle is the major arm extender?
Latissimus dorsi
What head of the triceps brachii is obscured by the long head?
medial head
What is the origin and insertion of the anconeus?
O: lateral epicondyle of humerus
I: lateral olecranon process & proximal ulna
What movement does the anconeus assist with?
Assists in extension of forearm (crosses in elbow joint)
What nerve innervates the anconeus?
radial nerve (C7-T1)
What is the anconeus covered by?
Thick fascia
What are five causes of Axillary Nerve Injury?
1) . Surgical neck fracture
2) . Glenohumeral dislocations
3) . Improper crutching fitting/use (supposed to sit 2 inches below axillary floor)
4) . Improper IM injections (supposed to be 2 fingerbreadths below acromion)
5) . Deltoid atrophy
What type of pain does axillary nerve injury cause?
Lateral shoulder numbness
What is degenerative tendinitis a preemptive condition for?
Rotator cuff tear
How does degenerative tendinitis happen?
Repetitive or forceful use of upper limb above horizontal plane
How is the pain caused when someone has degenerative tendinitis?
Supraspinatus tendon & humeral head grate on coracoacromial arch (supraspinatus tendon is relatively avascular)
What pain does someone have with degenerative tendinitis?
Shoulder stiffness
Pain on initiating abduction or reaching behind back
What tendon usually tears in a rotator cuff tear?
usually supraspinatus tendon
What two things can cause a rotator cuff tear?
Fall on shoulder or forceful lifting motion
If you have a rotator cuff injury, what two things can you not do?
unable to resist gravity from 90 degree abduction
cant initiate abduction
What is a good clinical sign of a rotator cuff tear?
Can’t put arm behind back & can’t maintain abduction
What two movements can lead to a glenohumeral dislocation?
Forceful extension & lateral rotation
Which direction does a glenohumeral dislocation usually occur? What nerve can this affect?
Nearly always inferior (dislocates inferiorly & then moves humerus)
Axillary nerve in quadrangular space
How is a glenohumeral dislocation clinically described?
Described by location of dislocated humeral head
anterior or posterior in relation to glenoid fossa
(anterior is most common- pectoralis major usually wins and pulls humerus)
dislocated inferior & then humerus moves anterior/posterior)
