Shoulder Script Flashcards
What is the subacromial impingement syndrome? What are the three main symptoms?
Occurs when the tendons of the rotator cuff muscles become irritated and inflamed as they pass through the subacromial space, the passage beneath the acromion. This can result in pain, weakness and loss of movement at the shoulder.
A painful arc of movement may be present during forward elevation of the arm from 60° to 120°
Passive movement at the shoulder will appear painful when a downwards force is applied at the acromion but the pain will ease once the downwards force is removed.
The ___________ is the most proximal bone of the upper limb
clavicle
Palpable parts of the scapula
Acromion
Corocoid process
Spine
Inferior angle
What are the three most powerful adductors and internal rotators of the arm at the shoulder joint?
Latissimus dorsi
Teres major
Pectoralis major
5 major nerves of the upper limb
Axillary Nerve. …
Median Nerve. …
Radial Nerve. …
Ulnar Nerve. …
Musculocutaneous Nerve
Nerve of the arm that is most at risk of injury from a fracture of the surgical neck of the humerus.
Axillary
The muscular branch of the axillary nerve curves immediately around the medial aspect of the ____________ of the humerus as it extends posteriorly through a space beneath the ____________ of the shoulder joint to reach the anterior border of the ___________ muscle.
surgical neck
fibrous capsule
Deltoid
The axillary nerve contains motor neurons which come from the _____ and _____ roots.
C5 and C6 cervical
The axillary nerve supplies sensory innevation to the skin of the _________ and motor innervation to the ____________.
Lateral arm
Deltoid and teres minor muscles
Branches of the axillary nerve
Superior laterial brachial cutaneous
Muscular brances that serve the deltoid and teres minor
Origin of the axillary nerve
Posterior cord of the brachial plexus
Origin of the median nerve
Lateral and medial cords of brachial plexus
Pathway of the median nerve
In the arm, it travels adjacent to the brachial artery.
In the forearm, it travels posterior to the flexor digitorum profundus.
Which arterior accompanies the median nerve, in the forearm? In the arm?
Anterior interossous artery
Brachial artery
Branches of the median nerve. Be specific.
Muscular branches to pronator teres, flexor carpi radialis, palmaris longus, and flexor digitorum superficialis
Vasomotor nerve to the brachial artery
Articular branches to elbow and proximal radioulnar joint
Anterior interosseous nerve
Palmar cutaneous branches
Medial and lateral divisions
What type of nerve is the median nerve? (Sensory/Motor/Mixed)
Mixed
Origin of the radial nerve
Posterior cord of the brachial plexus
Pathway of the radial nerve
- Descends against the posterior axillary wall and passes through the triangular interval to descend with the spiral radial groove.
- Pierces the lateral intermuscular septum to enter the anterior arm before reaching the cubital fossa
Branches of the radial nerve
Muscular branches
Posterior brachial cutaneous nerve
Posterior antebrachial cutaneous nerve
Two terminal branches (superficial and deep branches)
What is supplied by the radial nerve?
Muscles of the posterior arm and forearm
Skin of the posterior arm, forearm, and dorsum of hand
Radial nerve palsy
A.K.A Wrist Drop
the wrist and the fingers cannot extend at the metacarpophalangeal joints. The wrist remains partially flexed due to an opposing action of flexor muscles of the forearm. As a result, the extensor muscles in the posterior compartment remain paralyzed.
Possible causes of radial nerve injury
fracturing your humerus, a bone in the upper arm
sleeping with your upper arm in an awkward position
pressure from leaning your arm over the back of a chair
using crutches improperly
falling on or receiving a blow to your arm
long-term constriction of your wrist
Origin of the ulnar nerve
Medial cord of the brachial plexus
Pathway of ulnar nerve
- Descends on the medial side of brachial artery and pierces medual intermuscular septum to enter posterio arm.
- Passes behind the medial epicondyle of the hymerus, to descend in the forearm.
- Nerve enters the palmar aspect of the hand
Branches of the ulnar nerve
Muscular and cutaneous branches (Dorsal cutaneous branch, palmar cutaneous branch, and digital branches) and superficial and deep branches
The ulnar nerve consists of fibers from which spinal nerves?
C7, C8, and T1
Origin of the musculocutaneous nerve
Lateral cord of brachial plexus
Pathway of the musculocutaneous nerve
It accompanies the third part of the axillary artery in lower part of the axilla, pierces coracobrachialis to enter the front arm and descends between biceps brachii and brachialis muscle
Branches of the musculocutaneous nerve
Lateral antebrachial cutaneous nerve
Muscular and articular branches
What is supplied by the musculocutaneous nerve?
Motor innervation to flexor muscles of the arm
Sensory innervation to skin of lateral side of forearm and elbow joint
The musculocutaneous nerve contains nerve fibers from which spinal nerves?
C5-C7
Biceps reflex
a reflex test that examines the function of the C5 reflex arc and the C6 reflex arc.
test activates the stretch receptors inside the biceps brachii muscle which communicates mainly with the C5 spinal nerve and partially with the C6 spinal nerve to induce a reflex contraction of the biceps muscle and jerk of the forearm.
Indicates musculocutaneous nerve damage
A supracondylar humerus fracture can result in damage to which nerve?
Median nerve
Carpal tunnel syndrome
due to compression of the median nerve as it travels through the wrist at the carpal tunnel
Weak grip strength may occur, and after a long period of time the muscles at the base of the thumb may waste away
Sternoclavicular joint is found between which two bones?
Clavicle and sternum
What joint is the only joint between a bone of the upper limb and a bone of the axial skeleton?
Sternoclavicular joint
What ligament stabilizes the acromioclavicular joint?
Coracoclavicular ligament by attaching the clavicle to the coracoid process of the scapula
Do shoulder separations involve injury to the shoulder joint?
No
A partial dislocation is called a ____________
Subluxation
A subluxed AC joint is called a grade_______ shoulder separation.
II
. If a patient has a grade II shoulder separation, comparison of AP radiographs of the patient’s injured and non-injured shoulders shows a CC space of normal width in the injured shoulder but an AC space that is at least _________% wider than that measured in the uninjured shoulder.
50
A completely dislocated AC joint is called a grade _______separation.
III
Which joint provides more range and freedom of movement than any other synovial joint in the body?
The shoulder joint
The shoulder joint has a __________configuration in which the humeral head is free to rotate in any direction on the surface of the glenoid cavity.
ball-and-socket
What component of the shoulder joint enhances the extent to which the humerus can rotate?
The comparatively small surface area of the glenoid cavity.
NOTE: The glenoid cavity is not sufficiently extensive to hold the humeral head in place in the should joint. Hence, the shoulder can easily dislocate.
The lax fibrous capsule is also a contributing factor.
___________ dislocation of the humeral head is the most common type of shoulder joint dislocation.
Anterior
What is an anterior dislocation?
A dislocation that is produced by trauma that drives the humeral head anteroinferiorly from its articulation with the glenoid cavity
The head of the humerus typically comes to ret in a subglenoid, subcarocid, or subclavicular position
Clenidocranial dystosis
Characterized by defective ossification of cranial bones and the clavicles.
Defect can cause complete absence of the clavicles
Most commonly fractures bone in the body
Clavicle
Explain the strut role served by the clavicle. How can this role be abolished?
The strut role braces the shoulders superoprly, posteriorly and laterally.
The role is abolished by a fracture of the clavicle proximal to the coracoclavicular ligament.
*A patient with this fracture presents with a shoulder that is displaced inferiorly, anteriorly, and medially.
Bones that form the shoulder girdle
Scapula and clavicle
The shoulder girdle serves as a mobile boom for the upper limb because its movements at the sternoclavicular and acromioclavicular joints greatly extend the range of movement of the arm
6 ways in which the arm can be moved at the shoulder joint
Flexion
Extension
Internal rotation
External rotation
Abduction
Adduction
Forward and backward movement of the shoulder is achieved mainly through forward and backward rotation of the __________
Clavicle
On average during arm abduction, lateral rotation of the scapula contributes 1 degree arm abduction for every ________ degree arm abduction provided by upward rotation of the humerus.
2
4 shoulder muscles that suspend the shoulder girdle from the spine
Trapezius
Levator scapulae
Rhomboid major
Rhomboid minor
Which muscle provides much of the force required to lift the arm above the shoulder?
Trapezius
Which nerve innervates the trapezius?
Acessory nerve
Levator scapulae is innervated by the ___________ nerve and nerve fibers from ____ and ________.
Dorsal scapular (C5); C3 and C4
Functions of levator scapulae
Raising shoulder
Medially rotating the scapula
Innervation and function of rhomboid minor and major
Innervation: Dorsal Scapular Nerve (C5)
Function: Retract the shoulder and medially rotate the scapula
Muscles that pull upon the shoulder girdle from the anterior chest wall
Serratus anterior (most powerful)
Pectoralis minor
Subclavis
Function of serratus anterior. Innervation.
Protraction of the shoulder
Lateral rotation of the scapula
Innervation: Long Thoracic Nerve
Function and innervation of pectoralis minor.
Function: Lower the shoulder and protract the shoulder
Nerve: Medial pectoral nerve
Function and innervation of subclavis.
Function: Depression of the clavicle
Nerve: Nerve to Subclavis
Muscles of the rotator cuff
Supraspinatus
Infraspinatus
Teres Minor
Subscapularis
Tendons of insertion of the muscles that make up the rotator cuff form a ___________ cuff about the shoulder joint.
Musculoctendinous
Which nerve innervates the supraspinatus? Which nerve fibers?
Suprascapularis nerve; Fibers C5 and C6
Which nerve innervates the infraspinatus? Which nerve fibers?
Supracscapular nerve; C5 AND C6
Which nerve innervates the teres minor? Which fibers specifically?
Axillary nerve; C5 and C6
Main function of the muscles of the rotator cuff
Stabilizing the dynamic intergrity of the shoulder joint when powerful forces are exerted across the joint
Primer mover for abduction of the arm at the shoulder joint
Deltoid
Functions of the deltoid
Flexion
Internal rotation
Extension
External rotation
Which nerve innervates the deltoid muscle? Which nerve fibers?
Axillary nerve; C5 and C6
Prime movers of adduction of the arm at the shoudler joint
Pectoralis major
Teres major
Latissimus dorsi
Function and Innervation Pectoralis Major
Function: Fexion of the arm
Rotaion of the arm at the shoulder joint
Adduction of the arm
Innervation: Lateral pectoral nerve and Medial pectoral nerve
What nerve innervates the teres major? Which nerve fibers?
Lower subscapularis
C5 and C6
Function and innervation of the latissimus dorsi.
Functions: Extension of the arm, internal rotation of the arm, adduction of the arm
Innervation: Thoracodorsal nerve
Abduction of the arm 180 degres from the anatomical position is dependent on which 4 muscles
Suprapinatus (10-15 degrees)
Deltoid (120 degrees)
Trapezius
Serratus anterior
*Without Trapezius and Serratus anterior the arm could only go 110 degrees from anatomical position
Role of the subacromial-subdeltoid bursa
Establishes discontinuities between tissues which provide for much freedom of movement over a limited range.
The space in the shoulder bordered superiorly by the coracoacromial arch and inferiorly by the capsule of the shoulder joint is called the _____________.
subacromial space
