Shoulder Flashcards
Four important bones of the shoulder
- Humerus
- Scapula
- Calvicle
- Sternum
What is the top of the humerus called?
Humeral Head
Where is the Bicipital Groove and what’s important about it (which tendon attaches here?)
- on the humerus, groove between the tuberosities (greater and lesser tubercle)
- long head of biceps tendon
What are 3 important functions of the clavicle?
- attaches the shoulder to the axial skeleton
- elevates and rotates to allow for greater degree of motion
- prevents excessive anterior displacement of the scapula
Which part of the clavicle is convex and which part is concave?
- proximal 2/3 - convex anterior
- distal 1/3 flattens while curving concave
What is the importance of the convex/concave anatomy of the clavicle?
The transition point where it bends is anatomically weak and is a common site of fracture
What is the ossification date of the clavicle?
The medial clavicular epiphysis is one of the last to ossify and fuse at ~24 yo
What are the 4 important boney landmarks of the scapula?
- Scapular spine
- Acromion process -articulates with the clavicle
- Coracoid process
- Glenoid fossa
What is plane of the scapula
- glenoid fossa angles 30 degrees from the frontal plane
- face assumes a downward direction
What is the importance of the plane of the scapula?
- provides more functional full arc of motion
- places the rotator cuff muscles in options length tension relationship
What are the 4 joints of the shoulder?
- Glenohumeral joint
- Acromioclavicular joint
- Sternoclavicular joint
- Scapulothoracic joint (not a true joint)
What are two important facts about the stability of the shoulder joint?
- lacks intrinsic boney stability of other joints
- inherently unstable
- anatomically weak capsular structures - relies on muscular to provide stability
- depends more on muscles than any other joint
- needs musculature for proprioception
What are the motions of the sternoclavicular joint?
- elevation and depression
- protraction and retraction
- internal rotation and external rotation
What are the motions of the acromioclavicular joint?
AC joint is a synovial joint with gliding type motion
Motions:
- scapular rotation
- scapular winging
- scapular tipping
What causes scapular winging asymmetry?
Muscle imbalance
Nerve entrapment
Why isn’t the scapulothoracic joint a real joint?
- no synovium, no fibrous or cartilaginous connection to ribs
What are the motions of the scapulothoracic motions?
Elevation and depression
Protraction and retraction
upward and downward rotation
What type of joint is the glenohumeral joint?
Shallow ball and socket
What are the motions of the glenohumeral joint?
- flexion and extension
- abduction and addition
- internal and external rotation
- horizontal abduction and abduction (not true anatomically motions)
- circumduction
- elevation and depression
Importance of the glenoid leabrum?
- helps deepen the articulation
- increases the articulate surface
- dense fibrous connective tissue
- injury of glenoid labrum is associated with recurrent shoulder instability
Glenohumeral Joint Capsule importance?
- broad and large volume
- allows the joint to be distracted from fossa
What are the ligaments of the shoulder capsule?
- Gelnohumeral ligaments - superior, middle, inferior
- Coracohumeral ligament
What is the most stable position of the shoulder?
Closed packed position
- humerus abducted to 9o and externally rotated
What are the muscles that make up the rotator cuff ?
- subscapularis
- supraspinatus
- infraspinatus
- trees minor
What are the functions of the rotator cuff muscles?
- IR and ER of the humerus
- stabilized the head in the glenoid fossa
- in late abduction, it provides a downward pull so the head of the humerus clears the acromion
What is the consequence of damage/weakening of the rotator cuff muscles?
Impingement of rotator cuff and long head of he biceps tendon between the humeral head, subacromial bursa, and acromion process
What is the motion of the subscapularis?
IR
What is the motion of the supraspinatus?
Abduction and external rotation
What is the motion of the infraspinatus?
ER and horizontal abduction
What is the motion of the Teres Minor?
ER, horizontal abduction and extension
What does the term scapulothoracic rhythm refer to?
Motions of the GH joint, scapular, AC and SC joints are coupled and must occur in combination to get full shoulder ROM
MOI for SC Joint injury
Falling on outstretched hand
Forceful distraction of arm
What type of SC Joint injury is a medical emergency
Posterior dislocation
Tests for SC Joint Injury
ROM: pain with end range ABD, flexion, horizontal abduction, SC glide tests
Treatment for SC Joint Injury
- palliative measures
- arm sling
- progression to PT
MOI of AC joint injury
Falling on shoulder
Landing on AC joint
FOOSH -falling on outstretched hand
Long force to clavicle
Symptoms of AC joint injury
Pain with elevating humerus and protraction/retraction
Test for AC joint injury
- AC traction
- AC compression
- Apley’s test - pain above 90 degrees
What are the 3 associations of anterior Glenohumeral instability
- GH ligaments
- Bankart lesion
- Boney Bankart Lesions
What is Bankart lesion
- tear of the inferior GH ligament off the labrum
What is the boney Bankart lesion?
Avulsion during a Bankart lesion
With glenohumeral instability, how does the shoulder usually dislocate?
Anterior and inferior
Why is superior dislocation of the shoulder rare?
Presence of the acromion, coracoid process and rotator cuff
What is a Hill-Sachs lesion
- occurs with an anterior GH dislocation
- posterior humeral head articulate cartilage defect
- impact of humeral head on glenoid fossa as it tries to relocate
Rotator Cuff tendon it is considerations
- relatively poor vascularization of tendons
- most commonly injured is supraspinatus
- in overhead throwing, infraspinatus and terese minor are affected
What is rotator cuff impingement
Decrease in space between the coracoacromial arch and humeral head
What structures are in the area of a rotator cuff impingement
- rotator cuff tendons: supraspinatus
- long head of biceps tendon
- subacromial bursa
- GH capsule
Main cause of rotator cuff tear
Repetitive overhead motions and repetitive eccentric activity increases risk
What is a SLAP tear
Superior Labrum Anterior to Posterior
Rarely in isolation
More prone after age 35 because labrum is less firmly attached
Which tendon is involved in SLAP tear?
Bicep tendon
MOI of SLAP tear
- FOOSH
- repetitive throwing
- hyperextension
- heavy lifting
- direct trauma
- repetitive overhead activities
Where does biceps tendinitis occur?
Bicipital groove, typically in conjunction with rotator cuff dysfunction
Which tendon van be affected in biceps tendinitis and what’s it function
Transverse humeral Ligament
- hold tendon in the groove
- can be injured with sudden forefoot ext/ER
- leads o subluxation of tendon
What is thoracic outlet syndrome
- pressure on neurovascular bundle - subclavian artery and vein
Sources of thoracic outlet syndrome?
- presence of accessory cervical rib
- ironing event btw the clavicle and 1st rib
- compression btw the pec minor and ribs
- tightness of anterior and middle scalene muscles
Symptoms of nerve related TOS
Numbness, pain, paresthesia
Symptoms of Arterial related TOS
Cold skin, pallor, cyanosis of fingers, weakness
Symptoms of venous TOS
Stiffness, edema, thrombophlebitis
What is the Apley’s Scratch test - what are the 3 actions and corresponds motions produced
- patient touches opposite shoulder by crossing chest —> GH abduction, horizontal abduction and IR, scapular protraction
- Patient reaches behind the head and touches the opposite shoulder from behind —> GH abduction, ER, scapular elevation and upward rotation
- Patient teaches behind the back and touches the opposite scapular —> GH abduction and IR, scapular retraction and downward rotation
What is the anterior apprehension test
Passive ER of the GH joint, places the joint in the closets-pack position and replicates the mechanism of injury for anterior GH dislocations
What is the procedure of the apprehension test
- while supporting the humerus at 90 degrees abduction, the examiner passively externally rotates the GH joint by slowly applying pressure to the anterior forearm
What is the relocation test
Examiner externally rotates the humerus until pain, discomfort or apprehension of a dislocation is experiences by the patient or the normal ROM is met. Posterior pressure is then applied to relocate the subluxed joint
The anterior apprehension test is usually performed with what test
Reloacation test
What is the posterior apprehension test
Humeral head is moved Posteriorly on the glenoid fossa. In the presence of posterior Glenohumeral laxity or instability the patient will abruptly stop the test
What is the evaluate procedure of the posterior apprehension test
The examiner applies a longitudinal force to the humeral shaft, encouraging the humeral head to move Posteriorly on the glenoid fossa
What is the sulcus sign test
Test for inferior glenohumeral laxity
What is the evaluative procedure for sulcus sign test
A downward (inferior) traction force applied to humerus - look for indentation beneath the acromion process
What is the jerk test /posterior stress test
Test for labral tears
What is the evaluative procedure for the jerk test/ posterior stress test
Affected arm is passively horizontally adducted while the examiner applies a simultaneous axial load to the humerus, —> looking for clunk that may or may not be painful
‘What is the drop arm test
Test for rotator cuff tears
What is the evaluative procedure for stop arm test
-patient slowly lowers the arm to the side —> arm falls uncontrollably from a position of approximately 90 deg abduction to the side
What is the gerber lift off test
Test for subscapularis pathology
What is the evaluative procedure of the gerber lift off test
The patient attempts to actively lift hand off the spine while the humerus stays in extension
What is the empty can test
For supraspinatus pathology
What is the evaluative procedure of the empty can test
GH is abducted to 90 deg in scapular plane, the elbow extended and the humerus internally rotated and forearm pronated so that the thumb points downward. Evaluator resists abduction
What is the yurgason’s test
Test for subluxation of the biceps tendon
What is the evaluative procedure for the Yergason’s test
GH joint in anatomical position, elbow flexed to 90 deg, forearm positioned so that the lateral border of the radius faces upwards. Patient provides resistance while examiner concurrently moves the GH joint into external rotation and the proximal radioulnar joint into supination
What is the speed’s test
Test for long head of the biceps brachi tendinitis
What is the evaluative procedure of the speed’s test
Elbow e tending. Clinical resists flexion of the GH joint and elbow while palpating for tenderness over the Bicipital groove
What is the ludingotn’s test
Test for biceps brachial pathology
Evaluative procedure of the luidington’s test
Hands on top head with the fingers interlocked, patient contracts biceps brachial by applying force to the top of the head. Examiner palpates te long head of the biceps tendon, noting tension within the tendon
What is the O’Brien test
GH joint flexed to 90 deg and horizontally adduced 15 deg from the sagittal plane. The humerus in full internal rotation and the forearm pronated. The patient resists the examiners downward force. Test is repeated with the humerus externally rotated and the forearm supinated
AC traction test evaluative procedure
Examiner applied a downward traction on the humerus —>looking for humerus and scapular to move inferior to the clavicle, cause a step deformity, pain or both
AC compression test
Examiner squeezes the hands together, compressing the AC joint —> looking for pain at AC joint or excursion of the clavicle over the acromion process
Name the different shoulder pathologies
- Bursitis
- SC joint injury
- AC joint injury
- GH instability
- Rotator cuff tendinitis
- Rotator cuff tear
- SLAP tear
- Biceps tendinitis
- Thoracic outlet syndrome
