Musculoskeletal Flashcards
Muscles of the rotator cuff
Supraspinatus Infraspinatus Teres Minor Subscapularis (SITS)
Supraspinatus origin, insertion, innervation and function
- Supraspinous fossa
- superior facet of greater tuberosity
- Suprascapular nerve (C5)
- abduction
Infraspinatus origin, insertion, innervation and function
- infraspinous fossa
- middle facet of greater tuberosity
- suprascapular nerve (C5-6)
- External rotation
Teres minor origin, insertion, innervation and function
- lateral border of scapula
- inferior facet of greater tuberosity
- axillary nerve (C5)
- external rotation
Subscapularis origin, insertion, innervation and function
- subscapular fossa
- lesser tuberosity of humeral neck
- upper and lower subscapular nerves (C5-6)
- internal rotation
Red flag conditions of the shoulder and when to consider them
Polymyalgia rheumatica - bilateral shoulder pain and weakness
Acute compartment syndrome - pain disproportionate to injury, may result from significant limb swelling following injury or excessively tight bandage or cast
Open fractures
Fractures with nerve or vascular compromise
Skin or joint infections
Neoplasia
Serious and life-threatening conditions mimicking shoulder pain - e.g. referred ischaemic pain
What is impingement syndrome of the shoudler
The subacromial bursa and supraspinatus tendon become compressed between the humeral head, the acromion and the coraco-acromial ligament -> pain with forward elevation of the arm and narrowing of the subacromial space
Causes of impingement syndrome of the shoulder
Functional
- poor control of shoulder stabilisers (cephalad slippage of humeral head compressing the subacromial space, may result from overuse of shoulder, injury to shoulder resulting in altered biomechanics and poor stabiliser control)
Anatomical
- arthritis
- hypertrophic changes of the acromion -> narrowed subacromial space
Clinical presentation of impingement syndrome of the shoulder
Pain, especially with overhead movements of the arm
Sometimes lying on the affected shoulder at night may cause pain
Clinical examination findings in impingement syndrome of the shoulder
Positive Hawkins test (most sensitive, poorly specific)
Painful arc test - pain from 60-120 degrees improving at approx 120
Empty can test (highly specific for supraspinatus tear)
What is Hawkins test, what does it demonstrate and how is it performed?
Highly sensitive, poorly specific test for subacromial impingement.
With patient standing, elevate humerus to 90 degrees, 30 degrees anteriorly (ensuring humerus in line with scapula), flex elbow 90 degrees
Internally rotate the glenohumeral joint
Pain = positive test
What is painful arc test, how is it performed and what does it demonstrate
Patient actively abducts both arms together.
Test is positive for subacromial impingement if patient experiences pain between 60-120 degrees of abduction, then improving.
Pain presenting only at 170-180 degrees more likely to be secondary to acromial pathology
What is Jobe’s test, how is it performed and what does it demonstrate
AKA Empty Can test, highly specific for supraspinatus tear, but poorly sensitive
Elevate arms to 90 degrees angle forward 30 degrees
Internally rotate shoulder by pointing thumb down to ground
Apply downward force as patient attempts to resist
Pain worse on internal rotation v external rotation = positive
Management of subacromial impingement
Address underlying cause
Physio indicated most of the time
Surgical management unlikely to be of benefit, especially if functional cause (acromioplasty has no additional benefit over structured and supervised exercise program)
Cause of anterior shoulder instability
Secondary to acute or chronic stretching of the anterior shoulder capsule - can occur following anterior shoulder dislocation and subluxation
more commonly caused by repetitive and progressive stress on anterior shoulder capsule from loading and stretching beyond functional range (Swimmers, baseball pitchers)
Also frequently seen in resistance trainers using incorrect technique or too heavy weights (particularly in supine or semi-recumbent position)
Clinical presentation of anterior shoulder instability
Nonspecific symptoms are common
Shoulder ache
Occasional clicking or clunking
Pain may wake the patient at night when lying on the affected shoulder
If longstanding (or pronounced) laxity, may have hand or arm nerve symptoms from proximal nerve traction
Examination findings in anterior shoulder instability
Often unremarkable
Anterior and posterior drawer test to check for laxity of glenohumeral joint
Sulcus test:
- applying downward traction to humerus produces sulcus under acromion if positive
Anterior release test: (relatively highly sensitive and specific)
- patient supine, abduct and externally rotate shoulder
- examiner’s hand closest to patient applies downward force over humeral head attempting to relocate and secure it in the glenoid
- while firm pressure applied, externally rotate arm further (humeral head suddenly released)
- patient may experience pain, apprehension or combination
Management of anterior shoulder instability
Imaging if traumatic shoulder dislocation has occurred (pre- and post- reduction)
- all first time dislocations refer to PT and ortho assessment due to high risk of re-dislocation
No data to guide management of instability from chronic over use ?identify and correct predisposing factors +/- refer to PT
If instability does not improve, ortho opinion may be indicated
Rotator cuff tears
Common
Increase with age
>50% patients >50y have a tear (symptomatic or asymptomatic)
May be partial or full thickness - pain and dysfunction does not appear to correlate with degree of tear
Often progress from tendinopathy to tear if not addressed early
May occur as result of direct trauma or progressive wear and tear
Clinical presentation of rotator cuff tear
Broad spectrum of presentation
May present with symptoms similar to anterior shoulder instability
May have pain or weakness attempting to elevate arm
May be pain at night lying on affected shoulder
If longstanding may have numbness and tingling in affected arm
May have normal or near-normal shoulder function due to recruiting other muscles to perform task of injured muscle