Rotator Cuff Tendinopathy & Impingement Flashcards
What are the major functions of the rotator cuff muscles?
- Rotate the humerus
- Stabilize the glenohumeral joint
What are the two methods by which the rotator cuff muscles rotate the humerus?
- Contraction of individual RC muscles
- Use of a force couple
rotating the humerus
Which individual rotator cuff muscle performs abduction?
Supraspinatus (SSp)
rotating the humerus
Which individual rotator cuff muscle performs internal rotation?
Subscapularis (SSc)
rotating the humerus
Which rotator cuff muscles perform external rotation?
Infraspinatus and teres minor
What is a force couple?
Two forces of equal magnitude acting in opposite directions to rotate a body around its axis of motion
use of a force couple
In addition to the medial pull of subscapularis, infraspinatus, and teres minor, these muscles also…
pull in an inferior direction
Which force couple of muscles will aid in flexion and adduction of the humerus?
Infraspinatus, teres minor, and subscapularis coupled with deltoids
Which muscles are most important in stabilizing the glenohumeral joint in the mid-ranges of motion?
Rotator cuff muscles
Rotator cuff muscles are most important in stabilizing the glenohumeral joint in the ___ ranges of motion
mid-ranges
What is the compression of the humeral head into the glenoid fossa called?
Concavity-compression stability mechanism
What is the most important method of glenohumeral joint stabilization by the rotator cuff muscles?
Concavity-compression stability mechanism
stability mechanism
The more shallow the concavity of the glenohumeral joint, the greater ___ is required for stabilization
more shallow concavity = greater compression required
What is the concavity-compression stability mechanism?
Compression of the humeral head into the glenoid fossa; the most important method of glenohumeral joint stabilization by the rotator cuff muscles
What is the most common cause of shoulder pain in patients over 35 years old?
Rotator cuff disorders
What is tendinopathy?
A broad term used to describe any pathology involving a tendon and is inclusive of several different tendon pathologies
What are some examples of tendinopathy?
- Tendinitis
- Tendinosis
- Tenosynovitis
What is the inflammatory condition of a tendon termed?
Tendinitis
Tendinitis is often used incorrectly as…
a catch-all term since inflammatory infiltrates within a tendon are not usually seen
What are non-inflammatory degenerative changes in a tendon termed?
Tendinosis
What is the inflammation of the synovial sheath surrounding some tendons termed?
Tenosynovitis
What are some common causes of tendinosis?
- Aging
- Microtrauma
- Vascular compromise
- Failed healing
Is tendinosis symptomatic?
Not necessarily
What is tendinitis?
Inflammatory condition of a tendon
What is tendinosis?
Non-inflammatory degenerative changes in a tendon
What is tenosynovitis?
Inflammation of synovial sheath surrounding some tendons
Which tendon of the rotator cuff is most commonly affected by tendinopathies?
Supraspinatus
What age group is typically affected by rotator cuff tendinopathies?
Over 35 years old
Patients under 35 years old with rotator cuff tendinopathy are mostly ___
athletes
What are four major causes of rotator cuff tendinopathies?
- Major trauma
- Age-related degeneration
- Tension overload
- Subacromial impingement
What are some major traumas causing rotator cuff tendinopathies?
- FOOSH
- Traumatic dislocation
What are some age-related degeneration related causes of rotator cuff tendinopathies?
Etiology unknown
Most likely due to poor vascular supply of the supraspinatus tendon in the critical zone (area of the tendon where degeneration and tears most often occur)
When about does age-related degeneration begin causing rotator cuff tendinopathy?
Can begin after age 40
What is the prevalence of age-related degeneration causing rotator cuff tendinopathy?
Prevalence is unknown because it is often asymptomatic
tension overload
Repetitive eccentric contraction of the rotator cuff is needed to:
- Decelerate the arm during the follow through of the throwing motion
- Stabilize an unstable glenohumeral joint
Tension overload causing rotator cuff tendinopathy is seen in ___ athletes
overhead athletes
What is subacromial impingement?
Compression of tissue in subacromial space (between humeral head and undersurface of coracoacromial arch)
What is the most common cause of symptomatic rotator cuff tendinopathy?
Subacromial impingement
What is the subacromial space?
Space between coracoacromial arch and head of the humerus
What is made up of the following?
- Anterior third of acromion
- AC joint
- Coracoacromial ligament
- Coracoid process
Coracoacromial arch
What tissues can be found in the subacromial space?
- Subacromial bursa
- Supraspinatus tendon
- Long head of biceps tendon
In which position of the shoulder will tissues in the subacromial space normally compress?
Beginning at 60 degrees shoulder abduction
How are compressive forces normally distributed in the subacromial space?
Evenly distributed over a large area and are not excessive (if the shoulder is working correctly)
Compressive forces on the subacromial space can become concentrated on certain tissues and excessive if there is:
- Faulty mechanics (functional narrowing)
- Structural narrowing
- Swelling within the subacromial space
Which tissues are impinged in the subacromial space in order of prevalence?
- Subacromial bursa (subacromial bursitis)
- Supraspinatus tendon (supraspinatus tendinopathy)
- Long head biceps tendon (LHBT tendinopathy)
What are some major causes of subacromial impingement?
- Functional narrowing of subacromial space
- Structural narrowing of subacromial space
- Swelling in the subacromial space
What are some causes of functional narrowing of the subacromial space?
- RC/deltoid strength imbalance
- Tight posterior GHJ capsule (loss of A-P glide)
- Tight inferior GHJ capsule (loss of S-I glide)
- Decreased upward rotation of the scapula
What are some causes of structural narrowing of the subacromial space?
- AC joint spurs
- Abnormal shape of the acromion
What are some causes of swelling in the subacromial space?
- Secondary to tension overload
- Secondary to trauma
What is the most common cause of subacromial impingement?
Functional narrowing of subacromial joint space
If the humerus is pulled superior during flexion or abduction of the shoulder, what is the likely cause of the impingement in the SAS tissue?
Strength imbalance between the rotator cuff and deltoid
What happens if the strength of the deltoid overwhelms the concavity-compression stability mechanism of the rotator cuff muscles?
Strength imbalance between the rotator cuff and deltoid leads to impingement of the subacromial space
What are some causes of strength imbalance causing impingement of the subacromial space?
- Rotator cuff deconditioning
- Rotator cuff tendinopathy of another cause
- Rotator cuff tear
Does rotator cuff deconditioning (leading to impingement) affect the RC muscles or the deltoid more?
Affects RC muscles more
A tight inferior capsule causes ___ translation of the humeral head during ___
superior translation of the humeral head during shoulder abduction
Decreased upward rotation of the scapula occurs during which motions?
Flexion and abduction
During 180 degrees of shoulder abduction and flexion, the humerus moves ___ degrees and the scapula rotates upward ___ degrees
humerus moves 120 degrees
scapula rotates upward 60 degrees
As the scapula rotates upward, how does the acromion move?
Acromion moves out of the way of the humerus
With decreased upward rotation of the scapula, how does the acromion move?
Acromion will not move out of the way of the humerus and will cause impingement
The four most common causes of functional narrowing of the subacromial space can all be effectively treated with ___
conservative care
What are some general causes of swelling of the subacromial joint space?
- Tension overload (athlete)
- Acute trauma
swelling of the SAS
Repetitive, high intensity use can cause microtears and swelling of the ___ tendon
supraspinatus tendon
swelling of the SAS
FOOSH or GHJ dislocation causes swelling of which structures?
- Subacromial bursa (SAB)
- Supraspinatus tendon (SSp)
- Long head biceps tendon (LHBT)
FOOSH injury can push the humerus ___, pinching the contents of the SAS causing injury and swelling
superior
Any cause of rotator cuff tendinopathy can result in ___ which in turn can cause a secondary functional impingement
rotator cuff impingement
What are the common chief complaints presented with subacromial impingment?
- Anterolateral and/or anterior shoulder pain
- Deltoid insertion (frequent referred pain)
What are the less common complaints presented with subacromial impingement that may be present?
- LH biceps tendon pain
- Lateral arm referred pain (mimics C5 radiculopathy)
- Lateral forearm referred pain (mimics C6 radiculopathy)
A patient with subacromial impingement is typically greater than ___ years old
If younger, the patient is usually ___
greater than 35 years old
if younger, usually an athlete
___% of subacromial impingement has no cause or activity the patient can relate to symptom onset
30%
Most subacromial impingement is due to ___ combined with ___
functional and/or structural impingement combined with cumulative effects of repetitive impingement
What are some causes of repetitive impingement causing subacromial impingement?
- Overhead sports
- Overhead occupation
If causes of SAS impingement are present, and they are combined with high intensity overhead athletic activity, symptoms will…
develop in a short period of time
If causes of SAS impingement are present, and they are combined with prolonged low intensity overhead activity, symptoms will…
take time to develop
If causes of SAS impingement are present, and they are combined with no history of overhead activity, symptoms will…
take a very long time to develop
___ of patients have no single precipitating event to impingement, while ___ patients do
Majority do not have a single event
Minority have a single event/injury
Most patients with SAS impingement present ___ after onset of symptoms when they have not resolved on their own
weeks or months after onset
Symptoms of SAS impingement are aggravated by…
overhead activities
Upon palpation of SAS impingement, what are the probable areas of tenderness?
- AC joint
- Anterior and lateral edge of acromion
- Insertion of supraspinatus on greater tuberosity
- LHBT
What is suspected if the following are tender upon palpation?
- AC joint
- Anterior and lateral edge of acromion
- Insertion of supraspinatus on greater tuberosity
- LHBT
Subacromial impingement
What might be found upon passive range of motion of subacromial impingement?
Subacromial crepitus
What strength test is used for supraspinatus?
Thumb up (full can)
Doctor pushes flexed arm inferiorly against resistance
What strength test is used for infraspinatus/teres minor?
External rotation
Doctor pushes flexed arm with bent elbow medially (internal rotation) against resistance
What strength test is used for subscapularis?
Internal rotation: doctor pulls flexed arm with bent elbow laterally (external rotation) against resistance
Lift-off test: Patient puts arm behind back and tries to lift their hand off their back
orthopedic tests
What are the most common impingement tests?
Neer test and Hawkins test
(impingement sign)
orthopedic tests
How is the Neer test performed?
What is a positive result?
Humeral flexion is tested by slowly lifting the patient’s relaxed arm
Positive finding is induced pain
orthopedic tests
How is Hawkins test performed?
What is a positive result?
Humeral internal rotation is tested when holding the patient’s relaxed arm with 90 degrees shoulder flexion (on scapular plane) and 90 degrees elbow flexion
Positive finding is induced pain
orthopedic tests
What is a positive impingement sign?
Pain in top outer edge of shoulder upon orthopedic testing
orthopedic tests
What is the supraspinatus press test?
Thumb down (empty can)
Doctor presses inferiorly on patient’s flexed and internally rotated arms against resistance
orthopedic tests
Between the supraspinatus “thumb up” strength test and the supraspinatus press orthopedic test, which is more likely to cause pain if impingement is present?
Supraspinatus press test
Internal rotation of the humerus causes anterior tipping of the scapula which narrows the SAS
What types of imaging are used to diagnose subacromial space impingement and in what circumstances?
Plain radiographs: for structural causes of impingement or bony pathology
MRI: if a rotator cuff tear is suspected
manual treatment
What are some areas of treatment by a chiropractor when manipulating or mobilizing for subacromial impingement?
- Glenohumeral joint
- Acromioclavicular joint
- Sternoclavicular joint
- STA
- Thoracic and cervical spine
manual treatment
Which glenohumeral joint techniques can be beneficial for subacromial impingement?
- S-I glide
- A-P glide
- All techniques with arm above 30 degrees abduction in the scapular plane which slackens the tendon to minimize stress
What are some therapeutic modalities for treating subacromial impingement symptoms?
- Ice/heat
- Electrical stimulation
- Ultrasound
- Laser
When should a chiropractor refer a patient with subacromial impingement to another professional?
- Severe pain (>7/10)
- Difficulty sleeping due to pain
- Worsening pain, weakness, and/or dysfunction
- No subjective or objective improvement after 4-6 weeks of treatment
What are some medical treatments for subacromial impingement?
- Medication: NSAIDs
- Subacromial corticosteroid injection
- Physical therapy
Surgical treatment may be effective for ___ in the subacromial space, but is not effective for ___ causes of impingement
may be effective for structural causes or swelling in the SAS
not effective for functional causes of impingement
subacromial decompression
What is the removal of an inflamed and thickened bursa, which allows a normal bursa to reform?
Busectomy
subacromial decompression
What is the excision of dead or useless tissue such as tissue that is torn and cannot be repaired?
Debridement
subacromial decompression
What is the smoothing of rough bony edges on the coracoacromial arch and or the humeral head?
Smoothing (surgical treatment)
subacromial decompression
What is the bony resection of the anterior portion and undersurface of the acromion with release and resection of the anterior portion of the coracoacromial ligament?
Acromioplasty
Subacromial decompression (surgical) can include combinations of:
- Bursectomy
- Debridement
- Smoothing
- Acromioplasty
- Resection of AC joint inferior osteophytes
