Chronic Shoulder Flashcards
Describe the location of chronic shoulder pain for someone who participates in overhead arm movement
- lateral edge of acromiocn, pain shoots or aches into deltoid space, might get ache in posterior part of the scapula
- pain is aggravated in sports specific or ADL movements that include overhead arm movement
Is an ac joint sprain a chronic issue?
NO
happens after a specific event
What are some examples of athletes that do overhead movement of arm?
Swimmers, volleyball, waterpolo, throwing sports
What are some examples of ADL that may aggravate chronic shoulder pain
Putting on seatbelt
- reaching for something
- grab loop on bus/subway
- getting dressed
- sleeping (hard to find nice position)
Define an impingement
Pinching of some kind of anatomic structure/tissue (mechanism, not a name for a single type of injury)
- this leads to pathological tissue breakdown
- tendinopathies and bursitis can be impacted by this
How can impingement be categorized?
can happen in 2 categories based on location and mechanics
- sub-acromial impingement (SAI)
- posterior internal impingement (PII)
Describe the margins of the sub acromial space
- the coraco-acromial (CA) ligament forms a roof over the space, head of humerus on bottom
- anything in this space will be vulnerable to compression in margins
Describe a sub-acromial impingement
- some kind of pinching in sub-acromial space, pinching happens when person is in an overhead position
- when your arm is down the space is optimized
- when we raise arm the space can become really tight, applies pressure to structures within
Which structures are most likely to be compromised with a sub-acromial impingement?
1: supraspinatus tendon
2: sub-acromial bursa
3: tendon of long head of bicep
Describe the sub-acromial bursa
A little fluid filled sac to help with compression (free synovial pocket of synovial membrane and fluid)
Describe the location of the long head of the bicep
Goes inside the joint because it wants to travel to top of glenoid fossa
From a mechanical perspective, what is happening to scapular mechanics to cause an SAI?
- not enough ROTATION OF SCAPULA, difficult to raise properly and humerus has to do it
- insufficient POSTERIOR TILT
- excessive ANTERIOR TRANSLATION of humerus (catches anterior margin of sub-acromial space
- reduced acromio-humeral distance (varies in diff ppl, diff acromion features and humerus can slide up)
Which impingement is the most common?
SAI
In which population do we see a posterior internal impingement?
Athletic population
Describe a posterior internal impingement locationally and mechanically
- pinching between the posterior edge of glenoid rim and posterior aspect of the humeral head
- tissues get caught on the inside of the joint rather than superficial structures
*Sub-acromial structures usually get pinched on the superficial part
Pinching happens in very specific positions, which position would PII show up?
Vulnerable position for internal pinching is 90ish degrees abduction and external rotation (think of pitcher)
- get pinxg on posterior side of shoulder
Where does pinching happen in a PII?
Between posterior glenoid and humeral head
- usually humerus moves around a lot, which causes it to catch some of the tissues as it spins
- will gather tissues on the back of the shoulder and bring into pinching space
What could be caught in a PII?
Infraspinatus (running on posterior glenoid rim)
Supraspinatus (majority of fibres along the top but some posterior fibres can get caught)
Glenoid Labrum (superior part of the posterior aspect - internal structure!) Could have a labral tear
An impingement doesn’t tell you what the exact injury is, it tells you _
There is PINCHING happening SOMEWHERE
Looking at the mechanical side of PII, what might be happening at the GH/scapula/humerus?
- excessive SCAPULAR PROTRACTION
- excessive cross extension @GH joint
- GIRD (glenohumeral internal rotation deficiency)
Describe the excessive cross extension mechanical aspect
- when you throw a ball, the farther you want to throw, the more retraction @scapula you need to have
- if you CAN’T do this, your body will find a diff way
- in an effort to compensate, ppl have a tendency to cross extend through GH joint exclusively rather than @scapula
Describe GIRD
- everyone has the capacity to internal/externally rotate to some degree
- lack of internal rotations capacity means GIRD
- we don’t know if lack of internal is the problem or excessive external as a compensation
- GIRD has a 1.5x chance of having a PII issue
- if one group of ppl has 10% less internal rotation, they have 1.5 chance of PII
Key IDEA 1: impingement mechanics lead to _
Tissue pathology such as tendinopathy and bursitis
Key IDEA 2: there are _ categories of impingement conditions, with different _
2 categories, different impingement positions (SAI and PII)
Key IDEA 3: Both categories of impingement involve altered _
Scapular and glenohumeral mechanics
