Week 2: Shoulder Instability Flashcards
How many people does shoulder instability affect?
- As high as 2% of the population
- 3x more common in men than women
- Underestimate the true numbers, only include episodes of dislocation
What enhances shoulder stability?
- Labrum (bony congruency)
- Negative pressure in GH joint
- Muscle and tendons
- Ligaments and capsule
Differentiate b/t laxity and stability
-
Instability classifications
- Traumatic
- Atraumatic
- Acquired
What is subluxation?
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What is dislocation?
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Bankart lesion
Tear of the glenoid labrum in anterior region of glenoid
Reverse Bankart lesion
Tear of the glenoid labrum in posterior region of the glenoid
Hill-Sachs lesion
Compression fracture of the humeral head occurring as result of traumatic dislocation anteriorly
Reverse Hill-Sachs lesion
Compression fracture of the humeral head occurring as result of traumatic dislocation posteriorly
What part of the humerus is affected in a Hill-Sachs lesion?
Posterolateral humerus
What part of the humerus is affected in a reverse Hill-Sachs lesion?
Anteromedial humerus
What direction of instability is most common?
- Anterior
- 90-95%
What are the characteristics of anterior instability?
- Unidirectional w/ traumatic onset
- ABD and ER
- May have a Bankart lesion w/ it
How common is posterior instability?
2-10%
What are the characteristics of posterior instability?
- Unidirectional w/ repetitive loading
- ADD and IR
- May have a reverse Bankart lesion w/ it
How common is multidirectional instability?
1-3%
What are the characteristics of multidirectional instability?
- Atraumatic
- Congenital or acquired laxity
Biceps tendon/SLAP lesions
May or may not be associated w/ GH instability
What kind of traumatic MOI occurs with anterior dislocation?
- Combo of abduction, extension, and posteriorly directed force on arm
- Fall on an outstretched hand is common MOI for elderly
MOI for atraumatic injury to shoulder
- Anatomical anomaly
- General laxity
- Poor muscle balance
- Scapular dyskinesis
- Connective tissue diseases
Scapular dyskinesis
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Connective tissue diseases of the shoulder
- Ehlers-Danlos Syndrome
- Marfan Syndrome
Ehlers-Danlos Syndrome
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Marfan Syndrome
-
MOI for acquired instability
- Gradual development of laxity
- Excessive ER
- Posterior GH joint capsular tightness
- Strength imbalance
Clinical presentation for traumatic injury
- Pain generalized to shoulder, but localize to the involved tissues
- Apprehensive to moving arm out from body
What factors does traumatic injury presentation depend on?
- Etiology
- Direction of instability
- Severity
- Frequency
Clinical presentation for atraumatic injury
- General multi-joint hypermobility
- Loose inferior capsule
- Atrophy of shoulder girdle
- Dysfunctional movement patterns
Clinical presentation for acquired instability
Combo of traumatic and atraumatic
General principles to examine for instability
- Observation
- Pain/palpation
- Movement
- Strength
- Sensation/proprioception
Observation for examination of instability
- “Protective” posture
- Presence of observable deformities, muscle atrophy
Pain/palpation for examination of instability
Diffuse pain over anterior and posterior shoulder
Movement for examination of instability
Unable/unwilling to move into end ranges
Strength for examination of instability
- Limited by pain, weak ABD and ER
- Ability to co-activate dynamic stabilizers likely diminished
- Check rotator cuff and scapular muscles
Sensation/proprioception for examination of instability
- Conduct sensory screen of shoulder complex
- Proprioception deficits may be noticeable
Test item cluster for anterior instability
- Apprehension test
- Relocation test
- Surprise test
- Sp = 1.00
Apprehension test
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Relocation test
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Surprise test
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Anterior drawer test for shoulder instability
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Special test for posterior instability
Jerk test
Jerk test
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Special test for labral tear
- Kim test
- Biceps load test II
Kim test
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Biceps load test II
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Risks for recurring dislocations
- Age-related
- Gender
- Fractures
Age-related risks for recurring dislocations
- 20s have 60% rate of recurrence
- 30s have 20% rate of recurrents
Gender-related risks for recurring dislocations
- 47% recurrence for men
- 27% recurrence for women
Fractures and risks for recurring dislocations
Reduced risk of recurrence w/:
- Boney Bankart
- Greater tubercle fracture
Key Factors for Consideration with Rehab of an unstable shoulder
- Onset of instability
- Degree of instability (subluxation vs dislocation)
- Frequency of episodes
- Direction of instability
- Concomitant abnormalities/injuries
- End-range neuromuscular control
- Pre-morbid activity level
Phases of non-operative management of anterior instability
- Phase 1- Acute phase
- Phase 2- Intermediate phase
- Phase 3- Advanced strengthening
- Phase 4- Return to activity
Phase 1- Acute phase goals for non-operative management of anterior instability
- Diminish pain, inflammation, and muscle guarding
- Promote and protect healing soft tissues
- Prevent negative effects of immobilization
- Reestablish baseline dynamic joint stability
- Prevent further damage to GH joint capsule
Phase 1- Acute phase interventions for non-operative management of anterior instability
- Immobilization
- PROM- early motion in a protected range
- Strengthening: submaximal, pain free isometrics
- Dynamic stabilization
Dynamic stabilization for acute phase
- IR/ER in scapular plane
- Flexion at 100 degrees, 10 degrees horizontal ADD
- Closed kinetic chain
- Scapular re-training
Criteria to enter the intermediate phase of non-operative management
Reduced pain and improved motor control
Goal of the intermediate phase of non-operative management
Reestablish muscle balance and restore full AROM
Interventions for the intermediate phase of non-operative management
- PROM and AAROM to patient tolerance
- IR/ER at 90 degrees of ABD
- Strength/stabilization in mid-range
Criteria for entering the advanced strengthening phase of non-operative management
- Minimal pain
- Full ROM
- Symmetric capsular mobility
- Good strength (4.5 MMT)
- Strength, endurance, and dynamic stability of the scapulothoracic and UE regions
Focus of the advanced strengthening phase of non-operative management
- Strength and dynamic stabilization at end range
- Return to full daily activities (not sport)
Interventions for the advanced strengthening phase of non-operative management
- Low and high repetition exercises (20-30 reps)
- Co-contraction and dynamic stabilization
- Low intensity plyometric exercise for return to sport
Focus of the return to activity phase of non-operative management
Perform a strength program, dynamic stability, and NM control
Goal of the return to activity phase of non-operative management
Maintain full, functional, and pain-free ROM
Interventions of the return to activity phase of non-operative management
Sport specific activities w/ plyometrics, PNF, and isotonic strengthening
