RS

Comprehensive Notes on Shoulder Instability

Shoulder Instability

Definition

  • Shoulder instability is the loss of shoulder comfort and function due to undesirable translation of the humeral head on the glenoid fossa.

  • It manifests as excessive movement or a tendency for dislocation due to imbalanced stabilizing structures.

  • The shoulder's high mobility inherently compromises its stability.

Etiology

1. Traumatic Shoulder Instability

  • Typically results from a sudden injury forcing the shoulder out of its socket.

Acute Trauma

  • Most common cause, often from falls or accidents.

Anterior Dislocation

  • Most frequent type.

  • Occurs due to forceful blow or excessive external rotation and abduction of the arm.

Posterior Dislocation:

  • Less common.

  • Results from trauma like seizures or electric shock.

Recurrent Dislocations:

  • Ligaments and capsule may stretch after initial dislocation.

  • Increases the likelihood of repeated dislocations.

2. Atraumatic Shoulder Instability
Congenital:

  • Individuals born with lax joint capsule or ligamentous tissue.

  • Predisposes them to instability.

Overuse:

  • Repetitive overhead activities stretch capsule and ligaments.

  • Common in throwing sports (baseball, tennis).

Hyperlaxity:

  • General hypermobility increases instability risk without trauma.

  • Example: Ehlers-Danlos syndrome.

3. Other Causes
Shoulder Surgery:

  • Surgeries for fractures, rotator cuff repairs, or labral tears.

  • May lead to secondary instability if not managed properly.

Bankart Lesion:

  • Tear in the labrum (socket cartilage) due to dislocations.

  • Increases instability.

Hill-Sachs Lesion:

  • Compression fracture on the humeral head from dislocation.

  • Contributes to instability.

Clinical Features

  • Pain:

    • Felt in the shoulder joint, especially with movement.

    • May be present during sleep or rest.

  • Recurrent Dislocations or Subluxations:

    • Hallmark feature.

    • Sensation of "slipping" or "popping out."

  • Limited Range of Motion (ROM):

    • Restrictions, especially in the direction of dislocation.

  • Weakness:

    • In rotator cuff and scapular stabilizers.

    • Due to muscle inhibition from pain or fear.

  • Instability Sensation:

    • Feeling of "giving way."

    • Especially during overhead activities.

  • Tenderness:

    • Over the joint, particularly the anterior part.

  • Swelling and Bruising:

    • May occur after traumatic dislocation.

  • Positive Apprehension Test:

    • Psychological component.

    • Fear of dislocation with certain movements.

Physiotherapy Assessment

  • History Taking:

    • Onset, frequency, and nature of instability (traumatic vs. atraumatic).

    • Previous dislocations, surgeries, overhead sports history.

  • Posture:

    • Assessing shoulder and scapula posture.

    • Clues to muscular imbalances.

  • Range of Motion (ROM):

    • Active and passive movements.

    • Identify limitations in the direction of instability.

  • Strength Testing:

    • Rotator cuff muscles (supraspinatus, infraspinatus, teres minor, subscapularis).

    • Scapular stabilizers (serratus anterior, trapezius, rhomboids).

    • Weakness contributes to instability.

  • Palpation:

    • Manual examination for tenderness, muscle spasms, joint effusion.

  • Special Tests:

    • Assess for instability and associated damage.

    • Identify labral tears, ligament injury, or structural damage.

Physical Tests

  • Apprehension Test:

    • Shoulder abducted and externally rotated.

    • Pain indicates anterior instability.

  • Relocation Test:

    • Posterior force applied after apprehension test.

    • Relief suggests anterior instability.

  • Sulcus Sign:

    • Arm relaxed, pulled downward.

    • Visible "sulcus" indicates inferior instability.

  • Load and Shift Test:

    • Humeral head shifted forward and backward.

    • Assess instability extent.

  • Kim Test:

    • Assesses posterior instability.

    • Patient at 90 degrees abduction with external rotation.

    • Apply compressive load while moving arm.

  • O’Brien's Test:

    • Assess SLAP lesions.

    • Overhead motion while resisting force.

Physiotherapy Management

  • Vital role in non-surgical cases.

Phase 1: Acute Management (Post-Injury/Dislocation)

  • Protection:

    • Sling or immobilizer to reduce movement and allow healing.

  • Ice Therapy:

    • Reduces pain and inflammation.

  • Pain Management:

    • TENS (Transcutaneous Electrical Nerve Stimulation).

  • Isometrics:

    • Gentle exercises to maintain muscle activation without stressing joint.

Phase 2: Restoration of Range of Motion

  • Gentle ROM exercises:

    • Restore normal passive and active ROM in all planes.

  • Scapular Exercises:

    • Strengthen muscles around scapula.

    • Improve shoulder stability.

Phase 3: Strengthening

  • Rotator Cuff Strengthening:

    • Internal and external rotations, shoulder abductions, scapular retraction.

    • Improve rotator cuff function.

    • Prevent further dislocations.

  • Proprioception Training:

    • Train joint's position sense.

    • Balance exercises and resistance band work.

  • Closed Chain Exercises:

    • Functional exercises like push-ups and planks.

    • Provide more stability.

Phase 4: Functional Rehabilitation

  • Sport-Specific Training:

    • For athletes, mimic sport movements.

  • Return to Activity:

    • Progressive return once strength, ROM, and stability improve.

Surgical Intervention

  • Required in recurrent dislocations, failed conservative treatments, or significant labral tears.

  • Arthroscopic stabilization (Bankart repair, capsular shift) or open surgery.


Term 1: What is Shoulder Instability?
Definition 1: Loss of shoulder comfort and function due to undesirable translation of the humeral head on the glenoid fossa.
Term 2: What is Traumatic Shoulder Instability?
Definition 2: Sudden injury forcing the shoulder out of its socket, falls, or accidents.
Term 3: What causes Anterior Dislocation?
Definition 3: Forceful blow or excessive external rotation and abduction of the arm.
Term 4: What causes Posterior Dislocation?
Definition 4: Trauma like seizures or electric shock.
Term 5: What is Congenital Shoulder Instability?
Definition 5: Individuals born with lax joint capsule or ligamentous tissue.
Term 6: What causes Overuse Shoulder Instability?
Definition 6: Repetitive overhead activities stretch capsule and ligaments; common in throwing sports.
Term 7: What is Hyperlaxity in Shoulder Instability?
Definition 7: General hypermobility increases instability risk without trauma; Example: Ehlers-Danlos syndrome.
Term 8: How can Shoulder Surgery cause instability?
Definition 8: Surgeries for fractures, rotator cuff repairs, or labral tears may lead to secondary instability if not managed properly.
Term 9: What is a Bankart Lesion?
Definition 9: Tear in the labrum (socket cartilage) due to dislocations increases instability.
Term 10: What is a Hill-Sachs Lesion?
Definition 10: Compression fracture on the humeral head from dislocation that contributes to instability.
Term 11: What is Pain associated with Shoulder Instability?
Definition 11: Felt in the shoulder joint, especially with movement; may be present during sleep or rest.
Term 12: What are Recurrent Dislocations or Subluxations?
Definition 12: Hallmark feature is the sensation of 'slipping' or 'popping out.'
Term 13: What is Limited Range of Motion (ROM) in Shoulder Instability?
Definition 13: Restrictions, especially in the direction of dislocation.
Term 14: What Weakness is seen in Shoulder Instability?
Definition 14: In rotator cuff and scapular stabilizers due to muscle inhibition from pain or fear.
Term 15: What Instability Sensation is associated with Shoulder Instability?
Definition 15: Feeling of 'giving way,' especially during overhead activities.
Term 16: What Tenderness is seen in Shoulder Instability?
Definition 16: Over the joint, particularly the anterior part.
Term 17: What Swelling and Bruising happens in Shoulder Instability?
Definition 17: May occur after traumatic dislocation.
Term 18: What is a Positive Apprehension Test?
Definition 18: Fear of dislocation with certain movements as part of a Psychological component.
Term 19: What is involved in the History Taking?
Definition 19: Onset, frequency, and nature of instability (traumatic vs. atraumatic); previous dislocations, surgeries, overhead sports history.
Term 20: What should be Assessed in Posture examination?
Definition 20: Assessing shoulder and scapula posture that gives Clues to muscular imbalances.
Term 21: What Range of Motion (ROM) examinations exist?
Definition 21: Active and passive movements to Identify limitations in the direction of instability.
Term 22: What Strength Testing is involved?
Definition 22: Rotator cuff muscles (supraspinatus, infraspinatus, teres minor, subscapularis) and Scapular stabilizers (serratus anterior, trapezius, rhomboids).
Term 23: What Palpation exams are done?
Definition 23: Manual examination for tenderness, muscle spasms, joint effusion.
Term 24: What Special Tests are performed?
Definition 24: Assess for instability and associated damage, identify labral tears, ligament injury, or structural damage.
Term 25: What is the Apprehension Test?
Definition 25: Shoulder abducted and externally rotated; pain indicates anterior instability.
Term 26: What is the Relocation Test?
Definition 26: Posterior force applied after apprehension test; relief suggests anterior instability.
Term 27: What is the Sulcus Sign?
Definition 27: Arm relaxed, pulled downward; visible 'sulcus' indicates inferior instability.
Term 28: What is the Load and Shift Test?
Definition 28: Humeral head shifted forward and backward to assess instability extent.
Term 29: What is the Kim Test?
Definition 29: Patient at 90 degrees abduction with external rotation; apply compressive load while moving arm to assesses posterior instability.
Term 30: What is the O’Brien's Test?
Definition 30: Overhead motion while resisting force to assess SLAP lesions.
Term 31: What Protection is done in Acute Management?
Definition 31: Sling or immobilizer to reduce movement and allow healing.
Term 32: Why is Ice Therapy used?
Definition 32: Reduces pain and inflammation.
Term 33: What Pain Management is utilized?
Definition 33: TENS (Transcutaneous Electrical Nerve Stimulation)
Term 34: What Isometrics are done?
Definition 34: Gentle exercises to maintain muscle activation without stressing joint.
Term 35: What Gentle ROM exercises are done?
Definition 35: Restore normal passive and active ROM in all planes.
Term 36: What Scapular Exercises are done?
Definition 36: Strengthen muscles around the scapula to improve shoulder stability.
Term 37: What Rotator Cuff Strengthening exercises are done?
Definition 37: Internal and external rotations, shoulder abductions, scapular retraction to improve rotator cuff function and prevent further dislocations.
Term 38: What Proprioception
Definition 38: Train joint's position sense with Balance exercises and resistance band work.