Acromioclavicular (AC) Joint Sprain Rehabilitation Protocol

Pathophysiology

The acromioclavicular (AC) joint is formed by the articulation of the distal clavicle and the acromion of the scapula. Stability is provided by the AC ligaments (superior, inferior, anterior, and posterior) and the coracoclavicular ligaments (conoid and trapezoid). AC joint sprains, also known as shoulder separations, typically result from a direct blow to the acromion or a fall onto an outstretched arm. These injuries are graded based on the severity of ligamentous disruption, ranging from a Grade I sprain (ligament stretch without significant tear) to a Grade VI sprain (complete disruption of the AC and coracoclavicular ligaments, with displacement of the clavicle inferior to the acromion). This protocol focuses on non-operative management of Grades I-III AC joint sprains.

Common Special Tests

• AC Joint Tenderness Palpation: Direct palpation of the AC joint to assess for pain and tenderness.
• Cross-Body Adduction Test (Scarf Test): The patient actively or passively adducts the affected arm across the chest. Pain at the AC joint is a positive sign.
• O'Brien's Active Compression Test: The patient flexes the arm to 90 degrees and adducts it 10-15 degrees. The patient internally rotates the arm and resists downward pressure from the examiner. The patient then externally rotates the arm and resists downward pressure. Pain with internal rotation that is reduced with external rotation suggests AC joint pathology.
• Paxinos Test: The examiner applies pressure to the distal end of the clavicle and the acromion. Pain with this compression suggests AC joint pathology.
• AC Resisted Extension Test: Patient actively extends the arm against resistance. Pain in the AC joint suggests AC joint pathology.

Phase I: Protection (Weeks 1-2)

Goals: Pain and inflammation control, protect healing tissues, initiate gentle range of motion (ROM).

• Immobilization: Sling immobilization for comfort and protection, typically 1-2 weeks. Length of immobilization dependent on severity of sprain.
• Pain and Inflammation Management:
  • Cryotherapy: Ice packs applied for 15-20 minutes, several times per day.
  • Medications: As prescribed by physician (NSAIDs, analgesics).
  • Electrical Stimulation (e.g., TENS) for pain management.
• Range of Motion (ROM):
  • Pendulum exercises: Gentle swinging of the arm in all directions.
  • Scapular retraction and protraction exercises.
  • Elbow, wrist, and hand range of motion exercises.
  • Assisted range of motion (AROM) to tolerance, avoiding positions that provoke pain at the AC joint (e.g., horizontal adduction).
• Isometric Exercises: Begin with pain-free isometric exercises for shoulder girdle musculature (rotator cuff, scapular stabilizers) including:
  • Isometric shoulder abduction, adduction, flexion, extension, and internal/external rotation.
  • Isometric scapular retraction, protraction, elevation, and depression.
• Patient Education: Proper posture, sling usage, activity modification to avoid aggravating movements.

Phase II: Loading (Weeks 3-6)

Goals: Gradually increase ROM, restore strength and neuromuscular control, improve scapular mechanics.

• Progression of ROM:
  • Continue AROM exercises, gradually increasing the range.
  • Initiate gentle PROM exercises as tolerated, focusing on regaining full ROM in all planes.
  • Introduce cross-body adduction stretch (scarf stretch) with caution, monitoring for pain.
• Strengthening Exercises:
  • Begin with light resistance exercises using resistance bands or light weights.
  • Focus on strengthening rotator cuff muscles (e.g., external rotation, internal rotation, abduction, scaption).
  • Strengthen scapular stabilizers (e.g., rows, scapular squeezes, shrugs, lower trapezius exercises).
  • Progress to more challenging exercises as tolerated (e.g., lateral raises, front raises, bicep curls, triceps extensions).
• Scapular Stabilization Exercises:
  • Prone rows, prone horizontal abduction, prone extension.
  • Wall slides.
  • Push-ups against a wall and then on the floor.
  • Serratus punch exercises.
• Proprioception Exercises:
  • Closed kinetic chain exercises (e.g., weight shifting on the hands, rhythmic stabilization).
  • BOSU ball exercises.
  • Plyometric exercises (starting with low-impact).
• Cardiovascular Fitness:
  • Low-impact activities such as walking, cycling, or elliptical training.

Phase III: Return to Function (Weeks 7+)

Goals: Restore full strength, power, and endurance; return to pre-injury activity level.

• Advanced Strengthening Exercises:
  • Progress to heavier weights and more challenging exercises.
  • Introduce sport-specific exercises (e.g., throwing, overhead activities) gradually.
  • Continue rotator cuff and scapular stabilizer strengthening.
• Plyometric Training:
  • Progress to higher-impact plyometric exercises.
  • Incorporate sport-specific plyometric drills.
• Endurance Training:
  • Increase the duration and intensity of cardiovascular activities.
  • Incorporate endurance exercises for the shoulder musculature (e.g., high-repetition exercises).
• Functional Activities:
  • Gradually return to sport-specific or work-related activities.
  • Monitor for pain or discomfort.
• Maintenance Program:
  • Continue strengthening and stabilization exercises to maintain strength and prevent re-injury.
  • Proper warm-up and cool-down routines.
  • Activity modification as needed.

Progression Criteria: Progression through each phase is based on pain levels, ROM, strength, and functional abilities. The patient must demonstrate adequate control and strength before advancing to the next phase. Consult with the physician and physical therapist to determine appropriate progression.

Disclaimer: This rehabilitation protocol is a guideline and should be modified based on individual patient needs and physician recommendations. It is not a substitute for professional medical advice.