Upper limb
Subacromial-subdeltoid bursa
Bursa subacromialis et bursa subdeltoidea
- Origin
- Under-surface of acromion, coracoacromial ligament, and deep deltoid fascia
- Insertion
- Superior surface of supraspinatus tendon and greater tubercle of humerus
- Function
- Largest bursa in the body, providing a low-friction gliding plane between the coracoacromial arch and rotator cuff tendons
- Innervation
- Suprascapular and axillary nerves (highly rich in substance P nociceptive pain fibers)
- Movement & chain
- Glides beneath acromion during arm elevation throughout the painful arc (60°–120°)
- Palpation
- Palpable under anterolateral acromion in arm extension (Dawbarn's sign)
- Clinical
- Subacromial bursitis, calcific tendinitis, and impingement syndrome; classic painful arc sign; target for diagnostic/therapeutic subacromial injections.
- Segmental innervation
- C5–C6
- In clinical practice
- Subacromial injection, radial shockwave therapy (ESWT) for calcifications, and rotator cuff rehabilitation
- Region in the model
- Upper limb