Massage.
LandmarkShoulderDraft

Acromion

The flat bony tip of the shoulder, where the spine of the scapula ends and meets the clavicle.

BoneScapula
RegionShoulder

Find it

  1. Client seated, prone or supine.
  2. Follow the spine of the scapula laterally until it ends in a flat, roughly square shelf at the top of the shoulder.
  3. Feel its outer edge drop away to the rounded deltoid, then move medially to find the small step or dip of the acromioclavicular (AC) joint, where the clavicle meets it.
  4. Gently lift and lower the client's arm: the acromion stays still while the head of the humerus moves beneath it.

The middle fibres of deltoid arise from the outer border and upper surface of the acromion, and the upper fibres of trapezius attach to its inner border. The supraspinatus tendon passes underneath it to reach the humerus.

The acromion is close to the surface, so use broad, light pressure over it rather than digging in.

Muscles attaching or palpated here

  • Deltoid — Thick, triangular muscle that caps the shoulder and is the main muscle for lifting the arm out to the side.
  • Supraspinatus — Rotator cuff muscle above the spine of the scapula that starts arm abduction and holds the head of the humerus in its socket.

Sources

  1. Wikipedia: Acromion
  2. Gray's Anatomy (1918), The Scapula (Bartleby, archived)