The rhomboid major is a quadrilateral muscle lying deep to the trapezius and connecting the mid-thoracic spine to the medial border of the shoulder blade. It works with the rhomboid minor to retract the scapula toward the spine and stabilise it during pulling movements. Its downward rotational effect on the glenoid means it must stay balanced against the upward rotators to keep scapular kinematics healthy.
| Origin | Spinous processes of T2 through T5 |
|---|---|
| Insertion | Medial border of the scapula between the scapular spine and the inferior angle |
| Nerve Supply | Dorsal scapular nerve (C4, C5) |
| Blood Supply | Dorsal scapular artery |
| Actions | Retraction of the scapula; Downward rotation of the glenoid; Elevation of the medial scapular border |
|---|
It retracts and stabilises the medial scapular border during pulling activities, but excessive tightness relative to the serratus and trapezius impairs the protraction and upward rotation needed for overhead movement.
Rhomboid myofascial trigger points are one of the most common sources of interscapular pain in desk workers, producing a deep aching between the shoulder blades that is often mistaken for thoracic disc pathology. The muscle tends to be overstretched and inhibited in people with protracted shoulders, where the pectoralis minor is tight and dominant. Strengthening through rowing and scapular retraction exercises is a routine component of postural rehabilitation.
The rhomboid major is palpable as a broad band in the interscapular region between the medial scapular border and the thoracic spinous processes when the subject retracts the scapula against resistance.
Acute muscle fibre tears from a sudden forceful arm movement across the body or an unguarded rowing effort, producing sharp medial scapular pain that worsens with arm reach and scapular retraction.
Chronic trigger points in the rhomboid major producing deep aching between the shoulder blades that is exquisitely tender on direct sustained pressure and provoked by prolonged forward-head posture at a desk.
