Dysfunctional Scapular Depression and Shoulder Flexion Tests

Anatomy and Biomechanical Considerations:

The scapular depression tests are used to evaluate the strength/tone of the lower trapezius muscle. The lower trapezius works together with the serratus anterior in a force couple that results in upward rotation, posterior tilt and external rotation of the scapula that is required during elevation of the arm. Note that the lower trapezius is also an extensor of the lower thoracic spine so with restricted thoracic spinal extension (FRS dysfunctions from T6-10) the lower trapezius is inhibited. When the lower trapezius is inhibited the patient may substitute by using the latissimus dorsi to depress the shoulder resulting in downward rotation of the scapula and limited external rotation of the humerus. In addition, hypertonicity in the latissimus dorsi contributes to increasing the thoracic kyphosis and the lumbar lordosis. The bilateral shoulder flexion test in supine allows us to evaluate the length of the latissimus dorsi as well as observe that when it’s hypertonic the patient will compensate by arching the lower back as the latissimus dorsi reaches its end range.

Therefore before attempting to retrain the lower trapezius we must assess for and treat any FRS Dysfunctions from T6-10 and lengthen the latissimus dorsi.

Lower Trapezius:

  • Attaches to the spinous processes and the interspinous ligaments from T4-T12 and along the medial border of the scapula and medial end of the spine of the scapula.
  • Function: It upwardly rotates, posteriorly tilts and externally rotates the scapula and assists in extending the thoracic spine from T4-T12.
  • Innervation: Spinal Accessory Nerve Cranial XI and the dorsal rami from T4-T12.
  • Inhibited by FRS Dysfunctions from T6-T12.

Latissimus Dorsi:

  • Attached to the lower 6 thoracic spinous processes and all the lumbar vertebrae, sacrum, crest of ilium and lower 3-4 ribs
  • Function: adduction and internal rotation of the shoulder, depression of the scapula; extension of lumbar spine and anterior tilt of the pelvis
  • Innervation: thoracodorsal nerve – C6,7,8
    Cart