Which muscle has the thoracolumbar fascia as part of its origin?

• A. Trapezius
• B. Rhomboid major
• C. Latissimus dorsi.
• D. Deltoid

Answer: (C)

The thoracolumbar fascia serves as a broad connective tissue foundation that provides a major portion of the origin for the latissimus dorsi. This fascia covers the lower back and, along with attachments to the iliac crest and lower ribs, forms the medial origin of the latissimus dorsi. From this expansive origin, the muscle sweeps upward and laterally to insert on the floor of the intertubercular groove of the humerus, enabling actions like arm extension, adduction, and medial rotation.

Trapezius, rhomboid major, and deltoid have origins that come from the skull, nuchal ligament, spinous processes, or the scapula/clavicle, not from the thoracolumbar fascia. That specific connection between the thoracolumbar fascia and the latissimus dorsi’s origin is what makes this muscle the correct answer.