Which muscle has an origin at the SPs of T7 - L5 and also includes the sacrum and iliac crest?

The muscle that has its origin at the spinous processes of T7 to L5, along with the sacrum and iliac crest, is the latissimus dorsi. This muscle is a large, flat muscle that spans the lower back, and its origins are specifically designed to provide it with a significant range of movement and strength, particularly in actions such as adduction, extension, and internal rotation of the arm.

Understanding the anatomical origins of the latissimus dorsi helps emphasize its role in various physical activities. The muscle's connection to the sacrum and iliac crest, along with the thoracic spinous processes, allows it to engage effectively during activities requiring stabilization of the core and upper body movement. This comprehensive origin point enables it to play a pivotal role in lifting, pulling, and reaching motions.

The other muscles mentioned do not share the same origin points; for example, splenii originate from the spinous processes of the cervical and upper thoracic vertebrae, while psoas major originates from the lumbar vertebrae and the iliacus originates from the iliac fossa. Levator scapulae's origin is from the transverse processes of the cervical vertebrae. This distinctive origin of the latissimus