Latissimus dorsi

A large, flat muscle that spans the lower back and contributes to various movements of the shoulder and torso.

The latissimus dorsi is one of the largest muscles in the human body, mainly located in the back. It has a triangular shape and extends from the mid and lower spine to the upper arm bone, playing a vital role in various movements. This muscle is responsible for the extension, adduction, and internal rotation of the shoulder joint, making it crucial for activities involving arm movements.

Terminologia Anatomica

musculus-latissimus-dorsi

System

Muscular system

Function

The primary function of the latissimus dorsi is to facilitate upper limb movement and stability, particularly during activities that require lifting or pulling. It plays a significant role in actions such as pulling objects towards the body, raising the arms, and performing actions like swimming and climbing. Additionally, the latissimus dorsi aids in stabilizing the torso, which is essential for maintaining posture and balance during physical activities. In combination with other muscles, it contributes to the powerful movements required in various sports and manual labor, thus linking the upper body with the lower body in a synergistic manner.

Location

The latissimus dorsi is located on the posterior side of the body, stretching from the lower thoracic region of the spine to the lumbar region. Its origin is broad, attaching to the spinous processes of the lower thoracic vertebrae (ranging from T7 to T12), the lumbar vertebrae, the sacrum, and the lower three to four ribs. The fibers converge and insert at the intertubercular groove of the humerus, which is situated near the shoulder joint. This positioning allows the latissimus dorsi to serve as a vital link between the upper arm and the trunk, making it integral to a wide range of movements.

Did You Know?

The latissimus dorsi is sometimes referred to as the 'swimmer's muscle' due to its pivotal role in major swimming strokes.
This muscle is prominent in individuals who engage in activities requiring strong pulling motions, like rock climbers and rowers.
In addition to movement, the latissimus dorsi is involved in respiratory function; it assists in forced expiration.
The muscle can be used in surgical procedures, such as latissimus dorsi flaps, to reconstruct other areas of the body.