Time To Read
Date Last Modified
The latissimus dorsi—often nicknamed the “lats”—is the big, sweeping muscle of your back that gives bodybuilders that coveted “V-shape.” It’s broad, flat, and powerful, almost like nature’s built-in cape.
- Extension: pulling the arm backward (like when you’re swimming a freestyle stroke).
- Adduction: bringing the arm down toward the body (as in a pull-up).
- Medial rotation: rotating the arm inward.
Together, these make it the muscle you rely on whenever you’re climbing, swimming, or powerfully pulling something toward you. It also helps with forced expirationThe process of exhaling, which can be passive (relaxation of respiratory muscles) or active (involvi (like coughing) by pulling on the ribsCurved bones forming the rib cage; articulate with thoracic vertebrae and most with the sternum..
In short: the lats are your “power stroke” muscles. They’re what let you haul yourself up. They allow you to row a boat or slam a heavy door shut.
Photography, text, and labels by Rob Swatski, Assistant Professor of Biology, Harrisburg Area Community College – York Campus, York, PA.
Latissimus dorsi Origin
The latissimus dorsi muscle has a wide origin. It primarily originates from the thoracic and lumbar vertebraeLargest and thickest vertebrae; short, blunt spinous processes for weight-bearing stability.. It also comes from the lower ribs and iliac crestSuperior ridge of the ilium; easily felt along the waistline. (part of the pelvic bone).
Latissimus dorsi Insertion
The muscle fibers of the latissimus dorsi converge. They insert into the floor of the intertubercular groove of the humerusLong bone of the upper arm; articulates with scapula at shoulder and radius/ulna at elbow.. This provides a solid attachment to the upper arm bone.
Latissimus dorsi Actions
Shoulder Extension
Adduction of the Arm
Medial Rotation of the Arm
Interactive Materials
🩻 Draw on an Image
Use your mouse or finger to draw directly on the image. Change your highlighter color, undo or redo strokes, clear, or download your annotated image.
💡 Tip: The “pen” acts like a translucent highlighter.
Identify More Muscles
Link to more Muscle Identification
Upper Arm Muscles
Forearm Muscles
Calf Muscles
Anterior Thigh Muscles
Posterior Thigh Muscles
Knee Structures
Chest Muscles
Back Muscles
Abdominal Muscles
Neck Muscles
Head Muscles
List of terms
- expiration
- ribs
- latissimus dorsi
- lumbar vertebrae
- iliac crest
- humerus