Does Latissimus Dorsi assist in forced expiration?

The latissimus dorsi does indeed play a role in forced expiration. This muscle is primarily known for its functions in shoulder movement, including adduction, extension, and internal rotation of the arm. However, it also has a secondary function related to respiration.

During forced expiration, especially when engaging in activities like heavy breathing or vigorous exercise, the latissimus dorsi can assist in compressing the ribcage. It achieves this by pulling the lower ribs down and back, which helps to expel air from the lungs more forcefully. The muscle works alongside other muscles utilized in forced expiration, such as the abdominal muscles, to effectively decrease the volume of the thoracic cavity and push air out of the lungs.

This understanding highlights the multifaceted role muscles play in different bodily functions beyond their primary actions, demonstrating how they contribute to a broader system of movement and stability in the body.