The musculus transversalis abdominis, commonly referred to as the transversus abdominis muscle, is a thin, broad, and flat muscle located in the anterior (front) portion of the abdomen. It is one of the four muscles that make up the abdominal muscles, along with the rectus abdominis, external abdominal oblique, and internal abdominal oblique.
The transversus abdominis muscle is deep to the other abdominal muscles, and it plays a crucial role in stabilizing the abdomen and the spine. It originates from the inner surfaces of the lower six ribs, the linea alba (a fibrous structure in the midline of the abdomen), and the iliac crest (the upper curved border of the hip bone). From these origins, it inserts onto the abdominal aponeurosis, a broad, flat tendon that covers the anterior abdominal wall.
Functionally, the transversus abdominis muscle acts as a deep corset, as it wraps around the abdomen and provides compression and support to the internal organs. It also plays a significant role in maintaining abdominal pressure and stabilizing the spine, particularly during movements such as bending, lifting, and twisting.
Exercises that specifically target and engage the transversus abdominis muscle are commonly used in rehabilitation settings for strengthening the core muscles, improving posture, and preventing and treating lower back pain.
