The muscles next to the vest line mainly refer to the internal and external oblique muscles of the abdomen. In the structure of the human abdomen, abdominal muscles include the transverse abdominis muscle, internal oblique abdominis muscle, external oblique abdominis muscle, and rectus abdominis muscle. These four muscles intersect with each other to form an important muscle group in the abdomen. The vest line is actually the dividing line between the rectus abdominis muscle in the middle of the abdomen and the oblique muscles on both sides. In addition, the middle abdominal muscles themselves have a vertical line, which together form a contour similar to a vest, hence the name vest line.
The external oblique muscle of the abdomen is located in the shallow layer of the anterior outer side of the abdomen and is a broad flat muscle. Its starting point is serrated and starts from the outside of the lower 8 ribs. The muscle bundle slopes from the upper to the lower part, and the posterior muscle bundle ends at the anterior part of the iliac crest. The upper middle muscle bundle moves inward to the aponeurosis, passes through the anterior surface of the rectus abdominis muscle, and participates in the formation of the anterior layer of the rectus abdominis sheath. The lower muscle bundle slopes inward and downward, and ends at the outer edge of the pubic symphysis. The internal oblique muscle is located deep in the external oblique muscle, with a fan-shaped muscle bundle that originates from the inner surface of the six lower ribs, the transverse abdominis tendon, the iliac crest, and the anterior layer of the thoracolumbar fascia. The muscle bundle moves forward and upward, and moves from the outer edge of the rectus abdominis muscle to the tendon, participating in the formation of the anterior and posterior layers of the rectus abdominis sheath.
The muscles next to the vest line mainly refer to the internal and external oblique muscles of the abdomen, which play an important role in the formation of the vest line and the beauty of the abdomen. If you want to train your vest line, you need to strengthen the exercise and training of these muscles.