What are Abdominal Muscles?

Abdominal muscles are an important part of human connective tissue composition, including rectus abdominis, external oblique muscles, internal oblique muscles and transverse abdominal muscles. When they contract, they can bend and rotate the torso and prevent the pelvis from leaning forward. Abdominal muscles also play an important role in the movement and stability of the lumbar spine, and can also control the movement of the pelvis and spine. Weak abdominal muscles can lead to an increase in pelvic anteversion and an increase in the physiological curvature of the lumbar spine, and increase the chance of back pain.

Chinese name: Abs
Foreign name: Abdominal muscles

Category: muscle
Classification: Rectus abdominis, external obliques, internal obliques
Number of blocks: 10

Anterolateral abdominal muscles

The anterolateral group constitutes the anterior lateral wall of the abdominal cavity, including the external oblique muscle, internal abdominal oblique muscle, transverse abdominal muscle, and rectus abdominis.

Abdominal obliques

Located in the superficial layer of the anterior lateral lateral muscle of the abdomen, it is a broad flat muscle, starting from the outside of the lower 8 ribs with 8 teeth, staggered with the teeth of the serratus anterior and latissimus dorsi, and the muscle bundles obliquely forward from the outside The inferior and posterior lower muscle bundles stop at the anterior iliac crest, and the remaining muscle bundles move inward to act as the aponeurosis. They pass through the front of the rectus abdominis muscle and participate in the anterior layer of the rectus abdominis sheath until the midline of the abdomen finally becomes white. The lower edge of the external oblique tendon is thickened and curled. It is connected between the anterior superior iliac spine and the pubic tubercle. It is called the inguinal ligament inguinalligament. The medial end of the inguinal ligament has a small bundle of tendon fibers that returns to the pubic comb. Lacunar ligament (lacunar ligament) is called lacunarligamento, and the part where the lacunar ligament extends and is attached to the pubic comb is called the pubic comb ligament pectinealligament (cooper ligament). Both the inguinal ligament and the pubic comb ligament are important structures used to strengthen the inguinal wall during inguinal hernia repair. Above the pubic tubercle, the oblique tendon of the external oblique muscle forms a triangular hole, which is a superficialinguinalringo of the superficial (subcutaneous) ring of the inguinal canal.

Abdominal muscles

Located on the deep side of the external oblique muscle. It starts from the lateral 1/2 of thoracolumbar fascia, iliac crest, and inguinal ligament. The muscle bundles are fan-shaped. The posterior muscle bundles rise almost vertically and stop at the lower 3 ribs. Most of the muscle bundles extend forward to the aponeurosis. The lateral border of the rectus abdominis muscle is divided into anterior and posterior layers that enclose the rectus abdominis, and participate in the anterior and posterior layers of the rectus abdominis sheath, and finally the white line at the midline of the abdomen. The lower part of the internal oblique muscle moves forward and downward, passes over the front of the spermatic cord, and continues as the aponeurosis, meeting with the aponeurosis of the transverse abdominal muscle to form an inguinal sickle inguinalfalx, or joint tendon conjointtendon, which stops at the medial end of the pubic comb and Near the pubic tubercle. The lower part of the internal oblique muscle has a few scattered muscle bundles, which together with the lower muscle bundle of the abdominal transverse muscle wrap around the spermatic cord and testis, etc., known as the cremaster muscle, which can be raised when the contraction occurs.

Transverse abs

It is located on the deep side of the abdominal oblique muscle, starting from the inner side of the lower 6 rib cartilage, the thoracolumbar fascia, the iliac crest, and the outer 1/3 of the inguinal ligament. The muscle bundles extend forward to the aponeurosis, which crosses the rectus abdominis. The back part forms the posterior layer of the rectus sheath and ends at the white line. The lowest muscle tract of the transverse abdominal muscle and the medial part of the inferior edge of the aponeurosis are involved in the cremaster muscle and the inguinal sickle, respectively.

Rectus abdominis

It is located on both sides of the midline of the anterior abdominal wall. It is located in the rectus abdominis sheath, wide and narrow, starting from the pubic symphysis and pubic condyle. The muscle bundle stops upwards in front of the sternum xiphoid process and the 5th and 7th rib cartilage. The full length of the muscle is divided into multiple muscular abdomen by three or four transverse tendonous sections. The tendon plan is tightly combined with the anterior layer of the rectus abdominis sheath. At the back of the rectus abdominis, the tendon is not obvious and does not heal with the posterior layer of the rectus abdominis sheath, so the back of the rectus abdominis is free.

The role of the ventrolateral muscles is to protect the abdominal organs and maintain intra-abdominal pressure; participate in physiological functions such as defecation, childbirth, vomiting, and cough; and can lower the ribs to help expiration, and can also cause spinal forward flexion, lateral flexion, and rotation .

Abdominal rectus sheath

Wrap the rectus abdominis muscle, divided into anterior and posterior layers. The anterior layer is composed of the anterior oblique fascia and the anterior oblique fascia, and the posterior layer is composed of the posterior layer of the oblique fascia and abdominal transverse fascia. Below 4,5 cm below the umbilicus, the aponeurosis of the posterior layer of the rectus abdominis sheath is all turned to the front of the rectus abdominis muscle, and participates in the anterior layer of the sheath, making the posterior layer absent. Therefore, the posterior layer of the rectus abdominis sheath is due to The aponeurosis is interrupted to form a convex upward demarcation line called arcuate line or semicircularline.

Abdominal muscle white line

It is located on the midline of the front wall of the abdomen, between the left and right rectus sheaths, and is composed of three layers of flat aponeurotic fibers on both sides. The upper part starts from the xiphoid process and the lower part stops at the pubic symphysis. The white line is tough and lacks blood vessels. The upper part is wider and narrows into a line from below the umbilicus. At the midpoint of the white line, there is an umbilical ring, which is a weak point of the abdominal wall that passes through the umbilical blood vessel at the fetal stage. If the abdominal organs bulge through it, it is called an umbilical hernia.

Posterior abdominal muscles

The posterior group includes the psoas major and the psoas muscle. The psoas major will be described in the lower limb muscles.

The quadratuslumborum is located in the back of the abdomen, on both sides of the spine, with the psoas major muscles on the inside and the erector spinae muscles on the back. Starting from the posterior part, it stops at the 12th rib and the 1st and 4th lumbar vertebra process, and the role is to lower and fix the 12th rib and make the spine lateral flexion.

Abdominal muscle inguinal canal

The inguinal canal, inguinalcanal, is a crack between the three layers of the latissimus dorsi muscles and tendons in the anterior lateral wall of the abdomen. It is located in the lower part of the anterior lateral wall of the abdomen and above the medial half of the inguinal ligament. The male spermatic cord or the female uterine round ligament passes through.

The inguinal canal has two ports and four walls. The inner mouth is called deepinguinalring of the inguinal canal. The deepinguinalring is about 1, 5cm above the midpoint of the inguinal ligament. It is the outward protrusion of the transverse transverse fascia with the inferior abdominal wall artery on the inside. The outer mouth is the superficialinguinalring of the shallow (subcutaneous) ring of the inguinal canal. The front wall is the external oblique tendon and the internal oblique, the back wall is the transverse transverse fascia and the inguinal sickle, the upper wall is the arched lower edge of the inner oblique and transverse transverse muscle, and the lower wall is the inguinal ligament. The inguinal canal is a weak area of the abdominal wall and is a common site for hernias.

Abdominal muscle groin triangle

The inguinal (Hesselbach) triangle is a triangular area surrounded by the lateral edge of the rectus muscle, the inguinal ligament, and the inferior abdominal wall artery. It is located in the lower part of the anterior abdominal wall.

Abdominal muscle fascia

Abdominal fascia includes superficial fascia, deep fascia, and intra-abdominal fascia.

1. The superficial fascia is a layer in the upper part of the abdomen, and it is divided into shallow and deep layers below the umbilicus. The superficial layer contains fat, and the deeper layer of Camper's fascia is called the membranous layer, which contains elastic fibers, called Scarpa's fascia. It goes down inwardly with the broad fascia of the thighs and continues inwardly with the superficial fascia of the perineum and the scrotal meatus.

2. The deep fascia can be divided into several layers, covering the surface and deep side of each muscle of the anterolateral group.

3. The intra-abdominal fascia is attached to the inner surface of each wall of the abdominal cavity. The names of each fascia are mostly the same as the muscles they cover, such as the subfascia fascia, lumbar square fascia, fascia lumbar fascia, pelvic fascia, and abdominal fascia.