Are abdominal muscles hard or soft? Are abdominal muscles a physical defect?

We have always thought that abdominal muscles are hard like a washboard, but some people's abdominal muscles are soft. What's going on? Are abdominal muscles hard or soft? Is having abdominal muscles a physical defect?

Generally speaking, the abdominal muscles are soft when they are relaxed, and they only become hard when they are exerted. When the abdominal muscles contract, they can bend and rotate the trunk and prevent the pelvis from tilting forward. The abdominal muscles also play a very 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 may cause the pelvis to tilt forward and increase the physiological curvature of the lumbar spine, and increase the chance of low back pain.

The abdominal muscles are an important part of the human connective tissue, including the rectus abdominis, external obliques, internal obliques, and transverse abdominis. Contraction can prevent the trunk from bending or rotating and the pelvis from tilting forward. The abdominal muscles also play an important role in the mobility and stability of the lumbar spine, and can also control the movement of the pelvis and spine. Weak abdominal muscles can increase the pelvic tilt and physiological curvature of the lumbar spine, increasing the probability of low back pain.

The location of abdominal muscle differentiation is determined by genes and has nothing to do with acquired training methods. Exercise can only help reduce subcutaneous fat in the abdomen and make the abdominal muscles of the rectus abdominis more distinct.

The abdominal muscles include the rectus abdominis, external obliques, internal obliques, and transverse abdominis. When the muscles contract, they can bend and rotate the trunk and prevent the pelvis from tilting forward. The abdominal muscles also play a very 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 may lead to anterior pelvic tilt and increased physiological curvature of the lumbar spine, and increase the chance of low back pain.

The anterolateral group forms the anterolateral wall of the abdominal cavity and includes the rectus abdominis, external oblique muscles, internal oblique muscles, and transverse abdominal muscles.

⑴ The rectus abdominis is located on both sides of the midline of the anterior abdominal wall, in the rectus abdominis sheath. It is a band-shaped muscle that is wide at the top and narrow at the bottom. It starts between the pubic symphysis and the pubic tubercle, and the muscle bundle ends at the front of the xiphoid process of the sternum and the nearby costal cartilage. The entire length of the muscle is divided into multiple muscle bellies by 3-4 transverse tendons. The tendon stripes are composed of connective tissue and are closely integrated with the front layer of the rectus abdominis sheath.

⑵ The external oblique muscle is located in the shallow layer of the anterior and lateral part of the abdomen. It is a broad flat muscle that originates from the lower 8 ribs. The muscle bundles extend obliquely from the posterior and lateral to the anterior and lateral. A part of it ends at the iliac crest, while most of it transitions to the external oblique aponeurosis at the lateral edge of the rectus abdominis. The aponeurosis participates in the formation of the anterior wall of the rectus sheath to the inside. The lower edge of the aponeurosis curls and thickens and connects between the anterior superior iliac spine and the pubic tubercle to form the inguinal ligament. Above and outside the pubic tubercle, the aponeurosis forms a small triangular fissure, called the superficial ring of the inguinal canal (subcutaneous ring).

⑶ The internal oblique muscle is located deep to the external oblique muscle. Most of the muscle bundles are directed inward and upward, while the lower muscle bundles are directed inward and downward, and they become the internal oblique aponeurosis at the outer edge of the rectus abdominis. The aponeurosis is divided into two layers, anterior and posterior, and wraps around the rectus abdominis, participating in the formation of the anterior and posterior walls of the rectus sheath. The lower medial part of the aponeurosis forms a joint tendon with the transverse abdominal aponeurosis, which ends at the pubic bone and is also called the inguinal falx. The lowest muscle bundle of the internal oblique muscle follows the spermatic cord out of the superficial ring of the inguinal canal into the scrotum, wraps around the spermatic cord and testicles, and becomes the cremaster muscle.

⑷ The transverse abdominal muscle is located deep to the internal oblique muscle. The muscle bundles run forward and inward, and transform into the transverse abdominal muscle aponeurosis at the lateral edge of the rectus abdominis, participating in the formation of the rectus abdominis sheath. The lowest muscle bundle of the transverse abdominal muscle and its medial part under the aponeurosis participate in the formation of the cremaster muscle and the conjoint tendon, respectively.

Functions of the anterolateral abdominal muscles: They protect the abdominal organs together, shrink the abdominal cavity when contracted, increase abdominal pressure to assist defecation, childbirth and vomiting, and flex and rotate the spine, etc. The quadratus lumborum muscles are located on the posterior abdominal wall, on both sides of the spine, and behind them are the erector spinae muscles, which originate from the iliac crest and end at the 12th rib.

Function: flex the spine. Includes superficial fascia, deep fascia and intra-abdominal fascia.

⑴ The superficial fascia is a single layer in the upper abdomen, and is divided into two layers below the navel: the superficial layer contains fat, called the fat layer; the deep layer contains elastic fibers, called the membranous layer.

⑵The deep fascia can be divided into several layers, covering the surface and deep surface of the anterolateral muscles respectively.

⑶ The intra-abdominal fascia is attached to the inner surface of each wall of the abdominal cavity. The names of the various fascia are the same as the muscles they cover. Among them, the transverse abdominal fascia has a larger range and is attached to the inner surface of the transverse abdominal muscle, the rectus abdominis sheath, and the rectus abdominis below the semicircular line. It is a fissure through which the male spermatic cord or the female round ligament of the uterus passes. It is located in the lower part of the anterior and lateral abdominal wall, slanting from the outside to the inside and below, above the medial half of the inguinal ligament, and is about 4.5 cm long. The inner opening of the tube is called the deep ring of the inguinal canal (abdominal ring), which is about 1.5 cm above the midpoint of the inguinal ligament. It is the protrusion of the transverse abdominal fascia outward along the spermatic cord or the round ligament of the uterus. The outer opening of the tube is the superficial ring of the inguinal canal (subcutaneous ring).

The inguinal canal has four walls. The anterior wall is the external oblique aponeurosis and the internal oblique muscle, the posterior wall is the transverse abdominal fascia and the inguinal falx, the upper wall is the arched lower edge of the internal oblique muscle and the transverse abdominal muscle, and the lower wall is the inguinal ligament. Under pathological conditions, if the contents of the abdominal cavity enter the inguinal canal through the deep ring of the inguinal canal, they can also protrude through the superficial ring and descend into the scrotum, which is an inguinal oblique hernia. If it does not pass through the deep ring but protrudes directly to the superficial ring through the posterior wall of the inguinal canal, it is a direct inguinal hernia.