Rectus abdominis muscle: Origin, Insertion, Function, Exercise

What is Rectus abdominal muscle?

The rectus abdominis muscle also called the “abdominal muscle” or sometimes the “abs muscles”, is a paired straight muscle located at the front side of the abdominal area. The Rectus abdominis muscle is two parallel muscles, which are separated by the linea alba (midline band of connective tissue).

The rectus abdomen is derived from the Latin word that means straight abdominal.

It is also known as the “abdominal muscle” or “abs”, which is a paired muscle running vertically on each side of the anterior wall of the human abdomen, as well as that of some other mammals.

It arises from the pubic symphysis, pubic crest, and pubic tubercle inferiorly, and inserts into the xiphoid process and costal cartilages of ribs V to VII superiorly. This muscle has the rectus sheath, which consists of the aponeuroses of the lateral abdominal muscles.

Rectus abdominis muscles connective tissue separating it into sharp muscle bellies. In the abdomens of people with low body fat and strong muscles, these muscle bellies can be viewed clearly. They can appear in sets of as few as two to as many as twelve, although, six is the most commonly seen.

Anatomy of the Rectus abdominis muscles

Origin:

Crest of the pubis.

Insertion:-

costal cartilages of ribs 5-7 Xiphoid process of the sternum.

Nerve supply:

segmentally by thoracoabdominal nerves (T7 to T11) and subcostal (T12).

Antagonist muscle:

Erector spinae which works as a Back extensor.

Actions:

The main actions for rectus abdominis are:

• Back Flexion (flexion of the thoracic and lumbar spine).
• Tense the anterior wall of the abdomen and assist in stabilizing internal organs of the abdomen
• It is a chief muscle of the posterior pelvic tilt muscles group with other abdominal muscles.
• Play an important role in the core stability of the spine.

Flexion of the lumbar spine.

Rectus Abdominis muscle exercise:

Following are the few best exercise you can do to strengthen your Rectus Abdominis muscles.

Sit-Up Exercise :

In Supine Position Flexes Both Legs at a nearly 90-degree angle, Keep both Hands Behind your Head And gradually Flex your Spine And Heads Towards the Knee, Hold for 4 to 10 seconds as per your stamina and relax. You can start with 5 Repetitions on the first day and gradually increase practice as you improve.

Knee-to-chest Exercises

Single-Leg Knee to Chest: you can start with a supine Lie on your back with knees bent at a 90-degree angle and keep your feet flat on the floor. Gradually pull your right knee toward your chest and hold for 5 to 10 seconds. Lower the knee and repeat with the other knee.

Double Legs knee to chest: you can start by first pulling the right knee to the chest, then pulling the left knee to the chest and holding both knees for 5 to 10 seconds. Slowly lower one leg at a time. you can start with 5 to 10 repetitions and increase practice as you improve.

How to stretch rectus abdominis muscle?

To stretch your rectus abdominis muscle, you can try the cobra pose exercise.

Cobra Pose abdominal stretch

If you want to improve the flexibility of your back this is the best exercise you can try at home.

Cobra Pose stretches your hips muscles and also stretches your abdominal muscles thoroughly.

• To do this exercise you start with a prone lying position on a soft mat.
• While your hips are flat on the ground, try to push your upper body upward with the help of your both hands while looking straight upwards. This will stretch the rectus abdominis muscles.
• Hold the position for 10-15 seconds, then return to the first position.
• Repeat 5 to 10 times.

Size of the Muscle:

Rectus abdominis muscles are typically around 10 mm thick. However, some who perform regular exercise mainly sportsmen can have a rectus up to 20 mm thick. Typical volume is around 300 cm in a normal person while it can go up to 500 cm in those who perform regular exercise mainly abs exercise.

Where is the rectus abdominis muscle located?

The rectus abdominis muscle also called the “abdominal muscle” or sometimes the “abs muscles”, is a paired straight muscle located at the front side of the abdominal area. The Rectus abdominis muscle is two parallel muscles, which are separated by the linea alba (midline band of connective tissue).

What is the function of the rectus abdominis muscle?

The chief function of the muscles is Back flexion (Trunk flexion) means you can move your chest towards your pelvis while external oblique muscles which are located on each side of the rectus abdominis muscle is working as twist movement of the trunk while internal oblique muscles work as a side flexion of the trunk.

Which muscle is deep to the rectus abdominis?

The transversus abdominis muscles are located in the deepest of the ab muscles, and they work to stabilize the abdominal wall, compress the abdominal viscera (the internal organs of the abdomen), and also help to stabilize the pelvis and lumbar spine.

What causes pain in the rectus abdominis?

There are too many causes of pain in the rectus abdominis muscles, However, the most common is the nerve entrapment at the lateral border of the rectus abdominis muscle; this is known as anterior cutaneous nerve entrapment syndrome. It is caused by compression of an anterior cutaneous nerve as it travels through the abdominal wall musculature and aponeuroses.

How do you treat a strained rectus abdominis?

Use of RICE Principle – Few days of rest with an Ice pack and Compression by an abdominal support belt with NSAIDs medicine are helping to relieve pain, After a few days of rest you can start physiotherapy treatment and exercise for a permanent solution to the Rectus abdominis strain.

What are the 4 abdominal muscles?

There are mainly 4 abdominal muscles, which are

• rectus abdominis
• external oblique
• internal oblique
• transversus abdominis
• Pyramidalis muscle

How long does it take for rectus abdominis to heal?

It depends upon the severity of the condition, mild pain and strain heal mostly 2 weeks while more severe rectus abdominis strain may take up to 6 weeks.

What is the most superficial muscle of the abdominals?

The external Oblique is the most superficial and also the largest flat muscle located on the abdominal wall. It travels through an inferior-medial direction and at the midline, its fibers form an aponeurosis and in the midline merge with the linea alba.

Abdominal muscles are classified into 2 groups:

superficial muscles that are part of the muscular system and these are the rectus abdominis and the external oblique (EO)
Deep muscles that are part of the local muscle system are the transverses abdominis (TrA), the multifidus, and the internal oblique.

Clinic importance:

Low Back pain is related few conditions such as Lordotic posture, Lumbar spondylosis, and Lumbar spondylolisthesis where strengthening exercise of rectus abdominis muscles helps to relieve pain and function of the lumbar spine.

It is an important part of the core stability exercise group and also Williams flexion exercises (WFE).