The rectus abdominis is a long, flat muscle located in the front of the abdomen. It is made up of two parallel columns of muscle fibers that run vertically from the ribs down to the pelvis. It is responsible for several important functions in the body, including:
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- Flexing the spine – which allows us to bend at the waist and perform activities such as sit-ups.
- Stabilizing the trunk – helping to maintain proper posture and works on posterior pelvic tilt (1). It also works in conjunction with other muscles to support the spine and protect it from injury.
- Compressing the abdominal contents: this can assist in expelling gas, feces, and urine from the body.
- Assisting in breathing: During forced exhales, such as when blowing out candles or blowing up a balloon, the rectus abdominis helps to push air out of the lungs by contracting and compressing the abdomen.
In addition to these functions, the rectus abdominis is also an important muscle for overall physical appearance. It is often a muscle that people focus on when trying to achieve a “six-pack” or defined abdominal muscles. The rectus abdominis can be trained and strengthened through exercises such as crunches, sit-ups, and planks. (1)
Origin, Insertion and Function
Origin:
- The rectus abdominis originates from the pubic symphysis and the pubic crest.
Insertion:
- It inserts into the costal cartilage of the fifth, sixth, and seventh ribs.
Function:
- The rectus abdominis is responsible for several important functions in the body, including flexing the spine, stabilizing the trunk, compressing the abdominal contents, and assisting in breathing.
![rectus abdominis anatomy](https://cdn.britannica.com/13/125813-050-311A2192/Muscles-wall.jpg)
Common signs of weak rectus abdominis muscles
Here are a few signs that your rectus abdominis muscles are weak:
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Poor posture: Weak rectus abdominis muscles can cause the abdominal area to sag, resulting in poor posture and a rounded back.
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Difficulty in performing core exercises
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Lower back pain
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Difficulty in maintaining proper form during physical activity: Weak abdominal muscles can make it difficult to maintain proper form during physical activities.
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Difficulty in standing up straight
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Difficulty in lifting heavy objects
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Poor balance: Weak rectus abdominis muscles can affect balance and stability.
What exercise works your rectus abdominis?
There are many exercises that can help strengthen the rectus abdominis, including:
- Crunches: Crunches are a classic exercise for strengthening the rectus abdominis. To do a crunch, lie on your back with your knees bent and your hands behind your head. Lift your head and shoulders off the ground, then lower back down.
- Sit-ups: Sit-ups are similar to crunches, but you lift your entire upper body off the ground instead of just your head and shoulders.
- Planks: Planks are an excellent exercise for strengthening the rectus abdominis as well as the entire core. To do a plank, get into a push-up position with your forearms on the ground and your feet shoulder-width apart. Hold this position for as long as you can.
- Leg lifts: To do a leg lift, lie on your back with your arms at your sides and your legs straight. Lift one leg off the ground about six inches, then lower it back down. Repeat on the other side.
- Russian twists: Russian twists are a great exercise for strengthening the rectus abdominis and the obliques (the muscles on the sides of the abdomen). To do a Russian twist, sit on the ground with your knees bent and your feet flat. Hold your hands in front of your chest and twist your upper body from side to side.
It’s important to remember to start slowly and gradually increase the intensity of your workouts as your muscles get stronger.
References:
- Abdominal Wall,
Editor(s): Michael P. Federle, Melissa L. Rosado-de-Christenson, Siva P. Raman, Brett W. Carter, Paula J. Woodward, Akram M. Shaaban,
Imaging Anatomy: Chest, Abdomen, Pelvis (Second Edition),
Elsevier,
2017,
Pages 484-507,
ISBN 9780323477819,
https://doi.org/10.1016/B978-0-323-47781-9.50025-8.
(https://www.sciencedirect.com/science/article/pii/B9780323477819500258)