Rectus Abdominis

The rectus abdominis is a long, paired muscle that runs vertically along the front of the abdomen, extending from the pubic bone to the sternum. Commonly known as the “six-pack” muscle, it plays a key role in trunk flexion, stabilizing the pelvis, and maintaining proper posture.

For athletes, the rectus abdominis is especially important as it contributes to core stability, which is essential for efficient movement, balance, and force transfer between the upper and lower body.

A strong and well-functioning rectus abdominis helps enhance performance in sports that require running, jumping, twisting, and lifting, while also reducing the risk of injuries, particularly in the lower back and pelvis.

Abs
Rectus Abdominis

Rectus Abdominis

Anatomy

[Origin]

  • Pubic Symphysis and Pubic Crest

[Insertion]

  • Xiphoid Process and 5th-7th Costal Cartilages

[Action]

  • Flexes trunk (lumbar vertebrae)
  • Compresses abdominal viscera
  • Stabilizes and controls tilt of pelvis (anti-lordosis)

Clinical Relevance

Diastasis Recti Abdominis (DRA) is a condition marked by the separation of the rectus abdominis muscles along the midline at the linea alba, often presenting as a palpable gap greater than 2.5 cm or visible bulging during exertion. It typically occurs around the umbilicus but can extend from the xiphoid process to the pubic bone.

DRA is commonly seen in athletes and postpartum women, with a prevalence of up to 60% in postpartum populations. Contributing risk factors include multiparity, high body mass index (BMI), and diabetes, making clinical awareness and early intervention crucial for prevention and rehabilitation.

~ Evidence-Based Exercises ~

According to an EMG study, the exercises that demonstrated significant muscle contractions of Rectus Abdominis are;

  • Free Weights: Squat
  • Traditional Core: Sit Ups
          (Upper Abs = with hip flexed at 60 deg, Lower Abs = with leg straight)
  • Core Stabilization: Front Plank

Squat

Squat

Sit Ups

Sit Ups

Plank

Plank

< Reference >

  • Keith L. Moore, Anne M. R. Agur, Arthur F. Dalley. Moore Clinically Oriented Anatomy 7th Edition, Lippincott Williams & Wilkins, 2013
  • Oliva-Lozano JM, Muyor JM. Core Muscle Activity During Physical Fitness Exercises: A Systematic Review. Int J Environ Res Public Health. 2020;17(12):E4306.
  • Andersen V., Fimland M.S., Brennset Ø., Haslestad L.R., Lundteigen M.S., Skalleberg K., Saeterbakken A.H. Muscle activation and strength in squat and bulgarian squat on stable and unstable surface.  J. Sports Med. 2014;35:1196–1202.
  • Crommert M.E., Bjerkefors A., Tarassova O., Ekblom M.M. Abdominal muscle activation during common modifications of the trunk curl-up Exercise.  Strength Cond. Res. 2018:1
  • Effects of BOSU ball(s) during sit-ups with body weight and added resistance on core muscle activation. Saeterbakken AH, Andersen V, Jansson J, Kvellestad AC, Fimland MS. J Strength Cond Res. 2014 Dec; 28(12):3515-22
  • Maeo S., Takahashi T., Takai Y., Kanehisa H. Trunk muscle activities during abdominal bracing: Comparison among muscles and exercises.  Sports Sci. Med. 2013;12:467–474.
  • Cortell-Tormo J.M., García-Jaén M., Chulvi-Medrano I., Hernández-Sánchez S., Lucas-Cuevas Á.G., Tortosa-Martínez J. Influence of scapular position on the core musculature activation in the prone plank exercise.  Strength Cond. Res. 2017;31:2255–2262
  • Ishida H., Watanabe S. Maximum expiration activates the abdominal muscles during side bridge exercise.  Back Musculoskelet. Rehabil. 2014;27:481–484
  • Core Muscle Activation in Suspension Training Exercises. Cugliari G, Boccia G. J Hum Kinet. 2017 Feb; 56():61-71
  • Calatayud J., Casaña J., Martín F., Jakobsen M.D., Colado J.C., Andersen L.L. Progression of core stability exercises based on the extent of muscle activity.  J. Phys. Med. Rehabil. 2017;96:694–699
  • Calatayud J., Casaña J., Martín F., Jakobsen M.D., Colado J.C., Andersen L.L. Progression of core stability exercises based on the extent of muscle activity.  J. Phys. Med. Rehabil. 2017;96:694–699
  • Effects of BOSU ball(s) during sit-ups with body weight and added resistance on core muscle activation. Saeterbakken AH, Andersen V, Jansson J, Kvellestad AC, Fimland MS. J Strength Cond Res. 2014 Dec; 28(12):3515-22.
  • Vita F, Donati D, Amouso V, et al. Return to Sport After Partum in Patients With Diastasis of the Rectus Abdominis Muscles: Ultrasound Evaluation and Rehabilitation Protocol. Journal of Sport Rehabilitation. Published online 2025:1-8. doi:1123/jsr.2024-0252