Internal Oblique

The internal oblique muscle plays a crucial role in athletic performance by contributing to core stability, trunk rotation, and force transmission between the upper and lower body. Positioned deep within the abdominal wall, it works in coordination with other core muscles to stabilize the spine and pelvis during dynamic movements such as running, jumping, throwing, and twisting.

For athletes, a well-functioning internal oblique is essential not only for enhancing power and agility but also for reducing the risk of injuries, particularly in the lower back and hips. Strengthening this muscle helps support efficient movement mechanics and boosts overall athletic performance.

Internal Oblique
Internal Oblique

Internal Oblique

Anatomy

Origin:

  • Thracolumbar fascia
  • Anterior 2/3 of iliac crest
  • Connective tissue deep to lateral 1/3 of inguinal ligament

Insertion:

  • Inferior borders of 10th-12th ribs
  • Linea alba
  • Pecten pubis via conjoint tendon

Actions:

  • Compresses and supports abdominal viscera, flexes and rotates trunk

Clinical Relevance

Oblique Muscles and Athletes

Studies have shown that Internal Oblique strains are common in baseball players, particularly fielders, and can lead to significant time away from play (Komatsu et al., 2022).

The Internal Oblique exhibits greater thickness changes during contraction compared to the External Oblique in both sprint hurdlers and sprinters (Adams et al., 2022). 

~ Evidence-Based Exercises ~

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

    • Side Bridge
    • Russian Twist
    • Wood Chopper

Side Bridge

Side Bridge

Russian Twist

Russian Twist

Wood Chopper

Wood Chopper

< Reference >

  • Keith L. Moore, Anne M. R. Agur, Arthur F. Dalley. Moore Clinically Oriented Anatomy 7th Edition, Lippincott Williams & Wilkins, 2013
  • Komatsu, Shuro, Hironori Kaneko, and Masaki Nagashima. “Characteristics of Internal Oblique Muscle Strain in Professional Baseball Players: A Case Series.” BMC Sports Science, Medicine and Rehabilitation 14, no. 1 (December 2022): 118. https://doi.org/10.1186/s13102-022-00510-5.
  • Adams, Lauren, Nicolas Pace, Austin Heo, Iain Hunter, A. Wayne Johnson, and Ulrike H. Mitchell. “Internal and External Oblique Muscle Asymmetry in Sprint Hurdlers and Sprinters: A Cross-Sectional Study.” Journal of Sports Science and Medicine, January 25, 2022, 120–26. https://doi.org/10.52082/jssm.2022.120.
  • Horsak, Brian, Rüdiger Wunsch, Philipp Bernhart, Anna-Maria Gorgas, Romana Bichler, and Kerstin Lampel. “Trunk Muscle Activation Levels during Eight Stabilization Exercises Used in the Functional Kinetics Concept: A Controlled Laboratory Study.” Journal of Back and Musculoskeletal Rehabilitation 30, no. 3 (May 5, 2017): 497–508. https://doi.org/10.3233/BMR-140259.
  • Nakai, Yuki, Masayuki Kawada, Takasuke Miyazaki, and Ryoji Kiyama. “Trunk Muscle Activity during Trunk Stabilizing Exercise with Isometric Hip Rotation Using Electromyography and Ultrasound.” Journal of Electromyography and Kinesiology 49 (December 2019): 102357. https://doi.org/10.1016/j.jelekin.2019.102357.