Oblique Muscles: Anatomy, Functions, Importance, and Effective Training

What are the side side abs?

The term "side side abs" is a colloquial expression referring to the oblique muscles, which are a primary component of the core musculature located on the sides of the abdomen. These muscles are crucial for movements involving torso rotation, lateral flexion (side bending), and providing stability to the spine.

Clarifying the Terminology: The Oblique Muscles

While "side side abs" is a commonly used phrase, it is not an anatomical or scientific term. In exercise science and kinesiology, the muscles referred to are primarily the external obliques and internal obliques. These muscles, along with the rectus abdominis ("six-pack abs") and transversus abdominis, form the muscular wall of the abdomen, playing vital roles in movement, posture, and spinal stability.

Anatomy and Location

The oblique muscles are layered muscles that wrap around the sides of your torso, extending from the ribs to the pelvis. Their distinct fiber directions allow for complex rotational and bending movements.

• External Obliques:
  • These are the largest and most superficial of the abdominal muscles, located on the outer sides of the abdomen.
  • Their muscle fibers run downward and inward, similar to putting your hands in your pockets.
  • They originate from the lower eight ribs and insert into the iliac crest (top of the hip bone), pubic tubercle, and linea alba (the midline connective tissue of the abdomen).
• Internal Obliques:
  • Located beneath the external obliques, their fibers run upward and inward, perpendicular to the external obliques.
  • They originate from the iliac crest, thoracolumbar fascia, and inguinal ligament, inserting into the lower three or four ribs, linea alba, and pubic crest.
• Related Core Muscles: While the obliques are the primary "side abs," other muscles like the transversus abdominis (deepest abdominal muscle, acts like a natural corset) and the quadratus lumborum (located in the lower back, aids in lateral flexion) also contribute significantly to lateral trunk stability and movement.

Primary Functions of the Oblique Muscles

The obliques are highly versatile muscles, essential for a wide range of movements and for supporting the spine.

• Torso Rotation: This is one of their most well-known functions. Unilateral contraction (one side contracting) of the external oblique on one side combined with the internal oblique on the opposite side produces trunk rotation. For example, your right external oblique and left internal oblique work together to rotate your torso to the left.
• Lateral Flexion (Side Bending): When the obliques on one side contract simultaneously, they cause the trunk to bend laterally towards that side.
• Trunk Stability and Anti-Rotation: Both obliques working together bilaterally (on both sides) help to stabilize the trunk, prevent excessive rotation, and resist unwanted movement, particularly during dynamic activities or when carrying uneven loads. This "anti-rotation" function is critical for spinal health.
• Forced Expiration: The obliques assist in forced exhalation by pulling the ribs downward and compressing the abdominal contents, forcing air out of the lungs.
• Intra-abdominal Pressure: By compressing the abdominal cavity, the obliques contribute to increasing intra-abdominal pressure, which helps to stiffen the core and provide a stable base for limb movements, especially during heavy lifting.

Why are Strong Obliques Important?

Developing strong and functional oblique muscles offers numerous benefits for both athletic performance and everyday living.

• Injury Prevention: Strong obliques are vital for protecting the spine, especially the lower back. They help to control and limit excessive twisting and bending motions that can lead to injury.
• Improved Athletic Performance: Many sports involve rotational movements (e.g., golf swing, throwing, striking, tennis serve). Powerful and controlled oblique function is essential for generating force and transferring power efficiently.
• Enhanced Posture: By providing stability to the trunk and pelvis, the obliques contribute to maintaining proper spinal alignment and preventing slouching.
• Everyday Movement: From bending down to pick something up, twisting to reach for an object, or carrying groceries, the obliques are constantly engaged in supporting and facilitating daily activities.

Effective Exercises for the Obliques

Training the obliques effectively requires incorporating exercises that target their various functions: rotation, lateral flexion, and anti-rotation/stability.

• Rotational Exercises:
  • Cable Wood Chops: Mimics real-world rotational power. Can be performed high-to-low or low-to-high.
  • Russian Twists (controlled): Emphasize slow, controlled movement rather than speed to engage the muscles effectively.
  • Bicycle Crunches: Combines rotation with reciprocal leg movement, engaging both obliques and rectus abdominis.
• Lateral Flexion Exercises:
  • Side Planks: An excellent isometric exercise that builds endurance and stability in the obliques and quadratus lumborum.
  • Dumbbell Side Bends (controlled): Focus on controlled lateral flexion, avoiding excessive weight that can strain the spine.
• Anti-Rotational/Stability Exercises:
  • Pallof Press: An anti-rotation exercise where you resist the rotational pull of a cable or resistance band.
  • Bird-Dog: While often seen as a general core exercise, focusing on keeping the torso stable and preventing rotation while limbs move is key for oblique engagement.

Considerations and Common Misconceptions

Understanding the obliques also involves dispelling common myths and applying sound training principles.

• Spot Reduction is a Myth: Training your obliques will strengthen them, but it will not "burn" fat specifically from your sides. Fat loss is a systemic process influenced by diet and overall energy balance.
• "Bulky" Obliques: Some individuals fear that training obliques will lead to a "blocky" or "thick" waistline. While muscles do hypertrophy with resistance training, functional oblique training primarily enhances strength, endurance, and stability. Excessive hypertrophy is unlikely with typical resistance training, and a strong core generally contributes to a more athletic physique.
• Balanced Core Training: While focusing on obliques is beneficial, it's crucial to train all core muscles (rectus abdominis, transversus abdominis, erector spinae, glutes) for comprehensive strength, stability, and injury prevention.
• Proper Form Over Weight: For oblique exercises, prioritize precise, controlled movements over lifting heavy weights or performing fast, jerky repetitions. Incorrect form can lead to spinal strain and reduce the effectiveness of the exercise.

By understanding the true nature and function of the oblique muscles, you can develop a more effective and scientifically grounded approach to your core training, leading to improved performance, better posture, and a reduced risk of injury.