Spry Juncture, LLC
How to Evolve Gracefully
Internal Oblique
Region
Origin & Insertion
['Origin: Thoracolumbar fascia, iliac crest, inguinal ligament', 'Insertion: Ribs 10–12, linea alba']
Synergistic Muscles
['External oblique', 'Transverse abdominis']
Joints
['Thoracolumbar vertebrae']
Primary Actions
['Trunk flexion', 'Ipsilateral rotation', 'Lateral flexion']
Nerve & Spinal Segment
Thoracoabdominal nerves (T7–T11), subcostal nerve (T12), and iliohypogastric & ilioinguinal nerves (L1)
Thoracic and lumbar nerves; L1 from lumbar plexus
Interesting
Fibers run perpendicular to external oblique. [Clinically Oriented Anatomy]
Reversal of Action
Elevate pelvis with fixed trunk
Common Dysfunctions
Reduced abdominal pressure control, asymmetrical core engagement
How to Stretch
Rotate trunk away while side bending.
Trigger Points
How to Strengthen
Diagonal crunches, resisted oblique rotation.
Concentric Action
Rotate trunk to same side
Applications:
Improves spinal integrity and intercostal support for respiration
Eccentric Action
Control spine back from side bend
Isotonic Action
Twisting crunches, resisted rotations
Related Conditions
['Low back pain', 'Inguinal strain']
Isometric Action
Hold mid-range trunk rotation
Exercise Ideas
['Oblique crunch', 'Standing cable chop', 'Twisting lunge']