Spry Juncture, LLC
How to Evolve Gracefully
External Oblique
Region
Origin & Insertion
['Origin: External surfaces of ribs 5–12', 'Insertion: Linea alba, pubic tubercle, anterior iliac crest']
Synergistic Muscles
['Internal oblique', 'Rectus abdominis']
Joints
['Thoracolumbar vertebrae']
Primary Actions
['Trunk flexion', 'Contralateral rotation', 'Lateral flexion']
Nerve & Spinal Segment
Lower six thoracoabdominal nerves (T7–T11) and subcostal nerve (T12)
Thoracic spinal nerves; no plexus
Interesting
Fibers run 'hands in pockets' direction; largest abdominal muscle. [Moore’s]
Reversal of Action
Lift pelvis during trunk twist (reverse bicycle)
Common Dysfunctions
Trunk rotation weakness, poor core stabilization, rib pain
How to Stretch
Side bend and rotate toward opposite side.
Trigger Points
How to Strengthen
Twisting sit-ups, Russian twists.
Concentric Action
Rotate trunk to opposite side, lateral flexion
Applications:
Critical for trunk rotation, posture, and anti-rotation core control
Eccentric Action
Control return from rotation or side bend
Isotonic Action
Russian twists or oblique crunches
Related Conditions
['Core weakness', 'Sports hernia']
Isometric Action
Hold side plank or oblique crunch position
Exercise Ideas
['Cable rotation', 'Side plank with twist', 'Bicycle crunch']