Spry Juncture, LLC
How to Evolve Gracefully
Rectus Abdominals
Region
Origin & Insertion
['Origin: Pubic symphysis and pubic crest', 'Insertion: Xiphoid process and costal cartilages of ribs 5–7']
Synergistic Muscles
['External oblique', 'Transverse abdominis']
Joints
['Lumbar spine']
Primary Actions
['Trunk flexion', 'Compression of abdominal contents']
Nerve & Spinal Segment
Thoracoabdominal nerves (T7–T11), subcostal nerve (T12)
Thoracic spinal nerves; no plexus
Interesting
Forms the ‘six-pack’; anchored by tendinous intersections. [Gray’s Anatomy]
Reversal of Action
Lift pelvis toward ribcage (posterior pelvic tilt)
Common Dysfunctions
Poor posture, abdominal bulging, diastasis recti
How to Stretch
Full body extension or cobra pose.
Trigger Points
How to Strengthen
Crunches, leg lifts, bracing drills.
Concentric Action
Trunk flexion (crunch, sit-up)
Applications:
Supports spinal control and pelvic alignment in daily activity
Eccentric Action
Lower trunk slowly from flexion
Isotonic Action
Crunches, curl-ups
Related Conditions
['Diastasis recti', 'Poor posture']
Isometric Action
Hold partial sit-up or hollow body position
Exercise Ideas
['Crunches', 'Reverse curl', 'Dead bug']