click below
click below
Normal Size Small Size show me how
muscles of thorax
thorax
muscles | origin | insertion | function |
---|---|---|---|
Intercostal (internal) | superior margin of each rib | inferior border of next rib above | expiration; depresses ribs (25% of breathing) |
Rectus Abdominus | pubic crest and symphysis | xiphoid process and inferior ribs | flexes vertebral column; depresses thorax; compresses abdomen (sit ups / crunches) |
External Abdominal Oblique | fifth to twelfth ribs | Illiac crest, inguinal ligament, and rectus sheath | flexes and rotates vertebral column; compresses abdomen, depresses thorax (twisting flexion) |
Internal Abdominal Oblique | Illiac crest, inguinal ligament and lumbar fascia | tenth to twelfth ribs and rectus sheath | flexes and rotates vertebral column; compresses abdomen, depresses thorax (twisting flexion) |
Transversus Abdominus | seventh to twelfth costal cartilages ,lumbar fascia, Illiac crest, and inguinal ligament | Xiphoid process, linea alba, and pubic tubercle | compresses abdomen ( use this when you go #2) |
Quadratus Lumborum | Illiac crest and lower lumbar vertebrae | twelfth rib and upper lumbar vertebrae | rotates vertebral column and depresses 12th rib (twisting flexion) |
passive | * diaphragm * intercostals | ------------------------------------------------------------------------------- | ------------------------------------------------------------------------------- |
active | *diaphragm *intercostals *QL(ex breathing out) *scalenes (pulling up inhale) *sternocleidomastoid(inhale) *abs (exhale) | -------------------------------------------------------------------------------- | ------------------------------------------------------------------------------- |
Diaphragm | Interior of the ribs, sternum, and lumbar vertebrae | central tendon of the diaphragm | inspiration, depress floor of the thorax (75% of breathing) |
Intercostal (external) | inferior margin of each rib | superior border of next rib below | Inspiration; elevates ribs (25% of breathing) |