| A | B |
|---|
| Origin of the Trapezius | occiput, superior nuchal line, spinous processes of C7 through T 12 |
| Insertion of the Trapezius | lateral clavicle, acromion process and the spine of the scapula |
| Origin of the Latissimus dorsi | thoracolumbar aponeurosis, spinous processes of the lower thoracic vertebrae, posterior surface of the last 3 or 4 ribs and the posterior iliac crest |
| Insertion of the Latissimus dorsi | crest of the greater tubercle of the humerus |
| Origin of the Rhomboid minor | Spinous processes of C 7 through T 1 |
| Origin of the Rhomboid major | Spinous processes of T 2 through T 5 |
| Insertion of the Rhomboids | medial border of the scapula |
| Origin of the Quadratus lumborum | Posterior iliac crest |
| Insertion of the Quadratus lumborum | 12th rib, transverse processes of L 1 through L 4 or sometimes L 5 |
| Actions of the trapezius | elevate, adduct and depress the scapula |
| Action of the Latissimus dorsi | extend the humerous at the glenohumeral joint |
| Action of the Rhomboids | adduct the scapulae at the scapulothoracic joint |
| Action of the Quadratus lumborum (unilateral) | laterally flex the vertebral columnb, laterally fles the pelvis |
| Action of the Quadratus lumborum (bilateral) | fix the last rib during inhalation and assist in extension of the vertebral column |
| Origins of the erector spinpae group | thoracolumbar aponeurosis, posterior sacrum, iliac crest and the spinous processes of the lumbar and lower thoracic vertebrae |
| Insertions fo the erector spinae group | posterior ribs, spinous and transverse processes of the thoracic and cervical vertebrae and the mastoid process of the temporal bone |
| Action of the erector spinae (unilateral) | laterally flex the vertebral column to the same side |
| Action of the erector spinae (bilateral) | extend the vertebral column |
| Parts of the erector spinae group | spinalis, iliocostalis, longissimus |
| only portion of the erector spinae group to insert on the mastoid process | longissimus capitis |
