TRAPEZIUS

1
TRAPEZIUS

• It is a large flat triangular muscle.
• Origin
• 1. Occipital bone
• (a) medial third of superior nuchal line.
• (b) external occipital protuberance.

2
TRAPEZIUS

• 2. Ligamentum nuchae.
• 3. Spines of vertebrae
• C7.
• All thoracic.
• 4. Supraspinous ligaments.

3
TRAPEZIUS

• Insertion
• 1. Upper fibers Lateral 1/3 of the clavicle.
• 2. Middle fibers Acromion and upper border of
  the spine of the scapula.
• 3.Lower fibers
• Medial end of the spine of the scapula.

4
TRAPEZIUS

• Nerve supply
• 1. Spinal part of the acessory nerve (11th
  cranial).
• 2.Sensory (proprioceptive) from C3 4.

5
TRAPEZIUS

• Action
• 1. Upper fibers
• Elevate the scapula.
• 2. Middle fibers
• Retract and pull the scapula medially.
• 3.Lower fibers
• Pull the medial border of the scapula downwards
  so the glenoid cavity faces upward and forward.

6
TRAPEZIUS

• Action
• The upper and lower fibers together
• 1. Rotate the scapula (with serratus anterior).
• 2. Extend the head and neck.

7
LATISSMUS DORSI

• Origin
• 1.Posterior part of iliac crest.
• 2. Spines of the lower six thoracic vertebrae.
• 3. Lower three or four ribs.
• 4. Inferior angle of the scapula.

8
LATISSMUS DORSI

• It passes around the lower border of teres major
  (they have a triple relation).
• Insertion
• Floor of the bicipital groove of the humerus

9
LATISSMUS DORSI

• Nerve supply
• Thoracodorsal nerve.
• Action
• 1. Extension.
• 2. Adduction.
• 3. Medial rotation.
• of the arm.

10
LEVATOR SCAPULAE

• Origin
• Transverse processes of the upper (4) cervical
  vertebrae.
• Insertion
• Medial border of the scapula (opposite
  supraspinous fossa).

11
RHOMBOID MINOR

• Origin
• 1. Lower part of ligamentum nuchae.
• 2. Spines of C7 T1.
• Insertion
• Medial border of the scapula (opposite root of
  the spine).

12
RHOMBOID MAJOR

• Origin
• A. Spines of (T2-5).
• B. Supraspinous ligaments.
• Insertion
• Medial border of the scapula (opposite
  infraspinous fossa).

13
NERVE SUPPLY

• Dorsal scapular nerve supplies the Rhomboids and
  the Levator scapulae.
• Levator has another supply from C34.

14
ACTION

• 1. Elevation of the scapula (medial border).
• 2. Acting together and with the middle fibers of
  trapezius, they pull the scapula upwards and
  medially and brace the shoulder backwards
  (Retraction)