Spinal Anatomy 2 Class Notes

Spinal Anatomy II Lecture Notes
Stephen James, D. C., M.H.Sc.

Agonist: A muscle that creates a desired movement of a bone or body part. Antagonist: A muscle that opposes the action of the agonist. Synergist: A muscle that aids the action of a prime mover (agonist) by effecting the same movement or by stabilizing joints.

·-c - (,.J'.\--'-S -::. ~

.\d.u Isometric contraction: Contraction occurring in which the muscle does not shorten but
..,_internal tension increases. Isotonic contraction: The muscle changes in length and tension remains constant throughout the range of motion and the load. There are two types of isotonic contraction (concentric and eccentric).

ti) Concentric contraction: When a muscle shortens through constant tension and range of motion moving a load. b) Eccentric contraction: The muscle lengthens with constant tension throughout the range of motion moving a load. ~~~ 1·,_ .o eo! o'""ClrL n "'- -.;.y 'c , , ...., ~, -r ~ 0 (0 } , . _.
0

Flexion: Extension: Abduction: Adduction: Retraction:

4 .,);
4 1'

Protraction: Elevation: Depression:

2

LAYER ONE:

Trapezius (Consists of superior, middle and inferior fibers).
0: 1: A: EOP, medial 1/3 of superior nuchal line, ligamentum nuchae, spinous processes of C7-Tl2. Lateral 113 of clavicle, acromion process, spine of the scapula elevates the scapula, depresses scapula, rotation of the scapula superiorly, retracts the scapula spinal accessory nerve (CN XI) and ventral rami C3-C4 (sensory)

N:

Latissimus dorsi
0: 1: A: N: thoracolumbar fascia, spinous processes ofT7-L5, iliac crests intertuburcular groove of the humerus adduction, extension and medial rotation of the humerus thoracodorsal n. (C6-C8)

LAYER TWO:

Levator scapulae
0: 1: A: N: transverse processes C 1-C4 superior portion of medial border of scapula scapular elevation and rotation dorsal scapular nerve

3

Rhomboid minor 0: I: A: N: ligamentum nuchae, and spinous processes C7 and Tl medial