Spinal Anatomy Directional Terms

Anterior

toward the front

Posterior

toward the back

Cephalad (cranial)

toward the head

Caudal (inferior)

closer to the feet

Medial

toward the midline

Lateral

away from the midline

Proximal

Closer to the point of attachment

Distal

away from the point of attachment

Median

middle

unilateral

affecting only one side

bilateral

affecting both sides

Ipsilateral

affecting the same side of the body

Contralateral

affecting the opposite side of the body

Convex

curved outward

Concave

Rounded inward

Orthogonal

Meet each other at 90 degrees to each other

Sagittal Plane

Divides body into left and right portions (Y and Z axis)

mid-sagittal plane

divides the body into equal left and right halves

coronal plane

divides body into front and back (X and Y axis)

transverse plane

divides the body into superior and inferior parts (X and Z axes)

three dimensional coordinate system

a coordinate system with three axes: an x-axis, a y-axis, and a z-axis that describes anatomical relationships, planes, and movements.

X-axis

Horizontally right to left (Middle finger)

Y-axis

Runs superior to inferior (thumb)

Z-axis

Runs front to back (Pointer finger)

Positive direction

Finger pointed in the direction it is facing

Negative direction

Finger pointed in the opposite direction it is facing

Translation

Movement along or parallel to an axis

Rotation

Spinning or angular displacement of a body about some axis

+ 0X

Flexion

+ 0Z

Right lateral flexion

- 0Y

Right rotation

- 0X

Extension

+ 0Y

Left rotation

- 0Z

Left lateral flexion