by Brent Brookbush DPT, PT, MS, PES, CES, CSCS, ACSM H/FS
General Anatomy of the Spine - By Henry Vandyke Carter - Henry Gray (1918) Anatomy of the Human Body, invalid ID (See "Book" section below)Bartleby.com: Gray's Anatomy, Plate 111altered by User:Uwe Gille, Public Domain, https://commons.wikimedia.org/w/index.php?curid=1282158
The facet (zygapophysial) joints: of the spine are "gliding joints", allowing a small amount of motion in various directions. The large amount of movement we see from the spine is actually the summation of small amounts of motion at dozens of little joints. See the activity below for more on what joint actions the spine can perform.