Ch. 4.0: A Complex

A “complex” is a group of interconnected skin, muscles, and joints that work together to make motion happen.

Written by

Willem Kramer

Published on

July 20, 2025

Although the body is one whole, for the purpose of this atlas, it is split into nineteen interlocking, bite-sized pieces called complexes.

A complex consists of plane-specific, interconnected skin, muscles, and joints (the integumentary, muscular, and skeletal systems) that work together to facilitate motion.

The Complexes of the Body
  • Big Toe.
  • Lesser Toes.
  • Ankle.
  • Knee.
  • Hip.
  • Pubic Symphysis.
  • Sacroiliac.
  • Lumbar.
  • Thoracic.
  • Cervical.
  • Craniovertebral.
  • Rib cage.
  • Shoulder girdle.
  • Shoulder.
  • Elbow.
  • Radioulnar.
  • Wrist.
  • Thumb.
  • Fingers.

Per plane, each complex has one or more plane-involved joints, muscles that move the complex directly or indirectly, and skin that connects to these joints and muscles. 

In its plane and around its axis, a complex takes care of clockwise and counterclockwise motions, such as flexion-extension, abduction-adduction, and medial-lateral rotation.

Not every complex moves in every plane. Eighteen of the nineteen complexes move in the sagittal plane, and fourteen of them move in the frontal and transverse planes.

For if you didn’t know, the word complex means “consisting of different connecting parts.”

5 1 vote
Article Rating
Subscribe
Notify of
guest

0 Comments

Author

Willem Kramer is a Netherlands-trained physiotherapist and US-licensed massage therapist with over thirty years of experience working with professional athletes, entertainers, and executives worldwide. He reorganizes anatomy around how the body moves, working from the premise that motion is a whole-body event involving all twelve organ systems within the anatomical planes of motion. He is the author of Anatomy by Planes — a three-atlas set with a foreword by Andrew Luck — and its companion Clinical & Training Guide, and the creator of Motion Anatomy (motionanatomy.com), a free introduction to the framework.

booshop-org-icon_orange-EB801D-hover-637C77

Related posts

Including atlas "Introduction," "Comparison," "Quiz," "Bibliography," and "News" posts.
July 1, 2025

Dissection vs AxP Anatomy: Tibialis Anterior (L)

Compare dissection anatomy and soft tissue therapy anatomy: The left-sided tibialis anterior inverts the “frontal ankle,” is a single-complex muscle, has one single-complex synergist, two single-complex antagonists, three multi-complex synergists, and one multi-complex antagonist.
0
Would love your thoughts, please comment.x
()
x
Privacy Overview

This website uses cookies so that we can provide you with the best user experience possible. Cookie information is stored in your browser and performs functions such as recognising you when you return to our website and helping our team to understand which sections of the website you find most interesting and useful. For more information you can read our Privacy Policy.