The human body moves in three planes:
1) the Sagittal plane, divides our bodies into left and right hemispheres. Any movement- take running for example- in which your left and right sides oppose each other (move in opposite directions) takes place in the Sagittal plane.
2) the Frontal plane, differentiates between our front and back sides, anteriors and posteriors, whatever you want to call it. Movements that travel vertically or horizontally, up and down or side to side, fall in this plane.
3) the Transverse plane, separates our upper and lower halves. A movement in the Transverse plane involves a kind of rotation or twisting, in which your upper and lower halves oppose each other.
Now think for a moment: in the world of CrossFit, which movements fall into which plane(s)? I’ll give you a hint. A better question to ask would be, “Which plane of motion is often left out?”
Spoiler alert - the title of the article gives you the answer.
I love finding articles by authors that aren't afraid to tackle what is missing in Crossfit. It's easy to fall into the trap of "Crossfit is amazing and it's all you need for total fitness". While it does cover a lot of what one needs for general fitness, holes have been discovered and should be addressed. This lack of work in all three movement planes is one of them. Luckily this author points out that you may already be doing some exercises to help address this deficiency...you just don't know it because you probably don't do them enough.