If you haven't read Tri-Planar Consideration #1, please do. It will give you an idea of what common fault is often seen in training and why we need to begin in the sagittal plane. Today, we move into the frontal plane.
After sagittal plane competency has been trained (or at least warmed up) access to the frontal plane should be restored. However, depending on how long you have spent not fully utilizing your frontal plane musculature, you may need some serious training here.
Frontal plane muscles include your abductors, adductors, obliques, pecs, middle traps and their motion comprises abduction and adduction. Now abductors get a ton of hype because they help plenty of people get deeper into a squat and hold us up while we stand on one leg. In fact, when I was in graduate school for physical therapy we talked about the abductors at length. I came out thinking, jeez, if everyone would just do clamshells there'd be no issues! But that thinking is misguided (bullshit in fact.)
Sure, abductors balance single leg stance and give us power to push from side to side, but adductors pull our pelvis underneath us, help to drive pressure up through our abdomen on the same side and force air into the opposite side of our chest wall. This is vital for walking and breathing. If you walk and breathe, but only train your abductors and not your adductors, you're...misguided. Training your adductors is not sitting on that adductor machine and ruining your thigh gap. In fact, I hate that machine. Adductors pull on your pelvis. The joints that connect your left pelvis to your right pelvis do not move a whole lot. Therefore, they don't create a lot of motion when both sides pull at the same time.
In order to train tri-planar competency, you need to first establish a sagittal plane that allows access to the frontal plane musculature. Once you have that, you need to use your adductors (and abductors) to pull and push you from side to side. This is vital for beginning the holy process of rotation.
So let's look at a couple frontal plane exercises. We didn't do this with Tri-Planar Consideration #1 so I hope you are excited.
Two Point Stance
As you can see, the frontal plane muscles are fighting gravity. This is obvious with the side planks, the abs underneath you are pushing you up. With the Lateral Stairs, gravity is pulling straight down through your head. As soon as you pick up your non step leg, gravity begins to win but your brain is ready for that. So you lean your body weight way over your hip with your outside abs. Your adductor on that side now must balance with gravity against your abductors and abs to keep you up right. Just like a see-saw.
Muscle competency in the sagittal and frontal planes is necessary for positioning your skeleton in a position that allows for rotation (transverse plane). Rotation is the most common measurement in biomechanics assessments because it shows whether or not the human body is stiff and tight or is rotating freely. In Tri-Planar Consideration #3 we will go over how to optimize and maintain rotation.