You may be wondering why we emphasize a reciprocal reach with your arms, thorax and shoulders during movements like lunges.
First, keep in mind that this isn’t just about your arm. It’s about the way your entire body moves, from ankles to elbows. We’re looking at the positioning and movement of your body in a holistic, 3-dimensional way.
This reciprocal reach pattern trains the gait cycle (the way you walk) more effectively, which ties into a very deep motor pattern that’s a base component of everything that you do. It affects the way you breathe, the way you stand, and the way that you move and walk.
If you picture a healthy person walking, there is a contralateral (opposite sides) reciprocal movement happening at the hips, thorax and head. Picture a snowman, with three big spheres of snow, and each of those spheres is moving in an opposite way with each step.
When your left leg steps forward your pelvis rotates left to move with it. Above that your ribcage, t-spine and shoulders move in the opposite direction as your right arm reaches forward and towards centerline, and then your head is rotating in the opposite direction on top of your thorax to stay neutral.
This changes the position of every joint in your body. With good movement (alternating reciprocal motion on a neutral pelvis and spine) your pelvis is in neutral, rather than tipped forward into an anterior tilt, which improves the rotational motion of your hips and allows for better hip extension and muscular firing patterns.
This takes tension off your lower back because your lumbar spine and pelvis are in neutral, rather than locked in extension with tight lumbar muscles.
This tension and force is now coming from somewhere else, which is the muscles in your hips, instead of your lower back muscles.
If you picture the fascial train that runs from one hip (it actually starts at your foot and runs to the opposite hand) across to the opposite shoulder on the back of your body, reciprocal motion helps to lengthen that fascial train and then contract it more when you move into the opposite stance. So, rather than isolating tension in your lower back, it’s distributing it more evenly across a natural pattern through your entire body.
This is reinforcing 3D motion, and helping you body to work as one coordinated piece with large trains of muscle and fascia lengthening and contracting in an alternating rhythm.
This helps to train your body to generate force in a stable, 3D way, rather than in a 2D extension-only way. Rather than straight forward or straight up and down, you’re moving in rotation, from side to side and straight forward and up and down.
At your pelvis, this reciprocal motion means better AFIR (acetabulo-femoral internal rotation), which means that with each step the pelvis is rotating internally on the femur in order to maintain neutral positioning and keep the right muscles doing the work. It also increases relative tension from the abs (especially oblique) and encourages effective diaphragmatic breathing, which protects your spine, takes tension out of your lower back muscles and alters the way your ribcage moves, which helps your shoulders and neck move better.
This all works out to better resilience (less pain or vulnerability to injury + the ability to train harder and recover better), better muscular development, better athleticism and a happier nervous system because your body isn’t stuck in extension and chronic sympathetic tone.
So get your ribs down, reach across, and get out of your lower back and into your hips. It may seem silly, but it makes a big difference.