Bill Hartman 34:19–37:36
Hang on. Let's just talk this through. Let's make an assumption that we're moving forward. OK. Is that fair? That's how we know that both sides are concentric because they're going in the same direction. So the muscle orientation has to be the same if I'm going in the same direction, right? Okay. If I'm walking, so I'm stepping, right? So one foot is going ahead of the other, in a reciprocal fashion, okay? To get one foot ahead of the other, the one side has to slow down to allow the other one to be faster, okay? Now, knowing what we know about the rate of load on connective tissues, that's how we determine an overcoming versus a yielding strategy, right? And so, if I have a delay on one side and it's concentrically oriented, so it's still moving forward, it's just going to move forward as a slow rate, means I have to activate that side to slow that side down so the other side can get ahead, right? So then that becomes concentric yielding on that side, okay? As I move the other side forward, right. I'm still concentric because we're all going in the same direction. Okay. But because I need that to go faster than those connected tissues are going to be loaded at a higher rate, which means I'm going to have an overcoming action. Okay. So far, so good. Okay. So if I'm creating a delay on one side. So, think about when the first metatarsal head on the right foot hits the ground. Okay. The foot doesn't move. It's no longer going forward. Right. So that means that's the side I have to slow down on. So that's where I start to yield. I actually begin my yielding action at that point when the first metatarsal head hits the ground. Okay. So all the way up. So all the way from the foot up through the pelvis into the axial skeleton up into the thorax. That side is starting to yield. So it's holding back. Okay. So if I'm doing that, if I'm doing that, then to advance the other side, then I have to compress that posterior lower aspect on the left side to get it to go forward. Right? Because I have to get the spine to turn. We're talking about the right yield. I have to get the spine to turn to the right. Okay. And I would do that through the lowest part of the spine, which would be sacrum. Right? So that ischial tuberosity is being compressed closer to the sacrum. I have external rotation of the femur, right? And so if you think about like the, I can probably just show you.
biomechanicsmovement strategiesconnective tissue loadingyielding vs overcoming actionsgait mechanics