Transverse Sacral Axes

00:01 We're going to talk about the transverse sacral axes in more depth now.

00:05 Because you're going to see different things with a transverse sacral axis when a person takes a deep breath in and takes a deep breath out.

00:12 If you're taking a deep breath in, the sacral base is going to move posteriorly.

00:17 You're going to have the coccyx come down and move anteriorly.

00:22 That's normal functioning of the thorax along the sacral transverse axis when you take a deep breath in.

00:29 You're going to have the thoracic and pelvic diaphragm go down.

00:32 You're going to have the lumbar curve flatten.

00:36 That's normal inspiration and normal motion of the sacrum with inspiration.

00:43 In exhalation, you're going to see the sacral base move anteriorly.

00:48 You're going to see the coccyx come up and the inferior lateral angle increase.

00:53 Again, it's exhalation.

00:58 So, you can have the thoracic and pelvic diaphragm move superiorly and the spinal curve, the lumbar lordosis becomes exaggerated.

01:06 Another term that's important is nutation.

01:09 Nutation is the nodding that occurs along the middle transverse axis.

01:15 So, in anterior nutation, you're going to have the sacrum move anteriorly and the coccyx move posteriorly.

01:23 It's when the sacral base is moving anterior, then you're going to have bilateral sacral flexion.

01:33 That's motion along the middle transverse angle.

01:37 We talked about nutation and counternutation.

01:40 It's really how does breathing affect the sacrum and where does it go.

01:45 So, with posterior nutation or counternutation, the sacral base moves posterior and you're going to have a bilateral sacral extension.

01:54 So, that's the motion along the middle transverse angle.

01:58 You’re going to have postural motion and you're going to have sacral base motion.

02:05 One thing to mention is when I'm assessing the sacrum, you do the seated flexion test.

02:11 You assess the depth of the sacral sulcus.

02:14 And you look at the inferior lateral angle.

02:16 Why do you do the seated flexion test? Because if you're standing, the pelvis is going to help change the motion.

02:23 It's going to compensate.

02:24 When you sit, you're sitting on the pelvis and you take the pelvis out of the equation.

02:29 So, a seated flexion test is testing the sacrum.

02:33 When you're talking about the inferior transverse axis, we're pushing on the ILA to see if both sides move, to see whether or not you've got a torsion, whether it's this way or this way amongst where the action is occurring and the motion is occurring, or if one side is locked or not moving.

02:52 So, in the inferior transverse axis, you're going to see if there's motion on the pelvis.

02:58 That's a dynamic test, the springing test.

03:01 It's seeing where the motion is occurring and how it's occurring.

03:05 That's what's important here.

03:06 Again, it's the oblique axis that I focus on because it's walking that occurs and causes problem most often.

03:14 When you're going to name an oblique axis, you're going to name it by where the motion is occurring off of.

03:20 So, if you see that you're set in the left upper pole and the right lower pole of the sacrum, it's going to be a left axis, named from the top where the left is set and the motion is going to occur along that axis.

03:37 So yes, the right part is going to be moving in and the left lower part will be moving in and out.

03:43 That is an oblique sacral axis on the left.

03:47 On the right, it's the exact opposite.

03:49 The right upper is not moving and the left lower is not moving.

03:53 So, motion is going to be occurring at the top and the bottom on the other sides.

03:58 Naming the oblique sacral axis is important in helping you decide how to treat somebody and figuring out where the motion needs to be induced.

04:07 With gait, with walking, you're going to have right-right, left-left.

04:13 Then when you stop walking, you've got to stop functioning on an oblique axis.

04:20 You’re going to have to go back to the anatomic motion of the transverse or superior axis.

04:27 So, you’re changing axes.

04:29 If that doesn't happen, if you stop walking and you stay in an odd position, you're going to develop a sacral torsion that may need to be treated to get back to normal, or stretched, or pulled, or somehow allowed back into the normal functioning.

04:45 Here's a motion example of sacral dynamics and sacral biomechanics and motion.

04:54 So, hit click and watch it move.

04:56 And understand where the sacrum moves within the pelvis when somebody's walking.

05:01 Here's another example of sacral biomechanics in a skeleton showing you how the sacrum moves in relation to the legs and the pelvis.

05:09 Here's a third example of sacral motion within the pelvis to understand the motion and compensatory motion you can expect with sacral motion.