Um, just everything. Well maybe.... hmmm. Nope. Everything.
In the image to the left you're looking at the illio-psoas and above it the diaphragm. The places where your diaphragm attaches to the spine are simultaneous or integrated with the places where your psoas originates from the same places on the spine.
The psoas is the one muscle of the body that integrates torso and lower extremities, that attaches the top to the bottom. It's the only muscle that traverses front to back, top to bottom. It's the hinge of the body. Hinges can get stuck closed, be weak or even too flexible. One side of a hinge can be stronger than the other, and they can even get stuck open.
You can see from the image that the psoas comes from the vertebrae forward to the inside of the pelvis and then over the hip sockets, where the femoral heads insert into the pelvis. This is only one way the core directly effects the hips. When the core is weak, the hip socket takes too much load. Think of setting a heavy box down on a spring: your torso is the box and your hip joint - in which there is meant to be space and give - is the spring. Part of what confers this spaciousness is our ability to effortlessly stack and carry the rib cage over the spine because of core tone and balance.
The muscles of the pelvic floor run laterally in the space between and behind the right and left psoas, going back to the sacrum, that bone in the bottom middle that looks like a trilobite. Their attachments integrate with the other deep core muscles: the transverse abdominus (running from hip bone to hip bone laterally across the front and up to the ribs), as well as the multifidus (leap frogging along either side of the vertebrae, under the erectors).
The strength and flexibility of this system of muscles determines not only our ability to move, but to move gracefully, to carry ourselves in a way that allows all the parts of the system to function. Want to prove it to yourself? From wherever you are right now, simply lift your rib cage evenly up and away from your pelvis. Notice your sensations.
I was reminded of this so practically and so poignantly recently. A friend who has profound knee pain and injury and is putting off knee replacement was telling me about some of the consequences of her pain. She doesn't move as well any longer, so she moves less, so the ability to move well recedes a little more, so she moves a little less and so on. The thing is, it's not just the knee joints that aren't exercised, it's the core itself that looses tone.
I remember this cycle from the days before my own hip replacement. It took so much fortitude to continue to move despite the bone on bone pain that some days I just plain didn't have it. I empathized deeply with her.
Then one day she was on the commode and when she went to wipe - her back spasmed. She couldn't reach behind, and now she couldn't get up. She was mortified and spent the next hour breathing and relaxing until she could crawl from her unlikely perch.
I remember having difficulty twisting and lifting my hip for the wiping action, too, in the days after my hip replacement surgery - the strength was simply not there. I had lost some strength and lost connection to the strength that was left. I was fortunate that was able to muster what I needed and rapidly made gains in the days after surgery, but I could easily imagine being in her position.
This is all about core. Try it. Right now. You don't have to go to the bathroom to do it. From where ever you're sitting, turn your torso to one side and lift that side's hip. That's all those deep core muscles, along with the superficial core (obliques, rectus). Here's what's cool: you can't strengthen and stretch these deep muscles without doing the same for the superficial ones. But you can train the superficial ones without the deep ones. That's why I call the superficial core the "vanity" abs. It's not that they're not important - they are, but they must work in synergy with the deep core.
That ability to lift up works in our relationship to gravity as well as when we literally need to lift a hip. When this ability is decreased, our ability to carry ourselves in harmony is also decreased and the hips, the largest joint in the body, take a lot of the brunt. The stronger your core, the less pain you'll have. Will it take away all the pain from any type of injury - absolutely not. But it will decrease the pain and increase your ability to deal with it. Win-win.
Want to do something to strengthen your core right now, and do it in a way that will help you move with more harmony and less pain? Do that same move.
If you're just starting out, you can do it from any solid chair - turn and lift the same side hip. Begin to emphasize different areas of your pelvic bowl and notice how it affects your strength and sensation.
If you're fit, you can do "Charlie's Angels:" sit on the floor in modified boat pose (sitting bones pressing into the floor, heart lifted, knees bent, toes on foor; arms reaching out, hands interlaced with index fingers pointed like "Bang!"). On an exhale, turn to the left, draw thumbs to chest and lift the left hip off the floor (or try to, engaging those muscles - don't worry, it will come). Inhale back to center and exhale to the right. Start with 5 on each side and work up to 25.
Want even more challenge? Make the starting and center pose full boat, with the legs outstretched and the body in a "V" with the sitting bones pressing into the floor and the heart lifted. You'll want to stretch your arms out on either side of your legs. If you decide to challenge yourself with this version, pay close attention to the sitting bones down, low back in and not rounded. Often people advance to this version too quickly, compromising their low backs because the deep core isn't yet ready to bring the low back and low belly together.
How do you notice core strength effecting your everyday life? Leave a comment and let me know when you try the Charlie's Angels - whether it's on a chair or on the floor, you'll be glad you did!