05/31/2026
SACRO-ILIAC joint: where you can feel it when it flares up, what are the muscles to train to unblock it.
The sacroiliac joint is responsible for a percentage of back pain that surprises almost everyone when they hear it: About 30% of all lower back pain originates from this joint, making it one of the most common causes of low back pain.
Yet, despite being so common, the sacroiliac is also one of the most subtle structures of the body, because its pain almost never presents itself clearly and unanimously.
WHERE DO YOU FEEL HER (AND WHY SHE CONFUSES)
Sometimes it hurts exactly where it is: in the “dimples” area of your low back, lower than where you’d expect classic low back pain, often more from one side than the other. That deep end, that annoyance you just want to just press your thumb to make it disappear.
But sacro-iliac has a peculiarity of projecting pain into areas you don’t expect, and that’s why it’s constantly mistaken for other problems.
It can project into the center of the gluteum: and at that point you think it's the piriform, or a deep muscle contraction.
It can project into the back of the thigh: and at that point you think it's a sciatica, a disk pressing on a nerve.
It can even project to the groin: and at that point you think it's a hip problem, or something visceral.
In practice, the sacroiliac can "mimic" at least three or four different problems, and it's not uncommon for people to go on for months thinking they have a hip problem or sciatica, when actually the source is this joint that is lying down there, between the spine and the back. basin, doing its quiet job.
WHY DOES IT GET FLAMED SO EASILY
The sacro-iliac is the point where the column connects to the pelvis, meaning it is the first structure to manage the transfer of load between your upper body and your legs. All the body weight passes from there, with every step, and if there is any imbalance (in the upper posture, in the lower limb, in the muscles around it) the sacroiliac is the first to feel it.
But the main reason why it burns so easily is that the muscles around it are among the most "problematic" in the body, each for its own reasons.
THE FOUR MUSCLES THAT DETERMINE YOUR BALANCE
The psoas goes over the sacroiliac like a bridge and attaches to the lumbar vertebrae just above it. When it’s stiff (and sedentary, emotional stress, and an irritated bowel make it stiff with unparalleled ease), it pulls on the vertebrae and changes the way the load reaches the sacroiliac, overloading it asymmetrically.
The piriform is inserted directly onto the sacred bone, that is, on one of the two "pieces" that make up the joint. When he contractes (and we sit on it all day, crushing it between the basin and the chair), he pulls directly on the sacroiliac from below, irritating it. And because it is in faccial continuity with the pelvic floor, it also collects emotional tensions that we are often unaware of.
The square of the lumbar is the great lateral stabilizer of the area, which manages the load transition to the right and left at every step. When it's overloaded (and it almost always is because it's the muscle that compensates for everyone else), it creates a constant lateral tension that the sacroiliac has to absorb.
Gluteum is the largest muscle in the body and the main stabilizer of the pelvis. When it’s strong and active, it “embraces” the sacroiliac from the outside and protects it from any imbalance. When it's turned off (and the brain shuts it off first when it's not needed), the sacroiliac loses its primary protection and is exposed to all the forces coming from the other three muscles.
Basically: the sacro-iliac is tight between a psoas pulling from the top, a piriform pulling from the bottom, a square of the lumbar pulling to the side, and a gluteo that should protect everything but often doesn’t. When even one of these balances balances goes off, the joint overloads and the pain leaves.
HOW TO 'UNLOCK' (AND WHY ONE MANIPULATION IS NOT ENOUGH)
“Unblocking” the sacroiliac with a manipulation can give immediate and even quite spectacular relief, but the problem is that the forces that overloaded it are still all there: the psoas is still stiff, the piriform is still contracted, the gluteum is still off. Within a few days or weeks, the joint is in the same situation and the pain returns.
The real solution is to bring back balance to the four surrounding muscles. Relax the psoas, lengthen the piriform, discharge the square of the lumbar, and above all reactivate the gluteum that needs to be protected again.
When these muscles are working, the sacroiliac doesn't need to be "unblocked" because it doesn't get stuck anymore: the forces around it are balanced, and the joint does its job without overloading 💪
