Muscle Memory Massage

Why Does My Lower Back Hurt?: The Sacrum

Back in our October 2021 blog post on the effects of sitting, we discussed many of the ways being sedentary can affect the body—with one of the most obvious and often excruciating consequences being intermittent or chronic pain in the lower back.

Those with more active lifestyles, routines, and hobbies can find themselves struggling with these pains too, however, and continuing to practice massage therapy over the past year has led me to reflect on and learn more about the “how” and “why” this problem is so very widespread.


Low back pain (LBP) currently leads the charge as the number one cause of disability globally, as cited in a 2021 article from the International Association for the Study of Pain.

It follows that regardless of age, culture, profession, or perceived physical wellness, many of us will experience pain in our lower backs at some point in our lives.

While multiple potential causes for LBP exist both inside and outside of the soft tissue realm, a noticeable trend has emerged among my clients, pointing towards a major culprit for this unfortunate pain state.

In sum, I’ve learned that no one is exempt from hurting, and there appears to be one common offender of the lower back pain that indiscriminately plagues us: the sacrum.



The sacrum is a unique, roughly triangular bony structure at the base of the spine, resting directly above the coccyx (aka tailbone) and below the fifth (bottommost) lumbar vertebrae.

It has a delicate, C-curved shape, which then hooks back around with the addition of the tailbone (not a part of the sacrum itself), giving the end of our total spinal structure a look akin to a scorpion’s tail.

Six muscles attach to the sacrum, with three connecting on the anterior (front) and three on the posterior (back) side of the bone. Many nerves also weave in and out of the sacrum and surrounding area.


The anterior muscle connections include the piriformis, the coccygeus, and the iliacus. All three of these muscles exist in mirror on the left and right side of our bodies.


  • Sits deep in the musculature of our fleshy hip/glute areas
  • Can be aggravated both by movement and non-movement
  • It is a hip rotator and femur abductor, meaning we use it for walking, running, taking the stairs, and staying upright, to name a few

Runners and desk workers alike can develop tight or inflamed piriformis muscles, simply with different catalysts.

Serial sitting will compress the sacrum and piriformis muscles, while long-distance running or pushing too hard during exercise will overuse them.

Both active and nonactive groups will have resulting pain that can typically be felt in the hip and low back. Irritating the piriformis can also potentially lead to piriformis syndrome—a pain pattern that mimics sciatica. (We will discuss this a bit more in the “Nerves” section below.)


  • Exists within the pelvic region
  • A supportive muscle that is a part of the overall pelvic floor
  • It is not a huge, distinct muscle, so to speak, but it interacts with important surrounding musculature (including the piriformis), bony structures (including the sacrum), and nerve beds (which come from the low back and pass through the sacrum itself)

This muscle is integral in the overall pelvic formation, affecting and being affected by much of the area we use both when sitting and when moving our legs.


  • An inner hip muscle that makes up part of the main musculature that moves the hip
  • Grows out of and into multiple bony landmarks; importantly, its muscle fibers connect with another major muscle called the psoas (pronounced so-az)
  • Walking, running, and jumping (among other familiar movements) all depend on this muscle

While this muscle can be injured by heavy exercise (especially without proper stretching), it is also a common problem muscle for those who sit often, as it will get stuck in a shortened position and cause major dysfunction.

Both active and non-active influences on the iliacus can result in pain, lack of mobility in the hip joint, and even changes in natural gait.


The posterior muscle connections include the gluteus maximus, the multifidus lumborum, and the erector spinae.

Gluteus Maximus:

  • Nicknamed the “glute max,” this muscle is closest to the surface of our skin on the area we colloquially refer to as our bee-hind
  • The largest and heaviest of all our muscles (yes, in the whole body!) and one of the strongest, as well
  • This muscle is necessary for us to be upright creatures, and it plays a part in almost all of our movements

Both tight and weak glute max muscles can lead to tight low back muscles and resulting pain. Whether you are overly fatiguing this muscle, using it improperly, or not using it enough, your back is bound to feel it.

Conversely, exercising your gluteus maximus properly can help prevent and potentially help eliminate LBP.

Multifidus Lumborum:

  • Deep, spinal, core muscle that helps to stabilize the lumbar spine, working in conjunction with pelvic floor muscles and our side abs (transverse abdominus)
  • Having a weak core is a gigantic contributor to back pain, and a weakened/atrophied multifidus is often present with chronic LBP
  • This is a very important and often overlooked muscle!

Quality of life can be severely hindered by a multifidus lumborum that is not in great shape. Fatty atrophy of this muscle is linked with many spinal issues, which would be a primary concern for desk workers.

At the same time, many active people who might not have an extensive medical background or robust muscular education often harm their bodies by ignoring the multifidus. Again, it is a key, core and spinal muscle that can and should be intentionally strengthened.

Erector Spinae:

  • A muscle chain that extends all the way up the spine on either side of the vertebral column, affecting power and posture
  • Helps to maintain a happy union between the spine and pelvic floor, keeping us upright
  • A prime core and spinal muscle that contributes heavily towards LBP, even causing extreme and debilitating muscle spasms when aggravated

Athletes who perform movements such as deadlifts, planks, pull-ups, or rows can easily harm this muscle chain, as can folks who employ slouched posture at a desk all day.

If you’ve ever exercised and been told to keep a “flat back” while performing a movement, it is to be sure that you are engaging this muscle chain, which helps us pull against or resist weight.

The same concept pertains when sitting at your desk – it is important to actively keep yourself in good spinal alignment to avoid the shortening and weakening of a number of muscles you will want to be functional for active movements, including the erectors.

The erector spinae and glute muscles combined can be largely credited for our posture, whether we are sitting or standing, so keeping these muscles in good working condition is essential to warding off all sorts of back pain.


With all of that muscular information being crammed into your brain, we’re going to visit a very abridged (but still significant) version of the relationship between nerves and the sacrum.

There are two main things I want you to take away from the nerve discussion:

  1. A boatload of nerves (you can picture them like powerlines) come in and out of the sacral area. All of the openings in the bony picture of the sacrum are threaded with nerves that go up into the back and down into the legs.
  2. When muscles are short, tight, or otherwise dysfunctional, their misposition can press on nerves, causing pain and discomfort anywhere or everywhere along a nerve line.

A very common nerve issue in the sacral area is called piriformis syndrome, as briefly mentioned earlier.

When the piriformis muscle(s) are aggravated, it is easy for them to pinch on a nerve line called the sciatic nerve.

This nerve runs down the back of the leg (both sides, so this is a mirrored issue that can happen either on one side or both) and when pinched, it can cause pain, numbness, tingling, burning, and/or discomfort anywhere from the hip down to the feet.

Piriformis syndrome is different from the condition called sciatica, although the symptoms can feel very similar. Sciatica is caused by a herniated disc or when areas of the spine—where your spinal cord and nerves branch out of—collapse enough to bother the nerve. This is what we call osteoarthritis.

By loosening the muscles in a massage, sciatica and piriformis syndrome can be relieved. Since the causes of sciatica cannot be reversed, the relief will not be permanent; piriformis syndrome, on the other hand, can potentially dissipate entirely with massage and stretching.

It is believed in the massage therapy community that piriformis syndrome is more common than it is diagnosed.


The sacrum is a bridge between your upper and lower halves and therefore commands respect and attention from anyone wanting to avoid or eradicate lower back pain.

Our human abilities from sitting and being upright to carrying loads and walking depend on the sacrum, as it helps to create four major joints, routes nerves, and serves as the back of our pelvic girdle.

Due to its integral roles, any misalignment of the sacrum can easily cause discomfort, pain, and dysfunction—essentially from head to toe.

Whether you’re largely on your feet or on your seat, your sacrum is affected daily. Being an active person is great for your overall health, but it does not mean you will necessarily avoid these sorts of muscle pains.

If you’re in pain, before jumping to theories of herniated discs and degeneration, it is well worth checking in with your sacrum and its surrounding musculature. A massage therapist can offer substantial relief for this common lower back pain!


Resources: International Association for the Study of Pain, Cleveland Clinic


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