Pain in the Butt: Considering the Coccyx

Stay the CourseAs I write this, I am about to test to become a Certified Functional Manual Therapist. The certification, which tests on eight different manual physical therapy courses, covers an enormous breadth of material ranging from the big toe to the skull. By the time this article is published, I will have either passed or failed. Either way, I have learned a tremendous amount about the human body, not simply the nuts and bolts–the bones and muscles–but the whole system’s interconnectedness. I have learned about tissues and structures that, fresh out of school, I thought had no bearing on daily life or athletic function, but actually do. In fact, what I love about Functional Manual Therapy (FMT) is its holistic, systems-based approach to optimal health and function.

Of course, once Pandora’s box opens, things can get uncomfortable. In acknowledging that ‘everything matters,’ one must address areas and structures that, as a physical therapist who treats runners, you never thought you’d mention or treat. Chief among them is the coccyx. The coccyx, often referred to as the ‘tailbone,’ sits at the very tip (or inferior end) of the spinal column. It’s beneath the sacrum and, ahem, “in the superior gluteal cleft.” In ultrarunner translation, that’s the top of the butt crack!

Why should we as runners or medical professionals care about a little bone at the bottom of the spinal column that many have deemed a useless vestige of our evolutionary, tail-wagging days? It begins with folks who actually experience coccygeal pain and its debilitating effects. The impact of the coccyx goes beyond pain, though, and into hugely impactful realms of functional mobility, core stability, and pelvic-floor health.

What follows in this article is a brief primer on the coccyx: why you should care about it, how it can impact your running, and how to treat an injury of it.

The Tailbone: An Anatomy Review

The human spinal column consists of 22 separate bones: cervical, thoracic and lumbar. Below that is the sacrum, which is actually five bones that, over our evolution, have become fused into one large, triangular-shaped bone. At the very bottom of it all sits the coccyx. For most of us, it is the size of a nickel and consists of four tiny bones that, like its big brother the sacrum, are fused in a miniature triangle shape.

Like all the other bones in the spine, the coccyx can and should move. It has an efficient, neutral positioning that is susceptible to inefficiency. A coccyx becoming stuck or bent out of shape can have remarkable effects throughout our body. While it doesn’t seem like much, this little bone at the tail end of our spine is incredibly consequential to our function and athleticism as runners.

The vertebral column with the sacrum and coccyx at the bottom. Image: OpenStax College

Why the Coccyx Matters

The coccyx, due in part to its location and connections, is a crucial structure for two primary reasons:

1. The coccyx is the keystone of our pelvic floor.

The pelvic floor refers to the collection of small muscles that make up the core-stability system at the bottom of our pelvis. It is a hugely important system for function and athleticism. The pelvic floor has to, among other things, hold the weight of our guts, coordinate pelvic movement, and allow for the transit of things out of it!

Implication Every pelvic-floor muscle has either direct or indirect attachments to the coccyx. As such, coccyx mobility loss or malalignment can cause significant pelvic-floor and core-stability dysfunction. This includes weakness, hypertonicity (too stiff and tight), or both–where one side is weak and the other tight. And while the topic of pelvic-floor health is deserving of an entire column on its own, suffice it to say that coccygeal inefficiency can significantly impair pelvic-floor (and whole-system core-stability) function.

2. The nervous system attaches to the coccyx.

The nervous system also connects to the coccyx. The spinal cord has a thin fascial layer around it called the dura mater. If you imagine that the nerves are electrical cables, then the dura is a loose plastic sheath around the wiring. As the spinal cord flows down through spinal column, the connective-tissue sheath of the dura attaches to the tip of the coccyx.

Implication – Coccyx stiffness or malalignment can cause pervasive range-of-motion restriction. Nerves need to move freely through our tissues in order to have full, pain-free mobility and optimal function. Restriction of any part of the nerve (including its outer sheath) can cause motion loss elsewhere in the system that is often unaffected by stretching until the coccyx is treated.

These core-stability and mobility factors that, if impaired by coccyx dysfunction, can cause systemic issues. In most cases, no amount of strengthening or stretching can overcome a dysfunctional coccyx. As such, it is the keystone structure to address in an FMT treatment approach. Without addressing any coccyx dysfunction, it may not be possible to get sustained improvement in strength, stability, range of motion, and pain relief.

It’s a small bone, but a big deal!

How a Coccyx Gets Dysfunctional

The most common cause of coccyx dysfunction is trauma. Simply falling on your butt is enough to cause either a mobility or alignment fault in the coccyx that, once sustained, usually will not self-correct without treatment. Pregnancy and childbirth are other potential causes of coccygeal dysfunction, as the fetus can push or pull the coccyx out of its optimal alignment. Postural and movement imbalances can also cause coccyx inefficiency. Impairments in how we stand, sit, and move can, over time, stiffen or torque the coccyx out of its efficient state.

How to Assess a Coccyx

Because the coccyx is at the top of the gluteal cleft, it can be uncomfortable for both the patient and manual therapist to assess. Here’s how an assessment usually goes:

  • The best way to easily assess the coccyx is over skin, from top down, from below the pants or underwear.
  • It is possible to both palpate and treat over loose-fitting athletic clothing. (This is my preference.)
  • The coccyx can be assessed and treated without accessing any orifice.
  • A skilled manual therapist can determine coccyx mobility and alignment, namely whether it is shifted forward or back, flexed or extended, and sidebent or rotated. Self-assessment is possible but more difficult, and requires skill and experience to palpate the alignment.
  • Beyond the awkwardness, palpating and treating the coccyx can also be very tender. However, that stiffness and tenderness is usually similar to other stiff and tender joints in the body.
  • Treatments consist of small but often firm and potentially forceful pushes and pulls to the bone and its articulation to the sacrum and surrounding soft tissues.

In short, it’s a joint like any other, only in an awkward location. But this shouldn’t stop us from treating such an impactful structure!

Do You have a Coccyx Issue and Should You Consider Treatment?

This is by no means an exhaustive list, but here is some food for thought if you think you may have a coccyx issue:

  • You have coccyx pain! Anyone who’s had a hard fall or childbirth trauma and experiences coccyx pain should most certainly consider a manual assessment and treatment.
  • You have pelvic-floor dysfunction. As previously stated, this means either not enough or too much tone in the pelvic-floor muscles. This can manifest itself in several ways, including pelvic-floor pain, various types of incontinence, and/or sexual dysfunction. More subtle pelvic-floor dysfunction can create general hip, pelvis, and low-back pain.
  • Your ‘core is weak.’ If you’ve ever been tested or told your core is weak, or you do a lot of core work yet don’t seem to ever get stronger, a dysfunctional coccyx may be the cause.
  • You are really stiff! Significant stiffness, namely around the hamstrings (posterior thigh is usually sciatic nerve and fascia restriction), but also in the back, trunk, and even the neck, may be due to coccyx dysfunction. Again, in folks with this sort of neuro-fascial restriction, no amount of standard stretching improves mobility, and in fact, stretching might make the range of motion and pain worse.
  • You have a chronic injury. If you’re dealing with a chronic injury that seems impervious to rest and standard orthopedic treatment, it’s time to consider the coccyx. Either of the core-stability and neuro-fascial mobility factors are enough to cause a persistent chronic injury. Chronic nerve pain is a prime reason to assess and treat the coccyx.

As with ultrarunning, just because something is potentially awkward, difficult, and painful doesn’t mean it’s not worth doing. I began treating the coccyx six-plus years ago, first out of necessity. But when I began to see how it impacted other injuries and overall athletic function, coccyx treatment became an important part of my practice.

If you’re a medical professional, recognize that the tools that are often most painful and awkward are also the most potent. If you’re an ailing runner–perhaps someone who’s had a hard fall, experienced tailbone pain, or simply at wits’ end due to chronic pain and injury–seek out a skilled medical professional who can assess this vital structure.

Call for Comments (from Meghan)

  • Have you had a coccyx injury? How did it occur and what did it feel like?
  • Have you had a coccyx assessment and adjustment? What was the procedure like and did it help your ailment?
Joe Uhan

is a physical therapist, coach, and ultrarunner in Eugene, Oregon. He is a Minnesota native and has been a competitive runner for over 20 years. He has a Master's Degree in Kinesiology, a Doctorate in Physical Therapy, and is a USATF Level II Certified Coach. Joe ran his first ultra at Autumn Leaves 50 Mile in October 2010, was 4th place at the 2015 USATF 100K Trail Championships (and 3rd in 2012), second at the 2014 Waldo 100K, and finished M9 at the 2012 Western States 100. Joe owns and operates Uhan Performance Physiotherapy in Eugene, Oregon, and offers online coaching and running analysis at

There are 17 comments

  1. olga

    So, how do you treat it? 10 years ago I fell on my coccyx (mile 32 in a 100). and it broke (I did go on to finish that 100, of course). It healed, the break (while living normal life), but it is crooked, the Navasana in impossible, and the hamstring is surely tighter on one side. What now?

    1. Joe Uhan

      Hey Olga-

      Thanks for the comment.

      In short: you push or pull on it. Specific assessment looks at:

      * is it translated (shifted, but not bent) forward or back?
      * is it compressed (stiff) on the lower sacrum?
      * is it rotated?
      * is it sidebent?
      * is it flexed* or extended (bent forward or backward) (*flexed is extremely common, and usually what happens in falls).

      Again, a skilled/experienced manual therapist is key for this assessment and treatment! My general recommendation for great manual therapy PTs is anyone listed below:

      These folks have advanced training, outstanding manual therapy skills, and are educated similar to me.

      Good luck,

        1. Kristin Z

          Look for people through the institute of physical art for sure, Olga… come see my lady at Functional PT in Denver. She’s worth the drive and it won’t take but a few visits to correct the issue.

  2. MK

    I hope you passed!!!! Manual therapy is AMAZING. I tell my clients to get a PT with the OCS certification, bonus if they can do dry needling and manual therapy. I wish the manual therapy piece was more common!

  3. Trevor

    I’ve never experienced trauma to my coccyx, but in every ultra I’ve ever run without fail the first discomfort I always experience is my tailbone area. I don’t know if its the same for others but that is always where things start to really hurt. I manage it or eventually give in to a NSAID, but am wondering if there is some PT I can do to make it go longer without getting sore?

  4. Rachel

    I got a coccyx injury from a fall onto a hard gym floor about 4 years ago now. Whilst it doesn’t affect me every day and I still seem to be able to run okay, I know that some single leg strength work can cause it a bit of pain if I don’t warm up properly!

    My question is, is there any point in getting treatment 4 years on? I feel as though if I did any serious damage, that would be apparent by now, but could it affect me in the future?

    1. Joe Uhan


      Good question. I treat traumatic coccyx dysfunctions that happened up to 30 years ago. Like a fender-bender, once something gets “bent”, it’ll “stay bent” until something comes along and gets it aligned/moving properly.

      As such, it’s definitely worthwhile to have your coccyx be evaluated/treated. Moreover, it is definitley abnormal to get coccygeal pain from doing single leg strength.

      See above for my PT recommendations. Good luck,

  5. Jen

    I took a hard fall from my horse 5 days ago and I now hve a lot of discomfort when I run. Basically it feels like as my bottom moves up and down it hurts along the width of my back. Could this be my coccyx?

    1. Joe Uhan

      Sorry to hear about your fall, Jen.

      When you fall (even less severe than from a horse), the impact can reverberate throughout the pelvis and low back: any number of these structures can be affected.

      Many who injure themselves in falls like these can have pain for weeks. But if yours continues – and affects normal function – it’s best to see a MD and get some imaging done to rule out a fracture.

      Most of the folks on whom I mobilize the coccyx, had a fall like yours several weeks, months or years ago. A lot of the dysfunction tends to “creep up” after the acute state of healing is complete.

      Good luck,

  6. Elizabeth Johnson

    My son, age 17, a highschool sprinter, fell on his tailbone about two years ago and hasn’t been able to sit for long periods of time since. He is still able to compete but is frustrated by the impact the injury has on daily living.

    He tried PT last year via telemedicine (COVID) without much relief. He’s seen specialists, had x-rays and recently had a surgical procedure (steroid shots). The shots helped briefly around some parts of the cossyx but the pain never really went away.

    I read your article which gives me hope. I tried the links at the end of your article. One had expired the other I sent an email to. Waiting to hear.

    We live in the greater Boston, Massachusetts area. Any PT references you might have would be much appreciated.

    1. Joe Uhan

      Hi, Elizabeth-

      Thanks for the comment and sorry to hear about your son’s injury – and the long-lasting symptoms!

      Here’s the link for the other group that is very well-trained in coccyx treatment:

      (They do – or at least start with – “external” treatments, which are much less invasive, yet still effective).

      I treat the coccyx on probably 75% of all athletic lower extremity people I treat (of which maybe 1% have actual symptoms there). It’s an important structure! Thus, if you guys can connect with someone with CFMT certification, you should get some good results.

      Good luck!

  7. Savannah Miller

    Hello, I slipped and fell on the ice back in December. It hurt pretty bad but was not excruciating to the point I thought I may have done serious damage. Typical bruising and pain with sitting and movement, but has subsided to a constant, dull ache for the past month and half. The strange thing is, it seems my gluteal cleft has shifted down about an inch, and there is about an inch long oval shaped gap at the very top of it. The top part of my buttocks has flattened and my buttcrack is slightly crooked to the left of my body. Have you ever seen anything like this, and can it be corrected with treatment?

    1. Joe Uhan

      Hi, Savannah-

      Thanks for the message, sorry for the delay, and sorry about your fall!

      It’s *highly* likely that not (just) your coccyx but the sacrum is now out of alignment: It can shift upward, and only one one side, with hard falls. This would account for the appearance of both “shifting” and “crooked”-ness you’re observing.

      Yes, manual treatment can correct this and – in my opinion – is necessary to restore the alignment!

      Here’s a listing of highly-trained manual PTs that can perform this treatment:

      Good luck!

  8. Josie

    I have never fallen in my tailbone or experienced tailbone pain before in my life. Now I have started going to the gym and running a few miles in the treadmill. My tailbone is the only pain Im experiencing. It hurts to bend over!

    1. Joe Uhan


      Thanks for the comment and sorry to hear about your coccyx pain!

      You can have coccyx pain and dysfunction without a tailbone fall. (Any fall can do it; or no fall can do it, and aspects of core and pelvic floor stability can create strains on it).

      I would consult the above list for practitioners that can help you work on this and run pain-free!

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