Several bones sit beneath the muscle and fat of your buttocks, and yes, any of them can break. The coccyx (tailbone), sacrum, and ischial tuberosities (the bony points you sit on) are all vulnerable to fractures from falls, sports injuries, repetitive stress, and even childbirth. What makes buttock fractures particularly tricky is that they are frequently misdiagnosed or missed entirely, sometimes for weeks or months, because the pain can mimic common conditions like a herniated disc or muscle strain.
The Bones Underneath
Your buttocks are mostly soft tissue, dominated by the gluteus maximus, one of the largest muscles in the body. But underneath that muscle lies a ring of bone. The pelvis is formed by the right and left hip bones, each made up of three fused bones: the pubis, ischium, and ilium. At the back of the ring sit the sacrum, a broad triangular bone at the base of the spine, and the coccyx, the small tailbone at the very bottom.1PubMed. Anatomy, Bony Pelvis and Lower Limb: Pelvis Bones When people say they “broke their butt,” they are almost always talking about one of three structures: the coccyx, the sacrum, or the ischial tuberosity, which is the bony knob at the bottom of the ischium where your hamstring tendons attach. Each of these breaks in different ways, for different reasons, and with different consequences.
Coccyx Fractures From Falls and Direct Impact
The most common way to fracture a bone in your buttocks is to land hard on your tailbone. A slip on ice, a fall down stairs, or a direct blow during contact sports can crack or displace the coccyx. Because the coccyx is small and sits right at the surface, it takes the brunt of any seated impact. The pain is immediate, sharp, and typically worst when sitting down or leaning back. Standing and walking may feel tolerable by comparison, but sitting on a hard surface becomes agonizing.
Most coccyx fractures heal without surgery. Conservative treatment works in roughly nine out of ten cases, and many resolve without medical intervention beyond pain relief.2PubMed Central. Coccydynia: an overview of the anatomy, etiology, and treatment of coccyx pain A donut-shaped cushion, over-the-counter painkillers, and avoiding prolonged sitting are the standard advice. For the minority of cases where pain becomes chronic, options include pelvic floor rehabilitation, manual manipulation, steroid injections, nerve blocks, and in stubborn cases, surgical removal of the coccyx. But that last option is rare and reserved for pain that has resisted everything else for months.
Sacral Fractures
The sacrum is the wide, shield-shaped bone just above the tailbone. It connects the spine to the pelvis and bears a large share of your upper body weight. It can fracture from two very different causes, and those causes tend to show up in very different populations.
High-energy trauma, such as car crashes, falls from height, or heavy impacts during sports, can crack the sacrum as part of a broader pelvic ring injury. These fractures are often serious and may involve multiple pelvic bones at once. They tend to occur in younger, otherwise healthy people involved in accidents. Sacral fractures in this setting are relatively common among pelvic injuries, though they are frequently underdiagnosed even in emergency departments.3PubMed Central. Sacral fractures: issues, challenges, solutions
The second cause is far quieter and happens without any obvious injury at all. In older adults with osteoporosis, the sacrum can develop what are called insufficiency fractures. These occur when normal, everyday forces like walking or standing are enough to crack weakened bone. The patient may not recall any fall or impact. They just gradually develop deep low back or buttock pain that gets worse over weeks.4PubMed Central. Sacral insufficiency fracture, usually overlooked cause of lumbosacral pain Because sacral insufficiency fractures are becoming more frequent as populations age worldwide, they represent a growing clinical challenge.3PubMed Central. Sacral fractures: issues, challenges, solutions
Symptomatic improvement from sacral insufficiency fractures can take up to a year. The standard treatment is rest, pain management, limited weight-bearing, and sometimes a sacral corset. These fractures carry real risks of prolonged immobility in elderly patients, which itself leads to complications like blood clots and pneumonia.5PubMed. Percutaneous sacroplasty for osteoporotic sacral insufficiency fractures: a prospective, multicenter, observational pilot study
Ischial Tuberosity Avulsion Fractures
The ischial tuberosities are the two bony projections at the bottom of your pelvis, the ones you’re resting on right now if you’re sitting in a chair. Your hamstring muscles attach here via thick tendons, and in young athletes whose bones haven’t fully matured, a sudden powerful contraction can literally rip a chunk of bone away from the pelvis. This is called an avulsion fracture.
The typical scenario is a teenager or young adult making an explosive kicking motion during soccer, football, or dance. The hamstring contracts so hard and so fast that the tendon pulls a piece of the ischial tuberosity off with it.6PubMed Central. A novel approach to treatment for chronic avulsion fracture of the ischial tuberosity in three adolescent athletes: a case series It’s a sharp, sudden pain deep in the buttock, often accompanied by bruising that shows up a day or two later. The athlete can usually point to the exact moment it happened.
These fractures are more common in adolescents than adults because the growth plates at the ischial tuberosity haven’t fused yet, making that area structurally weaker than the tendon pulling on it. In a fully grown adult, the same force would more likely tear the tendon itself, producing a hamstring avulsion without a bone fragment. Most ischial avulsion fractures in young athletes heal with rest, but chronic or displaced cases sometimes need surgical fixation to reattach the bone fragment and restore normal hamstring function.
Stress Fractures in Runners and Endurance Athletes
The sacrum can also fracture from repetitive loading rather than a single traumatic event. Sacral stress fractures are an occupational hazard for long-distance runners and triathletes who put thousands of impact cycles through their pelvis every week. Some studies suggest the incidence of sacral stress fractures in athletes may be as high as one in five, though many go undiagnosed.7PubMed Central. Sacral stress fracture in a young-adult, long-distance runner: an underestimated cause of low back pain
The symptoms are vague enough to fool both athletes and their doctors. Deep buttock or low back pain that worsens with running but eases with rest sounds a lot like a disc problem or piriformis syndrome. A clinical exam can mimic findings seen in disc disease, which is one reason the fracture gets missed.8PubMed. Sacral stress fractures in long-distance runners One interesting anatomical quirk is that sacral stress fractures in endurance athletes usually show up on just one side, even though running and walking appear to load the sacrum symmetrically.9Sports Orthopaedics and Traumatology. Laterality of sacral stress fractures in trained endurance athletes: Are there biomechanical or orthopaedic risk factors? The exact reason for this asymmetry is still debated, but it suggests subtle differences in leg length, running form, or pelvic alignment may concentrate stress on one side.
An athlete with a sacral stress fracture needs to stop running, full stop. Continuing to train through the pain risks turning a hairline crack into a complete fracture, which can turn a few weeks off into months of recovery. This is where accurate diagnosis matters most, because the treatment for a stress fracture and the treatment for a herniated disc are essentially opposite: a disc problem often improves with carefully graded activity, while a stress fracture demands rest.
Why Buttock Fractures Are So Often Missed
A recurring theme across nearly every type of buttock fracture is how frequently they escape detection. Sacral insufficiency fractures in elderly patients are easy to mistake for degenerative spine disease. One study using MRI to screen patients with spinal compression fractures found that about three percent also had sacral insufficiency fractures, and over three-quarters of those cases had been missed by the treating physicians.10PubMed Central. Osteoporotic sacral insufficiency fracture: An easily neglected disease in elderly patients The symptoms overlap so heavily with lumbar disc disease and arthritis that neither the patient nor the doctor has a strong reason to suspect a fracture unless imaging picks it up.
Part of the problem is that the go-to imaging tool in an emergency, a plain X-ray, is poor at showing sacral fractures. The sacrum is overlaid by the bowel and other soft tissues on standard films, making subtle cracks invisible. CT scans are the typical first-line advanced option and serve as the gold standard for initial diagnosis of pelvic fractures. But even CT misses a meaningful share. In a direct comparison, MRI detected about 96 percent of all pelvic fractures while CT caught roughly 77 percent. For sacral fractures specifically, MRI picked up nearly 99 percent compared to about 66 percent for CT.11PubMed. Comparison of diagnostic accuracy of Magnetic Resonance Imaging and Multidetector Computed Tomography in the detection of pelvic fractures Despite MRI’s superiority for detecting hidden fractures, CT is often preferred in emergency settings because it is faster and practical for the many elderly patients who cannot undergo MRI.12PubMed Central. The Role of MRI and CT Scan in Classification and Management of Pelvic Fractures: A Systematic Review
If you have persistent deep buttock pain after a fall, a sports injury, or even without any clear trauma, and initial imaging comes back normal, it is reasonable to ask whether an MRI might reveal something the X-ray or CT missed. This is especially true for older adults with osteoporosis and for endurance athletes with pain that does not respond to the usual treatments for muscle or disc problems.
When Buttock Pain Is Actually a Hip Fracture
Not every fracture that causes buttock pain is actually located in the buttock. Hip fractures are notorious for referring pain to the groin, upper thigh, and buttock. “Hip pain” in clinical settings usually means pain felt in the groin, upper thigh, or buttock region.13PubMed. ‘Hip’ pain A person with a hip fracture may report buttock pain and an inability to bear weight on the affected leg, with the pain worsening when they try to walk.14Archives of Pharmacy Practice. Hip Bone Fracture Diagnosis and Management
This matters because a hip fracture is a medical emergency that needs prompt treatment, while a bruised buttock is not. If you fall and land on your side or back and develop deep buttock pain that makes it impossible to stand or walk, do not assume you simply bruised your tailbone. A hip fracture can feel like it’s coming from the buttock, and the consequences of delaying treatment are serious, particularly for older adults. Hip and pelvic fractures can also injure the sciatic nerve, causing weakness or numbness running down the leg.15PubMed. Hip and pelvic fractures and sciatic nerve injury
How Treatment Varies by Fracture Type
The treatment path depends heavily on which bone is broken and how badly. Simple coccyx fractures and stable sacral fractures are managed conservatively: rest, pain relief, and early return to movement as the pain allows.3PubMed Central. Sacral fractures: issues, challenges, solutions For coccyx fractures, a cushion with a cutout to relieve pressure on the tailbone is the most practical day-to-day aid. Most people are back to normal activities within a few weeks to a couple of months, though sitting on hard surfaces may remain uncomfortable longer than that.
Unstable fractures with significant displacement, particularly those involving the sacrum as part of a disrupted pelvic ring, often require surgical fixation.16PubMed Central. Surgical management of lumbosacral and sacral fractures: roles of the pelvic and spinal surgeons These injuries typically result from high-energy trauma and may involve bleeding into the surrounding soft tissues. One study of pelvic fractures found hemorrhage extending into the gluteal (buttock) area in about four out of five patients, underscoring how much soft tissue damage can accompany these injuries.17PubMed Central. Anatomic distribution of hematoma following pelvic fracture
For sacral insufficiency fractures in osteoporotic patients where pain remains severe despite weeks of conservative care, a procedure called sacroplasty may be considered. It is similar to vertebroplasty in the spine: bone cement is injected into the fracture site to stabilize it and reduce pain. This remains a specialized option available mainly at larger medical centers.
Coccyx Injuries During Childbirth
One cause of buttock fractures that rarely comes up in general discussions is vaginal delivery. The coccyx sits directly behind the birth canal and must flex backward as the baby’s head passes through. In most deliveries, this movement is tolerated without injury. But in difficult or prolonged labor, or when instruments like forceps are used, the coccyx can be bruised, dislocated, or fractured.18PubMed Central. Intrapartum Coccygeal Fracture in a Young Female: A Case of Prolonged Postpartum Coccygodynia Vaginal delivery is often linked to damage of the ligaments connecting the sacrum to the coccyx, and the passage of the baby can cause acute coccyx trauma, a risk further increased by forceps-assisted delivery.19INTI JOURNAL. Coccydynia and Disability on Postpartum Vaginal Delivery Women
Postpartum tailbone pain is often dismissed as normal soreness from delivery and may not be investigated with imaging unless it persists. A woman who has ongoing pain at the base of her spine weeks after delivery, particularly pain that is worst when sitting or transitioning from sitting to standing, should bring it up with her doctor rather than assuming it will resolve on its own. Most cases do improve with time and conservative measures, but identifying a fracture early can help guide appropriate pain management and avoid months of unnecessary suffering.
Protecting Against Buttock Fractures
For athletes, the most actionable prevention strategy for sacral stress fractures is monitoring training load. Sudden jumps in mileage or intensity, combined with inadequate nutrition (especially low calcium and vitamin D intake or low energy availability), create the conditions for bone stress injuries. Female athletes with disrupted menstrual cycles are at elevated risk because of the associated drop in estrogen, which is critical for bone maintenance. Addressing these factors does not guarantee prevention, but it meaningfully reduces the odds.
For older adults, fall prevention is the primary strategy. Most coccyx and sacral fractures in this population happen during falls, and the risk compounds when osteoporosis is present. Home modifications like grab bars in bathrooms, better lighting, and removing loose rugs are mundane but effective. Managing osteoporosis with medication when indicated can also reduce the likelihood that a fall results in a fracture rather than a bruise. Padding technology has advanced as well: 3D-printed protective pads designed to absorb impact to the hip and pelvis have demonstrated roughly an 80 percent reduction in impact force in testing.20PubMed Central. Developing Fall-impact Protection Pad with 3D Mesh Curved Surface Structure using 3D Printing Technology While hip protectors have had mixed adoption rates, the technology continues to improve.
For anyone who spends long hours sitting, especially on hard surfaces, the straightforward advice is to use a cushioned seat and change positions regularly. This won’t prevent a fracture from a fall, but it reduces the chronic irritation and bruising of the coccyx that can make the tailbone more vulnerable over time and can mimic fracture symptoms even when no break has occurred.