What Injuries Can Occur When You Fall on Your Buttocks?

When a person falls and lands directly on the buttocks—often referred to as a “sit-down” or “gluteal impact” fall—the force is transmitted vertically through the pelvis and spine, potentially injuring several anatomical structures. The most commonly affected areas include the sacrum and coccyx (tailbone), both of which are vulnerable due to their superficial location and limited soft-tissue protection. Coccydynia—a painful inflammation or injury to the coccyx—is among the most frequent diagnoses following such falls, especially in older adults or individuals with osteoporosis.

The sacrum, particularly its inferior portion, may sustain a compression fracture, especially in patients with diminished bone mineral density. In more severe cases, axial loading can propagate upward, leading to lumbar vertebral compression fractures—most commonly at L1 or L2. Rarely, high-impact falls may result in pelvic ring disruptions, including sacroiliac joint separation or pubic rami fractures, particularly when combined with rotational or lateral forces.

Soft-tissue injuries are also common: gluteal muscle contusions, sciatic nerve irritation (due to proximity to the piriformis and sacral foramina), and deep gluteal syndrome—characterized by chronic pain and functional impairment—may develop acutely or evolve subacutely. Clinicians should maintain a high index of suspicion for occult fractures in at-risk populations, as initial radiographs may be negative; MRI or bone scintigraphy may be warranted if clinical suspicion remains high despite normal X-rays.