The sudden, sharp pain felt at the base of the spine during or after squats is medically known as coccydynia. This localized discomfort in the tailbone area can transform a routine exercise into a source of frustration. While the squat is a fundamental movement, its nature can expose structural or mechanical vulnerabilities in the lower back and pelvis. Understanding the anatomy, biomechanics, and pre-existing factors is the first step toward pain-free lifting. This guide explores the structural, mechanical, and underlying reasons why your tailbone hurts during your squat routine.
Anatomy of the Coccyx and Its Role in Squatting
The coccyx, or tailbone, is the final segment of the vertebral column, typically composed of three to five small, fused vertebrae. This triangular bone serves as an anchor point for several soft tissues, including the gluteus maximus and pelvic floor muscles like the levator ani.
This placement means the coccyx is subject to tension and movement from these muscles during a squat. The bone also lacks the thick cartilage or cushioning discs found higher up the spine, making it sensitive to direct pressure. When sitting, the coccyx acts as a point of a tripod, distributing body weight alongside the ischial tuberosities, or sit bones.
The small, passive movements that occur at the sacrococcygeal joint, where the coccyx meets the sacrum, can be irritated if surrounding muscle tension is excessive. Because of its ligament and muscle attachments, any mechanical change in pelvic position during a squat can translate into strain on the tailbone.
How Poor Squat Form Creates Direct Pressure
The primary mechanical cause of tailbone pain during squats is a phenomenon commonly called “butt wink.” This happens at the deepest point of the squat when the pelvis tucks underneath the body, causing the lower spine to lose its neutral curve and round into flexion.
When the lumbar spine rounds, the weight-bearing load shifts away from the shock-absorbing muscles of the hips and legs. This action instead directs compressive force onto the lower spinal segments and the coccyx itself. Loading the spine in this flexed position under the weight of a barbell increases stress on the structures near the tailbone.
The butt wink often results from insufficient hip or ankle mobility, which prevents the femur from moving adequately within the hip socket. As the lifter attempts to squat deeper than their available range of motion allows, the body compensates by tilting the pelvis posteriorly. This excessive depth, coupled with external weight, causes the compression that leads to localized pain.
Underlying Physical Conditions That Exacerbate Tailbone Pain
In many cases, the squat itself is not the cause of the pain but rather the trigger for a pre-existing condition. A history of previous trauma, such as a direct fall onto the tailbone or injury sustained during childbirth, can make the coccyx hypersensitive. This past injury may have caused chronic inflammation or altered the alignment of the sacrococcygeal joint.
Chronic tightness in certain muscles can also pull on the coccyx, causing irritation. The piriformis muscle and the levator ani muscles of the pelvic floor both attach near the tailbone. Spasm or hypertonicity in these muscles can result in a constant tugging sensation that is aggravated by the movement of a squat.
Conditions like coccygeal bursitis or hypermobility of the sacrococcygeal joint also make the area reactive to pressure. Even without trauma, repetitive microtrauma from poor posture during prolonged sitting can create a baseline of pain, which the added strain of a squat exacerbates.
Immediate Adjustments and Long-Term Prevention
To immediately reduce tailbone pain, the most effective adjustment is to limit the depth of your squat. Only descend as far as you can while maintaining a neutral, unrounded lower back, stopping just before the onset of the butt wink. Widening your stance and allowing your toes to point slightly outward can accommodate your natural hip structure, often increasing hip mobility and reducing pelvic tucking.
Focus on maintaining a braced core throughout the movement, which helps stabilize the lumbar spine and pelvis. When initiating the squat, think about pushing the hips back rather than simply dropping straight down. Long-term prevention involves addressing underlying mobility and stability deficits.
Regular mobility work targeting the hip flexors and ankles can improve the range of motion necessary for a safe squat. Strengthening the deep core stabilizers and gluteal muscles ensures proper control over the lumbo-pelvic area. If sharp, persistent pain continues despite these adjustments, or if the pain is present even when not exercising, consult a healthcare provider or physical therapist for a comprehensive evaluation.