The two bony points you feel when you sit down, commonly called the sit bones, are anatomically known as the ischial tuberosities. These large, rounded protuberances form the lower part of the pelvis and are specifically designed to bear the body’s weight in a seated position. Using these structures correctly as your foundation is fundamental to achieving good posture and ensuring the spine is properly supported. Correct alignment helps distribute forces evenly throughout the musculoskeletal system, which can reduce the chronic strain that often leads to back and neck discomfort.
Identifying Your Ischial Tuberosities
To begin, sit on a firm, flat surface that allows you to feel the contact points beneath you. A dining chair or a stool is often better than a soft couch for this initial exploration. Place your hands, palms up, underneath your buttocks, positioning one hand under each side.
Gently rock your body side to side and forward and backward until you feel two distinct, hard points pressing into your palms. These are your ischial tuberosities. You may notice that when you slouch, the pressure shifts away from these bones and onto the tailbone area.
The goal of this exercise is simply to locate these bones and become aware of how your weight shifts as your pelvis moves. Once you have successfully identified the bones, remove your hands and try to maintain that conscious connection with the chair surface. This physical sensation serves as immediate feedback for your seated posture.
The Technique for Optimal Sitting Alignment
The primary objective for optimal sitting is to establish a neutral pelvic tilt, which allows the spine to maintain its natural, gentle S-curve. Once you have located your sit bones, slowly rock your pelvis forward and backward repeatedly.
When you rock too far back, you are in a posterior tilt, which rounds the lower back and shifts your weight behind the sit bones. When you rock too far forward, you are in an anterior tilt, which creates an exaggerated inward curve in the lower back. The neutral position is the point between these two extremes, where your weight feels centered directly on the base of the sit bones. In this balanced position, the pelvis is level, providing a stable foundation for the rest of the torso.
The next step is to vertically stack the ribcage directly over the newly aligned pelvis. This stacking allows the head to balance naturally over the shoulders, maximizing the skeletal system’s ability to support your weight. When the skeleton is properly aligned, the surrounding muscles can relax, requiring only minimal core engagement to maintain the upright position. For many people, sitting slightly forward of the absolute center of the sit bones helps to encourage the necessary slight anterior tilt of the pelvis.
Applying Alignment to Different Postures
The fundamental technique of sitting squarely on your ischial tuberosities must be adapted for real-world environments. In a typical office chair, the backrest and lumbar support should be used to gently reinforce the neutral pelvic tilt you established. Scoot back so your pelvis contacts the seat back, and then adjust the lumbar support to fill the natural inward curve of your lower back. This support prevents the pelvis from rolling backward into a slouched, posterior tilt over time.
For floor sitting, such as during meditation or yoga, the hips must be elevated above the knees to enable a neutral pelvis. Using a firm cushion, a meditation block, or a folded blanket under the sit bones is necessary to achieve this height difference. Without this elevation, the hips are forced to flex, which often pulls the pelvis into a posterior tilt, causing the lower back to round.
When driving, apply the same principle by adjusting the seat angle and position. Ensure the seat bottom is not excessively reclined, and use a small, rolled towel or a dedicated lumbar pillow to support the lower back’s natural curve. The goal is always to position the pelvis as closely as possible to the balanced, upright alignment.