A Protruding Lower Belly and a Stiff Lower Back: What the Psoas Muscle May Have to Do With It

Why Sitting Can Make It Worse

Long sitting keeps the hips bent for hours. Over time, this may contribute to tight hip flexors and weak glute or core muscles. When you stand up, the body may struggle to fully open the hips, and the lower back may compensate.

That is why many people feel stiff when they rise from a chair, after driving, or after working at a desk. Gentle movement often helps more than complete rest. The NHS advises staying active and continuing normal activities as much as possible for most back pain, while avoiding movements that make pain worse.

Signs the Psoas May Be Involved

The psoas may be contributing if you notice: