Lower back pain is strongly linked to prolonged static sitting. When sitting for long periods, the same muscles remain active. Incorrect desk or chair height forces the spine into poor alignment. This increases pressure on the lumbar area. Pain builds up gradually throughout the day.
Back pain often worsens as muscles become fatigued. Many people start the day with reasonable posture. As energy drops, posture collapses. The lower back absorbs more strain without support. This explains why pain peaks later in the day.