The number one cause of lower-back pain is a tight hip flexor (or psoas). It happens to everyone and is usually caused by sitting down; another cause is sleeping on your side in a fetal position.

The number one cause of lower-back pain is a tight hip flexor (or psoas). It happens to everyone and is usually caused by sitting down; another cause is sleeping on your side in a fetal position.

Original article and pictures take https://sciatica.sciatica-pain-relief.com site