The reason for your excessive arch in the lower back may be in the feet.

The condition of the feet directly affects the health of the back. If the arches of the feet are violated and the toes lose their ability to repel, then this leads to the shutdown of the gluteal muscles. And if the gluteus muscle is turned off, then the pelvis will tip forward. And this leads to the formation of too much deflection in the lower back. To restore the normal deflection in the lower back, you need to achieve the correct work of the gluteal muscles while walking. And this can be done by working with the feet. Strengthen the arches of your feet, include your toes in the process of walking, and you will notice that your gait and the state of the lumbar region have changed for the better.