What is a normal function and purpose of the lordotic curve in the lumbar spine?

The curves of the spine help to absorb shock and vibration that occurs during locomotion (walking or running). Visualize how a straight spine would transmit the jarring motion up to the head, just from the impact of walking. Also, when a fetus is developing, the spine is in a “C” shape. The lordotic curves of the cervical and lumbar spine develop after birth, and permit the human to get the torso over the pelvis and head over the shoulders when standing. The amount of lumbar range of motion depends more on the shape of the individual vertebra and characteristics of the ligaments.