• The pelvis is rocked by alternately tightening the glutei and the abdominal wall and then relaxing them.
• The lumbar spine is humped up and hollowed down alternately. (same as above)
• When Flexion and extension of neck is also done with the humping and the arching respectively, the neck is also exercised.

A very good exercise for the whole spine mobility especially in bamboo spine. (Ankylosing Spondylitis)