My Toddler is humping the floor.

Patient: My daughter is 19 months, at 14 months she started to hump the floor. She lays flat on her stomach, toes pointed, palms up and humps for long periods of time, I dont know if her stomach is hurting or what! But she does it for so long her face turns red and she sweats!But she is not indicating that she is in any pain.

Doctor: