primary curves:Thoracic and sacral curves: present at birth

Secondary curves: Cervical and lumbar: Develop at 3 and 9 months respectively

Include

• Cervical curvature; convex anteriorly (c1 – T2)
  
  
• Thoracic curve, concave anteriorly (T2 – T12)
  
  
• Lumbar curve, convex anteriorly (T12 and lumbosacral joint)
  
  
• Saccrococcygeal (pelvic) curve, concave anteriorly (lumbosacral joint to tip of the coccyx)

Note:
Vertebral column characterized by gentle sinuous bends, which give the column some resilience, but the intervertebral discs are the major shock absorbing devices.