Spinal anaesthesia should be injected into the space between –
L2-3 or L3-4 intervertebral space is used in adult as adult spinal cord ends at lower border of L1 vertebrae.
L4-5 intervertebral space is used in children as spinal cord ends at lower border of L3 vertebrae in children.
T12 – L1
L1 – L2
L3 – L4
L5 – S1