 Specifically, each needle tip was inserted to the bone at the groove between the transverse process and superior articular process on lumbar vertebra, or for sacral vertebrae at the lateral-superior border of the posterior sacral foramen. 
Specifically , each needle tip was inserted to the bone at the groove between the transverse process and superior articular process on lumbar vertebra , or for sacral vertebrae at the lateral - superior border of the posterior sacral foramen .