All the patients will undergo ultrasound imaging of the lumbar spine just before epidural insertion. Ultrasound imaging will be performed by one of the investigators. A different anesthesiologist will perform the epidural procedure based on the US information provided by the investigator. The investigator will provide information to the epidural performer on the insertion point, the angle of needle insertion and safe approximate distance before reaching the epidural space to facilitate the epidural performance. To maintain blinding and to prevent performer bias, the exact depth of the epidural space from skin, as seen on the ultrasound will not be disclosed. The investigator, with the aid of an in-built caliper, will measure this distance at a later time before saving the image.