Clinical Characteristics and Neurophysiology of Lumbosacral Herniated Nucleus Pulposus (HNP) Rindha Dwi Sihanto1*, Putu Setiani1, I Gusti Ngurah Purna Putra1, Kadek Ayu Wiswapawani2 Abstract Background: The most common causes of lower back pain (LBP) are lumbosacral herniated nucleus pulposus (HNP), especially at the L5-S1 disc. EMG is one of the