A slipped disc occurs when the jelly-like disc of cartilage that acts as a cushion between two vertebrae in the spine, slips or prolapses so it is pressing on the nerves causing the muscles of the back to go into spasm.

• 椎间盘脱出是由于脊柱两块椎骨中的起缓冲冲击作用的胶状椎间盘软骨发生滑动或脱垂时；压迫椎管内神经引起后背痉挛.