Back muscle spasm, mainly refers to some altered symptoms of lumbar myofasciitis or third lumbar transverse process syndrome, mainly with sudden lumbar pain and limited forward flexion and back extension of the lumbar region. Physical examination may reveal pressure points at the attachment points of the lumbar paraspinal transverse process muscles, and there is usually no straight leg raise test (+), nor is it accompanied by radiating sciatic nerve pain in the lower extremities. Sometimes the pressure points of the lumbar back muscles are not obvious due to large spasms, and can be manifested as stiffness and weakness of the entire lumbar back muscles, which will be slightly relieved after bed rest.