Leading contenders for the anatomical basis of spinal pain are the discs, zygapophyseal joints and spinal muscles. There are no scientific data, however, that sustain the belief that muscles may be a source of chronic pain. On the other hand, controlled studies have shown how common discogenic pain and zygapophyseal joint pain are. Cervical zygapophyseal joint pain accounts for for more than 50% of chronic neck pain after whiplash. Collectively, lumbar zygapophyseal joint pain, internal disk disruption and sacroiliac joint pain account for nearly 70% of chronic low back pain.