Muscle spasm is an involuntary contraction of a muscle that can cause a great deal of pain. When the facet joints of the spine become injured or inflamed, the muscles supporting the spine can spasm causing low back pain and limitation in motion.
Muscle spasm is typically treated conservatively with muscle relaxants and exercise therapy. Muscle relaxants inhibit painful contractions by sedating the muscle, while exercise stretches the muscles so they are less likely to strain, tear or spasm.
Applying heat therapy using a heat pad may also help relax muscle spasms.