Active and Passive Immunity. Naturally acquired active immunity occurs when the person is exposed to a live pathogen, develops the disease, and becomes immune as a result of the primary immune response. Artificially acquired active immunity can be induced by a vaccine, a substance that contains the antigen.
Lower back tightness can cause muscle twitching, pain and reduced range of motion. Lower back muscle tightness is the cause of a muscle spasm. This can be brought on by a strain, overuse or muscle weakness, according to BetterMedicine.com.
Lower back pain causes. Psoas muscle tightness is almost always involved in lower back pain causes. And the prevalence of low back pain is extremely common because modern society requires humans to sit for long periods of time. We sit while driving, we sit at desks all day for work or school, and we sit while flying in airplanes.