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 tightness can cause muscle twitching, pain and reduced range of motion. Photo Credit Dirima/iStock/Getty Images. 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. If your lower back muscles lack strength, and a stronger back muscle pulls on this weak muscle, it can create tightness or pain. While lower back tightness can be managed at home, occasionally medical intervention is needed to treat this common condition. Rest your lower back muscles.