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.
Tight back muscles are sometimes an indicator of imminent back pain. Other times, tightness is a chronic concern that can create worry and discomfort for a very long time-frame.Tight muscles are a natural expression of conscious and sometimes subconscious stress.any patients experience muscle tightness just prior to having an acute attack of pain and others experience a constant tightness corresponding to their chronic back pain conditions. Tension is not a natural condition for normal muscles.