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.
If you are going to heal back pain you must first know the cause. The most common causes of back pain include: 1  Inactivity. 2  Muscle strains or tight hamstrings. 3  Poor posture. 4  Arthritis. 5  Non-supportive shoes.