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.
Spine disease â Since nerves in the thigh muscles run through the spine, compression of the spinal canal from discs or degenerative arthritis may lead to a sensation of thigh tightness. Muscle strain â A new activity or increased exercise intensity can cause thigh discomfort. Tendonitis â Just as muscles can be strained, tendons (which connect muscles to bones) can be inflamed or irritated. This is especially true after injury or an unusual activity. There are other, rarer causes. See your doctor. Stretching may be all you need. But the treatment depends on the cause so getting a diagnosis is an important first step.