The spine consists of a series of bones, called vertebrae, and the soft spongy discs that separate them. Surrounding the spine is a tremendous number of different muscles that control spinal motion. A spasm is an involuntary contraction of a muscle that can be intermittent or prolonged, and is often painful and debilitating. According to the American Chiropractic Association, back pain is the second leading reason Americans visit a doctor.
Anyone who has been unfortunate enough to be in an auto accident has likely experienced the effects of back muscle spasms. When muscles are strained or torn, inflammation occurs which can lead to muscle spasm. Back muscle strains occur often in sports, such as weightlifting, golf, football, basketball and baseball, where quick, sudden movements are required, according to Cedars-Sinai. Back muscle spasm may be an attempt by the body to help immobilize the region where an injury has occurred to prevent further damage.
Muscles can be injured in ways other than trauma that can lead to inflammation and muscle spasm. According to Spine Universe, poor posture leads to back pain. Chronic poor posture causes muscles to be overstressed for long periods of time and leads to shortening or tightening of those muscles. Corresponding muscles on the opposite side become weak and lead to additional stress because, they are unable to do their job properly in maintaining posture and proper movement. Continual stress to the muscle fibers causes damage, inflammation and eventually, muscle spasm.
One cause of back muscle spasm is spinal joint dysfunction. Joints of the spine that are not moving and functioning properly will cause problems to arise in the surrounding soft tissues. The joints of the body, especially the spine, are designed to move and require movement for good joint health. When the muscles that attach to each of these joints are overstressed because of poor alignment or motion, they become injured in the same way as with poor posture. Inflammation and muscle spasms become the result of chronic joint dysfunction. According to Cedars-Sinai, an increase in the curvature, or lordosis of the spine and forward tilting of the pelvis can lead to muscle spasm. This is because these two conditions lead to stress and dysfunction in these joints.
Muscles in the legs, such as hamstrings, often become tight and inflexible and can contribute to muscle spasms in the low back. Other muscles, such as the gluteal and abdominal muscles often become weak. Both sets of muscles affect the function and balance of the lumbar spine. Weakness and tightness leads to additional stress and eventually muscle spasm.