One of the body’s natural, protective response mechanisms, a muscle spasm is an involuntary, sustained contraction of the muscle fibers in response to injury or inflammation, either in the muscles themselves or the nerves that serve them. In the back, muscle spasms also may signal injury or damage to an underlying spinal structure such as the vertebrae, discs or ligaments that connect the vertebrae. Back spasms may occur for a variety of reasons: a sudden or extended trauma to the spine or the muscles and tissue that support it such as a strain or sprain, or some other type of mechanical disorder that may be causing spinal nerve compression or irritation.

What Are The Symptoms Of Muscle Spasm?
The primary symptoms of a muscle spasm typically include acute back pain or neck pain, depending on the location of the underlying injury or condition, accompanied by a sensation of severe muscle tightening, which may occur in "cycles" that last from a few seconds to several minutes.

The pain and stiffness actually serve a two-fold purpose: to signal that something’s wrong and to protect the affected tissues and structures from further injury by limiting motion. Symptoms tend to appear suddenly following physical activity, and usually ease up following a period of rest.

Home Remedies for Muscle spasms
There are a number of home remedies that are useful in treating muscle spasms and cramps. One of the most common is apple cedar vinegar. A couple of teaspoons mixed with water are supposed to relax your muscles almost immediately. Keep in mind that vinegar should always be diluted before consumption and should never be consumed directly.

Heat is also supposed to relieve knotted muscles. In most cases, knotted muscles are overworked muscles and the application of heat will relax them. This is why relaxing in a hot bath will often relieve cramps. Even a warm towel or a hot water bottle applied on the affected area will give a lot of relief.

If you have Charley horse symptoms during the night, wearing socks before you sleep could help. Although there is no scientific reason for this, it has been found that people who suffer from spasms in their legs at night also have cold feet. Wearing socks may not have been proven to work in double blinded studies but there’s no harm in giving it a try.

In many cases, the spasms are caused due to dehydration and just drinking a lot of water will help.

Also muscles contract and relax through the movement of calcium and potassium into and out of the cells of the muscles. In this day of dieting, it is quite possible that the body is deficient in these important micronutrients.
Ensure that you eat well and get a sufficient amount of nutrients.