Muscle cramps are caused by spasms or when the muscle fibers contract with or without any effort. The muscles get tight and fail to relax during the spasmodic phase and one may feel bulging and hardness in the affected region. Cramps may occur in one or group of muscles that often subside after mild stretching and massage. But in severe cases, one may require muscle relaxant medications that help muscle to loosen up.
The most common groups of muscles prone to spasms are lower leg (calf), front of thigh (quadriceps) and back of thigh (hamstrings). However, muscle spasm may also occur in upper extremities, rib cage and abdomen. The causative factors include poor blood supply, overexertion, dehydration, nutritional deficiencies, muscle fatigue, etc. Muscle spasms and pain can be alleviated with the help of effective muscle relaxant drugs that has antispasmodic properties.