Muscular spasm, commonly known as muscle cramp, is a sudden and involuntary contraction of one or more muscles. There are several alternative terms that can be used to describe muscular spasm, which include spasmodic muscle contraction, twitching, convulsion, crick, kink, charley horse, and myoclonus. Spasmodic muscle contraction refers to a sudden and intermittent involuntary contraction of muscles that leads to rapid and jarring movements. Similarly, twitching refers to erratic, jerky movements of muscles that are often repetitive and involuntary. Convulsion is a more severe and longer-lasting form of muscular spasm that is characterized by violent and involuntary contractions of muscles. Crick, kink, and charley horse typically affect specific muscles and cause localized cramping and stiffness, while myoclonus refers to rapid, shock-like movements of a muscle or group of muscles.