Since the distance between the Zeeman sub-levels is a function of the magnetic field, this effect can be used to measure the magnetic field, e.g. that of the Sun and other stars or in laboratory plasmas.
Charley horse: Slang for a cramp in a muscle in the leg, usually caused by a strain or injury. A charley horse can last anywhere from a few seconds to over a quarter of an hour. It is not uncommon for one to recur before it finally resolves.
Thigh contusion explained. Although a dead leg or charlie horse can often seem a minor injury it is important the correct diagnosis is made. If you try to exercise on a bad intramuscular injury you can prevent healing or even cause permanent damage. If heat or massage is applied too early Myositis Ossificans or bone forming within the muscle.