An electromagnetic coil is an electrical conductor such as a wire in the shape of a coil, spiral or helix. Electromagnetic coils are used in electrical engineering, in applications where electric currents interact with magnetic fields, in devices such as inductors, electromagnets, transformers, and sensor coils.
Causes of lower back spasms. Back spasms can be the result of injuries to the muscles, tendons, and ligaments in the back or it can be related to more serious medical conditions. Heavy lifting is a common cause of back spasms. Any activity that puts excessive strain on the muscles and ligaments in the lower back can cause an injury.
Some spasms occur because the nerve that connects to a muscle is irritated. One example is a herniated disk irritates the spinal nerves and causes pain and spasm in the back muscles. Spasms in the calf often occur while kicking during swimming. They can also happen at night when you are in bed.