Spindle cells are bundles of fibers found embedded within the larger bundles of fibers that create movement in a given muscle. They gauge the amount of contraction and extension of the larger bundle, as well as the speed of that movement, and communicate that information to the spinal cord and brain. One advantage of this is to protect the muscle. For instance, if a muscle contracts too much too fast so that it might be damaged, the spinal cord can respond quickly and “turn off” the muscle. In Kinesiology, we manually manipulate the spindle cells to identify if a muscle is in proper communication with the brain, and to turn a muscle on and off if necessary. This is used through Energy Kinesiology methods to identify a clear circuit indicator muscle – making sure a muscle is able to respond properly as a reliable indicator of the information being explored. In fact, the spindle cells that are involved every time a muscle is being monitored!