Motor threshold (MT) refers to the threshold of intensity of transcranial magnetic stimulation necessary to trigger activation of the skeletal muscles when the coil is placed above the motor cortex. The motor cortex is a region of the brain central to movement and general motor function. At the motor threshold, the stimulation should effectively activate the motor cortex and thus skeletal muscles when TMS is used over the motor cortex,. Motor thresholds vary across individuals. Administering TMS in relation to an individuals motor threshold allows for determination of appropriate stimulation levels to ensure safety and maximize success of treatment. Motor thresholds have been shown to be correlated to the distance between an individuals scalp and their motor cortex.