This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Motor Centers gathers two of the nine centers in the bodygraph of Human Design, the modern system Ra Uru Hu began teaching in the early 1990s, the Heart or Ego or Will center and the Sacral, the two classed in this teaching as sources of drive rather than of awareness or pressure.
The Heart, Ego or Will center is one of the smallest in the chart, governing willpower, self esteem and the ability to make and keep promises to oneself and others, along with the drive to establish material worth; only a minority of people are said to have it defined. It sits near the physical location of the heart chakra of the older seven chakra system, but where that chakra is generally associated with love and compassion, Human Design assigns this center the narrower role of will and ego, locating love instead in the G center.
The Sacral is the teaching's source of the body's raw life force and work capacity, governing sustainable energy, sexuality and the gut level yes or no response the system calls sacral authority, said to be the most reliable form of decision making available to those who have it defined. It shares its name and generative association with the sacral, or svadhishthana, chakra, though Human Design gives it the further, specific role of a response mechanism rather than a general energy center; the teaching holds that a majority of people have this center consistently defined, making it the most commonly active center in the general population by its own account.
Between them the two motor centers cover opposite ends of the chart's own account of drive, the Sacral's response present in most people and the Heart's rarer, more selective will.