Motor Strip

The motor strip is a long narrow area in the frontal lobe. It is situated in the anterior central gyrus and runs down parallel to and in front of the central sulcus. The motor strip controls all bodily movements; the motor strip in the frontal lobe of the left cerebral hemisphere controls the movement of the right side of the body; and that of the right controls the movement of the left side of the body.

The most striking aspect of the motor strip map is that the areas assigned to various body parts on the cortex are proportional not to their size, but rather to the complexity of the movements that they can perform. Hence, the areas for the hand and face are especially large compared with those for the rest of the body. This is no surprise, because the speed and dexterity of human hand and mouth movements are precisely what give us two of our most distinctly human faculties: the ability to use tools and the ability to speak.