All parts of the brain › Movement

What part of the brain controls movement?

No single part. The primary motor cortex, in the precentral gyrus of the frontal lobe, sends the commands: its fibres run down through the internal capsule and the brainstem to the spinal cord. The cerebellum and the basal ganglia (caudate nucleus, putamen, globus pallidus) do not drive muscles themselves; they shape movement through loops that pass through the thalamus and back to the motor cortex. [1][2][3][4]

The 3D brain needs JavaScript. The list of parts still says what each one does for movement.

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All 9 parts are lit together. Drag to turn, pinch or scroll to zoom, tap a part on the brain or a name in the list to focus it; .

Movement: 9 parts lit

Precentral gyrus, postcentral gyrus, cerebellum, caudate nucleus, putamen, globus pallidus, internal capsule, thalamus and brainstem. Tap one to see where it is and what it does.

The parts and their roles

Holds the primary motor cortex (Brodmann area 4), laid out as a map of the body, the motor homunculus: the leg near the top midline, the arm and hand further down the side, the face lowest. [1][5] Where is the precentral gyrus?
Just behind the motor strip, it receives touch and body-position (proprioception) signals relayed by the thalamus, the feedback on where the body is; it also sends fibres into the corticospinal tract, which starts mostly in motor areas but about 40% outside them, in the somatosensory cortex, parietal lobe and cingulate gyrus. [6][2] Where is the postcentral gyrus?
Does not start movements, but contributes to their coordination, precision and accurate timing, using sensory input from the spinal cord and other parts of the brain to fine-tune motor activity. [4] Where is the cerebellum?
With the putamen it forms the dorsal striatum, the main input station of the basal ganglia, receiving fibres from the cortex; it takes part in planning the execution of movement. [7][8] Where is the caudate nucleus?
The striatum’s other half; it regulates movements at several stages, such as preparation and execution, and takes part in kinds of learning. [9] Where is the putamen?
The main output side of the basal ganglia: its internal segment sends inhibitory signals to the thalamus, taking part in regulating voluntary movement below the level of awareness. [10] Where is the globus pallidus?
A band of white matter between the thalamus and caudate on one side and the putamen and globus pallidus on the other; the corticospinal fibres from the motor cortex pass down through its posterior limb. [11] Where is the internal capsule?
Its ventral lateral and ventral anterior nuclei relay the output of the cerebellum and the basal ganglia on to the motor cortex. [12][13] Where is the thalamus?
The corticospinal tract runs through it, and most of its fibres cross to the other side in the lower medulla (the pyramidal decussation); brainstem nuclei also send their own tracts down, such as the reticulospinal and vestibulospinal tracts, for posture. [2][14] Where is the brainstem?

How they work together

Because most corticospinal fibres cross over in the medulla, the motor cortex of the left hemisphere moves the right side of the body, and the right moves the left. [2]
The basal ganglia work in a loop: cortex → striatum (caudate and putamen) → globus pallidus → thalamus → back to the cortex. In the usual model the direct pathway helps a chosen movement go ahead and the indirect pathway holds back competing ones. [3]
The cerebellum runs its own loop: the cortex sends copies of motor plans through the pons to the cerebellum, whose output returns through the thalamus to the motor cortex, so errors are corrected while a movement is under way. [4]
The body map is not to scale: the hand, the face and the lips take up far more of the motor cortex than the trunk or the legs, matching how finely they are controlled. [15]
Honest limit: the premotor cortex and the supplementary motor area in front of the precentral gyrus also plan movement but have no separate piece on this model, and the motor neurons that finally drive the muscles sit in the spinal cord, which the model does not include. [1][16][17]

Sources

Facts describe anatomy and normal function only. A part lit here takes part in movement; it does not do it alone, and it does other jobs too. The 3D model is the adult male BodyParts3D brain (credits and licence); on it the brainstem includes the midbrain, pons and medulla, so lighting the brainstem lights all three.