Motor skills

Brain Control of Voluntary Movements

Voluntary motor activity is controlled by the so-called pyramidal pathway. It consists of pyramidal or corticospinal neurons (from the motor cortex to the spinal cord) and motoneurons (from the spinal cord to the muscles).

Voluntary movements are produced by sequential or simultaneous activation of different brain regions (Scheme 1):

• the prefrontal cortex and parietal cortex integrate information to plan movement according to the environment,

• the premotor cortex and the extra motor cortex organize the sequence and coordination of complex movements,

• the motor cortex sends the command to the muscles to execute the gesture,

• basal ganglia and cerebellum modulate motor cortical area activity to regulate movement.

These brain areas are interconnected by networks of neurons that allow them to communicate, and this dialogue evolves as movement takes place. A motor cortex is found in both hemispheres of the brain, each controlling the opposite part of the body: the motor cortex of the right hemisphere controlling the movements of the left part of the body and vice versa.

It is the communication and synchronization of the activity of the different regions according to their importance in the programmed movement that will allow a gesture adapted to the environment.

There are differences between physical activities in reproducible environments such as running and in more unstable environments such as team sports where it is necessary to integrate the location and movements of each player.

The networks of neurons that allow different regions of the brain to communicate are plastic. Learning and practicing physical activity, that is, specific motor sequences, leads to morphological and functional changes in the brain.

The cerebellum is a structure at the back of the brainstem, beneath the brain. Despite its small size, it has all the characteristics of the brain with a cortex, deep nuclei and white matter. It also contains almost half of the neurons in the brain. The cerebellum plays a key role in motor control, in particular the adaptation of movement with sensorimotor information, its coordination. It is also important for balance. Finally, we now know that the cerebellum is involved in many cognitive functions, such as attention, language, and emotions.

Also known as basal ganglia, the basal ganglia are a system of several interconnected ganglia of grey matter located deep in the brain. These structures extract information from the cortex to be selected, reinforced, learned, and automated.