Motor function is divided into gross motor function and fine motor function. Gross motor skills are the basis of spatial orientation and summarize large movements of the body. Gross motor skills are movement coordination and reaction skills. Fine motor skills refer to dexterity of the hands, facial expressions, and oral motor skills. Gross motor and fine motor development are closely related.
What is motor development?
By motor function, physicians understand the totality of all actions that occur during all movements in the human body, that is, all movement processes controlled by the human brain. By motor skills, physicians understand the totality of all actions that occur during all movements in the human body, i.e. all movement sequences controlled by the human brain. Basic motor skills are coordination skills such as movement coordination. For basic motor movements to occur, good muscle tension is necessary. The best example of this is the sense of balance. A distinction is made between gross motor skills and fine motor skills. Each area can be promoted individually. When we think of fine motor skills, we first think of hands, for example holding a pencil, but facial expressions and mouth motor skills are also included. Gross motor skills include all larger movements such as climbing, running, jumping and maintaining balance. These are processes that require large amounts of movement. Without posture, balance, and stance, target motor skills cannot be performed. Larger muscle groups are used for gross motor skills, but the functions can fail due to even very small missing movements. Fine motor skills develop by age three and stabilize by age five.
Function and task
Every muscle movement of the body is directly or indirectly controlled by the brain. The motor end plate is significantly involved in this. It is a synapse and provides the connection between a motor nerve cell and a muscle cell. In order for gross and fine motor skills to function properly, humans require different coordination abilities. Seven basic abilities are distinguished: coupling ability, differentiation ability, reaction ability, balance ability, orientation ability, rhythmization ability and rearrangement ability. The coordinative abilities interact with the conditional abilities in any athletic performance. The motor areas of the cerebral cortex design and plan each movement and send the information to the muscles for execution. In order for the information to be implemented smoothly, two other brain structures are necessary: the cerebellum and the basal ganglia. Only with the support of the cerebellum can a specific movement be executed smoothly and accurately. An example of this is the movement of the extended finger to the tip of the nose. In order for this movement to occur correctly, several coordinated muscle contractions of the shoulder, arm and hand are necessary. It is the same when we stand on one leg, for example. The cerebral cortex performs additional fine corrections for all movements. If we lift a leg, the cerebellum passes on the commands to the muscles that prevent it from tipping over. All of this happens unconsciously. The basal ganglia, in turn, permanently select between desired and undesired action sequences. Only in this way is fine motor movement possible in the correct direction and with the correct intensity. By balancing alone, we manage to touch even a delicate object like a raw egg in such a way that it does not break. Again, through the cerebellum, initiated movements can be translated into precise and fluid action sequences.
Diseases and ailments
The cerebellum contains more than half of the brain’s neurons. This makes it easy to see how complex the neural connections are in this area of the brain. Even in early childhood, severe motor development disorders can occur, which are usually easy to treat. Larger amounts of alcohol considerably disturb the function of the cerebellum and the same effects are seen as in a person suffering from cerebellum disease. Balance disorders occur, the affected person staggers and walks with wide legs. Speech also appears choppy. The cerebellum is also heavily involved in motor learning processes. If it is damaged, we can no longer learn properly.The brain areas basal ganglia and thalamus filter out the correct movement patterns and allow the impulses to be transmitted to the cerebral cortex and thus the execution of the movement. To be able to make complex, learned movements, filtering in the basal ganglia is of utmost importance. However, the basal ganglia cannot initiate movement. In Parkinson’s disease, too much information gets stuck in this filter, so that movement impulses are not transmitted to the cerebral cortex. Conspicuous disturbances are recognizable: The sick person has a rigid facial expression, swallows less often than a healthy person and his arms hardly swing when walking. He also lifts his feet only slightly, so that he frequently stumbles. Slow tremors and muscle stiffness are other symptoms of this disease. In the hereditary disease Huntington’s disease, exactly the opposite happens; the filter lets through far too many signals. Muscle movements start suddenly and unexpectedly, the sick person has hardly any control over them, grimaces, for example, or flings arms and legs back and forth. With increasing age, most motor tasks require more concentration. A disturbance of the gross motor function is quickly visible, because the affected person becomes severely limited. Riding a bike, hopping on one leg, or playing sports are very difficult for people with gross motor disorders. Damage to the cerebrum almost always leads to motor disturbances in the musculoskeletal system as well. There are problems with postural control and paralysis. Either motor control of the muscles is impaired, absent altogether, or there are increases in tone in the muscle. Basal ganglia disorders, on the other hand, produce movement disorders because strategic planning and initiation of all movements are impaired.