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motion sickness discomfort felt by some people on a moving boat, train, airplane, or automobile, or even on an elevator or a swing. The discomfort is caused by irregular and abnormal motion that disturbs the organs of balance located in the inner ear. There may be mild symptoms of nausea, dizziness, or headache, as well as pallor and cold perspiration. In more acute cases, there may be vomiting and sometimes prostration. Though most people quickly adapt to travel by airplane, ship, and automobile, few are wholly immune to motion sickness. Even astronauts become ill if the inner ear organs of balance are continuously stimulated by unusual motion. Fortunately, most cases of motion sickness vanish quickly once the journey is over, leaving no ill effects.
Causes. The inner ear possesses three semicircular canals, located at right angles in three different planes. People are accustomed to movement in the horizontal plane, which stimulates certain semicircular canals, but not to vertical movements such as the motion of an elevator or a ship pitching at sea. These vertical movements stimulate the semicircular canals in an unusual way, producing the sensation of nausea, or motion sickness.

Anxiety, grief, or other emotions can also cause motion sickness. A person unaccustomed to traveling by boat or airplane may be apprehensive or nervous and therefore may develop symptoms of nausea. Some individuals with previous experience of motion sickness become ill on a boat at dock or on an airplane prior to take-off.

Airsickness usually occurs during a bumpy flight caused by stormy weather or turbulent air. However, it may also be triggered by poorly ventilated cabins, hunger, digestive upset, overindulgence in food and drink, and unpleasant odors, particularly tobacco smoke.
Treatment. Certain antihistamines have proved highly effective in treating symptoms of seasickness. Like depressants, they may be used alone or in combination with mild sedatives. Those who suffer from motion sickness should ask their health care provider for advice before they embark on a trip. Symptoms may also be reduced if the seasick person rests lying down, with the head low, in a comfortable, well aired place.
Prevention. Being rested and in good health prior to a journey helps to prevent motion sickness. During a voyage by boat, it is advisable for the passenger to remain near the center of the ship, where there will be the least motion. Ample fresh air and exercise and avoidance of stuffy rooms and disagreeable smells are also good precautions. The traveler should keep comfortably warm and avoid overeating and eating rich foods.

For those traveling by air, adequate hydration and small, easily digested meals taken during the flight help to prevent airsickness. The passenger who experiences motion sickness may benefit from reclining in the seat as far as possible and closing the eyes.

Carsickness is often relieved if the journey is interrupted for short walks in the fresh air and by keeping a window open. Children will frequently find it helpful to glance down, and to refrain from reading. Tobacco smoke can also be an aggravating factor.

mo·tion sick·ness

the syndrome of pallor, nausea, weakness, and malaise, which may progress to vomiting and incapacitation, caused by stimulation of the semicircular canals during travel or motion as on a boat, plane, train, car, swing, or rotating amusement ride.
Synonym(s): kinesia


/ki·ne·sia/ (kĭ-ne´zhah) motion sickness.


Etymology: Gk, kinein, to move
a condition caused by erratic or rhythmic motions in any combination of directions, such as in a boat or a car. Severe cases are characterized by nausea, vomiting, vertigo, and headache; mild cases by headache and general discomfort. Various antihistamines are used prophylactically. Motion sickness includes air sickness, car sickness, and seasickness (mal de mer). Also spelled cinesia. Also called kinetosis.

mo·tion sick·ness

(mō'shŭn sik'nĕs)
The syndrome of pallor, nausea, weakness, and malaise, which may progress to vomiting and incapacitation, caused by stimulation of the semicircular canals during travel or motion as on a boat, airplane, train, car, swing, or rotating amusement ride.
Synonym(s): kinesia.

kinesia (ki·nēˑ·zh),

n condition resulting from regular or irregular motions while moving in any combination of directions, such as riding in a car, boat, or an airplane. General discomfort or headaches are characteristic of mild cases, whereas severe cases are marked by nausea and dizzi-ness. Also called
kinetosis or
motion sickness.


motion sickness.
References in periodicals archive ?
Kinesia ProView quantitatively assesses motor symptoms in response to stimulation settings and provides tools to quickly visualize the programming space.
Fueled by strong funding support from the National Institutes of Health (NIH) in the United States, including the National Institute of Neurological Disorders and Stroke and the National Institute on Aging, the Kinesia technology suite has been commercialized and clinically validated in numerous studies and with hundreds of patients.
Because of the need for a physical surface on which to place visual cues and because most evidence indicates that the effects of kinesia paradoxa do not last after the removal of visual cues, the functional usefulness of this phenomenon to the lives of people with akinesia has been limited.
The technology used to create Kinesia is unique from other motion monitoring devices currently on the market such as actigraphy devices and tremor monitors.
The small, subtle details used to develop Kinesia 360 lie in protocol design, positioning and sensitivity of sensors, and intelligent algorithms to process data.
The trial will aid in development of Kinesia for continuous symptom monitoring in patients' homes, as well as further validate the correlation between the device and the Unified Parkinson's Disease Rating Scale (UPDRS).
Kinesia is a compact wireless system that uses accelerometers and gyroscopes to monitor three-dimensional motion.
He'd heard about a well-documented Parkinson's-related effect called kinesia paradoxa: a simple trick of mind and eye that enables some Parkinson's patients at certain stages of their disease to momentarily escape the halting, hesitant gait so characteristic of their disorder.