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Why rocking chairs and swings make some people uncomfortable

by Dr. Krishna Kumari Challa

Oct 8

Q: I feel very uncomfortable in a rocking chair and on swings, especially after getting out of them. Why is this?

Krishna: 

A rocking chair and a swing causes discomfort and a spinning sensation because the repetitive motion conflicts with how your brain processes balance and movement. 

To understand this first you have to learn how balance is achieved. 

Balance in human beings is achieved by the brain combining signals from three main sensory systems: the inner ear, the eyes, and the body's muscles and joints. 

 These are the sensory systems that help in the process
Image source: istock

Vestibular system (Inner ear): Fluid and tiny hair cells inside the inner ear detect gravity, rotation, and linear movement of the head. 
Sensory information about motion, equilibrium, and spatial orientation is provided by the vestibular apparatus, which in each ear includes the utricle, saccule, and three semi-circular canals. The utricle and saccule detect gravity (information in a vertical orientation) and linear movement. The semi-circular canals, which detect rotational movement, are located at right angles to each other and are filled with a fluid called endolymph. When the head rotates in the direction sensed by a particular canal, the endolymphatic fluid within it lags behind because of inertia, and exerts pressure against the canal’s sensory receptor. The receptor then sends impulses to the brain about movement from the specific canal that is stimulated. When the vestibular organs on both sides of the head are functioning properly, they send symmetrical impulses to the brain. (Impulses originating from the right side are consistent with impulses originating from the left side.)
Visual system (Eyes): Sight tracks your surroundings and relative verticality to show where your body is located in space. 
Proprioceptive system (Skin, muscles, and joints): Receptors in your body tell the brain about pressure, stretch, and movement against the ground. 

The CPU of balancing act
Integration and Response:  The brain—specifically the cerebellum and brainstem—constantly gathers and processes this sensory input. 
Balance information provided by the peripheral sensory organs—eyes, muscles and joints, and the two sides of the vestibular system—is sent to the brain stem. There, it is sorted out and integrated with learned information contributed by the cerebellum (the coordination center of the brain) and the cerebral cortex (the thinking and memory center). The cerebellum provides information about automatic movements that have been learned through repeated exposure to certain motions. For example, by repeatedly practicing serving a ball, a tennis player learns to optimize balance control during that movement. Contributions from the cerebral cortex include previously learned information; for example, because icy sidewalks are slippery, one is required to use a different pattern of movement in order to safely navigate them.
Motor Output: The brain instantly sends corrective signals to your eye and body muscles to make micro-adjustments, keeping your center of mass stable over your base of support.
Now you know how your body achieves this balance.

Balance is the ability to maintain the body’s center of mass over its base of support. A properly functioning balance system allows humans to see clearly while moving, identify orientation with respect to gravity, determine direction and speed of movement, and make automatic postural adjustments to maintain posture and stability in various conditions and activities.
 Maintaining balance depends on information received by the brain from the eyes, muscles and joints, and vestibular organs in the inner ear. When this system is disrupted by damage to one or more components through injury, disease, or the aging process you may experience impaired balance accompanied by other symptoms such as dizziness, vertigo, vision problems, nausea, fatigue, and concentration difficulties.
A person can become disoriented if the sensory input received from his or her eyes, muscles and joints, or vestibular organs sources conflicts with one another. For example, this may occur when a person is standing next to a bus that is pulling away from the curb. The visual image of the large rolling bus may create an illusion for the pedestrian that he or she—rather than the bus—is moving. However, at the same time the proprioceptive information from his muscles and joints indicates that he is not actually moving. Sensory information provided by the vestibular organs may help override this sensory conflict. In addition, higher level thinking and memory might compel the person to glance away from the moving bus to look down in order to seek visual confirmation that his body is not moving relative to the pavement.

Why rocking chairs or cradles affect some people

Vestibular Conflict: Your inner ear contains the vestibular system, which tells your brain whether your body is moving or still. When a rocking chair moves, your inner ear detects motion, but if your eyes focus on a stationary room, your brain receives mixed signals. 
Sensory Overload: This mismatch between what you see and what your inner ear feels mimics motion sickness. It can trigger dizziness, nausea, or a lingering spinning feeling. 
Sensitivity Differences: Some people have a more sensitive vestibular system than others. While the repetitive rhythm calms many people, it over-stimulates sensitive nerves in others, leading to sudden unease or disorientation.

So you belong to this group of people  whose nerves over-stimulate you making you uncomfortable.
Some people face these problems with closed lifts and escalators too!

Closing your eyes often reduces motion sickness or dizziness while you are in a moving object because it removes confusing visual signals.

Why closing your eyes helps

Stops mixed signals and  visual conflict: Your brain relies on your eyes, inner ears, and body position to know where you are.
 Your brain gets mixed messages when your inner ear feels movement, but your eyes see a still car/bus interior or a room.
Removes motion triggers: Shutting your eyes cuts off the moving scenery or flashing lights outside or a stationary room. When you swing or rock, your eyes see the world moving past you, but your inner ear detects motion that might conflict with what you see.

Removing conflicting sights helps your nervous system relax and re-center.
However, sometimes while travelling, this might not help. 
Closed eyes can be risky because this act
Reduces Stability: Closing your eyes takes away your main balance reference. 
If you are standing or walking inside a moving vehicle like a bus or train, closing your eyes removes your visual balance anchor and can make you unsteady. 
Causes Worsened Sway: If you stand up or walk with your eyes closed, your unsteadiness or dizziness can actually increase.
Best While Seated: Only close your eyes to rest while you are safely seated or lying completely still.

Alternative fixes
 Looking straight ahead at a fixed point on the distant horizon often works better than closing your eyes if you need to stay alert. 
Let me also add this information:
Some people feel uncomfortable in a moving vehicle even with their eyes closed because their inner ear still senses motion while their body and other senses report conflicting signals. 
Why motion sickness happens with eyes closed
Inner ear signals: Your inner ear contains a balance system with fluid that detects acceleration, turns, and bumps. It tells your brain that you are moving. 
Muscles and joints: The nerve endings in your body sense that you are sitting still in a seat, sending a message of rest. 
Sensory mismatch: Even though your eyes are closed and not seeing conflicting stationary objects, the mismatch between your active inner ear (feeling motion) and your muscles/joints (feeling stationary) still confuses the brain. 
The brain's alarm: When the brain receives these contradictory messages, it cannot process them properly and triggers nausea, dizziness, or cold sweats as a defensive response. 

Why only some people face this while others don't?

Not everyone gets motion sickness, and that’s where neurological factors come into play. Some people’s brains and bodies are just wired to handle motion better – or worse – than others. It’s not all random, though.

Science shows that things like genetics can make a difference. If your parents got uneasy on road trips, you might be more likely to feel it too. It’s like inheriting a sensitivity to motion the way you might inherit height with studies showing that up to 70% of the risk comes from your genes. 

Beyond genetics, how your brain processes signals matters. Some people have a nervous system that’s extra jumpy, especially when it comes to motion. This can lead to an overactive nausea response. In these cases, the brain overreacts to mixed signals and triggers alarm bells too soon. Certain conditions, like migraines or anxiety, can also turn up the volume on motion sickness. People with these issues might have a lower threshold for handling sensory overload, making them feel sick faster. Age plays a role too – kids often feel it more because their systems are still figuring things out, while older adults might dodge it better. It’s all about how your particular nervous system responds to movement.