negative g-force

physical force

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Last updated

July 16, 2026

Quick Summary

Negative g-force, also known as negative acceleration stress, occurs when the direction of acceleration is from feet to head. This causes internal organs to shift, leading to a rush of blood to the face and a feeling of congestion. As acceleration increases, so does the congestion, potentially causing throbbing head pains and vision disturbances like seeing red or temporary vision loss. High levels of negative g-force can lead to confusion and unconsciousness. This type of stress can also impair respiration and may cause bleeding under the skin of the face or rupture of blood vessels in the head. The body can only tolerate negative g-force for short periods, with tolerance decreasing as the force increases.1

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roller coaster
Overview
The so-called negative g-forces create the rider’s sense of weightlessness when lifted from the seat over the peaks of hills. On most roller coasters, riders remain seated beneath a safety bar, but variations include riders’ standing on a platform or hanging from a shoulder harness.
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The so-called negative g-forces create the rider’s sense of weightlessness when lifted from the seat over the peaks of hills. On most roller coasters, riders remain seated beneath a safety bar, but variations include riders’ standing on a platform or hanging from a shoulder harness.
Read More