A systematic review published in Ear, Nose & Throat Journal reported that postural instability often occurs before the onset of motion sickness, but current evidence does not support a definitive cause-and-effect relationship.
The review, led by Laavanya Rajendran, MBBS, and colleagues at Universiti Malaya, analyzed 16 experimental and observational studies involving 1,518 participants aged 9 to 63 years. The researchers assessed evidence for the postural instability theory, which proposes that motion sickness arises when patients are unable to maintain stable posture in challenging sensory environments.
“Although postural instability precedes MS, the quality of evidence is inadequate to determine the cause-and-effect relationship between MS and postural instability until extensive, multicenter, randomized controlled studies are conducted,” the researchers wrote.
The studies reviewed covered multiple motion sickness contexts, including car sickness, travel-related sickness, cybersickness, simulator sickness, visually induced motion sickness, and space-related motion sickness. Most included studies reported an association between postural instability and motion sickness, while a small number found no consistent relationship between measures of sway and symptom development. As the researchers noted, “these variations in symptom presentation, environments, and measurement tools across studies may limit direct comparability of findings and contribute to inconsistent conclusions regarding the role of postural instability.”
Across included studies, postural control was most commonly measured using force platforms or balance boards, often alongside symptom questionnaires such as the Motion Sickness Susceptibility Questionnaire, Simulator Sickness Questionnaire, and Misery Scale. Other methods included static posturography, Romberg testing, inertial measurement units for head-motion tracking, and galvanic vestibular stimulation.
The researchers recommended future prospective pediatric cohorts, randomized controlled trials of balance-based interventions, and multimodal studies integrating vestibular, visual, and postural measurements to clarify underlying mechanisms.
The researchers reported no conflicts of interest or funding sources.
Source: Ear, Nose & Throat Journal
