We evaluated the hypothesis that postural instability precedes the onset of motion sickness. Subjects standing in a "moving room" were exposed to nearly global oscillating optical flow. In the experimental condition, the optical oscillations were a complex sum-of-sines between 0.1 and 0.3 Hz, with an excursion of 1.8 cm. This optical motion was of such low frequency and magnitude that it was so...

BACKGROUND The Fahn's pull (or retropulsion) test is an item in the motor section of the Unified Parkinson's Disease Rating Scale, which is used almost exclusively to classify postural instability in Parkinson's disease (PD). However, the test is hard to standardize and is often performed incorrectly, making it hard to interpret. Moreover, it may not be safe to administer in patients who experi...

This study investigated how young healthy subjects control their equilibrium in situations of instability specifically elicited by a reduced capacity of force production in the postural muscle system. Ten subjects displaced a bar forward with both hands at maximal velocity toward a target while standing on the dominant leg (UNID), on the nondominant leg (UNIND), or on both legs. In each stance ...

UNLABELLED Motion sickness symptoms and increased postural instability induced by motion pictures have been reported in a laboratory, but not in a real cinema. We, therefore, carried out an observational study recording sickness severity and postural instability in 19 subjects before, immediately and 45 min after watching a 1 h 3D aviation documentary in a cinema. Sickness was significantly lar...

Current clinical assessments do not adequately detect the onset of postural instability in the early stages of Parkinson's disease (PD). The aim of this study was to identify biomechanical variables that are sensitive to the effects of early Parkinson's disease on the ability to recovery from a balance disturbance. Ten adults diagnosed with idiopathic PD and no clinically detectable postural in...

Postural instability and supranuclear gaze palsy represent the key symptoms of Richardson's syndrome, the most frequent clinical manifestation of progressive supranuclear palsy (PSP). However, a proportion of PSP patients never develops ocular motor symptoms, which prevents clinicians from establishing the diagnosis during lifetime according to current diagnostic criteria. We present one instru...

OBJECTIVE We examined motion sickness in an oscillating virtual environment presented via a video projector system. BACKGROUND Visible oscillation of the physical environment is known to induce both postural instability and motion sickness, but it cannot be assumed that the same phenomena will occur in a virtual simulation of such motion. METHOD Standing participants (3 men and 9 women, 20-...

BACKGROUND Reduced gait speed is common following traumatic brain injury (TBI). Several studies have found that people with TBI display increased lateral movement in their center of mass while walking. It has been hypothesized that reduced gait speed following TBI is a consequence of increased caution and postural instability, but reduced ankle power generation at push-off may also play a contr...

Elhers-Danlos syndrome (EDS) is the clinical manifestation of connective tissue disorders, and comprises several clinical forms with no specific symptoms and selective medical examinations which result in a delay in diagnosis of about 10 years. The EDS hypermobility type (hEDS) is characterized by generalized joint hypermobility, variable skin hyperextensibility and impaired proprioception. Sin...

Purpose. The aim of this paper is to review the published studies on the characteristics of impairments in the postural control and gait performance in diabetic peripheral neuropathy (DPN). Methods. A review was performed by obtaining publication of all papers reporting on the postural control and gait performance in DPN from Google Scholar, Ovid, SAGE, Springerlink, Science Direct (SD), EBSCO ...