Objective Internal representation of gravity can be quantified by measuring the subjective visual vertical (SVV). Modulation of verticality perception during head tilts may be perturbed in vestibular disorders causing SVV tilts in the upright head position. This study aimed to determine the influence of head tilts on the estimation of SVV in acute vestibular disorders. Methods We measured the...

The purpose of our study was to determine head and trunk movement responses that occur in healthy 7-year-old children during induced and self-induced lateral tilt. Twenty subjects, while tailor sitting on a tiltboard, participated in three trials of both induced and self-induced left and right lateral displacements. Measurements of neck and trunk lateral flexion; trunk counterrotation; and neck...

Recent research revealed that patients with spatial hemineglect show deficits in the judgment of the subjective vertical and horizontal. Systematic deviations in the subjective axes have been demonstrated in the visual and tactile modality, indicating a supramodal spatial orientation deficit. Further, the magnitude of the bias was shown to be modulated by head- and body-position. The present st...

background: syncope is a common clinical problem which can be remarkably debilitating and associated with high health care costs. syncope is a clinical syndrome with many potential causes. the aim of the study was to determine the etiologies of patients with syncope in the emergency department (ed) of a referral and general university hospital.  methods: one hundred sixty-five consecutive patie...

Subchondral insufficiency fracture (SIF) of the femoral head occurs in the elderly and recipients of organ transplantation. Osteoporosis and deficient lateral coverage of the acetabulum are known risk factors for SIF. There has been no study about relation between spinopelvic alignment and anterior acetabular coverage with SIF. We therefore asked whether a decrease of lumbar lordosis and a defi...

The "push-pull" effect denotes the reduced tolerance to +G(z) (hypergravity) when +G(z) stress is preceded by exposure to hypogravity, i.e., fractional, zero, or negative G(z). The purpose of this study was to test the hypothesis that an exaggerated, myogenically mediated rise in leg vascular conductance contributes to the push-pull effect, using heart level arterial blood pressure as a measure...

The "push-pull" effect denotes the reduced tolerance to +Gz (hypergravity) when +Gz stress is preceded by exposure to hypogravity, i.e., fractional, zero, or negative Gz. Previous studies have implicated autonomic reflexes as a mechanism contributing to the push-pull effect. The purpose of this study was to test the hypothesis that nonautonomic mechanisms can cause a push-pull effect, by using ...

Acute vestibular injury, such as vestibular neuritis (VN), can produce a profound alteration in balance manifested by perception disorder and impaired control of postural adjustment and execution of movements. Stabilometry assesses posture balance through the quantification of body oscillations from the orthostatic position in a force platform. It involves monitoring center of pressure (COP) di...

In order to distinguish between the use of visual and gravito-inertial force reference frames, the head tilt of drivers and passengers were measured as they went around corners at various speeds. The visual curvature of the corners were thus dissociated from the magnitude of the centripetal forces (0.30-0.77 g). Drivers' head tilts were highly correlated with the visually-available estimate of ...