Human postural control against external force perturbation applied to the high-back

Abstract

Many studies have reported postural control against support surface translation. However, postural control mechanism against external force perturbation is not clear. Therefore, in this study we investigated the postural recovery against external force (1~4Kg) applied to the high-back in health young male subjects (24±4 years). Kinematic data and center of pressure of the reaction to an unexpected perturbation were analyzed. Experimental results showed that the hill-lifting strategy with ankle plantarflexion and knee hyperextension was used in all subjects, regardless of the force magnitude. Specifically, maximum ankle plantarflexion and hip flexion increased with the perturbation force magnitude, the heel vertical excursion and anterior COP excursion. The results of this study show that the postural control strategy for the external force perturbation is quite different from that for surface translation and needs further investigation.

Analysis of sensory system aspects of postural stability during quiet standing in adolescent idiopathic scoliosis patients

“…Average values of each eyes open and eyes closed condition were used. CoP data were obtained using force plates (OR6–2000, AMTI Inc., Newton, Massachusetts, USA) and sampled at 120 Hz [ 43 ].…”

Comparison of gait and cognitive function among the elderly with Alzheimer’s Disease, Mild Cognitive Impairment and Healthy

“…Incidence of dementia in the elderly has increased worldwide, and it is predicted that by 2050 there will be more than 36.7 million dementia patients. 1,2 In comparison with younger adults, dementia is a geriatric disease that occurs mainly in the elderly; there are various types, such as Alzheimer's disease (AD), vascular dementia (VD), Parkinson's disease with dementia (PDD), and dementia with Lewy bodies (DLB), etc. ; each method of treatment is also different.…”

Hardware-In-the-Loop Equipment for the Development of an Automatic Perturbator for Clinical Evaluation of Human Balance Control

“…(2) are placed just above the cylinder in order to shorten the pipes and hence to improve the dynamic response of the actuator. The potentiometers (6) are linked in parallel to the viscoelastic dampers and are used to measure the absolute position of cylinder body and mass. The laser sensor ( 10) is fixed to the body of the cylinder and is used to measure the cylinder stroke.…”

“…The latter option requires that an adequate external perturbation be delivered to the patient, to evoke a postural response of sufficient magnitude. Typically, mechanical perturbations are imparted by direct application of a force to the body of the subject [1][2][3][4][5][6] or by sliding and tilting the base of support [7][8][9][10][11], as widely described in the literature. However, a system for postural perturbation should also allow for selecting magnitude, point of application and direction of the stimuli, to better fit the specific clinical purpose and patient conditions, but these features are not often guaranteed by the available technology.…”