We are interested in understanding the mechanisms behind and the character of the sway motion of healthy human subjects during quiet standing. We assume that a human body can be modelled as a single-link inverted pendulum, and the balance is achieved using linear feedback control. Using these assumptions, we derive a switched model which we then investigate. Stable periodic motions (limit cycle...

[This corrects the article DOI: 10.1098/rsos.160136.].

We carried out the present studies to determine whether the suppression of plasma renin activity (PRA) that follows inhibition of prostaglandin (PG) synthesis can be dissociated from the sodium-retaining effects of these drugs. In an initial investigation we studied the effect of indomethacin on PRA in normal subjects in balance on a 10 mM Na diet to prevent Na retention. Under these experiment...

Disability and mobility problems increase with age. Assistive devices such as canes, crutches, and walkers can be used to increase a patient's base of support, improve balance, and increase activity and independence, but they are not without significant musculoskeletal and metabolic demands. Most patients with assistive devices have never been instructed on the proper use and often have devices...

We carried out the present studies to determine whether the suppression of plasma renin activity (PRA) that follows inhibition of prostaglandin (PG) synthesis can be dissociated from the sodium-retaining effects of these drugs. In an initial investigation we studied the effect of indomethacin on PRA in normal subjects in balance on a 10 mM Na+ diet to prevent Na+ retention. Under these experime...

Humans are capable of pointing to a target with accuracy. However, when vision is distorted through a visual rotation or mirror-reversed vision, the performance is initially degraded and thereafter improves with practice. There are suggestions this gradual improvement results from a sensorimotor recalibration involving initial gating of the somatosensory information from the pointing hand. In t...

Balance control (the ability to maintain an upright posture) is asymmetrically controlled in a proportion of patients with Parkinson's disease. Gait asymmetries have been linked to the pathophysiology of freezing of gait. We speculate that asymmetries in balance could contribute to freezing by a) hampering the unloading of the stepping leg and/or b) leading to a preferred stance leg during gait...

This study used alterations in body position to identify differences in hemodynamic responses to passive exercise. Central and peripheral hemodynamics were noninvasively measured during 2 min of passive knee extension in 14 subjects, whereas perfusion pressure (PP) was directly measured in a subset of 6 subjects. Movement-induced increases in leg blood flow (LBF) and leg vascular conductance (L...