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Standing Posture (standing + posture)

Distribution by Scientific Domains

Medical Sciences	75%

Selected Abstracts

Dynamic Control of a Large Scale of Pneumatic Multichain Systems

JOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 4 2004
M. Guihard
The aim of this paper is to propose a general principle able to manage the supervision, coordination, and control problems of a large scale of multichain structures in dynamic and interacting tasks. The main originality lays in its modular feature. The number of chains and of joint per chain are indeed not restricted. The only assumption is that all the chains are linked to a principal element from which the dynamic stability will be computed. This is for example the case for multi-finger and multi-legged structures for which respectively the palm and the trunk represent the principal element. The principle consists in controlling the stability of this element and distributing the effort on the other chains to maintain the stability of the whole. To increase the compliant feature, we consider that each joint is pneumatically actuated. Each joint is then dynamically controlled to ensure the asymptotic stability of the local chain it belongs to. A global architecture is presented where each part is detailed. An example is then displayed showing the performances of a two-legged robot in the standing posture under external perturbation effects. © 2004 Wiley Periodicals, Inc. [source]

Four-week trunk-specific rehabilitation treatment improves lateral trunk flexion in Parkinson's disease,

MOVEMENT DISORDERS, Issue 3 2010
Michelangelo Bartolo MD
Abstract People with Parkinson's disease (PD) often have a posture characterized by lateral trunk flexion poorly responsive to antiparkinsonian drugs. To examine the effects of a rehabilitation programme (daily individual 90-minute-sessions, 5-days-a-week for 4-consecutive weeks) on lateral trunk flexion and mobility, 22 PD patients with mild to severe lateral trunk flexion, and 22 PD patients without trunk flexion were studied. Patients were evaluated using the Unified Parkinson's Disease Rating Scale motor subscale (UPDRS-III) score, and the kinematic behavior of the trunk was recorded by means of an optoelectronic system to determine: a) trunk flexion, inclination and rotation values in the erect standing posture; b) ranges of trunk flexion and inclination during trunk movements. After the treatment, significant decreases in trunk flexion [24°(4) vs. 14°(3), P < 0.001] and inclination in the static condition [23°(5) vs. 12°(4), P < 0.001)] were observed, both of which were maintained at the 6-month follow up. During the trunk flexion task, a significantly increased range of trunk flexion [64°(15) vs. 83°(15), P < 0.001] was observed; similarly, during the lateral bending task, the range of trunk inclination was found to be significantly increased, both toward the side of the trunk deviation [29°(8) vs. 42°(13), P < 0.01] and toward the contralateral side [14°(6) vs 29°(11), P < 0.01]. No further significant changes were observed at the 6-month follow-up. Trunk flexion and inclination values in the upright standing posture correlated slightly with the UPDRS-III score. Our findings show that significant improvements in axial posture and trunk mobility can be obtained through the 4-week rehabilitation programme described, with a parallel improvement in clinical status. © 2010 Movement Disorder Society [source]

Linear and nonlinear measures of blood pressure variability: Increased chaos of blood pressure time series in patients with panic disorder

DEPRESSION AND ANXIETY, Issue 2 2004
Vikram K. Yeragani M.B.B.S.
Abstract Arterial blood pressure (BP) variability increases progressively with the development of hypertension and an increase in BP variability is associated with end organ damage and cardiovascular morbidity. On the other hand, a decrease in heart rate (HR) variability is associated with significant cardiovascular mortality. There is a strong association between cardiovascular mortality and anxiety. Several previous studies have shown decreased HR variability in patients with anxiety. In this study, we investigated beat-to-beat variability of systolic and diastolic BP (SBP and DBP) in normal controls and patients with panic disorder during normal breathing and controlled breathing at 12, and 20 breaths per minute using linear as well as nonlinear techniques. Finger BP signal was obtained noninvasively using Finapres. Standing SBPvi and DBP BPvi (log value of BP variance corrected for mean BP divided by HR variance corrected for mean HR) were significantly higher in patients compared to controls. Largest Lyapunov exponent (LLE) of SBP and DBP, a measure of chaos, was significantly higher in patients in supine as well as standing postures. The ratios of LLE (SBP/HR) and LLE (DBP/HR) were also significantly higher (P < .001) in patients compared to controls. These findings further suggest dissociation between HR and BP variability and a possible relative increase in sympathetic function in anxiety. This increase in BP variability may partly explain the increase in cardiovascular mortality in this group of patients. Depression and Anxiety 19:85-95, 2004. © 2004 Wiley-Liss, Inc. [source]

Contribution of Jules Froment to the study of Parkinsonian rigidity

MOVEMENT DISORDERS, Issue 7 2007
Emmanuel Broussolle MD
Abstract Rigidity is commonly defined as a resistance to passive movement. In Parkinson's disease (PD), two types of rigidity are classically recognized which may coexist, "leadpipe " and "cogwheel". Charcot was the first to investigate parkinsonian rigidity during the second half of the nineteenth century, whereas Negro and Moyer described cogwheel rigidity at the beginning of the twentieth century. Jules Froment, a French neurologist from Lyon, contributed to the study of parkinsonian rigidity during the 1920s. He investigated rigidity of the wrist at rest in a sitting position as well as in stable and unstable standing postures, both clinically and with physiological recordings using a myograph. With Gardère, Froment described enhanced resistance to passive movements of a limb about a joint that can be detected specifically when there is a voluntary action of another contralateral body part. This has been designated in the literature as the "Froment's maneuver " and the activation or facilitation test. In addition, Froment showed that parkinsonian rigidity diminishes, vanishes, or enhances depending on the static posture of the body. He proposed that in PD "maintenance stabilization " of the body is impaired and that "reactive stabilization " becomes the operative mode of muscular tone control. He considered "rigidification " as compensatory against the forces of gravity. Froment also demonstrated that parkinsonian rigidity increases during the Romberg test, gaze deviation, and oriented attention. In their number, breadth, and originality, Froment's contributions to the study of parkinsonian rigidity remain currently relevant to clinical and neurophysiological issues of PD. © 2007 Movement Disorder Society [source]