Search results for "Posture"

Effect of fatigue on the precision of a whole-body pointing task.

2005

We addressed the issue of the possible degradation of the aiming precision of a whole-body pointing task, when movement coordination is deranged by selective fatigue of the postural task component. The protocol involved continuous repetition (0.1 Hz frequency) of rapid whole-body pointing trials toward a target located beyond arm length, starting from stance and requiring knee flexion. Six healthy human subjects repeated the trials until exhaustion. Such repetition led to electromyography signs of fatigue in rectus femoris (active in body lowering and raising), but not in deltoid (prime mover for arm reaching component). Rectus femoris fatigue affected the equilibrium control strategy, sinc…

Stance control is not affected by paresis and reflex hyperexcitability: the case of spastic patients.

2001

OBJECTIVES Spastic patients were studied to understand whether stance unsteadiness is associated with changes in the control of voluntary force, muscle tone, or reflex excitability, rather than to abnormal posture connected to the motor deficit itself. METHODS Twenty four normal subjects, 12 patients affected by amyotrophic lateral sclerosis (ALS), seven by spastic paraparesis, and 14 by hemiparesis were studied. All patients featured various degrees of spasticity and paresis but were free from clinically evident sensory deficits. Body sway during quiet upright stance was assessed through a stabilometric platform under both eyes open (EO) and eyes closed (EC) conditions. The sudden rotation…

Effect of Isometric Upper-Extremity Exercises on the Activation of Core Stabilizing Muscles

2007

Abstract Tarnanen SP, Ylinen JJ, Siekkinen KM, Malkia EA, Kautiainen HJ, Hakkinen AH. Effect of isometric upper-extremity exercises on the activation of core stabilizing muscles. Objective To evaluate whether isometric exercises for the upper extremities could sufficiently activate core stabilizing muscles to increase muscle strength. Design Cross-sectional study. Setting Department of physical medicine and rehabilitation at a Finnish hospital. Participants Healthy adult women (N=20). Interventions Not applicable. Main Outcome Measures Peak isometric strength of the back and abdominal muscles was measured and relative loading in 5 test exercises was evaluated by surface electromyography. Re…

Speeding up gait initiation and gait-pattern with a startling stimulus.

2008

Human gait involves a repetitive leg motor pattern that emerges after gait initiation. While the automatic maintenance of the gait-pattern may be under the control of subcortical motor centres, gait initiation requires the voluntary launching of a different motor program. In this study, we sought to examine how the two motor programmes respond to an experimental manipulation of the timing of gait initiation. Subjects were instructed to start walking as soon as possible at the perception of an imperative signal (IS) that, in some interspersed trials was accompanied by a startling auditory stimulus (SAS). This method is known to shorten the latency for execution of the motor task under prepar…

Effects of environmental intervention on sedentary time, musculoskeletal comfort and work ability in office workers

2016

Sit-stand workstations offer a potential strategy to reduce prolonged occupational sitting. This controlled intervention study examined the effects of an environmental intervention on occupational sedentary time, musculoskeletal comfort and work ability, and the usability of sit-stand workstations in office work via a self-reported questionnaire. The intervention group (n = 24) used sit-stand workstations during the 6-month intervention period, and the control group (n = 21) used traditional sitting workstations. The results showed that working at sit-stand workstations can reduce sitting time significantly compared to control workstations (-6.7% vs. 5.0%, p = .019), which is reallocated mo…

Sympathetic nervous activity and the pressor effect of noradrenaline under chronic?-?-adrenoceptor blockade with labetalol in hypertension

1983

In 14 patients with essential hypertension, the influence of the alpha- and beta-adrenoceptor blocking drug labetalol on blood pressure, heart rate, plasma renin, plasma noradrenaline and pressor effect of exogenous noradrenaline was investigated during long-term treatment. During the initial four weeks of treatment, labetalol at a dose of 400 mg/day showed a slight effect only on supine blood pressure, whereas upright blood pressure was already lowered effectively after the second week of treatment (p less than 0.01). An increase in the mean dose to 850 mg/day had an additional blood pressure-lowering effect (p less than 0.001), whereby a preferential decrease of the orthostatic blood pres…

In response to the article published by Dewolf et al, entitled: "Effect of walking speed on the intersegmental coordination of lower-limb segments in…

2019

Posturographic analysis of balance control in patients with haemophilic arthropathy

2007

Summary.  Musculoskeletal disorders in haemophiliacs represent the highest percentage of lesions, giving rise to haemophilic arthropathy (HA) which predominantly affects lower limbs, influencing postural control, standing and walking. Leading a sedentary lifestyle seems to influence strength and muscular resistance in haemophiliacs which, in turn, are related to articular stability and the prevention of articular degenerative processes. The objective of this work was to study alterations in balance to subsequently evaluate the appropriate therapeutics and how this influences the development of arthropathy. Twenty-five haemophiliacs with HA, 25 haemophiliacs without HA (NHA) and 25 healthy c…

The reliability, distribution, and responsiveness of the Postural Control and Balance for Stroke Test

2005

Abstract Pyoria O, Talvitie U, Villberg J. The reliability, distribution, and responsiveness of the Postural Control and Balance for Stroke Test. Objectives To determine the inter- and intrarater reliability of the Postural Control and Balance for Stroke (PCBS) test and to assess its distribution and responsiveness to changes during 1-year follow-up. Design Intrarater reliability of the PCBS test was assessed by comparing the repeat ratings of videotaped test performances by each of the 5 raters. Interrater reliability was assessed by comparing the ratings of the videotaped test performances between the raters. Setting Hospital neurologic ward and outpatient department of physiotherapy as w…

Evaluation of the postural stability of elderly persons using time domain signal analysis

2012

A force platform is widely used in the evaluation of postural stability in man. Although an abundance of parameters are typically retrieved from force platform data, no uniform analysis of the data has been carried out. In general, the signal analysis does not analyze the underlying postural event, i.e., whether the signal consists of several small corrections or large excursions. In the present work, we studied the postural stability of 4589 elderly persons from Iceland on a force platform under visual and non-visual conditions during stance on a solid surface. We analyzed the internal relationship between frequently used time domain variables. In addition, we conducted a factor analysis u…