Effects of dynamic workstation Oxidesk on acceptance, physical activity, mental fitness and work performance.

Background: Working in an office environment is characterised by physical inactivity and sedentary behaviour. This behaviour contributes to several health risks in the long run. Dynamic workstations which allow people to combine desk activities with physical activity, may contribute to prevention of these health risks.

Interventions to reduce sedentary behavior and increase physical activity during productive work: a systematic review.

Objective: This review addresses the effectiveness of workplace interventions that are implemented during productive work and are intended to change workers` SB and/or PA.

Methods: We searched Scopus for articles published from 1992 until 12 March 2015. Relevant studies were evaluated using the Quality Assessment Tool for Quantitative Studies and summarized in a best-evidence synthesis.

Comparison of the postural and physiological effects of two dynamic workstations to conventional sitting and standing workstations.

Increasing evidence is being found for the association of health risk factors with work-related physical inactivity. An increasing number of people are being exposed to this form of inactivity, and as a result, various interventions aimed at increasing physical activity during working hours are being developed. This study aims to investigate the differences in postural, muscular and physical activities resulting from two dynamic workstations, namely an elliptical trainer and a treadmill workstation, compared with a conventional sitting and standing workstation.

Effects of a standing and three dynamic workstations on computer task performance and cognitive function tests.

Sedentary work entails health risks. Dynamic (or active) workstations, at which computer tasks can be combined with physical activity, may reduce the risks of sedentary behaviour. The aim of this study was to evaluate short term task performance while working on three dynamic workstations: a treadmill, an elliptical trainer, a bicycle ergometer and a conventional standing workstation.

Joint coordination during whole-body lifting in women with low back pain after pregnancy.

Objective: To quantify differences in the kinematics of lifting between women with low back and/or pelvic pain after pregnancy and women without.

Design: Comparison study.

Setting: Research laboratory.

Dynamic posturography using a new movable multidirectional platform driven by gravity.

Human upright balance control can be quantified using movable platforms driven by servo-controlled torque motors (dynamic posturography). We introduce a new movable platform driven by the force of gravity acting upon the platform and the subject standing on it. The platform consists of a 1 m2 metal plate, supported at each of its four corners by a cable and two magnets.

Anticipatory postural adjustments in a bimanual, whole-body lifting task seem not only aimed at minimising anterior--posterior centre of mass displacements.

Anticipatory postural adjustments (APAs) were studied in a bimanual whole-body lifting task, using a mechanical analysis of the downward movement phase preceding loaded versus unloaded lifts. APAs in the backward ground reaction force were found to lead the perturbing forward box reaction with approximately 400 ms, thus inducing a backward centre of mass momentum. Both the APA onset and magnitude were scaled as a function of the load to be lifted.

Adaptation of center of mass control under microgravity in a whole-body lifting task.

Human balance in stance is usually defined as the preservation of the vertical projection of the center of mass (COM) on the support area formed by the feet. Under microgravity conditions, the control of equilibrium seems to be no longer required. However, several reports indicate preservation of COM control in tasks such as arm or leg raising, tiptoe standing, or trunk bending.

Scaling anticipatory postural adjustments dependent on confidence of load estimation in a bi-manual whole-body lifting task.

Anticipatory control of motor output enables fast and fluent execution of movement. This applies also to motor tasks in which the performance of movement brings about a disturbance to balance that is not completely predictable. For example, in bi-manual lifting the pick-up of a load causes a forward shift of the centre of mass with consequent disturbance of posture.

Anticipatory postural adjustments in the back and leg lift.

This study examined anticipatory postural adjustments in a dynamic multi-joint action in which a relatively fast voluntary movement is being executed while balance is maintained in the field of gravity. In a bi-manual whole body lifting task, the pickup of the load induces a forward shift in the position of the center of mass, challenging the dynamic balance regulation while simultaneously impeding the ongoing extension movement. We investigated whether anticipatory postural adjustments are an addition to a voluntary motor command or an inherent component of this command.

Anticipatory postural adjustments before load pickup in a bi-manual whole body lifting task.

Balance regulation and movement control were examined in the context of bi-manual lifting. Subjects picked up a load (20% body mass) after several unloaded cycles using the leg-lift technique. The addition of the load to the body caused the system center of mass to shift forward and thus presented the subject with an expected perturbation of balance.

Load knowledge affects low-back loading and control of balance in lifting tasks.

This study investigated the effect of the presence or absence of load knowledge on the low-back loading and the control of balance in lifting tasks. Low-back loading was quantified by the net sagittal plane torque at the lumbo-sacral joint. The control of balance was studied by the position of the centre of gravity relative to the base of support, the horizontal and vertical momentum of the centre of gravity and the angular momentum of the whole body.

Dissociated oxygen uptake response to an incremental intermittent repetitive lifting and lowering exercise in humans.

Five subjects performed a maximal exercise test of repetitive lifting and lowering, with a discontinuous protocol of incremental exercise (3 min) and relative rest (2 min). Exercise periods consisted of repetitive lifting and repetitive lifting and lowering at increasing movement frequencies. Relative rest periods consisted of ergometer cycling at a constant, low power output.

Controlling the Ground Reaction Force During Lifting.

The control of the ground reaction force vector relative to the center of gravity (CoG) was examined while subjects performed a back-lifting task. Six male subjects (aged 24.0 +/- 2.

Optimizing the determination of the body center of mass.

The position or trajectory of the body center of mass (COM) is often a parameter of interest when studying posture or movement. For instance, in balance control studies the body COM can be related to the ground reaction force or to the base of support. Since small displacements of the body COM are important in balance control studies, it is essential to obtain valid estimates of the body COM.

Relationships between energy expenditure and positive and negative mechanical work in repetitive lifting and lowering.

Determining the separate energy costs of the positive and negative mechanical work in repetitive lifting or lowering is quite complex, as a mixture of both work components will always be involved in the up- and downward motion of the lifter's body mass. In the current study, a new method was tested in which coefficients specifically related to the positive and negative work were estimated by multiple regression on a data set of weight-lifting and weight-lowering tasks. The energy cost was obtained from oxygen uptake measurements.