However, any clinical test of posture and muscle imbalance must also be able to differentiate patients whose symptoms relate to that imbalance and postural variation to those whose symptoms do not relate to their posture.
In nature, however, an unrelieved supine orientation is never encountered for extended periods; postural variation is innate.
To this end, studies identifying effective interventions to prevent sedentary work and lack of postural variation are needed.
Other studies report postural variation during computer work, either in the field [ 33, 34] or during controlled tasks in the laboratory [ 27, 35, 36], but these studies have concentrated on arm and neck postures.
We measured the following parameters: skin temperature; basal cutaneous blood flow recorded continuously throughout the stimulation protocol; vasoconstriction reflexes induced by deep breathing and postural variation (veno-arteriolar reflex); vasodilatation induced by local heating (from 32°C to 44°C for 6 min).
Model extensions are proposed to investigate postural effects involving variations in hands and feet positions and interaction of the driver's back with the backrest.
The 10th and 90th percentiles of the angular elevation distribution have been reported in many studies as measures of neutral and extreme postural exposures, and variation has been quantified by the 10th-90th perangeile range.
The measurements are performed for a total of 36 different sitting postural configurations realized through variations in hands position (in lap and on steering wheel), three seat heights (510, 460 and 410 mm), and seat design factors involving two different pan orientations (0° and 7.5°) and three different back support conditions (no support, and support with vertical and inclined backrest).
The measurements are performed for a total of 36 different sitting postural configurations realized through variations in hands position (in lap and on steering wheel), seat heights (510, 460 and 410 mm), and seat design factors involving pan (0° and 7.5°) and backrest (0° and 12°) orientations, and different back support conditions.
