A REVIEW OF THE BIOMECHANICS AND EPIDEMIOLOGY OF WORKING POSTURES (ITISNT ALWAYS VIBRATION WHICH IS TO BLAME)

Many vibrational environments also subject the worker to awkward, asym metric and prolonged postures. This paper reviews the epidemiological, biomechanical and physiological factors involved in working postures which could lead to musculoskeletal problems. Too little or too much s itting leads to low back pain. Sedentary postures, including driving, also lead to a higher risk of a herniated disc. In sitting the pelvis rotates and higher pressures exist in the disk. A backrest inclined to 110 degrees or more and with a lumbar support will reduce the disk pr essure. Jobs involving excessive force application will be more apt to cause muscular and ligamentous damage. However, these excessive deman ds can occur in whole body vibration environments too. Neck, shoulder and arm problems are usually related to posture but can occur in WBV e nvironments. Knee problems, in the standing worker, may be due to a fl exed knee posture in an attempt to attenuate vibrations. Excessive pos tural demands on the neck, shoulder and arm will lead to higher muscle forces and higher joint forces. Recommendations are given to reduce r isk of disability. (C) 1998 Academic Press.