Non binding guide to good practice for implementing Directive

ANNEX C Health risks, signs and symptomsC.1 EFFECTS OF WHOLE-BODY VIBRATIONON THE HUMAN BODYThe transmission of vibration to the body is dependenton body posture. The effects of vibration are thereforecomplex. Exposure to whole-body vibration causesmotions and forces within the human body that may:• cause discomfort,• adversely affect performance.• aggravate pre-existing back injuries and• present a health and safety risk.Low-frequency vibration of the body can cause motionsickness.Epidemiological studies of long-term exposure to wholebodyvibration have shown evidence for an elevated riskto health, mainly in the lumbar spine but also in the neckand shoulder. Some studies have reported evidence ofeffects on the digestive system, the female reproductiveorgans and the peripheral veins.C.2 LOWER-BACK PAIN AND BACK, SHOULDEROR NECK DISORDERSThe results of epidemiological studies showa higher prevalence rate of low-back pain,herniated disc and early degeneration of thespine in whole-body vibration exposed groups.Increased duration of vibration exposure andincreased intensity are assumed to increasethe risk, while periods of rest reduce the risk.Many drivers complain also about disordersin the neck-shoulder although epidemiologicalresearches are inconclusive on this effect.Low-back pain and back, shoulder or neckdisorders are not specifi c to vibration exposures.There are many confounding factors such asworking posture, anthropometric characteristics,muscle tone, physical workload, and individualsusceptibility (age, pre-existing disorders, muscleforce, etc.).Driving of mobile machines does not only involveexposure to whole-body vibration but also to severalother factors that put strains on the back, shoulder orneck. The most important being:• prolonged sitting in constrained postures,• prolonged sitting in poor postures,• frequent twisting of the spine• needing to adopt twisted head postures,• frequent lifting and material handling (e. g. driversof delivery trucks),• traumatic injuries,• unexpected movements,• unfavourable climatic conditions and• stress.In some countries and under certain conditions, lumbardisorders occurring in workers exposed to wholebodyvibration are considered to be an occupationaldisease.C.3 OTHER DISORDERSThe question of whether whole-body vibrationexposure might lead to digestive or circulatorydisorders or adverse affects on the reproductivesystem remains open. In some cases an increasedprevalence of gastro-intestinal complaints, pepticulcer and gastritis have been reported in drivers ofvibrating vehicles. Whole-body vibration seems to bea factor that in combination with the long-term sittingposture of drivers contributes to the occurrence ofvaricose veins and haemorrhoids. Some studieshave reported evidence of effects on the digestivesystem, the female reproductive organs and theperipheral veins. One study showed a greaterthan expected incidence of stillbirth among womenexposed to vibration in the transport sector.PART II Guide to good practice on Whole-Body Vibration – ANNEXES A-H87