Ergonomic factors and musculoskeletal pain in sonographers

Abstract: Background: Sonographers have a high risk of musculoskeletal disorders. Sonography involves strenuous postures in the neck and upper limbs, and is visually demanding. Echocardiography is especially challenging, with static postures and monotonous movements. Aim: The overall aim of this thesis was to identify ergonomic risk factors for pain in sonographers, and to propose actions for sustainable work conditions. Method: At baseline a questionnaire on occupational factors and perceived pain was distributed to all female sonographers in Sweden (N=291). A qualitative interview was performed in a subgroup (N=22). The physical workload was assessed by technical measurements of postures, movements and muscular load in another subgroup (N=33), comparing different tasks and different techniques for echocardiography. A follow up questionnaire concerning pain was distributed about 2.5 years after baseline. Results: At baseline neck/shoulder as well as elbow/hand pain were associated with computer related eye complaints, high mechanical exposure index (MEI) and high job demands. To perform echocardiography was associated with elbow/hand pain while transducer handling with a two-handed/alternating grip and straight wrist was associated with a low prevalence of elbow/hand pain. The patient´s comfort was often prioritised to the disadvantage of working posture. Suggested improvements included reducing the manual handling of the transducer and to alternate hands. Echocardiography was static with awkward wrist postures and a lack of forearm muscular rest. In comparison, none of the techniques explored was optimal. The prevalence of neck/shoulder pain increased during the follow up period. Computer related eye problems, high MEI, high job demands and pain at baseline predicted neck/shoulder pain at follow up in both regions. Full time work and high job demands were associated with a high incidence of pain during the follow up period, whereas full time work was associated with a low recovery of neck/shoulder pain. For elbows hands, high sensory demands and pain at baseline were predictors for pain at follow/up and high sensory demands were associated with a high incidence of pain during the follow up period. Conclusions: We recommend improved visual ergonomics and optimal adjustability of the equipment. For echocardiography, we recommend that the equipment should be arranged so that a variation in work postures is enabled, as none of the techniques was optimal.