Seven females, six laboratory assistants, participated in the experimental part of the study. The level of muscular activity in different sitting work postures was recorded, using surface electrodes, as full-wave-rectified and low-pass filtered EMG, and normalised. The laboratory assistants also rated the degree of exertion in four different body regions during their ordinary microtome sectioning work, comparing the use of anterior chest support with the use of their usual chair with lumbar support. The use of anterior chest support reduced the muscular activity in the lumbar back muscles but increased it in the shoulder muscles. Perceived exertion in the neck, shoulders and thoracic back regions increased. Anterior chest support does not seem to solve the problem of neck- and-shoulder load-elicited pain during the work of preparing laboratory sections.
Keywords: Anterior chest support; Cervical spine; Chair; EMG; Ergonomics; Female; Lumbar support; Muscle function; Neck/shoulder and back muscles; Sitting posture; Work posture.