Introduction Besides work-related low back pain, disorders of neck-shoulder-arm area have also become increasingly common amongst nursing personnel. Analysis of working postures according to OWAS method demonstrated that more than 25% of the working time the abduction of the upper limb was between 30 and 90 degrees. At that point ergonomic measures should be considered. This study was conducted to determine whether different bed positions effect deltoid muscle activity during nursing tasks.

Methods Seven nurses in a geriatric nursing home participated in the study. Surface electromyography was used to assess local strain of the deltoid muscle during standardised morning care routine of immobile patients. Each participant conducted measurements with four different bed conditions: 1. recommended bed height according to the anthropometric characteristics with side rails up; 2. recommended height with side rails down; 3. recommended height lowered by 10 centimetres with side rails up; 4. lowered height with side rails down. Statistical analysis was performed on the basis of non-parametric Wilcoxon matched pairs test. The value p<0.05 was considered to be statistically significant.

Result There were no statistically significant differences between all four cases. Deltoid muscle activity was neither influenced by the height of the bed (p=0.078–1.00) nor by the positions of the side rails (p=0,047–0.33).

Discussion Differences in bed height or the position of the side rails did not result in significant change of deltoid muscles activity. Therefore, further ergonomic evaluations need to be considered to determine the true origin of shoulder discomfort and why upper limb postures are above critical ergonomic values amongst nursing personnel.