| dc.description.abstract | Background: Office work is associated with prolonged awkward postures, overloading
body structures when associated with improper ergonomic conditions, and may be
associated with musculoskeletal disorders. Effective ergonomic interventions for reducing biomechanical exposure are not documented. Therefore it is necessary to
identify effective preventive measures, using objective measurements of occupational
exposure, for controlling and preventing these disorders. Objective: This study aimed to
evaluate the effectiveness of an ergonomic intervention by a cluster randomized and
controlled design using objective measures to evaluate head, cervical spine, thoracic
spine and shoulders postures during work, perceived discomfort and musculoskeletal
pain, among office workers. Methods: Sixty one administrative employees were
evaluated at a university sector where 95 employees work. The allocation of subjects to
the groups was performed by cluster randomization. The clusters was the rooms in
which the subjects work. Thus, two groups (experimental group [EG; n = 31] and
control group [CG; n = 30]) were compared before (T1) and 30 minutes (T2) after the
application of the intervention. Assessment of perceived discomfort, musculoskeletal
pain and postures of the head, cervical spine, thoracic spine and shoulders, and in
addition, photos were taken for both groups at T1 and T2 was held. The EG received a
workstation ergonomic intervention since the CG took a 15-minute break, but received
no intervention in the workplace. Kolmogorov-Smirnov test were used to test the data
distribution and Levene test for homogeneity of variances between groups. Then, a
linear mixed model analysis was performed to compare groups at the two assessments.
Mann Whitney test was applied to compare the groups for discomfort, pain and the final
score of the ROSA. The data were analyzed using SPSS (version 22.0) and the
significance level was set at 5%. The photos were analyzed descriptively and were also
punctuated using the ROSA tool. Results: A significant interaction between group and
time was found only for shoulders. The EG presented an arm lowering regarding the
elevation on T2, on P90 it lowered 8,81º and 8.46, on right and left shoulders,
respectively, since the CG had similar values in T1 and T2, with the P90 raising 0,88º
and 1,97º on the right and left shoulders. For the upper back was found a significant
difference in relation to time, showing a reduction on flexion in both groups at T2. The
head and neck postures were similar between the time in both groups. On T2, the EG
showed a significant reduction on perceived discomfort (2.2 mm), and pain on neck
(0.07 points), shoulders (0.16 points) and upper back (0.32 points) regions; and for CG
there was an increase of the same variables (0.72, 1.73, 0.82 mm and 1.06 points,
respectively). Conclusion: The furniture adjustment was important to reduce the
exposure of shoulders and perceived discomfort and pain referred to neck, shoulders
and upper back areas. The pause was beneficial to improve superior trunk posture,
probably due to postural changes. These results highlight the importance of using
objective measures to evaluate the effectiveness of ergonomics interventions. | |
