Affiliations: Department of Physical Therapy, College of Biomedical
Science and Engineering, Inje University, Gimhae, Gyeongsangnam-do, Republic of
Korea | Department of Physical Therapy, The Graduate School,
Yonsei University, Gimhae, Republic of Korea
Note: [] Address for correspondence: Won-Gyu Yoo, Department of Physical
Therapy, College of Biomedical Science and Engineering, Inje University, 607
Obang-dong, Gimhae, Gyeongsangnam-do, 621-749 Republic of Korea. Tel.: +82 55
320 3994; Fax: +82 55 329 1678; E-mail: won7y@inje.ac.kr
Abstract: Objective: This study was designed to identify the effect of seat
support characteristics on the neck and trunk muscles and forward head posture
of visual display terminal (VDT) workers working at computers. Participants: 22 VDT workers with forward head posture were asked to perform
computer work. Methods: Surface electromyography recorded the five neck
and trunk muscles Forward head angle was analyzed with a 3-D motion analysis
system. The significance of differences in the seat supports (hard, spongy,
unstable) was tested by repeated one-way ANOVA with the significance cutoff set
at α = 0.05. Results: Computer work seated on an unstable
cushion-ball as compared to a spongy soft-cushion seat support showed
significantly lower midcervical and L5 paraspinal muscle activity and
significantly higher lower trapezius and internal oblique abdominal muscle
activity. The mean forward head angle decreased in the order of spongy, hard,
and unstable seat supports. Conclusions: An unstable cushion-ball seat
support may prevent work-related neck and upper limb disorders associated with
forward head posture.
Keywords: Forward head posture, musculoskeletal disorders, seat support
