Is there a reduction in postural load when wearing progressive lenses during VDT work over a three-month period?
In an initial study, 18 VDT operators were found to have a higher muscle load in the neck/ shoulder region when using progressive lenses compared with single-vision lenses, while working on a VDT unit. For single-vision lenses, a higher flexion angle in the neck was also discovered. The present study investigates whether this higher muscle load is reduced when a progressive correction is worn for a three-month period. Adaptation in terms of reduced muscle load measured by electromyography (EMG) was not discovered. Head flexion angle was smaller when using progressive correction as compared with single-vision lenses. Some practical implications for occupational optometry are discussed.
Horgen
G
G
Kongsberg College of Engineering, Department of Optometry, Norway.
Aarås
A
A
Fagerthun
H
H
Larsen
S
S