Document holder usage when reading and writing.

The posture of the head and neck and subjective ratings of comfort were investigated while notetaking on a horizontal writing surface from a source document held either flat at 0° or on a document holder inclined at 29°. Twelve subjects performed the task for 20 minutes with and without the document holder, while photographs were taken every 5 minutes. The angle of the head to the neck was not found to differ (P > 0·05) but the neck was inclined significantly (P < 0·001) more vertically when using the document holder. The moment of the head about the atlanto-occipital joint was 38·0 × body mass (BM) N.mm in both conditions, while the moment of the head and neck about C7-T1 was 88·2 × BM N.mm without, and 79·1 × BM N.mm with, the document holder. This difference was significant (P < 0·01). Subjective ratings showed the document holder to be significantly preferred (P < 0·5). It was hypothesized that this preference occurred as a result of the decreased moment at the neck. Thus working posture can be influenced by environmental changes and the use of a document holder while notetaking may be beneficial.