Reaching in sitting: The effect of seat design and body manipulations.

Background: Sitting is a common and familiar position used daily as a platform for many motor activities in the workplace, at school, or at home.

Objective: To investigate how difference in the chair design and selected sitting manipulations contribute to reach distance in sitting.

Methods: Ten healthy subjects were required to reach forward as far as possible while sitting in an adjustable chair with 0°, 10° forward or 10° backward inclination of the seat, with and without footrest and leg support, with legs crossed, and when holding the edge of the seat with the contralateral arm.

Results: In comparison to sitting with feet on the footrest, the maximal reaching distance decreased significantly when sitting on either forward or backward inclined seat (p < 0.05) and it increased when the subjects held the edge of the seat while seated with footrest and the posterior leg support (p < 0.05). There was no major effect of crossing the legs or the use of anterior leg support on the maximal reach distance.

Conclusions: Modification of the chair design could increase or decrease reaching distance in sitting. The outcome of the study provides a background for future investigations of the effect of sitting positions on reaching distance in the workplace, at home, or at school.