Page 192 - HA Convention 2015

Service Priorities and Programmes Free Papers

SPP8.1 Young Hospital Authority Investigators Presentations 14:30 Room 221

Effects of Different Tilting and Reclining Seat Positions on Interface Pressure in Non-ambulant Individuals
Chan WS, Yui KY
Occupational Therapy Department, Cheshire Home Shatin, Hong Kong

Introduction

Wheelchair seating is usually recommended for people with impaired mobility function. In common seating prescription,
we aim at minimising the intensity of interface pressure for sore prevention, while maximising the duration of seating for
achieving the greatest functional level.

Objectives

(1) To investigate the effect of tilting, reclining and their combinations on the interface pressure between bony prominences at
buttocks and wheelchair; and (2) to suggest a seating position for a fixed duration without developing sore.

Tuesday, 19 May Methodology

12 male and 11 female wheelchair users from Cheshire Home Shatin were invited for study. A commonly available tilt-in-
space wheelchair was selected and adjusted by two variables: (1) tilting angle θ (0°, 10° and 20°) and (2) reclining angle β (90°,
105° and 120°). The participants were asked to sit on the wheelchair in nine positions created by the two variables in total.
The peak pressure at buttocks for each position was quantified and recorded by a pressure mapping system.

Results

In the test of within subject effect, there was a significant tilt effect (F(2,44)=10.865, p<0.001) and a recline effect
(F(2,44)=19.590, p<0.001) with a significant interaction effect among the two variables (F(4,88)=3.025, p=0.022) on peak
pressure. Pairwise comparisons show that the peak interface pressure was significantly decreased when the tilting angle
increased from 10° to 20° (p=0.017), or when the reclining angle raised from 90° to 105° (p=0.005) or from 105° to 120°
(p=0.001). By using pairwise t-test, the peak interface pressures was significantly decreased when the wheelchair was
adjusted from neutral position, i.e. 0° tilting with 90° reclining angle, to five out of nine specific positions.

Discussion
It is effective to reduce interface pressure by increasing the tilting and reclining angles of wheelchair. In our clinical practice,
we generally arrange a two-hour period for each seating session for any suitable patients with severe disability. Regarding to
a previous study, the peak pressure should be maintained at <140mmHg for sore prevention. Thus, we suggest a tilt-in-space
wheelchair positioned at “0° tilting and ≥120° reclining” or “≥10° tilting and ≥105° reclining”.

HOSPITAL AUTHORITY CONVENTION 2015

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