The effect of arm position and bed adjustment on comfort and pressure under the shoulders in people with tetraplegia: a randomized cross-over study

Study design: Randomized, within-in participant cross-over study.
Objective: The purpose of this study was to determine the effect on comfort and pressure of lying with the shoulders and bed in
different positions for people with tetraplegia.
Setting: Rehabilitation hospital.
Methods: Twenty people with tetraplegia were tested lying supine with the shoulders and bed in seven different positions. The
positions used a combination of three arm and two bed positions. Six of the positions reflected what is commonly recommended in
acute spinal cord injury units including a crucifix-type position. The seventh position was selected by participants and reflected their
preferred sleeping position. There were five outcomes: general comfort, shoulder comfort, participant choice of preferred position,
peak pressure under the shoulders and areal pressure under the shoulders. Pressure was measured using a pressure mapping system
and comfort using a visual analogue scale (VAS).
Results: The participants reported significantly higher (Po0.01) general comfort and shoulder comfort in their self-selected position
compared with all other positions. There was no statistical difference in peak pressure (P ¼ 0.15) or areal pressure (P ¼ 0.08) under
the shoulders between the seven positions. Most participants indicated that they preferred to lie with their shoulders adducted and
internally rotated and the hands either by their sides or on their stomachs.
Conclusion: The position of the shoulders has little effect on pressure but a notable effect on comfort. Participants preferred to sleep
with their arms beside their bodies, not with their arms in a crucifix position as commonly advocated.