The person can control trunk muscles to hold still, lift their bottom and arm while lying in a bed with bedrails. While seated in a chair with head support, the control of the trunk muscles is for a sense of balance. The chair must support their head and trunk in an upright position that is vertical to the floor.
The carer's tactile and verbal commands to move or hold still are apt to arouse their attention when a change of position involves the trunk and arm. Tactile cues and pointing are apt to make more sense to them than words.