The person usually continues to roll to their side when the motion is started by the caregiver. Once the arm is hooked over the bed rail, they will probably hold still for a few minutes when asked to do so. The person can assist with dressing by rolling, holding their arm over bed rail, and following the direction to "hold still."
Transfers to shower beds or tilt-in-space chairs are easier when you start rocking motions to sit up in bed.
When a tilt-in-space chair is propelled over toilet / shower commode, the person usually cooperates by holding still.
The person can assist with transfers by leaning into the direction of change in position, holding arms where placed and holding still where directed. Appreciation for being in an upright position or back to bed is often evident in facial expressions and sighs of satisfaction.
Your hoisting and manual handling methods must comply with your facility's risk assessment and work safety policies. If you disagree, you need to discuss and possibly negotiate a change in policy for your facility.