Final answer:
The patient is positioned standing facing the observer, with upper limbs extended out at a ninety-degree angle from the torso and lower limbs in a wide stance with feet pointing laterally.
Step-by-step explanation:
To visualize or "open" the right sacroiliac joint, the patient is positioned standing facing the observer, with upper limbs extended out at a ninety-degree angle from the torso and lower limbs in a wide stance with feet pointing laterally.