That wording appears to be incorrect, or at least very awkward. Perhaps some words are missing after "need the user to be" and before "physical position". Would it read better if it were written:
"VR Headsets need the user to be in particular physical positions to play."
Under Understanding XR and Accessibility Challenges, the first sentence of the second bullet reads "VR Headsets need the user to be a physical position to play."
That wording appears to be incorrect, or at least very awkward. Perhaps some words are missing after "need the user to be" and before "physical position". Would it read better if it were written:
"VR Headsets need the user to be in particular physical positions to play."