Dought & clear, - She cannot move her head because of severe pain; how should she pray?.

A sister is asking that she has a very strong pain in her head that
makes her vomit. When this happens she cannot pray in any position, as
she cannot raise her head. How shall she pray when prayer time comes?.
Praise be to Allaah.
Firstly:
We ask Allaah to grant our sister healing and well being in her
religious and worldly affairs.
Secondly:
If the time for prayer comes and she feels pain, then she may delay
the prayer until the end of its preferred time, in the hope that she
may be able to offer the prayer in the proper manner. But if the pain
persists, then she may pray in the manner that she is able to, even if
she is lying on her back.
The basic principle concerning that is the verse in which Allaah says
(interpretation of the meaning):
"Allaah burdens not a person beyond his scope"
[al-Baqarah 2:286].
And the Prophet(peace and blessings of Allaah be upon him) said to
'Imraan ibn Husayn: "Pray standing, and if you cannot, then sitting,
and if you cannot, then (lying) on your side." Narrated by al-Bukhaari
(1117) and Abu Dawood (952).
If a person prays sitting, then he should lean forward for rukoo'
(bowing) and sujood (prostration), and he should lean forward more for
prostration than for bowing.
If a person prays lying on his right or left side, then he should tilt
his head towards his chest for bowing and prostration. If a person
prays lying on his back, he should put his feet towards the qiblah and
tilt his head towards his chest for bowing and prostration. If he is
unable – when sitting or lying – to move his head, then the actions
are waived in his case, because that is the thing that he is unable to
do, but the words are not waived because he is able to say them, and
Allaah says (interpretation of the meaning):"So keep your duty to
Allaah and fear Him as much as you can"[al-Taghaabun 64:16]. So he
should say takbeer and recite Qur'aan, and intend to bow and say
takbeer and recite the tasbeeh of bowing, then he should intend to
stand up and saySami'aAllaahu liman hamidah, rabbana wa
laka'l-hamd(Allaah hears the one who praises Him, our Lord to You be
praise) etc. Then he should intend to prostrate and say takbeer and
the tasbeeh of prostration, because this is what is implied by the
shar'i principle,"So keep your duty to Allaah and fear Him as much as
you can".
End quote fromal-Sharh al-Mumti'(4/332).
And Allaah knows best.