The Islamic Din (Religion) is religion of ease. Therefore, the worship of the a person who is not well is also performed with in the physical capacty of the patient.
Anyone who is so sick as to be unable to stand, performs prayer in a sitting position. While sitting he/she is permitted to perform the acts of bowing and protrating. ne who is so sick as to be unable to do the bowing and prostrating of the prayer, or whose condition is likely to lengthen through bowing and prostrating, omits them and instead replaces them with gestures.
The gestures are done by bowing down the head in place of the acts of bowing and prostrating in a ritual prayer.
Nevertheless, the head is bowed down lower for the act of prostration than for the act of bowing. The omission of this cansels the prayer. The gestures are not to be performed with eyes or the ears.
Still, there are those who are ill to such an extent that they are unable to sit or lie down so that their legs are turned in the direction of the Holy Kaaba. They perform their ritual prayers by means of gestures they can also perform their ritual prayers by lying on one side so that the face should turn in the direction of the Holy Kaaba.
Furthermore, those who are very sick and lack the ability to carry out any of the above mentioned positions, may postpone their prayers and perform them later as qadha. In the case, they perform up to as many as five missed fixed time prayers. Allah, the All-forgiving than for gives those who have missed more then five fixed time prayers. In other words, they are not supposed to perform these prayers.