What is the ruling on sitting on a chair during prayer due to inflammation in the knee joints?

Question:
I am seventy-two years old, and in the year 1411 AH, I was afflicted with inflammation in my knee joints due to my advanced age. The treating doctor, an orthopedic specialist, advised me not to sit on the ground during my prayer and instructed me to sit on a chair during prostration and the tashahhud. I am currently praying according to the doctor's instructions, but because of this chair, I perform three movements in the morning prayer, five in the Maghrib prayer, and seven in the other prayers. These movements consist of pulling the chair when prostrating and returning it when standing up. My question is: does this movement affect the prayer? Please guide us. May Allah reward you with good.

Answer:
The saying of Allah (Glorified and Exalted is He) and the Prophet (peace and blessings be upon him) says: "When I command you with a matter, do it as much as you are able." The sick person prays according to his condition. He (peace and blessings be upon him) said: and lying on his back. What the questioner mentioned, that he was afflicted with a joint disease, and that the doctor advised him not to sit on the ground during prayer, but rather to sit on a chair, is a matter with which there is no harm. He sits on the chair during prayer instead of sitting on the ground until Allah cures him. And his statement that he moves the chair during prayer in order to sit on it is a matter with which there is no harm, and

The presenter:
no blame in it, if Allah wills. Praise be to Allah. May Allah reward you with good.