Question Details: Due to a problem with my knees, I am unable to sit on the ground, and I perform my prayer on a chair. Should I begin each rakʿah standing?
Answer: A person who, due to a condition affecting his knees, is unable to sit on the ground and cannot go into prostration (sujūd), and therefore performs the prayer on a chair, should begin each rakʿah standing. He performs the standing (qiyām), the recitation (qirāʾah), and the bowing (rukūʿ), and then completes the other essential elements of the prayer—namely the prostration (by gesture, imāʾ) and the sitting for tashahhud—while seated on the chair. He does not perform the entire prayer on the chair. This is because his difficulty lies in being unable to perform the prostration and to sit on the ground. As for the other elements, namely standing and bowing, he does not experience difficulty. A person is not responsible for the elements he is unable to perform; however, he is required to perform those elements he is able to carry out.