What is the ruling on prostrating while using one's hand for support to relieve pressure on an injured spot on the forehead, and is the prayer accepted with that?

Some scholars are of the opinion that what is obligatory in prostration (sujud) is merely placing the forehead on the ground with tranquility, and this is the view of the Maliki school.

Other scholars are of the opinion that mere touching is not sufficient; rather, it is necessary to press the forehead firmly onto the place of prostration. This is the view of the Shafi'i school.

According to this latter view, if your prostration involved pressing your forehead firmly, then your prayer is valid. If you merely touch the ground with your forehead due to inability to do otherwise, then your prayer is valid, based on the Almighty’s sayings: "So fear Allah as much as you are able" and "Allah does not burden a soul beyond its capacity."

However, if you did not press your forehead firmly onto the ground despite being able to do so, then according to the Shafi'is, you must repeat the prayers you performed in this manner.

If you place your forehead on the ground firmly without excessive pressure, then your prayer is valid.