Apparently most of the energies that a body abosrbs are straight away stored in our brains
because every kind of energy in our body comes from the brain and goes to the brain. In other words, you are charged with electromagnetic waves without realizing it. his causes discomfort such as headaches,laziness and mild body pain.
So putting ur head on the ground in the position of sajda is the BEST WAY to discharge the electomagnetic signals.
Other than that just to add up with researches, it has been proven that not only sajda but the position of rukuh keep ur body blood flow and your circulations good.