Palpitation is an awareness of the abnormal beating of the heart. It may occur in people with or without heart problems. Heart palpitations when lying down is not a common occurrence and can be caused by various factors.
Flat feet occur when the normal foot arches have partially or completely collapsed. When the foot is put to the ground the inner or middle side of the foot comes down to the floor rather than remaining raised. This can cause the whole foot to roll inwards (this is called over-pronation).
If instead, the arch remains flattened and the ankle remains turned inward, muscles and tendons will be stressed and the foot will undergo excessive wear and tear. This can cause the foot bones to shift position, which results in additional stress of the bones and joints above the pronated foot.