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).
That can lead to injury or other foot problems including plantar fasciitis, bunions and calluses. People with flat feet, low arches, or overly flexible arches tend to overpronate. Because your arches can't support your step, your foot rolls too far inward, twisting your foot, leg, and knee and forcing your body out of proper alignment.