Do your feet, ankles, knees crack when you first get out of bed? Don't panic, its only your joints
preparing for the day ahead. As you move during the day, bubbles form in the fluid that lubricates your joints. When they collapse, you hear them pop. It's a harmless phenomenon- and it might
even help your joints glide as you move.
However if your joints crack overtime you move it, it could be a tendon snapping against bone as a result of an injury or a muscle imbalance. If every pop is painful, talk to your doctor it could be sign of arthritis.