A concise demonstration of the exercise:
The front plank is an essential exercise for core postural stability.
Lie in prone position (face down).
Place toes on ground in dorsiflexed position.
Place elbows under shoulders.
Squeeze the quads. Squeeze the glutes. And raise into a plank.
Keep back flat. Do not let butt rise or sink. Stay flat.
Hold for 30 seconds to 3 minutes, breaking up with rest as needed.