The Sternalis Muscle is present in about 7% of the population and is insufficiently referenced in anatomy textbooks   Sternalis trigger points can cause considerable pain, and are too often overlooked. The sternalis muscle is a relative rarity that is believed to be prevalent in around 7-8% of the population. The sternalis typically sits in front of the pectoralis major, and parallel to the margin of the sternum. It may be a variation of the pectoralis major or of the rectus abdominis. The anatomy of the sternalis is variable and it may be present only on one side of the chest. The function...