Core stability is a kind of rootedness wherein a person's body reaches its best stance and balance. Having strength at the core of the body allows for better weight distribution during movement and at rest, so there is less wear and tear on the joints and bones. Exercise and training help in building core stability by strengthening the lower back and stomach muscles. Repeated movements with proper positioning also allow for body realignment to reinforce the core over time. Breathing from the diaphragm generally helps in feeling the parts of the anatomy that make up the core.
Some ballet dance teachers use an exercise to help students visualize a solid centered posture for turning. By imagining that there is a string going through the top of the head into the floor in a perfectly straight line, dancers can pull up onto the balls of their feet and adjust by thinking of the pull of the string as a centering force. If the head is thrust forward or the rear end is protruding too far to the back, the imaginary string is limp and no longer in a taut line pulling the body upward. This illustration works with core stability as well, as it shows how an un-centered frame is lacking balance somewhere in the core of the body.
When stomach muscles are weak, the back can hunch forward, and when back muscles are weak, the weight of the stomach can cause the upper torso to arch back with shoulders rolled forward. Visualizing the string again, there is no tightness pulling straight up, and core stability is wobbly rather than balanced. As the pelvis absorbs the uneven distribution of the back and stomach weight without the help of developed back and stomach muscles, core stability is compromised and the legs and feet typically receive too much of the body's weight; this is especially noticeable during impact activities such as walking and exercising.
Building core stability may lead to improvements in overall health. It can improve posture, which will distribute the frame and bone structure evenly from head to foot, allowing for improved range of movement with decreased pressure on the shoulders, torso, and legs. Positioning the head so the ears are over the shoulders creates a top balance check for aligning the hips underneath, and adding muscle-strengthening exercises for the stomach and lower back helps to hold everything in proper alignment; core stability is achieved through almost a rectangle of support from the shoulders through the torso without a tilt forward or back or side to side. An added benefit of core strengthening is that isolation exercises for other parts of the body are more effective when done from a centered stance.