Poor posture robs energy from the body. The better the postural alignment; the better the functional performance. Ideal posture occurs when the muscular-skeletal system functions most efficiently. Poor posture causes greater stress in the stabilizer muscles and joints and therefore increases the chance of injury. Good posture and alignment leads to better balance, agility, and even faster recovery from a workout.
A good posture allows us to use the center of the body, the base of effective techniques. All techniques and movement of legs or arms are controlled, initiated, and stabilized from this center. The center of mass of the body is located about 2 inches under the navel and toward the middle of the body (a point called the tan-den). Technically, we create energy from the center of the body by dynamics: rotation, vibration, shifting, dropping, lifting, or pendulum motion, and by using the breath to control the contraction and expansion of muscles. These energies extend and transfer to the other parts of the body depending on the technique.
The center of the body serves to transfer energy between the impact point a strikes and the floor, via the feet, and it acts as a stabilizer against impact shock. With firm center, energy will transfer smoothly. Energy transfers best in a straight line, therefore, when posture is misaligned, energy is wasted. Another problem with posture is imbalance between the front and back muscles. In life, we do much more flexion than extension, which leads to shortened abdominal muscles and a weak back. Most techniques to the front require use of the back muscles. Neglecting the body center results in more injuries and not fulfilling your potentials. Articles by prominent conditioning and athletic coaches and researchers stress the importance of developing the “core” of the body to enhance athletic performance and to prevent injuries. Those articles always mention martial arts as example of good use of the body center.