What is hypercross syndrome and its manifestations: Hypercross syndrome is a deviation from the normal body posture, especially when viewed from the side. First, let’s explain what the normal ideal body posture is. The so-called ideal body posture, when viewed from the side: if a vertical line is suspended, then this line passes through the earlobe, the acromion, the middle of the torso, the greater trochanter, the knee, and slightly in front of the ankle. Of course not everyone will achieve such a perfect posture, there will be more or less deviations, but if there is a very significant deviation, then it needs to be improved. Because it will not only affect the aesthetics, but also bring harm to the body at the same time. If “perfect posture” is the ultimate goal, then all we have to do is to try our best to move towards it. Figure 1 Now let’s look at the physical characteristics of lower crossed syndrome: many people have a pronounced anterior pelvic tilt and excessive forward bending of the lumbar spine compared to the ideal body posture. Those with beer bellies, pregnant women, and OL (office women) who wear high heels often present with this body posture. Both the beer belly and the fetus have weight, as the center of gravity shifts forward, it will pull the body to the front, but it is impossible to walk normally with the waist bent, so it will use the strength of the waist to pull the body back, and finally caused the “front and back pout” posture. Long-term such posture will lead to muscle imbalance. The formation of cross-site muscle weakness changes. The stronger/tensioned muscles are: iliopsoas, erector spinae; the weaker/relaxed muscles are: abdominal group, gluteus maximus. When the nerve control of a muscle is increased, it naturally inhibits the control of the antagonist muscle of this muscle. For example, if the recruitment of the iliopsoas muscle is enhanced and shortened in inferior cruciate syndrome, then the control of the antagonist muscle (gluteus maximus) will be reduced. If the abdominal muscle is elongated and control is weakened, then nerve control of its antagonist muscle (erector spinae) is increased. Adverse effects of inferior cruciate syndrome: If the pelvis is constantly tilted forward and the lumbar spine is excessively bent forward, the pressure on the joints (lumbar spine and knee joints) is increased and the soft tissues around the 5th lumbar spine and 1st sacrum are stressed, causing pain. It affects the dynamic posture of the hip joint during extension. It may also cause hyperextension of the knee joint because of the change in the center of gravity.