If the center of gravity sits forward as shown in the picture above, the core gets weak and the hip muscles are also out of its neutral position, making it difficult to function 100%. When the core and glutes weaken, other muscles in the lower extremities have to make up for this and take on extra work during everyday activities. As a result, the thigh and calf muscles gradually become overloaded and tight, which can also affect the nerves that pass through those muscles. (See from 4:00 for more details)

The second body imbalance is pelvic sway where the pelvis moves to one side, as shown in the picture above. This women's weight is shifted to the right, and in this case, the right hip muscles are placed in a lengthened position, while the left ones are relatively shorter. It does not matter whether the muscles are stretched or shortened. The key importance is that it is difficult to function properly if muscles are out of their neutral position. So the muscles that do not function 100% are likely to be overloaded and tight, which can possibly affect the nerve roots as described above.

The last one is pelvic rotation where the pelvis is twisted, as shown in the pictures above. The more twisted the pelvis, the more it turns to one side when you relax your body, as you can see in the picture of the man. In this case, his left pelvis is more anteriorly tilted, while his right pelvis is tilted relatively backwards. Hence, why his pelvis rotates to the right. This puts the right hip muscles in an elongated position and the left hip muscles in a relatively shorter position.

Again, muscles in extended positions tend to get tight because they do not want to stretch anymore. On the other hand, muscles in shorter positions tend to get tight due to their position itself. Tight muscles cannot function properly causing further muscle tightness in other muscles that compensate for the already tight muscles. This vicious cycle can eventually affect the nerves, causing sciatica. If lumbar discs/nerves are affected, it can be called 'discogenic sciatica', which will be discussed in more detail (See the next posting).