The primary difference between the way humans and nearly all other animals move is that our limbs move in isolation to the core. This is why we can walk vast distances, for when walking with limbs isolated from the core we don’t use much energy. Actually the human body has been designed for walking. Where we as homo sapiens gained in our ability to walk long distances, we lost in strength and power.
The art of human movement in all its forms includes understanding anatomy in detail and moving in the way the human body was designed. I define a healthy musculoskeletal system as: "Having no injuries or musculoskeletal pain where you can comfortably participate in any body movement you choose."
In terms of physical movement two of the most important features are skeletal alignment and engaging the transverse abdominal muscle. Skeletal alignment: Imagine you want to give someone a back massage. You put your palms on their back and start pushing. As your arm is bent, the force you use to push down is partially limited to the how much you can hold in the bend of the arm. In other words, you are fighting against yourself. The bent wrist will also hold your force back. Now this time straighten your arm, make a fist and press. Now you can put 100% body weight into the press. In this way you are using the alignment of your bones in the arm to give you strength and not just your muscles. All your muscles are really doing is holding the alignment in place.
Apply the same technique to our spinal column when sitting, walking or lifting something heavy and a lot more strength then normal can be generated. For example, you can do a deadlift using the alignment of the spinal vertebrae to lift the weight and not just the muscles.
The primary muscle used to create the alignment of the spine and also keep it in alignment is the transverse abdominus (TVA). Without a stable spine, one aided by proper contraction of the TVA, the nervous system fails to recruit the muscles in the extremities efficiently, and functional movements cannot be properly performed. What do you do before lifting something heavy? You hold your breath. This is not always healthy as it can cause haemorrhoids, hernia and high blood pressure. Why then does every human naturally do this? The answer is that it forces the body to bring on extra supporting muscles and especially the core ones. It also increases the intra abdominal pressure which stabilises the lumbar and thereby in-turn allows us to generate more power and strength.
The core of the body connects with the sacrum, pelvis and reproductive system, basically everything that is responsible for the continuing of human existence. The word sacrum comes from Latin and means sacred. The sacrum is a triangular shaped bone that is wedged between the two hip bones. It has three connections. On the sides it connects to the ilium portion of the hip, on the top it connects with the lumbar vertebrae and on the bottom the coccyx. On a muscular level the core contains; TVA external obliques, internal obliques, rectus abdominus, pelvic floor and the lower back muscles. The most important though is the TVA.
The TVA is the deepest of the abdominal muscles. It is like a huge belt from the pelvis all the way up to the area below the diaphragm. Learning to fully engage the TVA will connect the entire body as one unit instead of five separate ones as it connects the appendicular system to the axial system, while increasing the internal integration of the central unit as the top of the body connects to the bottom.
Engaging the TVA is done by pulling your sacrum forward. Having an engaged TVA makes it difficult to get injured other than by injuries caused by external trauma. Isolating muscles through body building type weight training is a common cause of modern day injury as when one uses the muscles outside of such an environment, they are unable to make more complex movements without injury as they have little supporting muscles and/or the coordination required to use muscles with the needed supporting muscles is lost. These type of muscles (ones that have been trained to isolate themselves) tend to be very weak in practice as they never recruit muscles to help when needed. This means that if the load gets too heavy, even though the body should be recruiting more muscles it doesn’t, so the load must either be dropped or the muscle will tear. Working muscles in isolation is the best away to achieve nice shape. The muscles look great but have little functional use.