Spiral and helixes
Every move we make is a kind of helix, an elongated spiral. Our skeleton is structured to allow rotation. This is obvious in shoulder or hip joint, but is also the case in how the lower arm moves with respect to the upper arm or the lower leg with respect to the upper leg. In everyday situations it's rare to use a pure bending movement - bending forward, backwards or sideways - without there being a component of rotation. And, for elegant, efficient, whole body movements, the rotation wants to be progressive, starting for example at the foot and spreading gradually through the skeleton as the movement unfurls.
Try this: stand with feet hip width apart. Start a spiral movement by circling your heel on the ground from the outside edge, round the back, to the inside edge. As you engage the inside edge of your heel the spiral travels up your leg to your hip joint, your pelvis begins to rotate as that hip joint comes forward a tiny bit and your weight moves a little towards the other hip joint. This tiny rotation of the pelvis asks your spine to lengthen, and the opposite side of the chest to get further from the knee of the initiating leg. The rotation travels up your spine vertebra by vertebra until you find yourself facing to the side away from the foot you started from.
Or this: from the same starting position, start with the opposite circle of the heel, coming from the inside edge, round the back, to the outside edge. Feel the spiral movement travel up your leg to the hip joint, which begins to move backwards a tiny bit. This spiral travels up your spine until you find yourself facing the side towards the foot you started from.
Generating these spirals smoothly and harmoniously requires all parts of you to engage in proportion. Nothing strains and nothing is passive. The foot initiates a rotation of the pelvis, which is enabled to turn by rotation of the spine. While the hip joint itself allows a lot of rotation, the joints between the vertebrae each only allow a little rotation, so it helps if each vertebra can contribute. The vertebrae of the lower back (lumbar spine) hardly allow any rotation but still need to move smoothly. The upper vertebrae have more range and so more rotation happens here. But the idea is not to seek out the outer limit of your range. It is to seek out the gradual quality of the movement as it progresses through your skeleton. So keep the movement small and centered close to your axis - so small that you can only just perceive the relative rotation of each different part, and can distinguish which parts move smoothly and which are stiffer. This requires all parts to work together. Without easy rotation in the upper back and chest, the pelvis will be inhibited, and the whole movement will be less pleasing.
The two turning movements described above are just examples. They can help us get a clearer mental picture of how our skeleton moves in space when making an optimally efficient movement. There are many other spiraling movements to discover - in fact, once you start finding them, you'll notice them everywhere, connecting our extremities with our center in movement.
If we consider the act of walking, it becomes clear we are constantly using some combination of spiral movements. A snapshot taken in any moment would show how, as we walk forwards, each part of us is in fact rotating. The foot rotates with respect to the pelvis, the pelvis with respect to the breastbone, the breastbone with respect to the shoulders. At all times the head can remain free to turn and face any direction.
How do you perceive yourself in the act of walking? Where do you experience planar movements and where do you experience rotation? Please leave a comment.