216 Edging in the long radius turn
Due in part to the deep sidecut on contemporary snowboards, it is possible, on much of the mountain, to simply ‘park and ride’ which is to say, get the board on edge somehow, and balance on the sidecut until the turn ends.
While this is fun, and sort of functional, it is not that versatile.
If you cannot alter the relationship between the board and the snow while in mid-turn, you will have difficulty avoiding obstacles, including other skiers and snowboarders, which may cross your path.
To facilitate agility an a snowboard, first take a look at how you stand on the board.
Is it possible, standing buckled in, on the carpet, to tilt the board to each side, lifting the opposite edge off the ground about an inch, without tipping over or flailing your arms around? Can you tilt the board with equal facility in either direction? Are you evenly weighted on both feet the whole time? If no to any of these situations, then get a screwdriver.
While it is possible to ride a snowboard with just about any stance angle and width, there are some combinations that make riding easier and more enjoyable.
Excessive foot splay does not facilitate movement from one edge to the other. The closer your binding angles are to parallel, the simpler the articulations of the lower extremities. If both knees follow the same path when they flex and extend, changes to both edge angle and pressure distribution will be more consistent, both in application and in outcome. Foot splay is largely the result of medial foot collapse; so if widely dissimilar binding angles feel better, get some support for your feet.
At lower binding angles, any flexing/extending of the knees will likely result in a change in edge angle. This will be more noticeable on the rear foot. This tendency can be attenuated somewhat by increasing the angle of both bindings, as well as by lacing the rear boot down one notch. Obviously, it is possible to add too much angle to the bindings, at which point it will be difficult to hold the board on edge at any kind of speed.
Once the stance angle has been improved, it is necessary to stand in such a manner as to allow for free joint articulation from one edge to the other. This can be achieved by standing with the hips, and to a lesser extent, the shoulders facing the same direction as the front foot.
Though at this point the function or necessity of angulation is debatable, it certainly makes balancing at slow speeds easier. It stands to reason then, that setting up a stance to facilitate angulation will have some benefit.
(By the way, inclination is commonly defined as creating angle between the body and the slope, whereas angulation is creating angles internal to the body, as well as to the slope).
Edge angle changes can come from several areas of joint articulation. Increasing or decreasing the amount of angulation, generally vial the hip sockets and spine is, perhaps, the easiest means. This can be achieved by tightening the muscles on one side of the torso, while allowing those on the opposite side to elongate. This is not terribly accurate, however.
The second possibility is movement of the knee joints laterally, with the movement originating in the hip sockets. In other words, if you stand equally weighted, with knees flexed somewhat, it is possible to swing the patellae back and forth a few inches, affecting the angle of the board edge relative to the ground. This is fairly accurate, but as the amount of lateral movement is somewhat proportional to the degree of knee flexion, it can be rather tiring. Similarly, vertical compliance of the legs for suspension is compromised. It is possible to alter the edge angle in this manner throughout most of the arc of the turn.
The third viable option to alter edge angle is via articulations of the ankle joint. Such movements can be extremely accurate, but are really only effective at those parts of a turn where the loads are at an absolute minimum. For the ankle to be effective in this context, the foot needs to be accurately supported with a quality footbed, and there can be no competing tensions on the joint. Coincidentally, those parts of the turn where the loads are lightest are same parts where foot dexterity is most important.
So, by combining some degree of angulation with more accurate articulations of the knees and ankles, it is possible to alter the angular relationship between the board and the snow. This is one way to alter the shape of a turn in progress.