This time, let's talk about "applying pressure with both feet." When we mention applying pressure to the board with both feet, we often subconsciously think of applying equal force with both feet. This kind of pressure application is limited to when we are standing on flat ground, that is, when we stand vertically on a horizontal line. When we glide down a snow-covered slope, the way our feet apply pressure to the ski board differs greatly from standing on flat ground. Generally speaking, during turning motions while gliding, the pressure on the downhill foot is greater than on the uphill foot. The situation where the pressure on the uphill foot exceeds the downhill foot is almost non-existent; if it does occur, it would only be in specific practice movements. Since we apply different levels of pressure with our feet while turning, why do we use terms like "both feet applying pressure (or exerting force)"? The purpose of using such terminology is to indicate that the act of both feet pressing on the ski board is not an isolated action but rather a coordinated whole: that is, although the intensity of pressure applied by the downhill and uphill feet may differ, the actions of both feet are not isolated but mutually coordinated, for the overall movement of the body. In other words, for the overall balanced movement of the body to drive the ski board to turn, the two feet need to work together, with the downhill foot as the main force and the uphill foot as auxiliary support, reasonably supporting the body according to the speed of gliding and the magnitude of centrifugal force to achieve balance.
Below, based on my personal experience with parallel skiing, I will elaborate on the roles of the outer foot (downhill foot) and inner foot (uphill foot) during gliding. Simply put, the role of the outer foot is to maintain the turning force and keep the body balanced, while the inner foot guides the direction of the turn. In other words, the downhill foot is the car's accelerator, and the uphill foot is the steering wheel! Of course, while the uphill foot acts as the steering wheel controlling the direction, it is not completely without force; the uphill foot must also apply pressure to the ski board as needed. So how can we effectively use the uphill foot? We need to adopt a reasonable gliding stance to transmit pressure to the ski board and fully absorb the resistance of the snow surface against the board. During turns, if the stance is unstable and wobbles left and right, the ski board will be unable to accurately bear the pressure from the snow surface. For example, when the center of gravity is shifted backward (i.e., sitting back), the feet lose the ability to make fine adjustments. At this point, if you try to adjust the edge angle by tilting your entire body, it becomes very easy to lose balance. I believe everyone has had such experiences, especially during the initial learning phase.
To summarize the above description, based on a reasonable gliding stance, allow the downhill foot to apply pressure to the ski board and let the uphill board effectively guide the gliding direction; in other words, let the pressure from the downhill foot create a reasonable gliding stance, guiding the uphill board to control the turning direction. Although modern wide-tipped boards can automatically glide into turns when pressured, this does not mean the board will entirely steer itself. Skiers at a high level, after entering a turn, can actively control the sliding direction of the board by driving and controlling the board's edge with a reasonable stance. Whether or not one can achieve this reasonable gliding stance depends on your ability to apply pressure to and control the inner foot (uphill foot)!
In the second half of a C-turn, when the ski board slides down the slope obliquely, imagine connecting the outside of the big toe and the inside of the heel of the downhill foot into a line; all the pressure is concentrated along this line, and the orientation of this line should align with the edge of the board. On the other hand, connect the outside of the little toe and the outside of the heel of the uphill foot into a line; the pressure on the uphill foot should be concentrated along this line, and the orientation of this line should be slightly inside the orientation of the board edge (meaning the tip of the uphill board should rotate towards the mountain). If the inner board does not perform this motion but simply applies pressure following the outer board (note: intermediate skiers should pay attention to the following text), what happens is that the inner board's tip will directly cut into the snow, resulting in the tips of both boards separating, forming a V-shape. Another scenario is that if the inner board tip does not rotate towards the mountain, there will be a conflict between the board tips, leading to the tails of the boards separating in an inverted V-shape. The former tends to happen to intermediate skiers because you already know how to apply pressure and edge properly, while the latter tends to happen to beginners because you cannot yet actively drive the board, especially the uphill board! Either way, such board configurations are one of the reasons for board vibrations during gliding.
When watching true experts perform parallel turns, especially large and medium-radius turns (if you cannot see them on the slopes, you can watch the translated videos on Tudou.com), upon entering the turn, the inner board has a motion of pulling back. The purpose of this is to ensure that both boards glide in the same direction, and to successfully execute this motion, there must be coordination with the inner foot applying pressure!
Especially when performing carve turns, it is emphasized that the body's orientation and the board tip's orientation should be consistent. If the tips of the two boards are misaligned, it can lead to the outside shoulder lagging behind, and conversely, if the stance is incorrect and the outside shoulder lags, the outside board tip will definitely lag behind the inside board tip. To minimize this distance difference between the two board tips while carving, one must be able to flexibly use the inner foot! To develop the skill of flexibly using the inner foot, one must start with the gliding stance!