Harnessing the Rule of 45º Angles

Key to Mastering Precision Control of Skier’s Body Stance.

In his new guidebook, The New Encyclopedia of Downhill Skiing — The Definitive Guide to Everything About Alpine Skiing from Novice to Expert Skier, Dr. Allan Hamilton offers some great tips for improving one’s stance and body position while skiing. He explains that when it comes to conquering the slopes with precision and control, understanding and applying what he calls “the Rule of Forty-Five Degree Angles” can provide a gigantic boost to maximizing the power of one’s stance. It refers to a whole series of angles the body makes that happen to all be forty-five degrees. The Rule of Forty-Five Degree Angles can be a game-changer for many skiers. This fundamental principle, rooted in physics and biomechanics, can significantly enhance your technique. In this article, we will explore the Rule of Forty-Five Degree Angles, its significance, and how to effectively apply it to your skiing style.

The Science Behind the Rule:

The Rule of Forty-Five Degree Angles is derived from observing professional skiers and observing how they keep their bodies fluid but stable. What we see are (see figure below) is profusion of relaxed forty-five degree angles:

1. The upper extremities are held out, away from the trunk, so there is a 45-degree angle between the shoulders and upper arms.

2. There is another 45-degree angle between the rib cage and the inner surface of the arm at the axilla (i.e., armpit)

3. There is another 45-degree angle at the elbow, where the upper arm meets the forearm.

4. If you were poised overhead, looking down on the skier, you would also see that the arms are outstretched, and the right and left arms are pointed at a 45-degree angle off to each side of the skier, down the fall line, to enhance balance.

Figure: The Rule of Forty-Five Degree Angles, referring to the angles made at the shoulder (1), the axilla (2), the arm and forearm (3), and the upper extremities and the trunk (4). Figure used with author’s permission.

Precision and Stability:

Many ski instructors refer to this body stance as the “beachball position” to describe the position of the arms. But, the Rule of Forty-Five Degree Angles can also be extended to the position of the upper body as it leans forward at a forty-five-degree angle while making turns. This helps to align the body with the gravitational forces acting on the skier and produces a natural balance, maximizing control and edge grip while skiing downhill. By adhering to the Rule of Forty-Five Degree Angles, skiers can achieve greater precision in their turns and maintain stability on varied terrain. When leaning forward at the proper angle, the body’s weight is distributed evenly over one’s skis, ensuring a solid connection with the snow. This balanced position minimizes the risk of skidding, promotes effective edge engagement, and enhances your ability to carve clean, precise turns.

Core Engagement and Fluidity:

Applying the Rule of Forty-Five Degree Angles enhances active core engagement and dynamic movements. As you lean forward, your core muscles engage to maintain stability and control. This engagement not only strengthens your core but also promotes a more fluid and efficient skiing technique. By actively driving your movements from your core, you can achieve seamless transitions between turns and maintain a consistent flow down the slopes.

Adaptability to Terrain:

The Rule of Forty-Five Degree Angles is a versatile principle that can be adapted to different types of terrain and skiing conditions. While it serves as a foundation for carving on groomed slopes, it can also be applied to off-piste skiing and variable terrain. Understanding the relationship between your body position and the angle of the slope allows you to adjust your stance accordingly, ensuring optimal control and adaptability in any skiing scenario.

Practicing and Perfecting:

Like any technique in skiing, mastering the Rule of Forty-Five Degree Angles requires practice and refinement. Start by focusing on your body position during turns, consciously leaning forward at the recommended angle. Experiment with different slopes and speeds, gradually increasing your comfort and confidence. Seeking guidance from a qualified instructor or coach can provide valuable feedback and help you fine-tune your technique. Short of a professional instructor, have a friend videotape you ski down a run and go back and observe how you hold your body and your upper extremities.

The upper extremities are vital to a skier’s balance. As the skis move from side-to-side in turns, the arms help keep the skier’s center of gravity poised over the “sweet spot” of the skis. It not only enhances skiers’ abilities to steer but, having the arms held well forward, ensures they will project themselves down the slopes. It is a virtual guarantee to ensure that a skier does not end up with all their weight on their heels.

Embrace the power of precision and control, and let the Rule of Forty-Five Degree Angles be part of your guiding principles to skiing on the slopes. If you’re intrigued by the Rule of Forty-Five Degree Angles and eager to improve your skiing technique, “The New Encyclopedia of Downhill Skiing” by Allan Hamilton is a valuable resource that can further enhance your understanding and skills. This comprehensive book captures the 21st-century science behind the best gear and techniques for alpine skiing, making it an ideal companion for skiers of all levels.

1. The upper extremities are held out, away from the trunk, so there is a 45-degree angle between the shoulders and upper arms.

2. There is another 45-degree angle between the rib cage and the inner surface of the arm at the axilla (i.e., armpit)

3. There is another 45-degree angle at the elbow, where the upper arm meets the forearm.