A framework for measuring alpine skiing technique

The analysis of alpine skiing technique is characterized by a gap between the qualitative, experience-based language of practitioners and the quantitative but often isolated measures used in science. Previous research has typically focused on single biomechanical variables (e.g. joint angles), which do not fully capture the whole-body movement patterns described by practitioners (e.g. forward - backward lean). This study aimed (I) to develop a framework that enables objective, quantitative measurement of skiing technique directly aligned with practitioners' descriptions, and (II) to explore its sensitivity by comparing curricular milestones (basic parallel, parallel dynamic and race carving technique) and differences between national education systems. Full-body kinematics of expert ski instructors were recorded with inertial measurement units (IMUs) as they performed instructed extremes of technique elements. Principal component analysis (PCA) of these datasets generated principal component (PC) vectors, which serve as quantitative scales for lateral tilt, horizontal movement, upper-body rotation, and vertical movement. Projecting runs onto these vectors provided objective scores that confirmed known differences between basic parallel and race carving turns, and revealed different upper-body rotation strategies between Austrian and German ski instructors. The framework bridges scientific and practical perspectives and offers a transferable tool for technique evaluation in skiing and other sports.