Skill Scoring System for Ski’s Parallel Turns

Abstract

Dynamic posture of sports activity is one of the most important aspects to evaluate the player's skill. Such sports that need evaluation from the objective observation like figure skating and skiing have difficulty in evaluation of skill. The conventional training method for such sports was the feedback of subjective comments from the experts regarding the performance. To overcome this problem, this paper focuses on developing a new training system to give a clear guide for body balance control to the athlete. The system gives scores and messages for raising up the performance skills. It causes improvement of the dynamic posture. This paper introduces a scoring system focusing on the ski's parallel turn. The system automatically scores skill for body balance control regarding three aspects: the tempo at turns of body balance changes between the right and the left, the distribution of body balance, and the angle between the snow slope and the body of the skier. The system has been implemented in an Android smartphone and evaluated the effects of the scoring functions from the three aspects applying to a middle level skier.

Influence of Turn Cycle Structure on Performance of Elite Alpine Skiers Assessed through an IMU in Different Slalom Course Settings

“…To our knowledge, this is the first study to date to determine turn phases by means of an IMU using kinematic criteria. A previous study already used lateral acceleration of the trunk to delimit linked turns in alpine skiing [33]. In this study, we wanted to follow this idea because of its high accuracy and precision [35].…”

“…On the other hand, if it moves away from the horizontal axis, the acceleration is increasing. Unlike a previous study [33], we identified two main phases within the ski turn using an IMU device. INI phase was limited to the zone in which the acceleration on the Y-axis fluctuated around the zero-value corresponding to the motion between turns and all movements leading to the turn initiation.…”

“…are synchronized optimizes data collection. In the field of alpine skiing, it has been demonstrated that the TS point can be detected with the use of a single IMU through the inclination of the pelvis [16], or data based on the lateral acceleration of the trunk [33] or the angular velocity of the boot [34]. The latter two have been two of the most accurate and precise methodologies [35].…”

Influence of the Slope and Gate Offset on Movement Variability and Performance in Slalom Skiing

“…In alpine skiing, IMUs can offer a number of advantages that go beyond the limitations of traditional or laboratory methods [43][44][45][46][47][48][49]: compact and lightweight, easily portable and positionable, capable of wireless operation, and with the ability to capture a substantial amount of data (i.e., several runs), instantaneous data acquisition, and the optimization of data collection due to automatic synchronization among all the built-in sensors. However, to the best of our knowledge, no research has been conducted yet to evaluate MV through IMUs in the domain of alpine skiing, nor has it been evaluated regarding how the characteristics of the terrain (flatter vs. steeper slopes) and course setting (gate offset: i.e., turned vs. straighter courses) influence skier MV.…”

Connected Skiing: Motion Quality Quantification in Alpine Skiing

“…More recently, there have been further developments in the area of motion quality assessment in alpine skiing. Yamagiwa and colleagues developed a simple system based on a single IMU mounted on the trunk of a skier to assess skiing quality based on turning tempo (turn frequency) [ 16 ]. The algorithm assessed only the variability of tempo during a run in order to differentiate between high- and low-skill skiers.…”