Development of a real-time performance measurement and feedback system for alpine skiers

Abstract

Timely and accurate feedback on athlete performance is a key contributing factor to improving that athletic performance. For alpine skiers, feedback usually comes in the form of video, coach's comments, and the timing system. Video and coach's comments come well after the performance (usually many hours) and are subjective. The timing systems give only one or a few data points which represent as many as 50 gates, making it too general as a training tool. The aim of the present article is to describe the development of a real-time performance measurement and feedback system for training alpine skiers using Optical Navigation Technology and to present the results of field work done with alpine ski racers. In order to understand the special needs of alpine skiers, the first section of this article describes what racers and recreational skiers consider to be the ideal turn. One of the key characteristics of this ideal turn is the lack of lateral displacement. This article explores a new method for precisely measuring lateral displacement, converting that measured displacement into audible feedback which is in turn fed back to the skier in real-time. Lastly, the results of a field study are presented in which the perceived benefits of real-time feedback were demonstrated with 100% of the subjects stating that real-time feedback had definitely or probably helped them better understand their carving skills and 83% of subjects stating that the real-time feedback definitely or probably helped them improve their carving skills after only one two-hour session.

Quantifying instantaneous performance in alpine ski racing

“…An important limitation of research into biomechanical and physical factors influencing 56 the success in ski races is that the existing methods to quantify skiing performance are 57 often inadequate for a detailed analysis (Kirby, 2009;. Section time, 58 which is probably the most frequently used variable to quantify racing performance, has 59 several important limitations .…”

“…But all other variables that have been 60 used for a performance analysis, e.g. speed, acceleration, differential specific 61 mechanical energy (Supej, 2008;, difference in mechanical energy 62 divided by initial speed , or lateral skidding of the skis (Kirby, 2009), 63 also suffer from an important limitation: They only quantify variables that relate to the 64 skiers' speed or energy state. The actual performance of a ski racer, however, depends 65 not only on speed, but also on the path chosen by the skier.…”

Augmented visual, auditory, haptic, and multimodal feedback in motor learning: A review

“…Movement variables have also been sonified in sports other than crawl-for example, breast stroke (arm, leg, waist movement; Effenberg, 2000b), karate (timing of wrist and ankle movement; Yamamoto, Shiraki, Takahata, Sakane, & Takebayashi, 2004), ski carving (lateral displacement of ski; Kirby, 2009), rowing (boat acceleration; Schaffert, Mattes, & Effenberg, 2009), and German wheel (its three dimensional orientation; Hummel, Hermann, Frauenberger, & Stockman, 2010). Athletes appreciated the developed sonification and mostly stated that the sonification may have helped them to improve their skills.…”

Assessing wireless inertia measurement units for monitoring athletics sprint performance

“…An extra feature of this specific IMU allows data to be supplied to the user in real time, allowing the coach and athlete to receive meaningful, useful information that can be implemented into their performance with more effect than if it was given during a review session [12], which is a limiting factor in the majority of the currently used performance monitoring techniques.…”