Mass point versus whole-body modelling of skiers for performance evaluation in alpine skiing

Hladnik, Jurij (avtor), Svenšek, Daniel (avtor), Jerman, Boris (avtor), Supej, Matej (avtor)

The altitude differential of the specific mechanical energy, diff (e$_{mech}$), is used to evaluate skiing performance. It is defined as the negative differential between the skier's total specific mechanical energy (e$_{mech}$) and the altitude of the skier's center of mass (COM). Till now, e$_{mech}$ was obtained upon a mass-point (MP) model of the skier's COM, which neither considered the segmental energies of their relative movements to the COM, nor their rotational kinetic energies. The aims of the study were therefore: (a) to examine the deviations in diff (e$_{mech}$) between the MP and a more complex linked segment (LS) skier model consisting of 15 rigid bodies, which encountered the aforementioned defectiveness, (b) to compare the energy fluctuations of the two skier models, and (c) to investigate the influence of the gate setup on (a) and (b) in giant slalom. Three-dimensional whole-body kinematics of nine skiers was measured using a global navigation satellite system and an inertial motion capture system while skiing on a predefined course divided into a turny and open gate setup. Mechanical energies including their altitude differentials were calculated for the LS and MP models. There were no significant differences in e$_{mech}$ and diff (e$_{mech}$) ski turn averages, as in individual data points, between both skier models for both analyzed gate setups. The energies additionally considered by the LS model presented a negligible part regardless of the gate setup. In conclusion, the MP skier model is sufficiently accurate for the evaluation of the skiing performance with diff (e$_{mech}$).

• Jezik: Angleški jezik
• Ključne besede: centre of mass, energy dissipation, linked-segment model, mechanical energy, biomechanics, giant slalom, kinematics, statistical parametric mapping
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FS - Fakulteta za strojništvo ; FMF - Fakulteta za matematiko in fiziko ; FŠ - Fakulteta za šport
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2023
• Št. strani: Str. 943-953
• Številčenje: Vol. 33, iss. 6
• PID: 20.500.12556/RUL-146035
• UDK: 531.1:796.92
• ISSN pri članku: 0905-7188
• DOI: 10.1111/sms.14325
• COBISS.SI-ID: 142031619
• Datum objave v RUL: 18.05.2023

Gradivo je del revije

• Naslov: Scandinavian journal of medicine & science in sports
• Založnik: Wiley
• ISSN: 0905-7188
• COBISS.SI-ID: 230378

Licence

• Licenca: CC BY-NC-ND 4.0, Creative Commons Priznanje avtorstva-Nekomercialno-Brez predelav 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by-nc-nd/4.0/deed.sl
• Opis: Najbolj omejujoča licenca Creative Commons. Uporabniki lahko prenesejo in delijo delo v nekomercialne namene in ga ne smejo uporabiti za nobene druge namene.

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: masno središče, disipacija energije, segmentalni model, biomehanika, veleslalom, kinematika, statistično parametrično kartiranje

Projekti

• Financer: ARRS - Agencija za raziskovalno dejavnost Republike Slovenije
• Številka projekta: P5-0147
• Naslov: Kineziologija monostrukturnih, polistrukturnih in konvencionalnih športov

• Financer: ARRS - Agencija za raziskovalno dejavnost Republike Slovenije
• Številka projekta: L5-4142
• Naslov: Vpiv širine smuči na varnost pri alpskem smučanju