gate distance and skier tactics in slalom€¦ · robert reid, matthias gilgien, tron moger,...

Gate Distance and Skier Tactics in Slalom

Robert Reid, Matthias Gilgien, Tron Moger, Håvard Tjørhom,

Per Haugen, Ronald Kipp, Gerald Smith

BACKGROUND METHODS RESULTS &

DISCUSSION SUMMARY

Ted Ligety, Alta Badia, 2007

Norges skiforubund Alpin Trenerseminar

30. Juni til 1. Juli, 2012


DISCUSSION SUMMARY



How do skier’s adapt their technique and tactics to courses of varying gate distance?


DISCUSSION SUMMARY



• 3D kinematic analysis.

• 6 male athletes on the Norwegian Europa Cup team.

• Slalom race simulations.

• April 2006.

METHODS


DISCUSSION SUMMARY

COURSE SETTING

• Open, rhythmical courses (10 m & 13 m distances).

• Even, medium terrain (19˚).

• Compact, hard snow conditions.




DISCUSSION SUMMARY

CAMERAS

• Software genlock

• 4 DV cameras

• 50 Hz

(Pourcelot et al., 2000)

• 720 x 576 resolution

• Panning, tilting, zooming

Y [m]

Z [m]

X [m]

CAM 1

CAM 2

CAM 3

CAM 4




DISCUSSION SUMMARY



RECONSTRUCTION

• 21 points digitized.

• 2nd-order Butterworth filter.

• Cut-off frequencies:

→ 10 Hz position data.

→ 5 Hz velocity, accerlation.


DISCUSSION SUMMARY



SKIER MODEL


DISCUSSION SUMMARY

TURN CYCLE STRUCTURE

INITIATION

TURN PHASE 1

TURN PHASE 2

COMPLETION

TURN START

GATE

TURN END

0 20 40 60 80 1000

10

20

30

40

50

% Turn Cycle

Cente

r of M

ass T

urn

Radiu

s [m

]

10 m courseINITIATION TURN PHASE 1 TURN PHASE 2 COMPLETION




DISCUSSION SUMMARY




DISCUSSION SUMMARY



Important to understand how ski characteristics and gate positioning influence

tactics and technique.

Great skiers are geniuses at adapting.

We need to develop skiers who are great adapters.

gate distance and skier tactics in slalom€¦ · robert reid, matthias gilgien, tron moger,...

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