Multi-dimensional coordination in cross-country skiing analyzed using self-organizing maps.

Area of Science:

• Biomechanics
• Motor Control
• Sports Science

Background:

• Understanding coordination dynamics is crucial for optimizing athletic performance in cross-country skiing.
• Previous research has focused on outcome variables, with less attention paid to the underlying coordination patterns during dynamic tasks.

Purpose of the Study:

• To investigate changes in multi-dimensional coordination patterns across five distinct poling speeds in elite cross-country skiers.
• To analyze coordination stability and identify variability in movement dynamics using advanced computational methods.

Main Methods:

• Employed self-organizing maps (SOMs), a type of artificial neural network, to analyze multi-dimensional time series data from 12 National Standard cross-country skiers.
• Utilized attractor diagrams and surfaces derived from SOM analysis to assess coordination stability and patterns.
• Examined coordination changes during roller skiing on a treadmill at varying poling speeds.

Main Results:

• Significant inter-skier variability in coordination dynamics was observed, with most skiers displaying multiple basins of attraction as poling speed changed.
• Coordination patterns were found to be more variable with changing speeds than outcome variables like poling frequency.
• Some skiers demonstrated degeneracy, exhibiting bi-modal basins of attraction at specific speeds.

Conclusions:

• Coordination dynamics in cross-country skiing are highly individualized and sensitive to changes in poling speed.
• Self-organizing maps provide a powerful tool for uncovering complex coordination strategies and inter-individual differences.
• The findings underscore the importance of considering unique coordination variability when developing training programs for skiers.