Phase space methods for non-linear analysis of pedalling forces in cycling

Area of Science:

• Biomechanics
• Dynamical Systems Theory
• Human Movement Analysis

Background:

• Biological signals exhibit stability and variability as adaptive responses to environmental changes.
• Dynamic systems theory provides a framework for understanding biological signal adaptation.
• The applicability of this theory to human motor control, specifically cycling, requires investigation.

Purpose of the Study:

• To investigate the applicability of dynamic systems theory to cycling pedalling movements.
• To analyze pedalling forces using non-linear measures under varying subjective load conditions.
• To determine if pedalling movement characteristics systematically change as an adaptive response to increased workload.

Main Methods:

• Ten subjects cycled a virtual terrain profile with varying resistance levels.
• Pedalling forces and heart rate were measured during the cycling task.
• Non-linear measures, including phase space attractor variables, were calculated from pedalling forces.

Main Results:

• Changes in pedalling load were strongly associated with alterations in non-linear phase space attractor variables.
• This association between pedalling load and non-linear dynamics was stronger than the association with heart rate.
• Systematic changes in pedalling movement were observed as an adaptive response to increased workload.

Conclusions:

• The pedalling movement in cycling exhibits adaptive changes in its dynamics in response to increased workload, aligning with dynamic systems theory.
• Non-linear analysis of pedalling forces provides a sensitive measure of these adaptive responses.
• Future research can explore links between subjective experiences (exhaustion, comfort) and biomechanical characteristics of pedalling.