Knee Angles After Crosstalk Correction With Principal Component Analysis in Gait and Cycling

Area of Science:

• Biomechanics
• Motion Analysis
• Sports Science

Background:

• Knee crosstalk errors in motion analysis can affect accuracy.
• Principal Component Analysis (PCA) is a common method to reduce these errors during gait analysis.
• Its effectiveness for exercises with higher knee flexion angles, like cycling, is less understood.

Purpose of the Study:

• To investigate the efficacy of PCA in correcting knee angle crosstalk during cycling.
• To compare PCA correction methods using all angles versus a subset of angles.
• To evaluate the impact of high flexion angles on PCA's accuracy for gait and cycling.

Main Methods:

• Fifteen participants underwent motion analysis during both gait and cycling.
• Kinematic data for knee flexion-extension (FE), abduction-adduction (AA), and internal-external rotation (IE) angles were collected.
• PCA was applied using all angles (FE-AA-IE) and a subset (FE-AA) for crosstalk correction.

Main Results:

• Significant differences were found between uncorrected and PCA-corrected angles for both gait and cycling.
• FE-AA PCA correction showed potential for preserving physiological IE angle correlations during cycling.
• FE-IE correlations persisted after FE-AA PCA correction, unlike FE-AA-IE PCA correction.

Conclusions:

• PCA is effective in reducing knee angle crosstalk for both gait and cycling.
• FE-AA PCA correction may be preferable for cycling due to better retention of IE angle correlations.
• Further research is needed to improve the accuracy of IE angle measurements during high-flexion activities.