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Using Mean Absolute Relative Phase, Deviation Phase and Point-Estimation Relative Phase to Measure Postural
Anne K Galgon1, Patricia A Shewokis2
1Temple University , Philadelphia, PA, USA.
Journal of Sports Science & Medicine
|March 10, 2016
Summary
Mean absolute relative phase (MARP) and deviation phase (DP) effectively measure postural coordination stability and patterns, distinguishing between proximal and distal movements during reaching tasks. Individual differences in coordination emerged with practice.
Area of Science:
- Biomechanics
- Motor Control
- Human Movement Analysis
Background:
- Postural coordination is crucial for skilled movements.
- Quantifying inter-joint coordination requires robust analytical methods.
- Relative phase measures offer insights into movement coordination patterns.
Purpose of the Study:
- To present methods for calculating mean absolute relative phase (MARP), deviation phase (DP), and point estimate relative phase (PRP).
- To compare the utility of MARP, DP, and PRP in assessing postural coordination during a serial reaching task.
- To evaluate how learning affects postural coordination using these relative phase measures.
Main Methods:
- Calculation of MARP and DP from continuous relative phase time series.
- Calculation of PRP based on angular displacement timing between segments.
- Application of these measures to shoulder-hip and hip-ankle coordination in young adults performing a serial reaching task over 3 days.
- Analysis of inter-joint relationships at early and late learning stages.
Main Results:
- MARP, DP, and PRP successfully differentiated between proximal (shoulder-hip) and distal (hip-ankle) postural coordination.
- No significant group-level effect of practice was observed on the relative phase measures.
- Individual differences in coordination patterns became apparent over the course of practice.
- MARP and DP provided estimates of coordination pattern stability (in-phase and anti-phase).
Conclusions:
- MARP and DP are valuable for quantifying coordination patterns and their stability, particularly in discrete tasks or movement phases.
- PRP is also effective for assessing coordination patterns.
- While group learning effects were not evident in these measures, individual variability highlights the importance of personalized analysis.
- Qualitative movement analysis may complement MARP and DP for a comprehensive understanding in complex serial tasks.
