Related Experiment Video
Updated: Jul 2, 2026
08:40
Quantifying Arms and Legs Contributions during Repetitive Electrically-Assisted Sit-To-Stand Exercise in Paraplegics: A Pilot Study
Published on: November 11, 2022
Neuromechanical synergy patterns explain metabolic efficiency differences during the sit-to-walk transition
Wanli Zang1, Jiarong Wu1, Chen Zhu2
1School of Physical Education, Soochow University, 215021, Suzhou, China.
Journal of Neuroengineering and Rehabilitation
|July 1, 2026
Summary
Understanding sit-to-walk (STW) metabolic cost is crucial. This study linked metabolic cost to localized neuromuscular coordination patterns using a novel simulation framework, revealing subtle differences in movement control.
Area of Science:
- Biomechanics
- Human Movement Science
- Computational Physiology
Background:
- The sit-to-walk (STW) transition is vital for daily activities and a key part of mobility assessments like the Timed Up and Go test.
- Neuromuscular control and coordination during STW, especially concerning metabolic cost, are not fully understood.
- Existing methods lack integrated approaches to link metabolic expenditure with detailed internal movement coordination.
Purpose of the Study:
- To develop and validate a simulation-informed framework for analyzing neuromuscular and cross-modal coordination during STW.
- To investigate the relationship between estimated metabolic cost and synergy features during the STW transition in healthy adults.
- To identify how different metabolic cost phenotypes relate to underlying biomechanical and electromyographic coordination patterns.
Main Methods:
- Developed a framework combining musculoskeletal modeling (OpenSim-Umberger), metabolic cost estimation, and factorization techniques (NMF, MMF).
- Recruited 71 healthy participants performing STW trials, collecting kinematic, ground reaction force, and surface electromyography (sEMG) data.
- Stratified participants into metabolic cost groups and analyzed differences in temporal activation coefficients and muscle/EMG-biomechanical weights.
Main Results:
- The simulation framework accurately estimated metabolic cost, validated against oxygen consumption.
- Non-negative matrix factorization (NMF) revealed localized differences in temporal activation patterns between metabolic cost groups, particularly in early and late STW phases.
- Mixed-matrix factorization (MMF) identified limited, localized differences in synergy patterns, suggesting specific EMG-biomechanical coordination variations.
- Despite similar external movement patterns, distinct metabolic cost groups exhibited subtle, localized differences in internal coordination features.
Conclusions:
- Metabolic cost during STW is associated with localized, rather than global, differences in neuromuscular synergy features.
- The developed framework offers a robust method for exploring the relationship between metabolic cost and coordination in human movement.
- This approach provides a healthy reference and generates hypotheses for studying coordination deficits in various populations and conditions.
