title: Influence of locomotion speed on biomechanical subtask and muscle synergy.
abstract: This paper investigates the relationship of biomechanical subtasks, and muscle synergies with various locomotion speeds. Ground reaction force (GRF) of eight healthy subjects is measured synchronously by force plates of treadmill at five different speeds ranging from 0.5m/s to 1.5m/s. Four basic biomechanical subtasks, body support, propulsion, swing, and heel strike preparation, are identified according to GRF. Meanwhile, electromyography (EMG) data, used to extract muscle synergies, are collected from lower limb muscles. EMG signals are segmented periodically based on GRF with the heel strike as the split points. Variability accounted for (VAF) is applied to determine the number of muscle synergies. We find that four muscle synergies can be extracted in all five situations by non-negative matrix factorization (NMF). Furthermore, the four muscle synergies and biomechanical subtasks keep invariant as the walking speed changes.
authors: State Key Laboratory of Mechanical System and Vibration, Institute of Robotics, School of Mechanical Engineering at Shanghai Jiao Tong University, China.
authors: Kai
authors: K
authors: Gui
authors: State Key Laboratory of Mechanical System and Vibration, Institute of Robotics, School of Mechanical Engineering at Shanghai Jiao Tong University, China. Electronic address: dgzhang@sjtu.edu.cn.
authors: Dingguo
authors: D
authors: Zhang
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D004576:Electromyography; D006801:Humans; D035002:Lower Extremity / Q000502:physiology; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D000072797:Walking Speed
keywords: Biomechanical subtask; Electromyography; Locomotion; Muscle synergy; Walking speed