Muscle synergies are modified with improved task performance in skill learning.

How do muscle synergies change as motor skills are learned? The purpose of this study was to investigate the relationship between synergy number and skill acquisition, and to examine learning-related changes in synergy structure and activation patterns. We performed muscle synergy analysis using non-negative matrix factorization to identify muscle synergies from activation patterns of ten major leg muscles before and after recreational cyclists learned a novel one-legged pedal force aiming task (Park, Van Emmerik, & Caldwell, 2021). Synergy number was defined as the smallest number of factors from the matrix factorization algorithm that could explain more than the predefined threshold values. Improvements in pedal force direction after practice occurred without a change in the number of muscle synergies (four), suggesting that task constraints (e.g. the need for smooth pedaling motion) in this novel targeting task may limit the CNS to the same number of muscle synergies before and after practice. Improved task performance while continuing to satisfy multiple biomechanical tasks was obtained with changes in structure (muscle weightings) for one synergy, and activation amplitudes without changes in timing or pattern for three synergies. In each crank cycle quadrant, multiple synergies were altered in either structure or activation amplitude, suggesting that the cooperative changes may be essential for improving task performance while producing a smooth pedaling motion. Changes in both synergy structure and activation levels could be muscle coordination strategies in motor skill learning.

• Publication year

  2022

• Venue

  Human Movement Science

• Publication date

  2022-03-22

• Fields of study

  Medicine

• Identifiers
  DOI 10.1016/j.humov.2022.102946PMID 35334208
• External record

  Open on Semantic Scholar

• Source metadata

  Semantic Scholar, PubMed

• No claims are published for this paper.

• No concepts are published for this paper.

• Changes in Muscle Control After Learning to Direct Pedal Forces in One-Legged Pedaling

  2021cited by this paper
• The effects of motor modularity on performance, learning and generalizability in upper-extremity reaching: a computational analysis

  2020cited by this paper
• Reorganization of Muscle Coordination Underlying Motor Learning in Cycling Tasks

  2020cited by this paper
• Plasticity of muscle synergies through fractionation and merging during development and training of human runners

  2020cited by this paper
• Temporal and spatial asymmetries during stationary cycling cause different feedforward and feedback modifications in the muscular control of the lower limbs

  2018cited by this paper
• Intra-Subject Consistency during Locomotion: Similarity in Shared and Subject-Specific Muscle Synergies

  2017cited by this paper
• Learning new gait patterns: Exploratory muscle activity during motor learning is not predicted by motor modules.

  2016cited by this paper
• Long-term Training Modifies the Modular Structure and Organization of Walking

  2015cited by this paper
• Long-term training modifies the modular structure and organization of walking balance control.

  2015cited by this paper
• Neuromuscular constraints on muscle coordination during overground walking in persons with chronic incomplete spinal cord injury.

  2014cited by this paper
• Effective force control by muscle synergies

  2014cited by this paper
• Shared muscle synergies in human walking and cycling.

  2014cited by this paper
• Feedback of mechanical effectiveness induces adaptations in motor modules during cycling

  2013cited by this paper
• Alterations in upper limb muscle synergy structure in chronic stroke survivors.

  2013cited by this paper
• Muscle synergy patterns as physiological markers of motor cortical damage

  2012cited by this paper
• Smoothing of electromyographic signals can influence the number of extracted muscle synergies.

  2012cited by this paper
• Common muscle synergies for control of center of mass and force in nonstepping and stepping postural behaviors.

  2011cited by this paper
• Consistency of muscle synergies during pedaling across different mechanical constraints.

  2011cited by this paper
• Locomotor Primitives in Newborn Babies and Their Development

  2011cited by this paper
• No evidence of expertise-related changes in muscle synergies during rowing.

  2011cited by this paper
• Modules in the brain stem and spinal cord underlying motor behaviors.

  2011cited by this paper
• Decomposing Muscle Activity in Motor TasksMethods and Interpretation

  2010cited by this paper
• Merging of healthy motor modules predicts reduced locomotor performance and muscle coordination complexity post-stroke.

  2010cited by this paper
• Modular control of human walking: Adaptations to altered mechanical demands.

  2010cited by this paper
• Evaluation of Abnormal Synergy Patterns Poststroke: Relationship of the Fugl-Meyer Assessment to Hemiparetic Locomotion

  2010cited by this paper
• The case for and against muscle synergies.

  2009cited by this paper
• Modular control of human walking: a simulation study.

  2009cited by this paper
• Endpoint force fluctuations reveal flexible rather than synergistic patterns of muscle cooperation.

  2008cited by this paper
• Functional muscle synergies constrain force production during postural tasks.

  2008cited by this paper
• Learning effects on muscle modes and multi-mode postural synergies

  2007cited by this paper
• Muscle synergy organization is robust across a variety of postural perturbations.

  2006cited by this paper
• Matrix factorization algorithms for the identification of muscle synergies: evaluation on simulated and experimental data sets.

  2006cited by this paper
• Central and Sensory Contributions to the Activation and Organization of Muscle Synergies during Natural Motor Behaviors

  2005cited by this paper
• Shared and specific muscle synergies in natural motor behaviors.

  2005cited by this paper
• Early Skill Learning Is Expressed through Selection and Tuning of Cortically Represented Muscle Synergies

  2003cited by this paper
• Muscle contributions to specific biomechanical functions do not change in forward versus backward pedaling.

  2000cited by this paper
• Algorithms for Non-negative Matrix Factorization

  2000cited by this paper
• Internal models for motor control and trajectory planning.

  1999cited by this paper
• Locomotor strategy for pedaling: muscle groups and biomechanical functions.

  1999cited by this paper
• Internal models in the cerebellum.

  1998cited by this paper
• The role of cutaneous information in a contact control task of the leg in humans

  1998cited by this paper
• Muscle coordination of maximum-speed pedaling.

  1997cited by this paper
• Linear combinations of primitives in vertebrate motor control.

  1994cited by this paper
• Computations underlying the execution of movement: a biological perspective.

  1991cited by this paper
• A Dual Piezoelectric Element Force Pedal for Kinetic Analysis of Cycling

  1990cited by this paper
• Why is it easy to control your arms ?

  1982cited by this paper
• Problems of Organization of Motor Systems

  1972cited by this paper

• Effects of fatigue on the activation characteristics and synergistic patterns of lower limb muscles during running

  2026cites this paper
• Comparative Analysis of Muscle Coordination Patterns During Squatting in Trained and Untrained Individuals.

  2026cites this paper
• The impact of transcranial direct current stimulation on the neuro-muscular control strategies of penalty kicks in soccer players

  2025cites this paper
• Analysis of muscle synergy in the lower extremities and associated adaptive strategies during single-leg landing

  2025cites this paper
• Effectiveness of Vibrotactile Feedback in an Exergame for Knee Joint Training

  2025cites this paper
• Assessing motor skill progression based on smoothness during integration of a new tool among hairdressers.

  2025cites this paper
• Neuromuscular Control Strategies in Basketball Shooting: Distance-Dependent Analysis of Muscle Synergies.

  2024cites this paper
• Increased Motor Time in the Lower Extremity Is Related to Fall History in Older Women

  2024cites this paper
• The effect of motor experience on knee stability and inter-joint coordination when cutting at different angles.

  2024cites this paper
• An analysis of the effect of motor experience on muscle synergy in the badminton jump smash.

  2024cites this paper
• Influence of Pedal Interface During Pedaling With the Upper Versus Lower Limbs: A Pilot Analysis of Torque Performance and Muscle Synergies.

  2024cites this paper
• Rectified Latent Variable Model-Based EMG Factorization of Inhibitory Muscle Synergy Components Related to Aging, Expertise and Force–Tempo Variations

  2024cites this paper
• A Study of the Effects of Motor Experience on Neuromuscular Control Strategies During Sprint Starts.

  2024cites this paper
• Concerto of movement: how expertise shapes the synergistic control of upper limb muscles in complex motor tasks with varying tempo and dynamics

  2024cites this paper
• Synchronous Muscle Synergy Evaluation of Jaw Muscle Activities during Chewing at Different Speeds, a Preliminary Study

  2023cites this paper
• Muscle Synergy Analysis of Upper Limb with Consideration of Muscle Fatigue

  2023cites this paper
• A Bibliometric Analysis Performance Assessment of Science Education on Science Process Skill

  2023influential citation
• Evolution of muscle coordination and mechanical output following four weeks of arm cranking submaximal training.

  2023cites this paper
• A muscle control strategy to alter pedal force direction under multiple constraints: A simulation study.

  2022cites this paper