Investigating reduction of dimensionality during single-joint elbow movements: a case study on muscle synergies
A long standing hypothesis in the neuroscience community is that the CNS generates the muscle activities to accomplish movements by combining a relatively small number of stereotyped patterns of muscle activations, often referred to as muscle synergies. Different definitions of synergies have been g...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2013-02-01
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| Series: | Frontiers in Computational Neuroscience |
| Subjects: | |
| Online Access: | http://journal.frontiersin.org/Journal/10.3389/fncom.2013.00011/full |
| _version_ | 1811204551149092864 |
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| author | Enrico eChiovetto Enrico eChiovetto Enrico eChiovetto Enrico eChiovetto Bastien eBerret Bastien eBerret Ioannis eDelis Ioannis eDelis Ioannis eDelis Stefano ePanzeri Stefano ePanzeri Thierry ePozzo Thierry ePozzo Thierry ePozzo |
| author_facet | Enrico eChiovetto Enrico eChiovetto Enrico eChiovetto Enrico eChiovetto Bastien eBerret Bastien eBerret Ioannis eDelis Ioannis eDelis Ioannis eDelis Stefano ePanzeri Stefano ePanzeri Thierry ePozzo Thierry ePozzo Thierry ePozzo |
| author_sort | Enrico eChiovetto |
| collection | DOAJ |
| description | A long standing hypothesis in the neuroscience community is that the CNS generates the muscle activities to accomplish movements by combining a relatively small number of stereotyped patterns of muscle activations, often referred to as muscle synergies. Different definitions of synergies have been given in the literature. The most well-known are those of synchronous, time-varying and temporal muscle synergies. Each one of them is based on a different mathematical model used to factor some EMG array recordings collected during the execution of variety of motor tasks into a well-determined spatial, temporal or spatio-temporal organization. This plurality of definitions and their separate application to complex tasks have so far complicated the comparison and interpretation of the results obtained across studies, and it has always remained unclear why and when one synergistic decomposition should be preferred to another one. By using well-understood motor tasks such as elbow flexions and extensions, we aimed in this study to clarify better what are the motor features characterized by each kind of decomposition and to assess whether, when and why one of them should be preferred to the others. We found that three temporal synergies, each one of them accounting for specific temporal phases of the movements could account for the majority of the data variation. Similar performances could be achieved by two synchronous synergies, encoding the agonist-antagonist nature of the two muscles considered, and by two time-varying muscle synergies, encoding each one a task-related feature of the elbow movements, specifically their direction. Our findings support the notion that each EMG decomposition provides a set of well-interpretable muscle synergies, identifying reduction of dimensionality in different aspects of the movements. Taken together, our findings suggest that all decompositions are not equivalent and may imply different neurophysiological substrates to be implemented. |
| first_indexed | 2024-04-12T03:16:12Z |
| format | Article |
| id | doaj.art-1d00e137178f419f8a96c059a4892ec5 |
| institution | Directory Open Access Journal |
| issn | 1662-5188 |
| language | English |
| last_indexed | 2024-04-12T03:16:12Z |
| publishDate | 2013-02-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Computational Neuroscience |
| spelling | doaj.art-1d00e137178f419f8a96c059a4892ec52022-12-22T03:50:07ZengFrontiers Media S.A.Frontiers in Computational Neuroscience1662-51882013-02-01710.3389/fncom.2013.0001140686Investigating reduction of dimensionality during single-joint elbow movements: a case study on muscle synergiesEnrico eChiovetto0Enrico eChiovetto1Enrico eChiovetto2Enrico eChiovetto3Bastien eBerret4Bastien eBerret5Ioannis eDelis6Ioannis eDelis7Ioannis eDelis8Stefano ePanzeri9Stefano ePanzeri10Thierry ePozzo11Thierry ePozzo12Thierry ePozzo13Hertie Institute of Clinical Brain ResearchUniversity of TuebingenUniversity Clinic TuebingenIstituto Italiano di TecnologiaIstituto Italiano di TecnologiaUniversité Paris-Sud 11Istituto Italiano di TecnologiaUniversity of GenoaUniversity of GlasgowIstituto Italiano di TecnologiaUniversity of GlasgowIstituto Italiano di TecnologiaUniversité de BourgogneINSERMA long standing hypothesis in the neuroscience community is that the CNS generates the muscle activities to accomplish movements by combining a relatively small number of stereotyped patterns of muscle activations, often referred to as muscle synergies. Different definitions of synergies have been given in the literature. The most well-known are those of synchronous, time-varying and temporal muscle synergies. Each one of them is based on a different mathematical model used to factor some EMG array recordings collected during the execution of variety of motor tasks into a well-determined spatial, temporal or spatio-temporal organization. This plurality of definitions and their separate application to complex tasks have so far complicated the comparison and interpretation of the results obtained across studies, and it has always remained unclear why and when one synergistic decomposition should be preferred to another one. By using well-understood motor tasks such as elbow flexions and extensions, we aimed in this study to clarify better what are the motor features characterized by each kind of decomposition and to assess whether, when and why one of them should be preferred to the others. We found that three temporal synergies, each one of them accounting for specific temporal phases of the movements could account for the majority of the data variation. Similar performances could be achieved by two synchronous synergies, encoding the agonist-antagonist nature of the two muscles considered, and by two time-varying muscle synergies, encoding each one a task-related feature of the elbow movements, specifically their direction. Our findings support the notion that each EMG decomposition provides a set of well-interpretable muscle synergies, identifying reduction of dimensionality in different aspects of the movements. Taken together, our findings suggest that all decompositions are not equivalent and may imply different neurophysiological substrates to be implemented.http://journal.frontiersin.org/Journal/10.3389/fncom.2013.00011/fullEMGdimensionality reductionnon-negative matrix factorizationmuscle synergiesElbow RotationsTriphasic Pattern |
| spellingShingle | Enrico eChiovetto Enrico eChiovetto Enrico eChiovetto Enrico eChiovetto Bastien eBerret Bastien eBerret Ioannis eDelis Ioannis eDelis Ioannis eDelis Stefano ePanzeri Stefano ePanzeri Thierry ePozzo Thierry ePozzo Thierry ePozzo Investigating reduction of dimensionality during single-joint elbow movements: a case study on muscle synergies Frontiers in Computational Neuroscience EMG dimensionality reduction non-negative matrix factorization muscle synergies Elbow Rotations Triphasic Pattern |
| title | Investigating reduction of dimensionality during single-joint elbow movements: a case study on muscle synergies |
| title_full | Investigating reduction of dimensionality during single-joint elbow movements: a case study on muscle synergies |
| title_fullStr | Investigating reduction of dimensionality during single-joint elbow movements: a case study on muscle synergies |
| title_full_unstemmed | Investigating reduction of dimensionality during single-joint elbow movements: a case study on muscle synergies |
| title_short | Investigating reduction of dimensionality during single-joint elbow movements: a case study on muscle synergies |
| title_sort | investigating reduction of dimensionality during single joint elbow movements a case study on muscle synergies |
| topic | EMG dimensionality reduction non-negative matrix factorization muscle synergies Elbow Rotations Triphasic Pattern |
| url | http://journal.frontiersin.org/Journal/10.3389/fncom.2013.00011/full |
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