The center of pressure and ankle muscle co-contraction in response to anterior-posterior perturbations.
Though both contraction of agonist muscles and co-contraction of antagonistic muscle pairs across the ankle joint are essential to postural stability, they are perceived to operate independently of each other, In an antagonistic setup, agonist muscles contract generating moment about the joint, whil...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2018-01-01
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| Series: | PLoS ONE |
| Online Access: | https://doi.org/10.1371/journal.pone.0207667 |
| _version_ | 1818934531541958656 |
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| author | Dongwon Kim Jong-Moon Hwang |
| author_facet | Dongwon Kim Jong-Moon Hwang |
| author_sort | Dongwon Kim |
| collection | DOAJ |
| description | Though both contraction of agonist muscles and co-contraction of antagonistic muscle pairs across the ankle joint are essential to postural stability, they are perceived to operate independently of each other, In an antagonistic setup, agonist muscles contract generating moment about the joint, while antagonist muscles contract generating stiffness across the joint. While both work together in maintaining robustness in the face of external perturbations, contractions of agonist muscles and co-contractions of antagonistic muscle pairs across the ankle joint play different roles in responding to and adapting to external perturbations. To determine their respective roles, we exposed participants to repeated perturbations in both large and small magnitudes. The center of pressure (COP) and a co-contraction index (CCI) were used to quantify the activation of agonist muscles and antagonistic muscle pairs across the ankle joint. Our results found that participants generated moment of a large magnitude across the ankle joint-a large deviation in the COP curve-in response to perturbations of a large magnitude (p <0.05), whereas the same participants generated higher stiffness about the ankle-a larger value in CCI-in response to perturbations of a small magnitude (p <0.05). These results indicate that participants use different postural strategies pertaining to circumstances. Further, the moment across the ankle decreased with repetitions of the same perturbation (p <0.05), and CCI tended to remain unchanged even in response to a different perturbation following repetition of the same perturbation (p <0.05). These findings suggest that ankle muscle contraction and co-contraction play different roles in regaining and maintaining postural stability. This study demonstrates that ankle moment and stiffness are not correlated in response to external perturbations. |
| first_indexed | 2024-12-20T05:05:45Z |
| format | Article |
| id | doaj.art-3d32a941b10146e5a1540cffade21f2a |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-20T05:05:45Z |
| publishDate | 2018-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-3d32a941b10146e5a1540cffade21f2a2022-12-21T19:52:23ZengPublic Library of Science (PLoS)PLoS ONE1932-62032018-01-011311e020766710.1371/journal.pone.0207667The center of pressure and ankle muscle co-contraction in response to anterior-posterior perturbations.Dongwon KimJong-Moon HwangThough both contraction of agonist muscles and co-contraction of antagonistic muscle pairs across the ankle joint are essential to postural stability, they are perceived to operate independently of each other, In an antagonistic setup, agonist muscles contract generating moment about the joint, while antagonist muscles contract generating stiffness across the joint. While both work together in maintaining robustness in the face of external perturbations, contractions of agonist muscles and co-contractions of antagonistic muscle pairs across the ankle joint play different roles in responding to and adapting to external perturbations. To determine their respective roles, we exposed participants to repeated perturbations in both large and small magnitudes. The center of pressure (COP) and a co-contraction index (CCI) were used to quantify the activation of agonist muscles and antagonistic muscle pairs across the ankle joint. Our results found that participants generated moment of a large magnitude across the ankle joint-a large deviation in the COP curve-in response to perturbations of a large magnitude (p <0.05), whereas the same participants generated higher stiffness about the ankle-a larger value in CCI-in response to perturbations of a small magnitude (p <0.05). These results indicate that participants use different postural strategies pertaining to circumstances. Further, the moment across the ankle decreased with repetitions of the same perturbation (p <0.05), and CCI tended to remain unchanged even in response to a different perturbation following repetition of the same perturbation (p <0.05). These findings suggest that ankle muscle contraction and co-contraction play different roles in regaining and maintaining postural stability. This study demonstrates that ankle moment and stiffness are not correlated in response to external perturbations.https://doi.org/10.1371/journal.pone.0207667 |
| spellingShingle | Dongwon Kim Jong-Moon Hwang The center of pressure and ankle muscle co-contraction in response to anterior-posterior perturbations. PLoS ONE |
| title | The center of pressure and ankle muscle co-contraction in response to anterior-posterior perturbations. |
| title_full | The center of pressure and ankle muscle co-contraction in response to anterior-posterior perturbations. |
| title_fullStr | The center of pressure and ankle muscle co-contraction in response to anterior-posterior perturbations. |
| title_full_unstemmed | The center of pressure and ankle muscle co-contraction in response to anterior-posterior perturbations. |
| title_short | The center of pressure and ankle muscle co-contraction in response to anterior-posterior perturbations. |
| title_sort | center of pressure and ankle muscle co contraction in response to anterior posterior perturbations |
| url | https://doi.org/10.1371/journal.pone.0207667 |
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