Changes in postural strategy of the lower limb under mechanical knee constraint on an unsteady stance surface.
Joint constraint could limit the available degrees of freedom in a kinematic chain for maintaining postural stability. This study investigated adaptive changes in postural synergy due to bracing of bilateral knee joints, usually thought to have a trifling impact on upright stance. Twenty-four young...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2020-01-01
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| Series: | PLoS ONE |
| Online Access: | https://doi.org/10.1371/journal.pone.0242790 |
| _version_ | 1819110538006757376 |
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| author | Yi-Ying Tsai Gwo-Ching Chang Ing-Shiou Hwang |
| author_facet | Yi-Ying Tsai Gwo-Ching Chang Ing-Shiou Hwang |
| author_sort | Yi-Ying Tsai |
| collection | DOAJ |
| description | Joint constraint could limit the available degrees of freedom in a kinematic chain for maintaining postural stability. This study investigated adaptive changes in postural synergy due to bracing of bilateral knee joints, usually thought to have a trifling impact on upright stance. Twenty-four young adults were requested to maintain balance on a stabilometer plate as steadily as possible while wearing a pair of knee orthoses, either unlocked (the non-constraint (NC) condition) or locked to restrict knee motion (the knee constraint (KC) condition). Knee constraint led to a significant increase in the regularity of the stabilometer angular velocity. More than 95% of the variance properties of the joint angular velocities in the lower limb were explained by the first and second principal components (PC1 and PC2), which represented the ankle strategy and the combined knee and hip strategy, respectively. In addition to the increase trend in PC1 regularity, knee constraint enhanced the mutual information of the stabilometer angular velocity and PC1 (MISTBV-PC1) but reduced the mutual information of the stabilometer angular velocity and PC2 (MISTBV-PC2). The MISTBV-PC1 was also positively correlated to stance steadiness on the stabilometer in the KC condition. In summary, in the knee constraint condition, postural synergy on the stabilometer was reorganized to increase reliance on ankle strategies to maintain equilibrium. In particular, a stable stabilometer stance under knee constraint is associated with a high level of coherent ankle-stabilometer interaction. |
| first_indexed | 2024-12-22T03:43:18Z |
| format | Article |
| id | doaj.art-a1f5e2e4346d442394da7a68b38f1e73 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-22T03:43:18Z |
| publishDate | 2020-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-a1f5e2e4346d442394da7a68b38f1e732022-12-21T18:40:11ZengPublic Library of Science (PLoS)PLoS ONE1932-62032020-01-011511e024279010.1371/journal.pone.0242790Changes in postural strategy of the lower limb under mechanical knee constraint on an unsteady stance surface.Yi-Ying TsaiGwo-Ching ChangIng-Shiou HwangJoint constraint could limit the available degrees of freedom in a kinematic chain for maintaining postural stability. This study investigated adaptive changes in postural synergy due to bracing of bilateral knee joints, usually thought to have a trifling impact on upright stance. Twenty-four young adults were requested to maintain balance on a stabilometer plate as steadily as possible while wearing a pair of knee orthoses, either unlocked (the non-constraint (NC) condition) or locked to restrict knee motion (the knee constraint (KC) condition). Knee constraint led to a significant increase in the regularity of the stabilometer angular velocity. More than 95% of the variance properties of the joint angular velocities in the lower limb were explained by the first and second principal components (PC1 and PC2), which represented the ankle strategy and the combined knee and hip strategy, respectively. In addition to the increase trend in PC1 regularity, knee constraint enhanced the mutual information of the stabilometer angular velocity and PC1 (MISTBV-PC1) but reduced the mutual information of the stabilometer angular velocity and PC2 (MISTBV-PC2). The MISTBV-PC1 was also positively correlated to stance steadiness on the stabilometer in the KC condition. In summary, in the knee constraint condition, postural synergy on the stabilometer was reorganized to increase reliance on ankle strategies to maintain equilibrium. In particular, a stable stabilometer stance under knee constraint is associated with a high level of coherent ankle-stabilometer interaction.https://doi.org/10.1371/journal.pone.0242790 |
| spellingShingle | Yi-Ying Tsai Gwo-Ching Chang Ing-Shiou Hwang Changes in postural strategy of the lower limb under mechanical knee constraint on an unsteady stance surface. PLoS ONE |
| title | Changes in postural strategy of the lower limb under mechanical knee constraint on an unsteady stance surface. |
| title_full | Changes in postural strategy of the lower limb under mechanical knee constraint on an unsteady stance surface. |
| title_fullStr | Changes in postural strategy of the lower limb under mechanical knee constraint on an unsteady stance surface. |
| title_full_unstemmed | Changes in postural strategy of the lower limb under mechanical knee constraint on an unsteady stance surface. |
| title_short | Changes in postural strategy of the lower limb under mechanical knee constraint on an unsteady stance surface. |
| title_sort | changes in postural strategy of the lower limb under mechanical knee constraint on an unsteady stance surface |
| url | https://doi.org/10.1371/journal.pone.0242790 |
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