Co-activation: its association with weakness and specific neurological pathology
<p>Abstract</p> <p>Background</p> <p>Net agonist muscle strength is in part determined by the degree of antagonist co-activation. The level of co-activation might vary in different neurological disorders causing weakness or might vary with agonist strength.</p> &l...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
BMC
2006-11-01
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| Series: | Journal of NeuroEngineering and Rehabilitation |
| Online Access: | http://www.jneuroengrehab.com/content/3/1/26 |
| _version_ | 1828213565909106688 |
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| author | Wiles Charles M Busse Monica E van Deursen Robert WM |
| author_facet | Wiles Charles M Busse Monica E van Deursen Robert WM |
| author_sort | Wiles Charles M |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>Net agonist muscle strength is in part determined by the degree of antagonist co-activation. The level of co-activation might vary in different neurological disorders causing weakness or might vary with agonist strength.</p> <p>Aim</p> <p>This study investigated whether antagonist co-activation changed a) with the degree of muscle weakness and b) with the nature of the neurological lesion causing weakness.</p> <p>Methods</p> <p>Measures of isometric quadriceps and hamstrings strength were obtained. Antagonist (hamstring) co-activation during knee extension was calculated as a ratio of hamstrings over quadriceps activity both during an isometric and during a functional sit to stand (STS) task (using kinematics) in groups of patients with extrapyramidal (n = 15), upper motor neuron (UMN) (n = 12), lower motor neuron (LMN) with (n = 18) or without (n = 12) sensory loss, primary muscle or neuromuscular junction disorder (n = 17) and in healthy matched controls (n = 32). Independent t-tests or Mann Witney U tests were used to compare between the groups. Correlations between variables were also investigated.</p> <p>Results</p> <p>In healthy subjects mean (SD) co-activation of hamstrings during isometric knee extension was 11.8 (6.2)% and during STS was 20.5 (12.9)%. In patients, co-activation ranged from 7 to 17% during isometric knee extension and 15 to 25% during STS. Only the extrapyramidal group had lower co-activation levels than healthy matched controls (p < 0.05). Agonist isometric muscle strength and co-activation correlated only in muscle disease (r = -0.6, p < 0.05) and during STS in UMN disorders (r = -0.7, p < 0.5).</p> <p>Conclusion</p> <p>It is concluded that antagonist co-activation does not systematically vary with the site of neurological pathology when compared to healthy matched controls or, in most patient groups, with strength. The lower co-activation levels found in the extrapyramidal group require confirmation and further investigation. Co-activation may be relevant to individuals with muscle weakness. Within patient serial studies in the presence of changing muscle strength may help to understand these relationships more clearly.</p> |
| first_indexed | 2024-04-12T14:52:15Z |
| format | Article |
| id | doaj.art-171b9e1e2b0246e9a8a827a4701f2e7d |
| institution | Directory Open Access Journal |
| issn | 1743-0003 |
| language | English |
| last_indexed | 2024-04-12T14:52:15Z |
| publishDate | 2006-11-01 |
| publisher | BMC |
| record_format | Article |
| series | Journal of NeuroEngineering and Rehabilitation |
| spelling | doaj.art-171b9e1e2b0246e9a8a827a4701f2e7d2022-12-22T03:28:23ZengBMCJournal of NeuroEngineering and Rehabilitation1743-00032006-11-01312610.1186/1743-0003-3-26Co-activation: its association with weakness and specific neurological pathologyWiles Charles MBusse Monica Evan Deursen Robert WM<p>Abstract</p> <p>Background</p> <p>Net agonist muscle strength is in part determined by the degree of antagonist co-activation. The level of co-activation might vary in different neurological disorders causing weakness or might vary with agonist strength.</p> <p>Aim</p> <p>This study investigated whether antagonist co-activation changed a) with the degree of muscle weakness and b) with the nature of the neurological lesion causing weakness.</p> <p>Methods</p> <p>Measures of isometric quadriceps and hamstrings strength were obtained. Antagonist (hamstring) co-activation during knee extension was calculated as a ratio of hamstrings over quadriceps activity both during an isometric and during a functional sit to stand (STS) task (using kinematics) in groups of patients with extrapyramidal (n = 15), upper motor neuron (UMN) (n = 12), lower motor neuron (LMN) with (n = 18) or without (n = 12) sensory loss, primary muscle or neuromuscular junction disorder (n = 17) and in healthy matched controls (n = 32). Independent t-tests or Mann Witney U tests were used to compare between the groups. Correlations between variables were also investigated.</p> <p>Results</p> <p>In healthy subjects mean (SD) co-activation of hamstrings during isometric knee extension was 11.8 (6.2)% and during STS was 20.5 (12.9)%. In patients, co-activation ranged from 7 to 17% during isometric knee extension and 15 to 25% during STS. Only the extrapyramidal group had lower co-activation levels than healthy matched controls (p < 0.05). Agonist isometric muscle strength and co-activation correlated only in muscle disease (r = -0.6, p < 0.05) and during STS in UMN disorders (r = -0.7, p < 0.5).</p> <p>Conclusion</p> <p>It is concluded that antagonist co-activation does not systematically vary with the site of neurological pathology when compared to healthy matched controls or, in most patient groups, with strength. The lower co-activation levels found in the extrapyramidal group require confirmation and further investigation. Co-activation may be relevant to individuals with muscle weakness. Within patient serial studies in the presence of changing muscle strength may help to understand these relationships more clearly.</p>http://www.jneuroengrehab.com/content/3/1/26 |
| spellingShingle | Wiles Charles M Busse Monica E van Deursen Robert WM Co-activation: its association with weakness and specific neurological pathology Journal of NeuroEngineering and Rehabilitation |
| title | Co-activation: its association with weakness and specific neurological pathology |
| title_full | Co-activation: its association with weakness and specific neurological pathology |
| title_fullStr | Co-activation: its association with weakness and specific neurological pathology |
| title_full_unstemmed | Co-activation: its association with weakness and specific neurological pathology |
| title_short | Co-activation: its association with weakness and specific neurological pathology |
| title_sort | co activation its association with weakness and specific neurological pathology |
| url | http://www.jneuroengrehab.com/content/3/1/26 |
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