Excessive muscle tone or stiffness secondary to stroke frequently involves the ankle plantarflexors and has been associated with decreased mobility and reduced function. Although becoming more common in clinical practice, the effectiveness of botulinum toxin A (BTX-A) injected in the ankle plantarflexors on gait biomechanics is not well established. The primary objective of this study was to describe the kinematic and kinetic changes that occur during walking following BTX-A treatment of the hypertonic ankle plantarflexors. As well, the study explored whether there were clinical characteristics uniquely associated with subjects that exhibited biomechanical improvement. The study was a single group, open label trial with repeated measures, including multiple baseline and three post-intervention time points. Seven chronic hemiparetic stroke subjects with ankle hypertonicity were included in the study. Full lower limb bilateral gait analysis provided joint kinematic and kinetic information throughout stance. As well, clinical measures of ankle range of motion and spasticity were assessed pre and post treatment. Data were analyzed using paired samples t-tests and repeated measures ANOVA with Least Significant Difference adjustment for post-hoc analysis as necessary (significance level p≤0.05). Of the kinematic variables, significant improvements in peak dorsiflexion and plantarflexion and the ankle angle at initial contact were found 10 weeks post-injection relative to baseline. No significant kinetic changes were detected, however 2 subjects showed improved positive work at the ankle post-injection and 5 subjects demonstrated increased positive work at the hip post-treatment. Although subjects were classified as “responders” or “non-responders” based on clinical improvement observed 2 weeks post-injection, there was no observable association between those who responded clinically and those who demonstrated improved gait. The major findings suggest that BTX-A injection results in tone reduction and in some cases improves the biomechanical efficiency of gait. In cases where kinetic variables remained unchanged following treatment, perhaps the increased tone was not the limiting factor of reduced function. / Thesis (Master, Neuroscience Studies) -- Queen's University, 2007-08-30 09:41:03.24
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OKQ.1974/684 |
| Date | 17 September 2007 |
| Creators | Novak, Alison C |
| Contributors | Queen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.)) |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Format | 3458113 bytes, application/pdf |
| Rights | This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. |
| Relation | Canadian theses |
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