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dc.contributor.advisorNigg, Benno Maurus
dc.contributor.advisorEmery, Carolyn A.
dc.contributor.authorMohr, Maurice
dc.date2019-06
dc.date.accessioned2018-12-06T17:56:34Z
dc.date.available2018-12-06T17:56:34Z
dc.date.issued2018-12-05
dc.identifier.citationMohr, M. (2018). Lower Extremity Muscle Activation Following a Previous Knee Injury: Implications for Post-Traumatic Knee Osteoarthritis (Unpublished doctoral thesis). University of Calgary, Calgary, AB. doi:10.11575/PRISM/34902en_US
dc.identifier.urihttp://hdl.handle.net/1880/109239
dc.description.abstractIndividuals who sustain an intra-articular knee injury are at a high risk of developing post-traumatic knee osteoarthritis (PTOA) 10-20 years later. Compensatory activation patterns of knee muscles in response to the trauma may persist past the acute injury phase and result in abnormal mechanical loading and subsequent osteoarthritis of the knee. This dissertation aimed to use surface electromyography (sEMG) to explore abnormal leg muscle activation patterns and their possible involvement in PTOA development in individuals who suffered a previous knee injury 3-12 years ago. The first part of this thesis presents methodological investigations related to two sEMG-based assessments of knee muscle activation strategies. It was shown that 1) sEMG amplitude-based co-contraction indices during gait exhibit poor between-day reliability and 2) the magnitude of intermuscular coherence strongly depends on the configuration and alignment of the sEMG electrodes. Building on the methodological findings, the second part of this thesis investigated the association between a previous knee injury and leg muscle activation during walking and squatting while considering the influence of sex. Sex-specific abnormalities in quadricep and hamstring muscle activation patterns were present for the affected leg in individuals more than three years after a previous knee injury. Altered quadricep and hamstring muscle activation may result in abnormal movement and loading of the knee joint and thus be linked to mechanical risk factors for PTOA development. This dissertation could not provide evidence, however, that altered thigh muscle activation was associated with more self-reported knee pain or symptoms indicative of PTOA development. From a methodological perspective, the poor reliability of current sEMG-based markers for abnormal muscle activation may lower the sensitivity to detect associations with risk factors for PTOA. From a conceptual perspective, the development of PTOA is not solely based on joint mechanics but depends on the interplay between mechanical, biological, and structural abnormalities of the joint following a knee injury. Therefore, the pathway to PTOA is likely unique to each individual such that a consistent association between abnormal muscle activation following a knee injury and PTOA risk may not exist.en_US
dc.language.isoeng
dc.rightsUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subjectAnterior Cruciate Ligament (ACL)
dc.subjectBiomechanics
dc.subjectGait Analysis
dc.subjectElectromyography
dc.subjectMotor Unit
dc.subjectPost-traumatic Osteoarthritis
dc.subjectKnee Injury
dc.subjectMuscle Activation
dc.subjectMuscle Co-contraction
dc.subjectMotor Control
dc.subjectMuscle
dc.subject.classificationNeuroscienceen_US
dc.subject.classificationMedicine and Surgeryen_US
dc.subject.classificationRehabilitation and Therapyen_US
dc.subject.classificationEngineering--Biomedicalen_US
dc.titleLower Extremity Muscle Activation Following a Previous Knee Injury: Implications for Post-Traumatic Knee Osteoarthritis
dc.typedoctoral thesis
dc.publisher.facultyGraduate Studies
dc.publisher.facultyKinesiology
dc.publisher.institutionUniversity of Calgaryen
dc.identifier.doihttp://dx.doi.org/10.11575/PRISM/34902
thesis.degree.nameDoctor of Philosophy
thesis.degree.namePhD
thesis.degree.grantorUniversity of Calgary
dc.contributor.committeememberVon Tscharner, Vinzenz
dc.contributor.committeememberHerzog, Walter
dc.publisher.placeCalgaryen
ucalgary.item.requestcopytrue


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University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.