{"id":{"repo_id":"uwo","oai_identifier":"oai:uwo.scholaris.ca:20.500.14721/35284"},"canonical_url":"https://search.dev.ndltd.org/etd/uwo/oai:uwo.scholaris.ca:20.500.14721/35284","repository":{"repo_id":"uwo","name":"Western University","base_url":"https://uwo.scholaris.ca/server/oai/request"},"display":{"title":"Decreased Peak Muscle Power is Associated with Motor Unit Loss in the Lower Limb of Older Adults","abstract":"This study investigated the relationship between motor unit (MU) properties and the strength and power of two lower limb muscles in healthy young and old adults. Twelve older adults (mean age, 77 ± 5 yrs) and twelve young adults (mean age, 24 ± 3 yrs) were studied. MU properties of the tibialis anterior (TA) and vastus medialis (VM) muscles were determined using decomposition-enhanced spike-triggered averaging (DE-STA). Motor unit number estimates (MUNE) of the TA were significantly reduced (p>0.05) in older adults (102 ± 76) compared to young adults (234 ± 109), primarily as a result of significantly larger surface-detected motor unit potentials (S-MUP) in older adults. Although VM S-MUP values were larger in older adults (60 ± 31 μV) compared to young (48 ±42), the difference was not significant. Maximal strength and power were significantly larger in both the TA and knee extensors of young adults compared to old. Maximal power output displayed greater deficits than isometric strength in both lower limb muscles of older adults. Results from this study indicate that there are changes in MU properties with age, and that this effect may be greater in the TA muscle. Further, power, especially in the knee extensors, may be a more sensitive measure of neuromuscular health than isometric strength, and should be the focus of exercise programs in elderly subjects.","abstract_html":"This study investigated the relationship between motor unit (MU) properties and the strength and power of two lower limb muscles in healthy young and old adults. Twelve older adults (mean age, 77 ± 5 yrs) and twelve young adults (mean age, 24 ± 3 yrs) were studied. MU properties of the tibialis anterior (TA) and vastus medialis (VM) muscles were determined using decomposition-enhanced spike-triggered averaging (DE-STA). Motor unit number estimates (MUNE) of the TA were significantly reduced (p>0.05) in older adults (102 ± 76) compared to young adults (234 ± 109), primarily as a result of significantly larger surface-detected motor unit potentials (S-MUP) in older adults. Although VM S-MUP values were larger in older adults (60 ± 31 μV) compared to young (48 ±42), the difference was not significant. Maximal strength and power were significantly larger in both the TA and knee extensors of young adults compared to old. Maximal power output displayed greater deficits than isometric strength in both lower limb muscles of older adults. Results from this study indicate that there are changes in MU properties with age, and that this effect may be greater in the TA muscle. Further, power, especially in the knee extensors, may be a more sensitive measure of neuromuscular health than isometric strength, and should be the focus of exercise programs in elderly subjects.","abstract_has_math":false,"creators":["McKinnon, Neal B"],"institution":"The University of Western Ontario","degree_name":"M Sc","degree_level":null,"degree_discipline":"Kinesiology","degree_department":null,"school":null,"contributors":[],"advisors":["Timothy Doherty"],"committee_chairs":[],"committee_members":[],"year":2014,"date_issued":"2014-08-28","date_published":"2014-08-28","updated_at":"2026-07-27T21:55:54Z","subjects":["Aging","Decomposition-enhanced spike-triggered averaging (DE-STA)","Electromyography (EMG)","Motor unit number estimation (MUNE)","Power"],"languages":["en_ca"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/20.500.14721/35284","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Timothy Doherty"]},{"key":"dc:creator","label":"Author","values":["McKinnon, Neal B"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2025-07-10T20:36:31Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2025-07-10T20:36:31Z"]},{"key":"dc:date.issued","label":"Date","values":["2014-08-28"]},{"key":"dc:publisher","label":"Institution","values":["The University of Western Ontario"]},{"key":"dc:type","label":"Dc Type","values":["thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Kinesiology"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M Sc"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Aging","Decomposition-enhanced spike-triggered averaging (DE-STA)","Electromyography (EMG)","Motor unit number estimation (MUNE)","Power"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en_ca"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/20.500.14721/35284"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The thesis cover page in the PDF document includes references to Western University’s previous institutional repository platform, known as Scholarship@Western, and links to that platform (beginning with ir.lib.uwo.ca). In citing or referring to this thesis, use the DOI or handle from this page instead. Sample citation: Author name, \"Thesis title.\" (Year). Western University Open Repository. https://doi.org/10.71858/123456."]},{"key":"dc:description.abstract","label":"Abstract","values":["This study investigated the relationship between motor unit (MU) properties and the strength and power of two lower limb muscles in healthy young and old adults. Twelve older adults (mean age, 77 ± 5 yrs) and twelve young adults (mean age, 24 ± 3 yrs) were studied. MU properties of the tibialis anterior (TA) and vastus medialis (VM) muscles were determined using decomposition-enhanced spike-triggered averaging (DE-STA). Motor unit number estimates (MUNE) of the TA were significantly reduced (p>0.05) in older adults (102 ± 76) compared to young adults (234 ± 109), primarily as a result of significantly larger surface-detected motor unit potentials (S-MUP) in older adults. Although VM S-MUP values were larger in older adults (60 ± 31 μV) compared to young (48 ±42), the difference was not significant. Maximal strength and power were significantly larger in both the TA and knee extensors of young adults compared to old. Maximal power output displayed greater deficits than isometric strength in both lower limb muscles of older adults. Results from this study indicate that there are changes in MU properties with age, and that this effect may be greater in the TA muscle. Further, power, especially in the knee extensors, may be a more sensitive measure of neuromuscular health than isometric strength, and should be the focus of exercise programs in elderly subjects."]},{"key":"dc:title","label":"Title","values":["Decreased Peak Muscle Power is Associated with Motor Unit Loss in the Lower Limb of Older Adults"]}]}],"canonical_facts":{"dc:contributor.advisor":["Timothy Doherty"],"dc:creator":["McKinnon, Neal B"],"dc:date.accessioned":["2025-07-10T20:36:31Z"],"dc:date.available":["2025-07-10T20:36:31Z"],"dc:date.issued":["2014-08-28"],"dc:description":["The thesis cover page in the PDF document includes references to Western University’s previous institutional repository platform, known as Scholarship@Western, and links to that platform (beginning with ir.lib.uwo.ca). In citing or referring to this thesis, use the DOI or handle from this page instead. Sample citation: Author name, \"Thesis title.\" (Year). Western University Open Repository. https://doi.org/10.71858/123456."],"dc:description.abstract":["This study investigated the relationship between motor unit (MU) properties and the strength and power of two lower limb muscles in healthy young and old adults. Twelve older adults (mean age, 77 ± 5 yrs) and twelve young adults (mean age, 24 ± 3 yrs) were studied. MU properties of the tibialis anterior (TA) and vastus medialis (VM) muscles were determined using decomposition-enhanced spike-triggered averaging (DE-STA). Motor unit number estimates (MUNE) of the TA were significantly reduced (p>0.05) in older adults (102 ± 76) compared to young adults (234 ± 109), primarily as a result of significantly larger surface-detected motor unit potentials (S-MUP) in older adults. Although VM S-MUP values were larger in older adults (60 ± 31 μV) compared to young (48 ±42), the difference was not significant. Maximal strength and power were significantly larger in both the TA and knee extensors of young adults compared to old. Maximal power output displayed greater deficits than isometric strength in both lower limb muscles of older adults. Results from this study indicate that there are changes in MU properties with age, and that this effect may be greater in the TA muscle. Further, power, especially in the knee extensors, may be a more sensitive measure of neuromuscular health than isometric strength, and should be the focus of exercise programs in elderly subjects."],"dc:identifier.uri":["https://hdl.handle.net/20.500.14721/35284"],"dc:language.iso":["en_ca"],"dc:publisher":["The University of Western Ontario"],"dc:subject":["Aging","Decomposition-enhanced spike-triggered averaging (DE-STA)","Electromyography (EMG)","Motor unit number estimation (MUNE)","Power"],"dc:title":["Decreased Peak Muscle Power is Associated with Motor Unit Loss in the Lower Limb of Older Adults"],"dc:type":["thesis"],"thesis:degree_discipline":["Kinesiology"],"thesis:degree_name":["M Sc"]},"updated_at":"2026-07-27T21:55:54Z"}