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dc.contributor.authorRubenson, Jonas
dc.contributor.authorG. Lloyd, David
dc.contributor.authorB. Heliams, Denham
dc.contributor.authorF. Besier, Thor
dc.contributor.authorA. Fournier, Paul
dc.date.accessioned2017-05-03T15:57:09Z
dc.date.available2017-05-03T15:57:09Z
dc.date.issued2011
dc.date.modified2011-09-22T06:50:55Z
dc.identifier.issn1742-5662
dc.identifier.urihttp://hdl.handle.net/10072/40928
dc.description.abstractThe purpose of this study was to examine the mechanical adaptations linked to economical locomotion in cursorial bipeds. We addressed this question by comparing mass-matched humans and avian bipeds (ostriches), which exhibit marked differences in limb structure and running economy. We hypothesized that the nearly 50 per cent lower energy cost of running in ostriches is a result of: (i) lower limb-swing mechanical power, (ii) greater stance-phase storage and release of elastic energy, and (iii) lower total muscle power output. To test these hypotheses, we used three-dimensional joint mechanical measurements and a simple model to estimate the elastic and muscle contributions to joint work and power. Contradictory to our first hypothesis, we found that ostriches and humans generate the same amounts of mechanical power to swing the limbs at a similar self-selected running speed, indicating that limb swing probably does not contribute to the difference in energy cost of running between these species. In contrast, we estimated that ostriches generate 120 per cent more stance-phase mechanical joint power via release of elastic energy compared with humans. This elastic mechanical power occurs nearly exclusively at the tarsometatarso-phalangeal joint, demonstrating a shift of mechanical power generation to distal joints compared with humans. We also estimated that positive muscle fibre power is 35 per cent lower in ostriches compared with humans, and is accounted for primarily by higher capacity for storage and release of elastic energy. Furthermore, our analysis revealed much larger frontal and internal/external rotation joint loads during ostrich running than in humans. Together, these findings support the hypothesis that a primary limb structure specialization linked to economical running in cursorial species is an elevated storage and release of elastic energy in tendon. In the ostrich, energy-saving specializations may also include passive frontal and internal/external rotation load-bearing mechanisms.
dc.description.peerreviewedYes
dc.description.publicationstatusYes
dc.languageEnglish
dc.language.isoeng
dc.publisherRoyal Society Publishing
dc.publisher.placeUnited Kingdom
dc.publisher.urihttp://rsif.royalsocietypublishing.org/content/8/58/740.short
dc.relation.ispartofstudentpublicationN
dc.relation.ispartofpagefrom740
dc.relation.ispartofpageto755
dc.relation.ispartofissue58
dc.relation.ispartofjournalJournal of the Royal Society Interface
dc.relation.ispartofvolume8
dc.rights.retentionY
dc.subject.fieldofresearchAnimal Structure and Function
dc.subject.fieldofresearchBiomechanics
dc.subject.fieldofresearchcode060807
dc.subject.fieldofresearchcode110601
dc.titleAdaptations for economical bipedal running: the effect of limb structure on three-dimensional joint mechanics
dc.typeJournal article
dc.type.descriptionC1 - Articles
dc.type.codeC - Journal Articles
gro.date.issued2011
gro.hasfulltextNo Full Text
gro.griffith.authorLloyd, David


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