{"id":{"repo_id":"cape-town","oai_identifier":"oai:open.uct.ac.za:11427/31392"},"canonical_url":"https://search.dev.ndltd.org/etd/cape-town/oai:open.uct.ac.za:11427/31392","repository":{"repo_id":"cape-town","name":"University of Cape Town","base_url":"https://open.uct.ac.za/oai/request"},"display":{"title":"Understanding the mechanism of injury associated with long bone fractures through dynamic bending impact","abstract":"Blunt force trauma may result from homicide and assault cases, child abuse and motor vehicle accidents. Such incidents often result in skeletal trauma. Trauma to the lower limbs due to bending forces often involves a fracture pattern known as a butterfly or wedge fracture. Forensic analysis of the butterfly fracture aids in the establishment of directionality of the force applied. Currently, forensic anthropologists employ a method dictating that the base of the butterfly fragment pertains to the side of impact, while the apex of the fragment pertains to the opposite side of impact. Recent studies have demonstrated that this theory leads to erroneous forensic reconstructions as it assumes that all butterfly fractures are produced due to bone failing in tension. Furthermore, it requires the presence of a detached piece in order to be applicable, which is also the case for other proposed methods. The current study explores the biomechanics involved in the production of butterfly fractures by conducting 3-point bending impacts through a drop apparatus. It also investigates the accuracy of current and proposed forensic methods and aims at establishing a more reliable method of inferring directionality from the fracture pattern. From the sample fractured in this study, 11.8% of the fractures produced were tension wedges and 14.7% were compression wedges. When applying the existing methods of inferring directionality to the fractured sample, the accuracies ranged from 5.9% to 59%, while the method developed during this study achieved an accuracy of 97.1%. These results highlight the need of considering compression wedges during forensic reconstructions and understanding the impact of employing methods conceptualised on the assumption that all butterfly wedges are produced in tension.","abstract_html":"Blunt force trauma may result from homicide and assault cases, child abuse and motor vehicle accidents. Such incidents often result in skeletal trauma. Trauma to the lower limbs due to bending forces often involves a fracture pattern known as a butterfly or wedge fracture. Forensic analysis of the butterfly fracture aids in the establishment of directionality of the force applied. Currently, forensic anthropologists employ a method dictating that the base of the butterfly fragment pertains to the side of impact, while the apex of the fragment pertains to the opposite side of impact. Recent studies have demonstrated that this theory leads to erroneous forensic reconstructions as it assumes that all butterfly fractures are produced due to bone failing in tension. Furthermore, it requires the presence of a detached piece in order to be applicable, which is also the case for other proposed methods. The current study explores the biomechanics involved in the production of butterfly fractures by conducting 3-point bending impacts through a drop apparatus. It also investigates the accuracy of current and proposed forensic methods and aims at establishing a more reliable method of inferring directionality from the fracture pattern. From the sample fractured in this study, 11.8% of the fractures produced were tension wedges and 14.7% were compression wedges. When applying the existing methods of inferring directionality to the fractured sample, the accuracies ranged from 5.9% to 59%, while the method developed during this study achieved an accuracy of 97.1%. These results highlight the need of considering compression wedges during forensic reconstructions and understanding the impact of employing methods conceptualised on the assumption that all butterfly wedges are produced in tension.","abstract_has_math":false,"creators":["Emrith, Toshika Sheshna"],"institution":"Department of Pathology","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Mole, Calvin","Heyns, Marise"],"committee_chairs":[],"committee_members":[],"year":2019,"date_issued":"2019","date_published":"2019","updated_at":"2026-07-22T22:23:45Z","subjects":["Biomedical Forensic Science"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/11427/31392","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Mole, Calvin","Heyns, Marise"]},{"key":"dc:creator","label":"Author","values":["Emrith, Toshika Sheshna"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2020-02-28T12:12:26Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2020-02-28T12:12:26Z"]},{"key":"dc:date.issued","label":"Date","values":["2019"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Department of Pathology"]},{"key":"dc:type","label":"Dc Type","values":["Master Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Masters"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["MPhil"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Biomedical Forensic Science"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/11427/31392"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Blunt force trauma may result from homicide and assault cases, child abuse and motor vehicle accidents. Such incidents often result in skeletal trauma. Trauma to the lower limbs due to bending forces often involves a fracture pattern known as a butterfly or wedge fracture. Forensic analysis of the butterfly fracture aids in the establishment of directionality of the force applied. Currently, forensic anthropologists employ a method dictating that the base of the butterfly fragment pertains to the side of impact, while the apex of the fragment pertains to the opposite side of impact. Recent studies have demonstrated that this theory leads to erroneous forensic reconstructions as it assumes that all butterfly fractures are produced due to bone failing in tension. Furthermore, it requires the presence of a detached piece in order to be applicable, which is also the case for other proposed methods. The current study explores the biomechanics involved in the production of butterfly fractures by conducting 3-point bending impacts through a drop apparatus. It also investigates the accuracy of current and proposed forensic methods and aims at establishing a more reliable method of inferring directionality from the fracture pattern. From the sample fractured in this study, 11.8% of the fractures produced were tension wedges and 14.7% were compression wedges. When applying the existing methods of inferring directionality to the fractured sample, the accuracies ranged from 5.9% to 59%, while the method developed during this study achieved an accuracy of 97.1%. These results highlight the need of considering compression wedges during forensic reconstructions and understanding the impact of employing methods conceptualised on the assumption that all butterfly wedges are produced in tension."]},{"key":"dc:title","label":"Title","values":["Understanding the mechanism of injury associated with long bone fractures through dynamic bending impact"]}]}],"canonical_facts":{"dc:contributor.advisor":["Mole, Calvin","Heyns, Marise"],"dc:creator":["Emrith, Toshika Sheshna"],"dc:date.accessioned":["2020-02-28T12:12:26Z"],"dc:date.available":["2020-02-28T12:12:26Z"],"dc:date.issued":["2019"],"dc:description.abstract":["Blunt force trauma may result from homicide and assault cases, child abuse and motor vehicle accidents. Such incidents often result in skeletal trauma. Trauma to the lower limbs due to bending forces often involves a fracture pattern known as a butterfly or wedge fracture. Forensic analysis of the butterfly fracture aids in the establishment of directionality of the force applied. Currently, forensic anthropologists employ a method dictating that the base of the butterfly fragment pertains to the side of impact, while the apex of the fragment pertains to the opposite side of impact. Recent studies have demonstrated that this theory leads to erroneous forensic reconstructions as it assumes that all butterfly fractures are produced due to bone failing in tension. Furthermore, it requires the presence of a detached piece in order to be applicable, which is also the case for other proposed methods. The current study explores the biomechanics involved in the production of butterfly fractures by conducting 3-point bending impacts through a drop apparatus. It also investigates the accuracy of current and proposed forensic methods and aims at establishing a more reliable method of inferring directionality from the fracture pattern. From the sample fractured in this study, 11.8% of the fractures produced were tension wedges and 14.7% were compression wedges. When applying the existing methods of inferring directionality to the fractured sample, the accuracies ranged from 5.9% to 59%, while the method developed during this study achieved an accuracy of 97.1%. These results highlight the need of considering compression wedges during forensic reconstructions and understanding the impact of employing methods conceptualised on the assumption that all butterfly wedges are produced in tension."],"dc:identifier.uri":["http://hdl.handle.net/11427/31392"],"dc:publisher.department":["Department of Pathology"],"dc:subject":["Biomedical Forensic Science"],"dc:title":["Understanding the mechanism of injury associated with long bone fractures through dynamic bending impact"],"dc:type":["Master Thesis"],"dc:type.qualificationlevel":["Masters"],"dc:type.qualificationname":["MPhil"]},"updated_at":"2026-07-22T22:23:45Z"}