Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.

xiii, 79 p. : ill. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / Subacromial impingement syndrome is the most common disorder of the shoulder. Abnormal superior translation of the humeral head is believed to be one of the major causes of this pathology. The overall purpose of this study was to better understand glenohumeral kinematics in normal healthy individuals using fluoroscopy to help comprehend the mechanism of shoulder impingement. This research was divided into three sections: a validation study to measure humeral head translation, a comparison between dynamic and static arm elevation and lastly, humeral head translation after a suprascapular nerve block. In the first study, fluoroscopy was used to take images of human cadaver shoulders. Scapular orientation was manipulated in different positions while the humerus was at 90 degrees of elevation. Humeral head translation was measured using two methods and was compared to the known translation. Additionally, the accuracy of the contour registration method to measure 2-D scapular rotations was assessed. For the second study, subjects elevated their dominant arm while fluoroscopic images were taken. An edge detection software was utilized to digitize points on both the humeral head and glenoid. Humeral head translation and scapular upward rotation were measured using a contour registration method with respect to the glenoid during arm elevation. Five different arm elevation angles were investigated to measure differences in humeral head translation between trials. There was no difference found between humeral head translation and scapular upward rotation between static and dynamic shoulder elevation. For the third study, humeral head translation was measured before and after a suprascapular never block. The humeral head was superiorly located and the scapula was more upwardly rotated after the block. The differences were observed during mid range of motion. This result showed that there was a compensatory increase in both humeral head translation and scapular upward rotation due to the nerve block. These results suggest that increasing muscular strength and endurance of the supraspinatus and infraspinatus muscle could prevent any increased superior humeral head translation. This may be beneficial in preventing shoulder impingement or rotator cuff tear over time. This dissertation includes unpublished co-authored materials. / Committee in charge: Andrew Karduna, Chairperson, Human Physiology; Li-Shan Chou, Member, Human Physiology; Louis Osternig, Member, Human Physiology; Stephen Frost, Outside Member, Anthropology

The physical demands of archery involve strenuous movements that place repetitive mechanical loads on the upper body. Given that bone remodels in response to mechanical loading (Ruff, 2008), it is reasonable to assume that repetitive bow and arrow use impacts upper limb bone morphology in predictable ways. The introduction and increased use of archery have been suggested to impact bilateral humeral asymmetry (Rhodes and Knüsel, 2005; Thomas, 2014). However, this claim is yet to be tested in vivo. This project aims to use kinematic and electromyographic approaches to validate claims inferring that, 1. archery places mechanical loading on the non-dominant arm resulting in lowered asymmetry, and 2. the dominant arm in archery has more mechanical loading placed in the anterior-posterior direction while the non-dominant arm has more mechanical loading placed in the medial-lateral direction. Some muscles (i.e. Pectoralis major and posterior Deltoid) act symmetrically on both humeri, while most muscle groups (i.e. Biceps brachii, Triceps brachii, Deltoid (lateral), and Latissimus dorsi) are activated asymmetrically on the humerus. On the whole, asymmetrically acting muscle groups acting on separate arms result in similar overall directional bending. Therefore, the overall cross-sectional shape of the bone would be similar for the draw and bow arm. Repeated bow use would undoubtedly induce humeral modification consistent with increased non-dominant arm robusticity, which in turn would lower asymmetry. Findings from this project thus support the hypothesis that the adoption of the bow and arrow results in decreased humeral asymmetry and strengthen morphological approaches to behavioral reconstruction.

L'analyse morpho-fonctionnelle précise de l'épaule, notamment au niveau de l'articulation glénohumérale (GH), permettrait d'améliorer notre compréhension des dysfonctions de l'épaule associées aux ruptures de la coiffe des rotateurs. Cependant, des difficultés techniques compliquent l'analyse de la morphologie et du mouvement de l'épaule dans un contexte clinique. Dans le cadre de la présente thèse, une méthode d'analyse 3D des translations GH basée sur l'acquisition de séquences de radiographies biplanes sous EOS™ a été développée. Une étude pilote sur 10 sujets sains a d'abord permis de vérifier la facilité d'application d'un protocole d'acquisition des images et d'évaluer la répétabilité de l'identification des repères anatomiques de l'épaule sur les radiographies. La méthode proposée en dernier lieu permet, suite à l'acquisition de radiographies, de reconstruire un modèle personnalisé morpho-réaliste de la scapula et un modèle simplifié de l'humérus. Ces modèles sont ensuite recalés interactivement sur les images acquises à différentes positions du bras et utilisés pour décrire les translations GH à ces positions. La méthode a été validée en termes de précision et de répétabilité sur des images acquises d'épaules cadavériques et de patients ayant des ruptures de la coiffe des rotateurs. La dernière partie du travail présenté ici consiste à appliquer la méthode développée à 30 sujets (25 patients et 5 sujets sains) pour lesquels l'état de la coiffe des rotateurs et la fonction de l'épaule ont été évalués, puis à étudier les corrélations entre les translations GH et la fonction de l'épaule. / Precise morpho-functional analysis of the shoulder, including of the glenohumeral (GH) joint, would allow improving our understanding of shoulder dysfunction associated to rotator cuff tears. However, technical difficulties make analysis of shoulder morphology and motion difficult in a clinical setting. The work carried out during this thesis allowed developing a method for 3D analysis of GH translations relying on the acquisition of sequences of biplanar radiographs with the EOS™ system. A pilot study carried out on 10 healthy subjects allowed verifying the ease of application of an image acquisition protocol and evaluating the repeatability of shoulder landmark identification on the radiographs. The final proposed method allows, following the acquisition of radiographs, obtaining a personalized morphologically realistic reconstruction of the scapula and a simplified model of the humerus. These models are then interactively registered to the images acquired at different arm positions and used to describe GH translations for these positions. The proposed method was validated in terms of precision and repeatability on images acquired of cadaveric shoulders and of patients with rotator cuff tears. The last part of the work presented here consists in applying the developed method to 30 subjects (25 patients and 5 asymptomatic subjects) for whom rotator cuff condition and shoulder function were assessed, and to study correlations between GH translations and shoulder function.

O tratamento de fraturas umerais distais em aves impõe grande dificuldade, devido a córtices muito finas dos ossos A artrodese com fixador externo da articulação úmero-rádio-ulnar é inviável para aves que se pretende reintroduzir ao meio ambiente. Doze animais foram divididos em dois grupos: cirurgias bilaterais com anquilose de uma asa (asa estática) e manutenção da articulação da outra (asa dinâmica) (grupo 1), e cirurgia unilateral, com manutenção da função da articulação (asa dinâmica), sendo a outra controle (asa intacta) (grupo 2). Foram feitas avaliações clínicas, radiológicas, morfológicas do osso, histomorfométricas (de ambos os grupos) e de capacidade de vôo (grupo 2). A 6 semanas, todos os animais apresentavam fraturas consolidadas, com excessão de dois animais do grupo 1, que somente apresentaram consolidação das asas dinâmicas às 9 semanas e das estáticas às 12 semanas. Todos os animais do grupo 2 apresentaram capacidade de vôo adequada, antes de 13 semanas após a cirurgia. No grupo 1 o úmero da asa dinâmica representava 99,1% do comprimento do da asa estática, e no grupo 2, estes eram 99,5% em relação à asa intacta. A amplitude da asa, no grupo 2, demonstrou que a relação da asa dinâmica/intacta foi de 93%, e no grupo 1 a relação asa dinâmica/estática foi de 105%. O volume do osso intacto foi de aproximadamente 29% da área estudada, enquanto o da asa estática foi de 19% e das asas dinâmicas, de 22%. Houve diferença entre o número de osteoblástos das asas intactas e dinâmicas, porém não houve diferença entre as asas estáticas e intactas e entre as dinâmicas e as estáticas, e também não houve diferença do número de osteoclástos entre nenhum tipo de asa. A razão da superfície óssea pelo volume ósseo indica a quantidade de áreas de reabsorção. Não houve diferença entre as asas estática e dinâmica, porém houve diferença entre estas e os controles. O método proposto de técnica para fixação de fraturas umerais distais, sem a anquilose da articulação úmero-rádio-ulnar, demonstrou ser efetivo em manter o comprimento ósseo, a amplitude da asa e assim, garantindo a capacidade de vôo das aves tratadas, além de demonstrar ser equivalente histológicamente à técnica tradicional e mais estável de anquilose da articulação, para este tipo de fratura, e até mesmo, no período estudado, ser equivalente ao osso são, sendo um método adequado para a reparação de fraturas distais de úmero em aves quando se pretende a reabilitação destes animais. / The treatment of humeral distal fractures in birds is very difficult, because these bones are very brittle. Ankylosis of the humeral-radio-ulnar joint with an external fixator is unviable for birds intended for re-habilitation and reintroduction. Twelve animals were used and they were divided in two groups: bilateral surgeries, with ankylosis of one wing (static wing) and maintenance of the joint function of the other wing (dynamic wing) (group 1), and unilateral surgery, with maintenance of the joint function of the wing (dynamic wing), and the other was used as control group (intact wing) (group 2). Clinical, radiographic, morphologic and histomorphometric evaluations of the wings and bones (of both groups) and of evaluations of flight capacity (in group 2) were made. At 6 weeks, all animals had healed fractures, except two animals in group 1, that only presented consolidation of the dynamic wing at 9 weeks and the static wings at 12 weeks. All animals in group 2 were capable of flying before 13 weeks after surgery. In group 1, the humerus of the dynamic wing was 99.1% the length of that of the static wing, and in group 2, these were 99.5% compared to the intact wing. Wing amplitude, in group 2, showed a dynamic/ intact ratio of 93%, and in group 1 the dynamic/ static wing ratio was 105%. The volume of the intact bone was approximately 29% of the studied area, while in the static wing it was of 19% and in the dynamic wing, 22%. There was a difference in the number of osteoblasts of the intact and dynamic wings, but there was no difference between static and intact, and between dynamic and static wings, and also, there was no difference in the numbers of osteoclasts between any wings. The bone surface/ volume ratio indicates the amount of resorption areas. There was no significant difference between static and dynamic wings, but there was a difference between static and intact wings. The proposed method of distal humeral fracture fixation technique, without ankylosis of the humerus-radius-ulna joint, demonstrated being effective in keeping bone length, wing amplitude e therefore, guaranteeing flight capacity of the birds treated, as well as being histologically equivalent to the tradicional, more stable, joint ankylosis technique, for thise kind of fracture, and even, for the studied period, being equivalent to healthy bone, being an adequate method for fracture repair for this kind of fracture in birds, when one intends rehabilitation of these animals.

Proximal humeral fractures requiring surgical stabilization remain a therapeutic challenge, and a fully functioning joint is rarely the outcome after traumatic proximal humeral fractures. A systematic review was conducted to present the current state of knowledge concerning the postoperative rehabilitation. Tree databases was searched (PubMed, PEDro and the Cochrane library), presenting 25 publications eligible for further review and assessment. The literature was evaluated using PEDro and The Swedish Council on Health Technology, SBUs, evaluation grading system GRADE. The main functional impairments were pain and reduced range of motion in the shoulder joint, and were measured by several different scoring systems for functional outcome. Reported results were contradictory and inconsistent, and current studies typically lack randomization, and independent evaluation, with a resultant inability to produce clinical conclusions. According the post-operative rehabilitation procedure, only careful conclusions can be drawn from the literature reviewed which does not focus on, emphasize or explore the physiotherapeutic interventions at any length. It was therefore not possible to compare or connect the Axelina rehabilitation regimen with the literature. The Axelina rehabilitation program of the shoulder joint, are the most commonly used regimen at the physiotherapeutic ward at Uppsala University hospital. Neither was it possible to determine if the post-operative treatment should be different according to classification of fracture or method of stabilization. The results from this systematic review suggest that the data from the published literature are inadequate for evidence-based decision making as regards the treatment and post-operative rehabilitation for complex proximal humeral fractures.

Throwing with power and accuracy is a uniquely human behavior and a potentially important mode of early hunting. Chimpanzees, our closest living relatives, do occasionally throw, although with much less velocity. At some point in our evolutionary history, hominins developed the ability to produce high performance throws. The anatomical changes that enable increased throwing ability are poorly understood and the antiquity of this behavior is unknown. In this thesis, I examine how anatomical shifts in the upper body known to occur during human evolution affect throwing performance. I propose a new biomechanical model for how humans amplify power during high-speed throwing using elastic energy stored and released in the throwing shoulder. I also propose and experimentally test a series of functional hypotheses regarding how four key shifts in upper body anatomy affect throwing performance: increased torso rotational mobility, laterally oriented shoulders, lower humeral torsion, and increased wrist hyperextensability. These hypotheses are tested by collecting 3D body motion data during throws performed by human subjects in whom I varied anatomical parameters using restrictive braces to examine their effects on throwing kinematics. These data are broken down using inverse dynamics analysis into the individual motions, velocities, and forces acting around each joint axis. I compare performance at each joint across experimental conditions to test hypotheses regarding the relationship between skeletal features and throwing performance. I also developed and tested a method for predicting humeral torsion using range of motion data, allowing me to calculate torsion in my subjects and determine its effect on throwing performance. My results strongly support an important role for elastic energy storage in powering humans’ uniquely rapid throwing motion. I also found strong performance effects related to anatomical shifts in the torso, shoulder, and arm. When used to interpret the hominin fossil record, my data suggest high-speed throwing ability arose in a mosaic-like fashion, with all relevant features first present in Homo erectus. What drove the evolution of these anatomical shifts is unknown, but as a result the ability to produce high-speed throws was available for early hunting and likely provided an adaptive advantage in this context. / Anthropology

Εισαγωγή: Η θεραπεία των σύνθετων καταγμάτων του άνω πέρατος του βραχιονίου είναι αμφισβητήσιμη και παραμένει ένα θέμα διαρκούς αντιπαράθεσης στη διεθνή βιβλιογραφία. Οι ιδιομορφίες των καταγμάτων αυτών, η μικρή αξιοπιστία και αναπαραγωγικότητα των υπαρχόντων συστημάτων ταξινόμησης, η έλλειψη πολυκεντρικών προοπτικών ερευνών και ο μη καθορισμός αντικειμενικών κριτηρίων αξιολόγησης του θεραπευτικού αποτελέσματος, είναι μερικές μόνο από τις αιτίες που οδηγούν σε ασυμφωνία τους ερευνητές. Η επικρατούσα τάση στη διεθνή βιβλιογραφία σήμερα, επικεντρώνεται στις ελάχιστα παρεμβατικές τεχνικές οστεοσύνθεσης, που περιλαμβάνουν περιορισμένες αποκολλήσεις γύρω από τα κατεαγότα τμήματα, προσπάθεια διατήρησης της αιμάτωσης της κεφαλής και περιορισμό των μεταλλικών υλικών που απαιτούνται για την επίτευξη σταθερής οστεοσύνθεσης. Τα βασικά πλεονεκτήματα της μεθόδου που προτείνουμε είναι η ατραυματική προσπέλαση, η αποφυγή βίαιων χειρισμών επί του κατάγματος, η μη χρησιμοποίηση μεταλλικών υλικών οστεοσύνθεσης, η αποκατάσταση της ρήξης του μυοτενόντιου πετάλου και η χιαστί συγκράτηση των αποσπασθέντων τμημάτων της κεφαλής σε ένα ενιαίο τμήμα, δίκην ταινίας ελκυσμού (tension band effect), που επιτρέπει την σταθερή οστεοσύνθεση του κατάγματος και διευκολύνει την πρώιμη κινητοποίηση του ώμου. Υλικό-Μέθοδος: Την χρονική περίοδο 1991-2003 αντιμετωπίστηκαν χειρουργικά στην κλινική μας με τη μέθοδο της οστεοσυρραφής 214 ασθενείς. Πρόκειται για 123 γυναίκες και 91 άνδρες με πρόσφατο κάταγμα του άνω πέρατος βραχιονίου και μέσο όρο ηλικίας τα 52,7 έτη (από 18 έως 82 ετών). Συνολικά, με βάση την ταξινόμηση και τα κριτήρια του CS. Neer, αντιμετωπίστηκαν 71 κατάγματα 2-τμημάτων, 75 κατάγματα 3-τμημάτων και 64 κατάγματα 4-τμημάτων (48 ενσφηνωμένα σε βλαισότητα) καθώς και 4 περιπτώσεις με κάθετο διαχωρισμό της αρθρικής επιφανείας. Ο μέσος χρόνος παρακολούθησης ήταν 5.2 έτη και αφορούσε το 92% των ασθενών. Συνολικά 13 ασθενείς δεν προσήλθαν στον τελευταίο επανέλεγχο ενώ 4 απεβίωσαν για λόγους μη σχετιζόμενους με το κάταγμα ή την θεραπεία του, αφήνοντας 197 ασθενείς για πλήρη κλινική και ακτινολογική αξιολόγηση. Μελετήθηκαν και αξιολογήθηκαν όλα τα διεγχειρητικά ευρήματα, οι προεγχειρητικές και μετεγχειρητικές ακτινογραφίες, η επάρκεια και διατήρηση της ανάταξης, οι πρώιμες και απώτερες επιπλοκές, τα στοιχεία νοσηλείας, η επίπτωση μετεγχειρητικών φλεγμονών, η συμμόρφωση με το πρόγραμμα φυσιοθεραπείας, η ικανοποίηση του ασθενούς με τη θεραπεία και το τελικό κλινικό αποτέλεσμα, με βάσει τις παραμέτρους του Constant Score. Ακτινολογικά, η εξέλιξη της πώρωσης αξιολογήθηκε με προσθοπίσθια και διαμασχαλιαία ακτινογραφία στον 1ο, 3ο, 6ο και 12ο μήνα, καθώς και στον τελευταίο επανέλεγχο. Η παρουσία πλήρους ή τμηματικής άσηπτης νέκρωσης της κεφαλής, απορρόφησης ή παρεκτόπισης των ογκωμάτων, απώλειας της ανάταξης ή πώρωσης σε πλημμελή θέση, καθώς και οι όποιες ενδείξεις παρουσίας δευτεροπαθούς οστεοαρθρίτιδας και συνδρόμου υπακρωμιακής προστριβής κατεγράφησαν σε όλους τους ασθενείς που συμπεριελήφθησαν στη μελέτη. Σε 16 κατάγματα 4-τμημάτων εκπονήθηκε επιπλέον κλινική αγγειογραφική μελέτη για την διερεύνηση της διατήρησης της αιμάτωσης της βραχιονίου κεφαλής μετά την εφαρμογή της οστεοσυρραφής. Αποτελέσματα: Όλα τα κατάγματα πωρώθηκαν σε διάστημα 10.4 εβδομάδων κατά μέσο όρο (από 6.5 έως 14.6 εβδομάδες), εκτός από τέσσερις περιπτώσεις που παρουσίασαν ψευδάρθρωση. Η μέση τιμή του Constant score κατά τον τελευταίο επανέλεγχο ήταν 80.2 (από 35 έως 100 βαθμούς) ανεξαρτήτως τύπου κατάγματος, ενώ ως ποσοστό επί της λειτουργικότητας του υγιούς ώμου κυμάνθηκε στο 87.5%. Συνολικά 61 ασθενείς (30.9%) είχαν άριστο αποτέλεσμα, 96 (48.8%) πολύ καλό, 24 μέτριο (12.2%) και 16 πτωχό (8.1%). Η συνολική επίπτωση άσηπτης νέκρωσης της βραχιονίου κεφαλής ήταν 22/197 περιπτώσεις (11.1%), με πλήρη καθίζηση της κεφαλής σε 9 ασθενείς και μερική σε 13. Η παρουσία «λύσης» του ΜΒΟ επισημάνθηκε σε 18 ασθενείς (9.1%), έκτοπης οστεοποίησης σε 21 (10.6%), συμπτωματικής οστεοαρθρίτιδας σε 9 (4.5%) και συνδρόμου υπακρωμιακής προστριβής σε 11 (5.5%). Η συνολική επίπτωση επανεγχείρησης λόγω επιπλοκών κυμάνθηκε στο 7.1%. Η ανάλυση των αποτελεσμάτων της αγγειογραφικής μελέτης κατέδειξε διατήρηση της ενδοστικής αιματικής παροχής μετά από την εφαρμογή οστεοσυρραφής στα κατάγματα 4-τμημάτων ενσφηνωμένων σε βλαισότητα. Συμπεράσματα: Προτείνουμε την ανοικτή ανάταξη και εσωτερική οστεοσύνθεση με μη-απορροφήσιμα ράμματα σε όλα τα παρεκτοπισμένα κατάγματα του άνω πέρατος του βραχιονίου που είναι επιδεκτικά οστεοσύνθεσης (2-τμημάτων ΜΒΟ, 3-τμημάτων και 4-τμημάτων ενσφηνωμένων σε βλαισότητα). Αποφεύγοντας τις πιθανές επιπλοκές των μεταλλικών υλικών μπορούμε, με την τεχνική της οστεοσυρραφής, να επιτύχουμε ικανοποιητική ανάταξη, σταθερή οστεοσύνθεση και αποκατάσταση του μυοτενόντιου πετάλου, που επιτρέπουν την πρώιμη κινητοποίηση της άρθρωσης και την επίτευξη ενός καλού τελικού κλινικού και ακτινολογικού αποτελέσματος. Σε νεαρούς ασθενείς με παρεκτοπισμένα κατάγματα 4-τμημάτων χωρίς ενσφήνωση και σε κατάγματα-εξαρθρήματα 3- και 4- τμημάτων, μπορεί να εφαρμοστεί αρχικά η οστεοσυρραφή, με σκοπό την απώτερη βιωσιμότητα της κεφαλής, αλλά η έκβαση είναι λιγότερο προβλέψιμη και η επίπτωση των επιπλοκών σημαντική. / Background: Ideal treatment of displaced proximal humeral fractures remains controversial and a matter of continuous debate in the international literature. The particularities of those fractures, the under strength reliability and reproducibility of the existing classification systems, the lack of multicenter prospective studies and the heterology definitions about the evaluation of results are only some of the reasons that bring researchers out of step. Current trends in operative treatment of these fractures are focused in minimal invasive techniques of reconstruction, involving limited soft tissue detachments, preserving blood supply of the humeral head and eliminating of necessary hard material application for stable osteosynthesis. The main advantages of our proposed technique are the minimal approach, without forced manipulations on the fracture, the avoidance of any hard material application, the repair of coexisting rotator cuff tears and the cruciate, tension-band like manner of bone fragments retention to a uniform part that allows stable internal fixation of the fracture and early shoulder joint motion. Material-Methods: Between 1991 and 2003, 214 patients underwent transosseous suturing for displaced fractures of the proximal humerus in our Department. There were 123 women and 91 men with a mean age of 52.7 years (range, 18-82). According to Neer criteria and fracture classification we managed 71 two-part fractures, 75 three-part and 64 four-part (48 of them was of valgus impacted subtype) as well as 4 splitting head fractures. Mean follow up period was 5.2 years and concerned the 92% of the patients. Overall, 13 patients were lost from the last follow up appointment and 4 died from reasons unrelated to the fracture or its treatment, leaving a total of 197 patients for full clinical and radiological evaluation. We recorded and investigated all preoperative and postoperative radiographs, intraoperative details, kind of reduction, early and late complications, hospital stay details, the incidence of infection, the cooperation with the rehabilitation program, the patient satisfaction and the objective clinical outcome according to the parameters of Constant score. Radiologically, the union progress was evaluated with anteroposterior and auxiliary views at 1st, 3rd, 6th, and 12th month as well as at the last follow up. All radiographs were investigated for the presence of partial or total collapse of the head, lysis or tuberosity displacement, loss of reduction or malunion as well as for signs of post-traumatic osteoarthritis and subacromial impingement syndrome. In 16 patients with four-part valgus impacted fractures, a digital angiographic evaluation was performed for further investigation of humeral head supply after transosseous suturing. Results: All fractures were united until the 10.4 week (range, 6.5 to 14.6 weeks), except four that developed nonunion. The mean Constant score at the last follow up was 80.2 (from 35 to 100 points) singly from fracture type, whereas the functional score as a percentage to that of the unaffected shoulder was 87.5%. Overall, 61 patients (30.9%) were rated as excellent, 96 (48.8%) very good, 24 good (12.2%) και 16 poor (8.1%). The overall incidence of avascular necrosis was 22/197 cases (11.1%); 9 patients showed total collapse and 13 partial collapse. Greater tuberosity lysis was noted in 18 patients (9.1%), heterotopic ossification in 21 (10.6%), posttraumatic osteoarthritis in 9 (4.5%) and subacromial impingement syndrome in 11 (5.5%). The overall rate of reoperation due to complications was 7.1%. The results of angiographic investigation showed conservation of endosteal blood supply of the humeral head, after transosseous suturing. Conclusions: We suggest open reduction and internal fixation in all displaced fractures of the proximal humerus that were amenable for fixation (2-part greater tuberosity, 3-part and 4-part valgus impacted fractures). Avoiding the complications of any hard material application, we are able, with the solely use of transosseous sutures, to accomplish adequate reduction, stable osteosynthesis and repair of rotator cuff tears, allowing for early shoulder joint motion and a satisfactory clinical and radiological outcome. In young patients, with displaced four-part fractures without impaction or 3- and 4-part fractures-dislocations, the transosseous suturing can be applied initially, as a head preserving treatment, but the outcome is less predictable and the rate of complications prominent.

The central concern of this study is the social, cultural and political position of traditional birth attendants (TBA), known as yiey maap (grandmother midwives) in Chup Commune (pseudonym). In particular, this study explores strategies yiey maap use to negotiate or bypass Western model health services in an attempt to maintain their personal integrity and cultural capital as birth attendants, and to ensure the physical, emotional, economic and cultural safety of the woman they care for. / This thesis explores traditional maternity knowledges and practices using ethnographic methods to investigate the central issues, concerns and barriers confronting rural woman as they make choices to adapt, resist or negotiate Western maternity care. It is vital to consider historical, political, cultural and economic factors that influence women's decisions in order to understand how and why women hold onto or surrender their traditional childbirth knowledges and practices, including the preservation of yiey maap, their favoured birth attendant. / Safe Motherhood initiatives were introduced into resource-poor countries by the World Health Organization in 1987 with the goal of reducing maternal mortality rates. They were based on the premise that pregnancy, childbirth and postpartum care were safer when provided by skilled birth attendants in a modern health facility. TBAs were not considered skilled birth attendants by Safe Motherhood partner agencies, as training and utilizing TBAs in Safe Motherhood initiatives did not have a measurable impact on maternal mortality rates. Instead, TBAs' roles have been recast, and TBAs are expected to be health promoters and educators, referral agents and information gatherers. / I argue that Khmer women do not engage with the modern health system because it is unfamiliar and expensive, and health personnel provide poor quality care. Instead, in times of obstetric emergencies, women attempt to negotiate their own and their family's safety through personal autonomy and agency. / I conclude by proposing alternative approaches and strategies, including the increased utilisation of yiey maap in Cambodian Safe Motherhood programs. A central question is whether the Ministry of Health, supported by bilateral and multilateral agencies, should train and utilize yiey maap or midwives in maternity care. I argue that both are of equal importance. Until yiey maap are valued for their contribution to, and enjoy equitable inclusion in midwifery care, initiatives that involve yiey maap as program "extras", who undertake peripheral tasks, will not reduce maternal mortality rates.

xvi, 128 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / There were two primary goals of this work. The first goal was to investigate humeral and scapular kinematics in a simulated workplace environment. The second goal was to validate a triaxial accelerometer (Virtual Corset) for the collection of humeral elevation exposure data in an occupational setting. To achieve the first goal, healthy subjects were asked to perform constrained and functional humeral elevation motions. Differences were observed in scapular kinematics. In addition, the variability between constrained arm elevation and functional overhead tasks was found to be similar. Therefore, to compare scapular kinematics in an occupational group (dental hygienists) a functional work related task was determined to be more appropriate. The dental hygienists performed teeth instrumentation on simulated patients' with both big and average chest girth in a simulated work environment. Dental hygienist's humeral elevation and scapular upward rotation angles were found to be higher while working on the big chest girth manikin. These differences may increase dental hygienists susceptibility for musculoskeletal disorders. To achieve the second goal, an in-vitro comparison of angles measured with the Virtual Corset and an inclinometer was conducted under static conditions. Under dynamic conditions the Virtual Corset was compared to a potentiometer, in a pendulum setting. It was found that the Virtual Corset can accurately reconstruct elevation angles under static conditions, root mean square error less than 1[white square]. Under dynamic conditions, the error size was related to the angular velocity and acceleration, and the radius of rotation. To further investigate the Virtual Corset's ability to measure exposure parameters in-vivo the Virtual Corset was compare to a magnetic tracking device. To do so dental hygienists performed flossing tasks in a simulated work station. It was found that the Virtual Corset can be used to reconstruct elevation angles, with an acceptable angle error, and to identify exposure parameters in occupational settings similar to the one simulated in the present study. This dissertation includes unpublished co-authored material. / Adviser: Andrew R. Karduna