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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

The Effect of Mechanical Stimuli on Healing Achilles Tendons in Rats

Malis, Emma January 2009 (has links)
<p>Tendon healing is a slow process and the tendon may not regain its initial mechanical properties after rupture. Mechanical stimuli have shown to have positive effect on tendon healing. This study is the first to investigate the effect of vibration stimuli on healing tendons. Vibration was also compared to treadmill running, which has previously been used for mechanical stimuli.63 female Sprauge-Dawley rats were used. A 3 mm segment was removed from the Achilles tendon and the tendon was left to heal. The animals were subjected to 15 min of daily exercise, vibration or treadmill running or acted as controls without exercise. The study was divided into three experiments. Experiment 1; the animals had full time cage activity and was randomized into running, vibration and control group. Experiment 2; the animals were unloaded and randomized into vibration, running and control group. There was also a control group with full time cage activity in experiment 2. Experiment 3; the animals were unloaded and randomized into vibration and placebo group. 14 days after surgery the animals were killed and mechanical testing of the Achilles tendons was performed. The results showed no significant difference between the groups in experiment 1. Experiment 2 showed that controls with full time cage activity had higher peak load, stiffness and cross sectional area than unloaded running, vibration and control groups. In experiment 3, there was no significant difference between vibration and placebo group. In conclusion, this study shows that vibration, as applied here, does not affect tendon healing.</p>
42

Chronic exertional compartment syndrome of the lower leg : a novel diagnosis in diabetes mellitus: a clinical and morphological study of diabetic and non-diabetic patients

Edmundsson, David January 2010 (has links)
Chronic exertional compartment syndrome (CECS) of the lower leg, defined as a condition with exercise-induced pain due to increased intramuscular pressure (IMP), has previously mainly been described in running athletes, and etiologic factors are poorly described. CECS has not been reported to occur together with other diseases and information about consequences on muscles morphology after treatment with fasciotomy is largely unknown. We investigated etiologic and pathophysiologic aspects to CECS in a consecutive series of 63 patients with exercise-related leg pain and in 17 diabetic patients with symptoms of intermittent claudication but no circulatory insufficiency. Clinical examination, radiography, scintigraphy and IMP measurements at rest and after reproduction of symptoms were done. Patients with CECS were recommended treatment with fasciotomy. Biopsies were taken from the tibialis anterior muscle at time of fasciotomy and at follow-up 1 year later. For comparison muscle samples were taken from normal controls. Enzyme- and immunohistochemical and morphometric methods were used for analysis of muscle fiber morphology/pathology, fiber phenotype composition, mitochondrial oxidative capacity and capillary supply. Thirty-six of the 63 patients fulfilled the criteria for diagnosis of CECS in the anterior tibial compartment. The CECS patients could be divided into different etiologic groups: 18 healthy, 10 with history of trauma against the lower leg, 4 diabetic patients and 4 others. Only 5 of 36 CECS patients were athletes. The results after fasciotomy were good or excellent in 41 of 57 treated legs.  Sixteen of the 17 diabetic patients were diagnosed with CECS, 11 with diabetes type 1 and 5 with type 2. The diabetic patients differed from the other groups with longer symptom-duration, shorter pain-free walking distance, firm and tender lower leg muscles and higher IMP. The postoperative outcome was good or excellent in 15 of 18 treated legs. The muscle biopsies taken at fasciotomy showed frequent histopathological changes including small and large sized fibers, fiber atrophy, internal myonuclei, split fibers, fibrosis, disorganization of mitochondria in contrast to healthy CECS subjects having low muscle capillarization as the main finding. Muscular abnormalities were generally more complex, severe and widespread in diabetic patients. After 1 year, the majority of CECS patients could return to unrestricted physical activity and the histopathological muscle changes were clearly reduced. The muscle fiber size was larger and the muscles contained signs of regeneration and repair. Remaining muscle abnormalities were present mainly in diabetic patients. CECS is a new differential-diagnosis in diabetic patients with symptoms of claudication without signs of vascular disease. A low ability for physical activity, reflected by the signs of both myopathy and neuropathy, indicates that high IMP and circulatory impairment has deleterious effects for the involved muscles. Increased physical activity and normalization of muscle morphology 1 year after treatment shows the benefit of fasciotomy. The more severe clinical and morphological findings in diabetic compared to healthy subjects with CECS indicate differences in the pathogenesis. The unrestricted physical ability after treatment is very important for diabetic patients, since physical activity is an essential part of the therapy of the disease.
43

The Effect of Mechanical Stimuli on Healing Achilles Tendons in Rats

Malis, Emma January 2009 (has links)
Tendon healing is a slow process and the tendon may not regain its initial mechanical properties after rupture. Mechanical stimuli have shown to have positive effect on tendon healing. This study is the first to investigate the effect of vibration stimuli on healing tendons. Vibration was also compared to treadmill running, which has previously been used for mechanical stimuli.63 female Sprauge-Dawley rats were used. A 3 mm segment was removed from the Achilles tendon and the tendon was left to heal. The animals were subjected to 15 min of daily exercise, vibration or treadmill running or acted as controls without exercise. The study was divided into three experiments. Experiment 1; the animals had full time cage activity and was randomized into running, vibration and control group. Experiment 2; the animals were unloaded and randomized into vibration, running and control group. There was also a control group with full time cage activity in experiment 2. Experiment 3; the animals were unloaded and randomized into vibration and placebo group. 14 days after surgery the animals were killed and mechanical testing of the Achilles tendons was performed. The results showed no significant difference between the groups in experiment 1. Experiment 2 showed that controls with full time cage activity had higher peak load, stiffness and cross sectional area than unloaded running, vibration and control groups. In experiment 3, there was no significant difference between vibration and placebo group. In conclusion, this study shows that vibration, as applied here, does not affect tendon healing.
44

Biopsychosocial evaluation of a spinal triage service delivered by physiotherapists in collaboration with orthopaedic surgeons

2012 January 1900 (has links)
Background: Low back pain (LBP) and low back related disorders are highly prevalent and associated with a considerable burden of pain, disability and work loss. People with a variety of low back-related complaints comprise a large proportion of referrals made to orthopedic surgeons and many of these patients are not considered to be surgical candidates or have not maximized their non-surgical options for managing their low back-related complaints. Objectives: We sought to evaluate the impact of a triage assessment program delivered by physiotherapists using a variety of approaches. Informed by a biopsychosocial model, the objectives of this dissertation were: 1) To determine the short term impact of a physiotherapy triage assessment for people with low back-related disorders on participant self-reported pain, function and quality of life and patient and referring practitioner satisfaction. 2) To determine which demographic, clinical, psychosocial and environmental factors are predictive of improved self-reported pain, function, quality of life and participant and referring practitioner satisfaction. 3) To determine the diagnostic and treatment recommendation concordance between physiotherapists and orthopaedic surgeons, using a newly developed clinical classification tool, for people presenting to a spinal triage assessment service with low back complaints. Methods: Two approaches were used to achieve the aforementioned objectives: a prospective observational study (n=115) to address the first two objectives and a sub-group reliability study (n=45) to address the third objective. Results: There was a mean overall significant improvement in the SF-36 Physical Component Summary at the 4-6 week post-test time point and relatively high satisfaction reported by participants and referring care providers. Qualitative analysis of comments revealed a variety of positive, negative and other contextual factors that may impact outcomes. A variety of different sociodemographic, psychological, clinical and other variables were associated with success or improvement in each respective outcome. There may be a potential mechanism of reassurance that occurs during the spinal triage assessment process as those with higher psychological distress were more likely to improve on certain outcomes. There was high diagnostic concordance between physiotherapists and an orthopaedic surgeon; however, there were more differences in management recommendations between the surgeon and a solo physiotherapist versus physiotherapists working in a collaborative team. Conclusions: A spinal triage assessment program delivered by physiotherapists has the potential to positively impact a variety of patient-related short term outcomes including satisfaction. Further study is needed to examine longer-term outcomes and which biopsychosocial factors may impact these outcomes.
45

Perceptions of care and caring : an orthopaedic perspective

Flynn, Sandra Dawn January 2013 (has links)
“Too often we underestimate the power of a touch, a smile, a kind word, a listening ear, an honest compliment, or the smallest act of caring, all of which have the potential to turn life around,” (Leo F Buscaglia 1924-1998). Caring is a universal phenomenon (Leininger, 1988a, 1991) that influences the way we think, feel and act and is the focus of debate worldwide. Studied since the days of Florence Nightingale and reflected in the literature are numerous theoretical opinions in the search for a comprehensive understanding of caring in the health experience of human beings (Newman et al., 1991). This ethnographic thesis has a caring science perspective (caring in orthopaedics) with the aim of acquiring a greater understanding of perceptions of caring in an orthopaedic clinical setting from both patient and health care professional perspectives. There is a wealth of literature relating to caring which attempts to define and interpret its meaning from several theoretical perspectives. In respect of institutional or professional caring, nursing has historically been synonymous with the notion of care and caring, modest research has been attributed to caring amongst other health care professionals in the wider context. The study used a sequential exploratory mixed methods design and was underpinned by Watson’s Theory of Transpersonal Care in order to discover and illuminate the essential caring behaviours valued by both care givers and care recipients. A total of 30 patients and 53 health care professionals consisting of doctors, nurses, physiotherapists and occupational therapists participated in the study through a three stage approach consisting of questionnaires, observation and semi-structured interviews. The findings revealed both similarities and differences between patients and health care professionals relating to the importance of positive caring behaviours revealed during caring interactions. The questionnaires disclosed that patients statistically rated caring behaviours demonstrated by health care professionals lower than the professionals rated themselves. The data analysis from the participant observation and semi-structured interviews established that although all of the caring caratives according to Watson’s Theory of Care were evident in caring interactions they varied as to the number of times they were exhibited by the respected health care professional groups. Overall patient perception of caring focused upon behaviours related to the caring carative ‘assurance of human presence’ whilst health care professionals considered caring behaviours relating to the caring carative ‘respectful deference’ as the most important. This thesis highlights the need of the patient to feel ‘cared for’ and ‘cared about’ and in today’s modern health care system caring should not be monopolised by one profession but instead the caring concept embraced and the caring dais shared by other professions.
46

Hip Resurfacing Arthroplasty: Investigating the Femoral Component in the Sagittal Plane

Morison, Zachary 14 December 2011 (has links)
The outcomes of hip resurfacing arthroplasty are largely dependent on prosthesis positioning. The biomechanics of notching, accurate measurement of femoral implant version and the use of computer navigation of the Birmingham Hip Resurfacing procedure were studied in this work. First, biomechanical tests were conducted with varying notch sizes and femoral positions, and it was determined that anterior notching weakens the construct (p=0.027) when the femur is in flexion and less so when in single-leg stance (p=0.155). Second, three novel techniques were used by three observers to measure the implant version in a lateral radiograph to determine which displayed a more accurate intra-class correlation. The third study examined the role of computer navigation as a learning device for improving the accuracy of femoral implant positioning using a manual alignment jig to curtail sequelae associated with malalignment.
47

Hip Resurfacing Arthroplasty: Investigating the Femoral Component in the Sagittal Plane

Morison, Zachary 14 December 2011 (has links)
The outcomes of hip resurfacing arthroplasty are largely dependent on prosthesis positioning. The biomechanics of notching, accurate measurement of femoral implant version and the use of computer navigation of the Birmingham Hip Resurfacing procedure were studied in this work. First, biomechanical tests were conducted with varying notch sizes and femoral positions, and it was determined that anterior notching weakens the construct (p=0.027) when the femur is in flexion and less so when in single-leg stance (p=0.155). Second, three novel techniques were used by three observers to measure the implant version in a lateral radiograph to determine which displayed a more accurate intra-class correlation. The third study examined the role of computer navigation as a learning device for improving the accuracy of femoral implant positioning using a manual alignment jig to curtail sequelae associated with malalignment.
48

Fretting wear of total hip replacement femoral stems

Cook, Juliette Emma January 1998 (has links)
No description available.
49

Tribological and mechanical properties of compliant bearings for total joint replacements

Burgess, Ian C. January 1997 (has links)
The tribology of a wide range of designs of compliant layer acetabular cups has been evaluated using a simulator. The simulator applied a dynamic load of 2 kN and a sinusoidal motion of ±25 , and measured the frictional resistance directly. In general the friction developed in these joints was extremely low, with friction factors typically below 0.01. When the experimental results were compared with theoretical estimates of friction a poor correlation was found. Further analysis suggested that the design of compliant layer acetabular cups was insensitive to many of the parameters suggested by theory. In particular, the radial clearance and femoral head size were not found to be critical. In addition, methods were proposed and their effectiveness demonstrated to measure friction at the on-set of motion (start-up friction), and the steady state friction in realistic compliant layer knees. The adhesion between compliant layers and a rigid backing have been investigated, with the aim of developing a good bond between them. The peel test was used to demonstrate an excellent diffusion bond between a low modulus medical grade polyurethane, and a similar high modulus grade of polyurethane. The processing conditions used to manufacture the test piece were optimised to maximise the bond strength. The bond was found to be stable after immersion in Ringers solution at 37 C for 52 weeks, and after acetabular cups were subjected to 14 million 4 kN loading cycles. A six station knee wear simulator was designed and commissioned. The simulator applied a dynamic load and an anterior-posterior translation individually to each station, as well as a flexion-extension motion common to all six stations. The simulator was computer controlled entirely using servo hydraulics. Wear rates were obtained from tests lasting up to 8 million cycles conducted on UHMWPE joints.
50

Påverkar skon styvheten i ankel-fotortoser? : En funktionell analys / Does the shoe affect the stiffness of an ankle-foot orthosis?  : A functional-analysis.

Sidenvall, Josef, Gustavsson, Matilda January 2018 (has links)
Bakgrund: Varierande styvhet mot dorsal-/plantarflektion i en ankel-fotortos (AFO)kan påverka kinematik och kinetik kring ankel och knä hos personer med cerebral pares eller post-stroke. Kunskap om huruvida skon påverkar styvheten i ett AFO-sko-benkomplex är begränsad. En tidigare studie har undersökt ämnet men använde bänktester för att adressera frågan. Syfte: Syftet var att, med funktionell analys, undersöka huruvida skor påverkar styvheten i ett AFO-sko-benkomplex, i sagittalplanet. Studiedesign: Överkorsningsstudie. Metod: Gånganalys genomfördes på fem friska individer. Deltagarna fick gå med tre olika AFO-skokombinationer. Data om ankelvinklar och ankelmoment extraherades för att beräkna styvheten för respektive AFO-skokombination. Styvheten för de olika kombinationerna jämfördes under fyra intervall. Resultat: Det fanns en skillnad i styvhet med olika skor. Styvheterna varierade mellan 0,0314–0,1652 Nm/° under de olika intervallen. Vilken AFO-skokombination som hade störst styvhet varierade beroende på vart i gångfasen de befann sig. Största skillnaden som uppmättes mellan två skor var 49,6%. Konklusion: Styvheten hos ett ben-AFO-sko-komplex kan variera beroende på vilken sko som används hos friska individer. Endast mindre skillnader kunde o mellan de olika AFO-skoalternativen varvid den kliniska relevansen av resultatet kan ifrågasättas. / Background: Variation in stiffness against dorsal- and/or plantarflexion in an ankle-foot orthosis (AFO) can affect the kinematics and kinetics of the knee and ankle in people with cerebral pares and post-stroke. The knowledge of whether the shoe influence the overall stiffness in a limb-AFO-shoe-complex is limited. A previous study has investigated the subject but used a bench-analysis to address the question. Objective: The objective of the study was to use functional-analysis to investigate the influence of shoe-choice on the overall stiffness in a limb-AFO-shoe-complex in the sagittal-plane. Study Design: Crossover study. Methods: Gait analysis was performed on five healthy participants who wore three different AFO-shoecombinations. Data about the ankleangle and anklemoment was extracted to calculate the stiffness of each AFO-shoecombination. The stiffness’ were compared in four different intervals. Results: There was a difference in stiffness between the AFO-shoecombinations. The stiffness’ varied between 0,0314–0,1652 Nm/° during the different intervals. Which AFO-shoecombination that had the highest stiffness also varied during the extracted phase. The biggest difference in stiffness between two shoes was 49,6%. Conclusions: Stiffness in a limb-AFO-shoe-complex may depend on the shoechoice in healthy individuals. Only small differences were observed between the different AFO-shoecombinations, thus the results’ clinical relevance can be questioned.

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