Low back pain in collegiate athletes has been reported at a rate of 37% from a wide array of sports including soccer, volleyball, football, swimming, and baseball. Whereas, in a military population the prevalence of low back pain is 70% higher than the general population. Compensatory movement strategies are often used as an attempt to reduce pain. Though compensatory movement strategies may effectively reduce pain, they are often associated with altered lower extremity loading patterns. Those who suffer from chronic low back pain tend to walk and run slower and with less trunk and pelvis coordination and variability. Individuals with low back pain also tend to run with more stiffness in their knees. Moving with less joint coordination and more stiffness are potential compensatory movement patterns acting as a guarding mechanism for pain. Overall the purpose of this project was to determine how chronic low back pain influences lower extremity biomechanics and shock attenuation in active individuals compared to healthy individuals and examine how the altered lower extremity biomechanics are related to clinical outcome measures. We hypothesized that individuals who present with chronic low back pain are more likely to exhibit higher vertical ground reaction forces and less knee flexion excursion during landing, compared to healthy individuals. We also hypothesized that individuals with chronic low back pain will have a reduced ability to attenuate shock during landing compared to the healthy individuals. This study was a case control design in which physically active individuals suffering from chronic low back pain were matched to healthy controls. All participants reported for one testing session to assess self-perceived knee function in the form of the Knee Osteoarthritis Outcomes Score (KOOS), lower extremity strength and mechanics during three landing tasks. Isometric strength was assessed using an isokinetic dynamometer during hip abduction, hip extension, and knee extension. The landing tasks included a drop vertical jump, a single leg hop, and a crossover hop. A three-dimensional motion analysis system with two in-ground force plates and four inertial measurement units were used to assess lower extremity mechanics during the landing tasks. Individuals with low back pain presented with reduced KOOS scores compared to healthy individuals in four of the five subscales, including Symptoms (p=0.007), Pain (p=0.002), Activities of Daily Living (p=0.021), and Quality of Life (p=0.003). Alternatively, while there were some strength, kinematic, and kinetic between limb asymmetries noted in the low back pain group, there were not between group differences with the healthy individuals. In the low back pain group, individuals presented with greater dominant limb knee extension strength (p=0.039) and greater dominant limb ankle plantarflexion at initial contact during the drop vertical jump, compared to the non-dominant limb (p=0.022). Individuals with low back pain also presented with greater non-dominant limb tibia impact during the single limb hop (p=0.008). While we did not identify any mechanical differences between individuals suffering from chronic low back pain and those who do not, we did identify that an active population suffering from low back pain does present with decreased self-perceived knee function compared to active individuals without low back pain. As these groups biomechanically perform similarly, they do not clinically perform the same, specifically, in terms of the KOOS. Such differences should not be overlooked when treating active populations with low back pain. If this population is presenting with altered self-perceived knee function at a young age, it is likely that it will continue to decline and negatively affect their function.

of the doctoral dissertation Extreme precipitation is related to flooding which is one of the most frequent natural hazards in Central Europe. Detailed understanding of extreme precipitation is the precondition for an efficient risk management and more precise projections of precipitation, which include uncertainties, especially at regional scale. The thesis focuses on extreme precipitation in the Ore Mountains (OM) and the Vosges Mountains (VG); two low mountain ranges in Central Europe experiencing orographic effect on precipitation. Based on state of the art about precipitation in OM and VG, a currently missing analysis of the temporal distribution of precipitation in VG was needed prior to the analysis of extremes. The original dataset of daily precipitation totals from 14 weather stations used in the initial study was extended to 168 stations covering a broader area of VG. The study of temporal distribution of precipitation during 1960-2013 led to a classification of stations: (i) mountainous stations with winter maxima and highest mean annual totals due to orographic enhancement of precipitation, (ii) stations on leeward slopes with two maxima (summer and winter), (iii) lee side stations with summer maxima and lowest mean annual totals due to rain shadow and more continental character, and...

Bakgrund: Diabetes mellitus är en global folksjukdom. Sjukdomen kan orsaka flera allvarliga komplikationer varav en är amputation av nedre extremitet. Förlust av en kroppsdel till följd av sjukdomen innebär både fysiska och psykiska påfrestningar, vilket kan resultera i positiva och/eller negativa upplevelser. Syfte: Syftet var att beskriva patienters upplevelser kring amputation av nedre extremitet till följd av diagnosen diabetes mellitus. Metod: En litteraturöversikt baserad på 11 kvalitativa vetenskapliga artiklar. Resultat: Resultatet visar att patienternas upplevelser är individuell och innefattar både positiva och negativa aspekter. Upplevelserna involverade rörelseförmågan, känslor, stöd, information och utbildning. Stödet från anhöriga och vårdpersonal hade en avgörande inverkan på patienterna under hela amputationsprocessen. Stödet hade även betydelse för patienternas acceptans och anpassning till den förändrade livssituationen. Konklusion: Studien visar att patienterna upplevde ett bristande stöd från sin omgivning, vilket påverkade upplevelserna negativt. När sjuksköterskan erhåller en förståelse för patienten kan det underlätta bemötandet och den stödjande funktionen i vårdmötet. / Background: Diabetes mellitus is a public disease that is seen on a global scale. The illness can cause several complications and amputation of the lower extremity is one of them. To lose a limb as a result of the disease cause both physical and psychological distress, which can cause positive or negative experiences for the patient. Aim: To describe the patient's experience about amputation of the lower extremity as a result of the diagnose diabetes mellitus. Method: A literature review based on 11 qualitative scientific articles. Results: The results show that the patient’s experience is individual and include both positive and negative aspects. The experiences involved mobility, emotions, support, information and education. The support had a determinant effect on the patients whole amputationprocess. This was also crucial for patients ability to adapt and accept the changes in their life. Conclusions: The study showed that the patients felt a lack of support from the people around them, which had negative effects on their experience. When the nurse has a deeper understanding for the patient it might facilitate to be a supportive function for the patient.

Explosives have become increasingly common on the battlefield worldwide. Military personnel and civilians often experience blast loading to the lower extremity due to its direct contact with the ground and floor of vehicles. The pressure and axial loading from these incidents often lead to detrimental injuries. These injuries can be due to a number of mechanisms terming them primary, secondary, tertiary, or quaternary blast injuries. Of these injuries, this study will focus on primary and tertiary injuries, specifically bone fractures, compartment syndrome, and soft tissue disruption which often result from blast loading due to these mechanisms. However, the pressure and load levels causing these injuries are unknown. Currently, the methodologies, which study the injury criteria and design of blast mitigating structures, are limited. The main limitations are the lower rates of testing (automobile), specimen limitation (cadavers, surrogates, etc.), cost, and testing repeatability. Consequently, the goal of this dissertation is to develop a realistic computational model which can be used to improve the injury criteria, personal protective equipment (PPE), and vehicular structure in a cost effective and timely manner. Three Aims were thus pursued. For Specific Aim 1, a standing lower extremity was developed, verified, and simulated with several open-air blast loading conditions. Specific Aim 2 focused on validating the lower extremity model using experimental drop tower test results. In the drop tower simulation, the lower extremity model was successfully converted into a seated posture model and setup with similar loading and boundary conditions as the experiment. Specific Aim 3 involved incorporating a boot into the standing lower extremity model and evaluating its ability to mitigate pressure waves. In summary, Specific Aims 1 and 2 developed, verified, and validated a realistic human lower extremity model for the use in blast simulations. Specific Aim 3 further confirmed the models use in developing PPE.

The shoulder is one of the most complex joints in the body. It has a large range of motion and has active, as well as passive, components to its stabilization. Many injuries occur every year due to overexertion and strain on the shoulder. Musculoskeletal models can be used as a proactive ergonomics tool for shoulder specific job task design, and to help prevent these injuries before they occur. The purpose of this thesis was to critically evaluate the performance of four optimization criteria (sum of squared activation, sum of cubed activation, sum of quartic activation, and entropy assisted) using the open source modeling platform OpenSIM. Experimental torque, kinematic, and EMG data were collected using ten participants for a variety of dynamic arm movements, and static arm postures, in different planes of action. The kinematic and torque data were processed and used as inputs to OpenSIM to calculate predicted muscle activations and joint reaction forces. Experimental EMG was cross correlated with the predicted muscle activity of 8 muscles, and RMSD was calculated between experimental and predicted muscle activity for evaluation. A co-contraction index was also used to assess the model’s ability to predict co-activation between muscle pairs. Overall, the sum of cubed activation and sum of quartic activation model predictions explained significantly more variance (38 ±2.5%, p<0.01) than the sum of squares and entropy models, when compared with experimental EMG. In conclusion, the type of optimization criterion chosen had an effect on the accuracy of the model predictions. Future research, in the development of optimization criterions for the shoulder, will create better model predictions of muscle forces and joint reaction forces, enabling musculoskeletal models to be more useful as a tool to the clinical and ergonomic populations. / Thesis / Master of Science (MSc) / The shoulder is one of the most complex joints in the body. It has a large range of motion and has muscles and ligaments to support the stability of the complex. Many injuries occur every year due to overexertion and strain on the shoulder. Proactively modelling can help reduce these injuries by evaluating a job's likelihood to injure a worker before the worker does the job. The purpose of this thesis was to evaluate the performance of several different shoulder models. Experimental torque, kinematic, and EMG data were collected using ten participants for a variety of dynamic arm movements, and static arm postures, in different planes of action. The kinematic and torque data were used by the model to predict muscle activations and joint reaction forces. Experimental EMG was cross correlated with the predicted muscle activity of 8 muscles, and RMSD was calculated between experimental and predicted muscle activity for evaluation. A co-contraction index was also used to assess the model’s ability to predict co-activation between muscle pairs. Overall, the sum of cubed activation and sum of quartic activation model predictions explained significantly more variance (38 ±2.5%, p<0.01) than the sum of squares and entropy models, when compared with experimental EMG. In conclusion, the type of model chosen had an effect on the accuracy of the model predictions. Future research, in the development of optimization criterions for shoulder models, will create better model predictions of muscle forces and joint reaction forces, enabling musculoskeletal models to be more useful as a tool to the clinical and ergonomic populations.

Introduction: Lower extremity (LE) work-related musculoskeletal disorders (WMSDs) are known to occur with cumulative exposure to occupational and personal risks. The objective of this dissertation study was to find if creating a quantifiable risk detection model for the LE was feasible. The primary product of the literature review conducted for this study resulted in focusing the attention of the model development process onto creating the initial model of the LE for assessing knee disorder risk factors. Literature Review: LE occupational disorders affect numerous industries and thousands of people each year by affecting any one of the musculoskeletal systems deemed susceptible by the occupational and personal risk factors involved. Industries known to be affected tend to have labor intensive job descriptions. Some of the numerous industry examples include mining, manufacturing, firefighting, and carpet laying. Types of WMSDs noticed by the literature include bursitis, osteoarthritis, stress fractures, tissue inflammation, and nerve entrapment. In addition to the occupationally related disorders that may develop, occupationally related discomforts were also taken into consideration by this study. Generally, both the disorders and the discomforts can be traced to either a personal or occupational risk factor or both. Personal risk factors noted by the literature include a person's physical fitness and health history (such as past injuries). Meanwhile, occupational risks can be generalized to physical postures, activities, and even joint angles. Prevalence data over a three year interval (2003-2005) has found that LE WMSDs make up on average approximately 7.5% of all the WMSD cases reported to the US Occupational Safety and Health Administration (OSHA). When the literature is refined to the information pertaining to occupational knee disorders, the mean prevalence percentage of the same three year range is about 5%. Mean cost for knee injuries were found to be $18,495 (for the year between 2003 and 2004). Methodology: Developing a risk model for the knee meant using groups of subject matter experts for model development and task hazard analysis. Sample occupational risk data also needed to be gathered for each of a series of tasks so that the model could be validated. These sample data were collected from a sample aircraft assembly plant of a US aerospace manufacturer. Results: Based on the disorder and risk data found in the literature, a knee risk assessment model was developed to utilize observational, questionnaire, and direct measure data collection methods. The final version of this study's knee model has an inventory of 11 risk factors (8 occupational and 3 personal) each with varying degrees of risk exposure thresholds (e.g., high risk, moderate risk, or minimal risk). For the occupational risk assessment portion of the model, the results of task evaluations include both an occupational risk resultant score (risk score) and a task risk level (safe or hazardous). This set of results is also available for a cumulative (whole day) assessment. The personal risk assessment portion only produces a risk resultant score. Validation of the knee risk model reveals statistically (t (34) = 1.512, p = 0.156), that it is functioning as it should and can decide between hazardous and safe tasks. Additionally, the model is also capable of analyzing tasks as a series of cumulative daily events and providing an occupational and personal risk overview for individuals. Conclusion: While the model proved to be functional to the given sample site and hypothetical situations, further studies are needed outside of the aerospace manufacturing environment to continue testing both the model's validity and applicability to other industrial environments. The iterative adjustments generated for the occupational risk portion of the model (to reduce false positives and negatives) will need additional studies that will further evaluate professional human judgment of knee risk against this model's results. Future investigations must also make subject matter experts aware of the minimal risk levels of this knee risk assessment model so that task observational results are equally comparable. Additional studies are moreover needed to assess the intimate nature between variable interactions; especially multiple model defined minimal risks within a single task.

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Bakgrund: En amputation innebär ett avlägsnade av en kroppsdel. De flesta amputationer utförs i de nedre extremiteterna. I Sverige sker årligen ungefär 2250 amputationer i de nedre extremiteterna. Orsaken till amputation kan vara kärlsjukdomar, diabetes samt trauma. Sjuksköterskan har i sin profession en betydande roll i mötet med patienten. Syfte: Syftet var att beskriva patienters upplevelser efter amputation av nedre extremitet. Metod: En litteraturöversikt genomfördes utifrån Fribergs metodbeskrivning. Tio kvalitativa originalartiklar inhämtades via databaserna PubMed och Cinahl Complete. Primära sökord som användes var amputation, nedre extremitet och livsförändrade händelser med begränsningar såsom engelska och peer reviewed. Resultat: Fyra teman identifierades: Upplevelsen av psykiska och fysiska förändringar, Att uppleva rollförändring och förlust av självständighet, Förändrad kroppsuppfattning och känslan av sårbarhet samt Vägen tillbaka efter amputation. Resultatet visade att patienterna upplevde en förlust av självständighet vilket gav upphov till en känsla av att vara en börda för sin familj. Den fysiska förmågan försämrades vilket bidrog till att de inte kunde ta sig utanför hemmet. Detta resulterade i att de kände sig ensamma och isolerade. Slutsats: Patienter upplevde känslomässig chock och rädsla inför framtiden. Att inte kunna prestera till fullo, bidrog till en känsla av förlust av identitet och självständighet. Vikten av stöd från familj, vänner och vårdpersonal har en central betydelse för återhämtning efter amputation. Amputation innebär att patienten genomgår en övergång till en ny fas i livet, en transition. / Background: An amputation implies a removal of a body part. Most amputations transact at the lower extremities. In Sweden approximately 2250 lower extremity amputations are made a year. The causes of amputation may be vascular diseases, diabetes or trauma. The profession of a nurse has a major role in the relation to the patient. Aim: The aim was to investigate patients’ experiences after an amputation of lower extremity. Method: To approach the aim a literature review was performed by the method of Friberg. Ten qualitative original articles were collected by the databases PubMed and Cinahl Complete. Primary keywords were amputation, lower extremity and life change events. Limitations were English and peer reviewed. Results: Four themes were identified: Experience of psychological and physical changes, To experience changes of identity and loss of independents, Changes of self-perceptions and the feeling of being vulnerable and How to recover after an amputation. The result showed that the patients’ experienced a loss of independence which resulted in a feeling of being a burden. The physical ability was impaired and contributed to a feeling of being isolated and lonely. Conclusion: The patients’ experienced emotional shock and a fear for the future. Not being able to perform to the fullest produced a loss of identity and independence. Support from family, friends and healthcare professionals has a central value for the recovery. To be amputated results in a transitioning and a new phase in life.