Background: Idiopathic parkinsonism is a neurodegenerative syndrome of unknown cause and includes Parkinson’s disease (PD) and atypical parkinsonian disorders. The atypical parkinsonian disorders are: Multiple system atrophy (MSA), progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). The incidence rates of these diseases in Sweden are largely unknown. The diagnosis of each disease relies mainly on clinical examination although several imaging and laboratory parameters may show changes. A diagnosis based on clinical examination is especially difficult early in the course of each disease; diagnosis is easier later on when disease-charactersistic signs have evolved and become more prominent. However, even in later stages it is not uncommon that patients are misdiagnosed. PD can be divided into subgroups based on the main clinical symptoms, i. e. tremor dominant, postural instability and gait difficulty (PIGD), and indeterminate. The PIGD subtype has worse prognosis including higher risk of dementia. The aims were to study the incidence of idiopathic parkinsonism and the different specific parkinsonian disorders in the Umeåregion and to investigate the patients early in the course of the disease with brainmagnetic resonance tomography (MRI), external anal sphincterelectromyography (EAS-EMG) and oculomotor examination. Can these methods improve the differential diagnostic work-up and/or differentiate between the subtypes of PD? Methods: We examined all patients in our catchment area (142,000 inhabitants) who were referred to us due to a suspected parkinsonian syndrome. Our clinic is the only clinic in the area receiving referrals regarding movement disorders. During the period (January 1, 2004 through April 30,2009) 190 patients fulfilled the inclusion criteria and were included in the study. Healthy volunteers served as controls.  Results: Incidence: We found the highest incidences reported in the literature: PD (22.5/100,000/year), MSA(2.4/100,000/year), and PSP (1.2/100,000/year). No CBD patients were encountered. Brain MRI: Degenerative changes were common both in controls and PD. There were no differences between the PD subtypes. EAS-EMG: Pathological changes in EAS-EMG examination were common in PD, MSA and PSP. It was not possible to separate PD, MSA and PSP by the EAS-EMG examination. Oculomotor examination: Pathological results were common in all diagnosis groups compared to controls. It was not possible to separate PD, MSA and PSP or the PD subtypes with the help of oculomotor examination. Conclusions: The incidences of idiopathic parkinsonism, PD, MSA and PSP were higher than previously reported in the literature. It is not clear weather this is due to a true higher incidence in the Umeå region or a more effective casefinding than in other studies. MRI, EAS-EMG and oculomotor examination could not contribute to the differential diagnostic work-up between PD, MSA and PSP nor differentiate between PD subtypes early in the course of the disease.

The prevalence of work-related muscle pain (WRMP) is large in the general population in the industrialized world. Despite significant advances over recent years in some research areas, the mechanisms of why WRMP occurs and the pathophysiological mechanisms behind the disorders are still unclear. One suggested explanation is that WRMP is caused initially by a limitation of the local muscle circulation and oxidative metabolism. There is a lack of objective methods to gauge the development and diagnosis of WRMP. Near infrared spectroscopy (NIRS) is a non-invasive technique that allows for determinations of oxygenation and blood flow. The purpose of this thesis was to evaluate NIRS (1) as a method for measuring muscle oxygenation and hemodynamics for the extensor carpi radialis (ECR) and trapezius descendens muscles (TD), and (2) to investigate whether variables measured by NIRS differed between patients diagnosed with WRMP and healthy subjects. Several variables of NIRS were produced and investigated. These included muscle oxygenation (StO2%), changes during contractions (ΔStO2%) and StO2% recovery (Rslope), total hemoglobin (HbT) as an indication of blood volume and its changes during contractions (ΔHbT). In addition, for the ECR, by applying an upper arm venous occlusion (VO) HbTslope increase as a surrogate of blood flow, and for both VO and arterial occlusion (AO) HHbslope increase (i.e. deoxyhemoglobin slope) as a surrogate of oxygen consumption were variables of interest. A first objective was to determine how StO2% and HbT responded to various contraction forces and how it related to muscle activation measured by electromyography (EMG). For both muscles isometric contractions of 10, 30, 50 and 70% of maximal voluntary contraction (MVC) were maintained for 20 s each by healthy males and females; additionally a 10% MVC contraction was sustained for 5 min. For the different contraction levels, predictable relationships were seen between ΔStO2% and force, and between ΔStO2% and EMG RMS amplitude. The general trend was a decrease in ΔStO2% with increasing force and increasing EMG. Females showed a tendency for a higher oxygen use (i.e., drop in StO2%) for the ECR over force levels than males and a higher RMS% MVC for the TD. For the 10% MVC contraction sustained for 5 min gender specific changes over time for HbT and RMS for the ECR, and for StO2% for the TD muscle were seen. A second objective was to determine the day-to-day reliability of NIRS variables for the ECR and TD muscles at group level (Pooled data) and at gender level (males and females). Measurements were performed on two occasions separated by 4-6 days and intraclass correlation coefficients (ICC) and limits of agreement (LOA) were determined as reliability and reproducibility indicators, respectively. Variables tested were ΔStO2% during submaximal isometric contractions of 10, 30, 50 and 70% MVC and StO2% recovery (Rslope) after contractions and after AO. For the ECR, HbTslope as an indication of blood flow (using VO) and HHbslope as a surrogate of oxygen consumption for both VO and AO were computed. For ΔStO2% for the ECR the highest ICC was at 30% MVC for both the pooled data and at gender level. For the TD ICCs were comparably high for 30, 50, 70 % MVC (for both muscles the ΔStO2% at 10% MVC showed the lowest ICC). Further, females showed a higher ICC than males for contraction levels of 50 and 70% MVC. For both muscles, LOA for ΔStO2% was lowest at 10% and highest at 50 and 70% MVC. For the ECR Rslope ICCs were high for all contraction levels, but was lower for AO; LOA was lowest at 70% MVC. For the TD, Rslope ICCs were also high for all contraction levels and LOA was lowest at 30 % MVC. ICC for HbTslope was the lowest of all variables tested. For HHbslope ICC was higher for AO than for VO, and LOA was lower for AO. A third objective was to determine if there were differences between healthy subjects and patients diagnosed with WRMP in ΔStO2% and ΔHbT responses during varying submaximal contractions (10, 30, 50 and 70% MVC), and StO2% recovery (Rslope) immediately after contractions and AO. Additional variables tested in the ECR at rest were HHbslope to indicate oxygen consumption (using AO) and HbTslope as an indication of blood flow. There were no differences between groups in ΔStO2% and ΔHbT variables during the contractions or Rslope in the recovery after contractions or AO. Furthermore, HbTslope was not different between groups However, oxygen consumption for the ECR and StO2% for the TD at rest were significantly greater for healthy subjects compared to patients. A fourth objective was to determine if there were differences in StO2% and HbT between healthy subjects and WRMP patients during a 12 min sustained contraction of 15 % MVC. In addition, the protocol included a recovery period of 30 min. Prior to contraction, as well as during the recovery period, HbTslope as a surrogate of blood flow was determined for the ECR. Neither the ECR nor the TD exhibited significant differences between groups for StO2% and HbT during the contraction. For the TD patients showed a lower StO2% value at rest and throughout the contraction than healthy subjects. For the ECR HbT during the sustained contraction the general trend was an initial decrease with gradual increase throughout the contraction for both groups. For HbTslope no differences were seen between patients and healthy subjects before the sustained contraction and during the recovery period for both muscles. NIRS is deemed a suitable technique for assessing physiological measurements of the upper extremity, including for day-to-day testing. NIRS was not able to distinguish between the patients with WRMP and controls. A concern in the thesis is the characteristics of the patient group in being equally active in recreational sports, actively working, and similar in muscle strength as controls. Thus, applying NIRS for studying a more severe patient group could yield different results.

Low-load repetitive work (LLRW) and mental load are important risk factors for the development of workrelated muscle pain. The link between these risk factors and the development of pain is still not understood, but stimulation of chemo-sensitive receptors in the muscle probably plays an important role. It has been suggested that sensitising substances may accumulate in the muscle during LLRW, especially when combined with mental load. The overall purpose of this thesis was to try to shed some light on the effects of LLRW on the concentration of sensitising substances (glutamate, prostaglandin E2 (PGE2), norepinephrine (NE)) and on metabolism (lactate, pyruvate and oxygenation) in the trapezius muscle of healthy controls (CON) and subjects with trapezius myalgia (TM). A first step was to investigate whether females with TM exhibit higher absolute concentrations of glutamate and PGE2 in the affected muscle during rest. Using Microdialysis (MD) females with TM and asymptomatic controls were studied during four hours of rest. [Glutamate] and [PGE2] during rest did not differ between groups. A second step was to investigate, in a simulated occupational setting, the effects of LLRW on the concentration of sensitising substances and metabolism in the trapezius muscle of TM and CON, and whether increased work duration resulted in a progressive effect. Asymptomatic females were studied during baseline rest, 30 versus 60 min work and recovery, using MD and near infrared spectroscopy (NIRS). Subjects with TM were studied during baseline rest, 30 min work and recovery. [Glutamate] and [lactate] increased in response to work, but not progressively with increased work duration. [Glutamate] was at all time points significantly lower in TM. [PGE2]and oxygenation remained unchanged during work for CON, while for TM oxygenation decreased significantly during work. In TM [pyruvate] increased during both work and recovery, and a significant interaction between groups was found for [pyruvate] during recovery; while moderately increased in CON it increased progressively in TM. The effects of LLRW with and without superimposed mental load on intramuscular [NE], muscle activity and oxygen saturation in the trapezius were also investigated and compared. Using MD, electromyography and NIRS, healthy females were studied on two occasions; during 30 min LLRW and during 30 min LLRW with superimposed mental load. During work [NE], and muscle activity, were increased, while oxygenation decreased, but no differences between occasions. However, recovery of [NE] to baseline was slower after LLRW with superimposed mental load. The findings of the present thesis suggest: (i) no inflammation, or increased interstitial [glutamate] in TM; (ii) LLRW causes an increased anaerobic metabolism in both TM and CON; (iii) no effect of work duration was found; (iv) a significant difference in the effects of LLRW on the interstitial milieu of the trapezius muscle in TM as compared to CON; (v) LLRW causes a significant increase in [NE], but superimposed mental load does not cause a further increase; (vi) LLRW with a superimposed mental load may result in a slower recovery to baseline [NE] as compared with LLRW alone.

A computer model simulating the electrical activity of muscles of the upper arm during elbow motion is presented. The output of the model is an Electromyographic (EMG) signal. System identification is performed on the EMG signals using autoregressive moving average (ARMA) modelling. The calculated ARMA coefficients are then used as the feature set for pattern recognition. Pattern recognition is performed on the EMG signals to attempt to identify which of four possible motions is producing the signal. The results of pattern recognition are compared with results from pattern recognition of real EMG signals. The model is shown to be useful in predicting general trends found in the real data, but is not robust enough to predict accurate quantitative results. Simplifying assumptions about the filtering effects of body tissue, and about the size and position of muscles, are conjectured to be the most likely reasons the model is not quantitatively accurate. / Graduation date: 1992

CONTEXTO: El entrenamiento aplicando elementos de inestabilidad está siendo ampliamente utilizado en el campo del entrenamiento como una herramienta novedosa y eficaz. No obstante, recientes hallazgos aportan datos contrarios a esta creencia y sugieren que la ejecución de ejercicios tradicionales sobre superficies inestables o ejercicios calisténicos específicos para el fortalecimiento estabilizador pueden no resultar estímulo suficiente para personas con un nivel de entrenamiento elevado llegando incluso a interferencia en el rendimiento final por la reducción de la capacidad de fuerza y la carencia de especificidad del entrenamiento. OBJETIVO: Cuantificar y comparar la actividad muscular paraespinal y la capacidad de generar fuerza máxima isométrica durante ejercicios globales que requieres de estabilidad frente a los ejercicios específicos calisténicos para el fortalecimiento estabilizador y los ejercicios que combinan inestabilidad externa. MATERIAL Y MÉTODOS: 31 sujetos altamente entrenados, con experiencia en el entrenamiento con elementos inestables y sin patologías de espalda fueron reclutados voluntariamente para la realización del estudio descriptivo. Tras un calentamiento estandarizado fueron colocados los electrodos para el registro muscular del multifidus (lumbar, torácico), erector espinae (lumbar, torácico). Con esta instrumentación los sujetos realizaron de forma aleatoria y dejando siempre un mínimo de 3 minutos de descanso los siguientes ejercicios: i) extensión lumbar; ii) extensión lumbar T-Bow; iii) lunge; iv) sentadilla con inestabilidad [Bosu, T-Bow]; v) peso muerto; vi) peso muerto con inestabilidad [Bosu, T-Bow]. Para todos los ejercicios se realizaron dos condiciones de evaluación, fuerza máxima contracción isométrica voluntaria (MCIV) y 10 repeticiones al 70% (MCIV). Los datos fueron registrados y almacenados para su posterior tratamiento estadístico con el SPSS 17.0. RESULTADOS: Durante las mediciones estáticas y dinámicas de siempre existió una mayor activación muscular y registros de fuerza máxima isométrica (MCIV) (p<0.05) para las condiciones de estabilidad frente a las de inestabilidad. Los registros más elevados los obtuvo el ejercicio de peso muerto donde la fuerza máxima isométrica voluntaria media fue de 107.85 (5.15) Kg. Mientras que la respuesta muscular global paraespinal en condiciones de estabilidad realizado al 70% (MCIV) fueron [máximo registro dinámico 117.38 (5.49) % y media dinámica 88.53 (2.97) %)]. CONCLUSIÓN: Añadir elementos de inestabilidad reduce la capacidad de generar fuerza máxima isométrica. La realización de los ejercicios globales al 70 % (MCIV) en condiciones de estabilidad generan la misma (lunge) o mayor (peso muerto) actividad muscular que los mismos ejercicios realizados con elementos de inestabilidad o con ejercicios específicos calisténicos. Por último, los datos parecen indicar que las respuestas musculares y la reducción en la capacidad de generar fuerza dependerán de los grados de inestabilidad que genere el dispositivo sobre el que se realice el ejercicio. / CONTEXT: It’s unclear whether unstable conditions during traditional resistance exercises performed at moderate loads can provoke higher levels of paraespinal muscular activation in healthy/athletic populations than the stable exercises performed at high loads. By other hand it has suggested that use unstable devices can reduce de strength performance output. PURPOSE: To quantify and to compare paraespinal muscular activity and maximum isometric voluntary contraction (MIVC) while carrying out different exercises polyarticular and calisthenic specific lumbar strengthening exercises in both stable and unstable conditions. MATERIAL AND METHODS: 31 subjects highly trained, experienced in training with instability and without pathologies were voluntarily recruited back to the descriptive study. Following a standardized warming the electrodes were placed to record the multifidus and erector espinae both in lumbar and thoracic portion. Subjects performed at random and always leaving a minimum of 3 minutes of rest for the following exercises: i) lumbar extension; ii) T-Bow lumbar extension; iii) lunge; iv) unstable squat [Bosu, T- Bow]; v) deadlift; vi) unstable deadlift [Bosu, T-Bow].This exercises were performed two testing conditions, (MIVC) and 10 repetitions at 70% (MIVC). Data were recorded and stored for later statistical analysis with SPSS 17.0. RESULTS: Data shows that there was a greater muscle activation and maximal isometric force records (MCIV) (p <0.05) for the conditions of stability against instability. Records obtained higher the deadlift exercise where the maximum voluntary isometric force average was 107.85 (5.15) kg. While global paraspinal muscle response in a stable made of 70% (MCIV) were [maximum dynamic registration 117.38 (5.49)% and 88.53 running average (2.97 )%)]. CONCLUSION: Add elements of instability reduces the ability to generate maximal isometric force. The overall exercise performance 70% (MCIV) in stable conditions generate the same (lunge) or higher (deadlift) muscle activity that these exercises with elements of instability or specific exercises calisthenics.

Objectives: Based on the analysis of electromyographic (EMG) data muscles are often characterized as normal or affected by a neuromuscular disease process. A clinical decision support system (CDSS) for the electrophysiological characterization of muscles by analyzing motor unit potentials (MUPs) was developed to assist physicians and researchers with the diagnosis, treatment & management of neuromuscular disorders and analyzed against criteria for use in a clinical setting. Methods: Quantitative MUP data extracted from various muscles from control subjects and patients from a number of clinics was used to compare the sensitivity, specificity, and accuracy of a number of different clinical decision support methods. The CDSS developed in this work known as AMC-PD has three components: MUP characterization using Pattern Discovery (PD), muscle characterization by taking the average of MUP characterizations and calibrated muscle characterizations. Results: The results demonstrated that AMC-PD achieved higher accuracy than conventional means and outlier analysis. Duration, thickness and number of turns were the most discriminative MUP features for characterizing the muscles studied in this work. Conclusions: AMC-PD achieved higher accuracy than conventional means and outlier analysis. Muscle characterization performed using AMC-PD can facilitate the determination of “possible”, “probable”, or “definite” levels of disease whereas the conventional means and outlier methods can only provide a dichotomous “normal” or “abnormal” decision. Therefore, AMC-PD can be directly used to support clinical decisions related to initial diagnosis as well as treatment and management over time. Decisions are based on facts and not impressions giving electromyography a more reliable role in the diagnosis, management, and treatment of neuromuscular disorders. AMC-PD based calibrated muscle characterization can help make electrophysiological examinations more accurate and objective.

Research suggests that playing violent video games increases the likelihood of aggression. However, less clear is how individual characteristics influence the mechanisms that lead to aggression. Using Anderson and Bushman’s (2002) General Aggression Model as a framework, the present study examined the independent and joint effects of individual differences and situational factors on affective and physiological reactivity to playing a violent video game. One hundred thirty-three participants completed self-report measures of trait aggression and violent video game exposure. They were randomly assigned to groups instructed to play a video game using either violent or nonviolent strategies while facial electromyography, heart rate, and electrodermal activity were measured. Positive and negative affect was assessed via self-report prior to and following video game play. It was hypothesized that trait aggression and level of past exposure to violent video games would be positively related to increases in physiological arousal and negative affect among participants in a violent, relative to a nonviolent, condition. Hierarchical regression analyses failed to detect a significant relationship between trait aggression and changes in heart rate, facial electromyography, or self-reported affect as a function of game condition. However, significant positive relationships were found between trait aggression and skin conductance, but only in the nonviolent condition. Analyses revealed that past exposure to violent video games was positively related to increased skin conductance among participants in the non-violent, but not the violent video game condition. Past exposure to violent video games was also positively related to increased heart rate, but this was among participants in the violent, but not the non-violent condition. Significant relationships between past exposure to violent video games and changes in facial electromyography and self-reported affect as a function of video game condition were not found. Findings are discussed in terms of how trait aggression and past exposure to violent video games influence arousal, and potentially, the likelihood of aggressive behavior.

Objectives: Based on the analysis of electromyographic (EMG) data muscles are often characterized as normal or affected by a neuromuscular disease process. A clinical decision support system (CDSS) for the electrophysiological characterization of muscles by analyzing motor unit potentials (MUPs) was developed to assist physicians and researchers with the diagnosis, treatment & management of neuromuscular disorders and analyzed against criteria for use in a clinical setting. Methods: Quantitative MUP data extracted from various muscles from control subjects and patients from a number of clinics was used to compare the sensitivity, specificity, and accuracy of a number of different clinical decision support methods. The CDSS developed in this work known as AMC-PD has three components: MUP characterization using Pattern Discovery (PD), muscle characterization by taking the average of MUP characterizations and calibrated muscle characterizations. Results: The results demonstrated that AMC-PD achieved higher accuracy than conventional means and outlier analysis. Duration, thickness and number of turns were the most discriminative MUP features for characterizing the muscles studied in this work. Conclusions: AMC-PD achieved higher accuracy than conventional means and outlier analysis. Muscle characterization performed using AMC-PD can facilitate the determination of “possible”, “probable”, or “definite” levels of disease whereas the conventional means and outlier methods can only provide a dichotomous “normal” or “abnormal” decision. Therefore, AMC-PD can be directly used to support clinical decisions related to initial diagnosis as well as treatment and management over time. Decisions are based on facts and not impressions giving electromyography a more reliable role in the diagnosis, management, and treatment of neuromuscular disorders. AMC-PD based calibrated muscle characterization can help make electrophysiological examinations more accurate and objective.

People use facial appearance to infer the social attributes of others. A primary indicator of facial attractiveness is prototypicality (the proximity of an object to its categorical central tendency); faces and objects closer to the central tendency are judged as more attractive. Perceptual fluency theory suggests that cognitive processing speed directly generates positive affect. This dissertation examined the relationships among attractiveness, prototypicality, and affective response in faces and non-face objects across adult and 8-year-old participants using a reaction time (RT) paradigm. RT predicted positive affect and disgust responses to facial stimuli. Of particular note are the series of complementary findings suggesting that reaction to unattractive faces may be both quantitatively (i.e., longer RT latencies) and qualitatively (i.e., judged to be less typical) different from high and medium attractive faces. These findings may help explain how appearance-based stereotypes are formed and maintained. / text

Introduction: Occupational drivers of terrain vehicles are exposed to several risk factors associated with musculoskeletal symptoms in the lower back as well as in the neck and upper limbs. Vibration has been suggested to be a main risk factor. These drivers are exposed to both whole-body vibration (WBV) and hand-arm vibration (HAV). Aim: This study establishes the association between driving terrain vehicles and musculoskeletal disorders (MSDs) in the neck and upper limbs as well as hand-arm vibration syndrome (HAVS). In addition, this study examines the effect on muscles in the neck and upper limbs of the type of vibration exposure that occurs in occupational driving of terrain vehicles. Methods and results: In Paper I, a cross-sectional questionnaire study on occupational drivers of terrain vehicles, increased Prevalence Odds Ratios (POR) were found for numbness, sensation of cold and white fingers (POR 1.5-3.9) and for MSDs in the neck (POR 2.1-3.9), shoulder (POR 1.8-2.6) and wrist (POR 1.7-2.6). For the shoulders, neck and elbow, there appears to be a pattern of increased odds with increasing exposure time. In Paper II, an experimental study on the trapezius muscle, which included 20 men and 17 women, the mean frequency of the electromyography signal (EMGMNF) decreased significantly more in a three minute sub-maximal contraction without vibration (-3.71Hz and -4.37Hz) compared to with induced vibration (-3.54Hz and -1.48Hz). In Paper III, a higher initial increase of the mean of the root-mean-square of the electromyography signal (EMGRMS) was seen in a three minute sub-maximal contraction with vibration exposure compared to without vibration (0.096% vs. 0.045%). There was a larger mean EMGMNF decrease for NV compared to V in the total three minutes, and a larger decrease also in the first time period was seen for the NV compared to V. A small gender effect was also noticed. In Paper IV, the combination of HAV and WBV was studied in laboratory settings and resulted in a higher trapezius EMGRMS compared to the HAV and WBV separately. Conclusion: Occupational drivers of terrain vehicles are likely to experience symptoms related to HAVS and musculoskeletal symptoms in the neck and upper limbs. Local vibration does not seem to have any negative acute effects on trapezius muscle fatigue. Vibration exposure seems to cause an initial increase in muscle activity in the trapezius that could be related to recruitment on new motor-units. A combination of HAV and WBV causes a larger muscular demand on the trapezius muscle.