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1.	Andersson, Nina, et al. (författare) Air transport of patients with intracranial air : computer model of pressure effects 2003 Ingår i: Aviation, Space and Environmental Medicine. - 0095-6562 .- 1943-4448. ; 74:2, s. 138-144 Tidskriftsartikel (refereegranskat)
2.	Broberg, Anders G, 1950, et al. (författare) Utveckling av bedömningsinstrument och stödinsatser för våldsutsatta barn 2015 Rapport (övrigt vetenskapligt/konstnärligt)
3.	Broberg, Anders, et al. (författare) Utveckling och prövning av metoder för att kartlägga våld i familjen 2015 Ingår i: iRiSk – UTVECKLING AV BEDÖMNINGSINSTRUMENT OCH STÖDINSATSER FÖR VÅLDSUTSATTA BARN. - Göteborg : University of Gothenburg. - 9789163785597 Bokkapitel (övrigt vetenskapligt/konstnärligt)
4.	Brändström, Helge, et al. (författare) Autonomic nerve system responses for normal and slow rewarmers after hand cold provocation : effects of long-term cold climate training 2013 Ingår i: International Archives of Occupational and Environmental Health. - : Springer-Verlag New York. - 0340-0131 .- 1432-1246. ; 86:3, s. 357-365 Tidskriftsartikel (refereegranskat)abstract PURPOSE: Differences among individuals concerning susceptibility to local cold injury following acute cold exposure may be related to function of the autonomic nervous system. We hypothesized that there are differences in heart rate variability (HRV) between individuals with normal or more pronounced vasoconstriction following cold exposure and that there is an adaptation related to prolonged cold exposure in autonomic nervous system response to cold stimuli.METHODS: Seventy-seven young men performed a cold provocation test, where HRV was recorded during cold hand immersion and recovery. Forty-three subjects were re-examined 15 months later, with many months of cold weather training between the tests. Subjects were analyzed as 'slow' and 'normal' rewarmers according to their thermographic rewarming pattern.RESULTS: For the 'pre-training' test, before cold climate exposure, normal rewarmers had higher power for low-frequency (P(LF)) and high-frequency (P(HF)) HRV components during the cold provocation test (ANOVA for groups: p = 0.04 and p = 0.005, respectively). There was an approximately 25 % higher P(HF) at the start in normal rewarmers, in the logarithmic scale. Low frequency-to-high frequency ratio (P(LF)/P(HF)) showed lower levels for normal rewarmers (ANOVA for groups: p = 0.04). During the 'post-training' cold provocation test, both groups lacked the marked increase in heart rate that occurred during cold exposure at the 'pre-training' setting. After cold acclimatization (post-training), normal rewarmers showed lower resting power values for the low-frequency and high-frequency HRV components. After winter training, the slow rewarmers showed reduced low-frequency power for some of the cold provocation measurements but not all (average total P(LF), ANOVA p = 0.05), which was not present before winter training.CONCLUSIONS: These HRV results support the conclusion that cold adaptation occurred in both groups. We conclude that further prospective study is needed to determine whether cold adaptation provides protection to subjects at higher risk for cold injury, that is, slow rewarmers.
5.	Brändström, Helge, et al. (författare) Hand cold recovery responses before and after 15 months of military training in a cold climate 2008 Ingår i: Aviation, Space and Environmental Medicine. - 0095-6562 .- 1943-4448. ; 79:9, s. 904-908 Tidskriftsartikel (refereegranskat)abstract INTRODUCTION: The ability of fingers to rapidly rewarm following cold exposure is a possible indicator of cold injury protection. We categorized the post-cooling hand-rewarming responses of men before and after participation in 15 mo of military training in a cold environment in northern Sweden to determine: 1) if the initial rewarming category was related to the occurrence of local cold injury during training; and 2) if cold training affected subsequent hand-rewarming responses. METHODS: Immersion of the dominant hand in 10 degrees C water for 10 min was performed pre-training on 77 men. Of those, 45 were available for successful post-training retests. Infrared thermography monitored the dorsal hand during 30 min of recovery. Rewarming was categorized as normal, moderate, or slow based on mean fingertip temperature at the end of 30 min of recovery (TFinger,30) and the percentage of time that fingertips were vasodilated (%VD). RESULTS: Cold injury occurrence during training was disproportionately higher in the slow rewarmers (four of the five injuries). Post-training, baseline fingertip temperatures and cold recovery variables increased significantly in moderate and slow rewarmers: TFinger30 increased from 21.9 +/- 4 to 30.4 +/- 6 degrees C (Moderate), and from 17.4 +/- 0 to 22.3 +/- 7 degrees C (Slow); %VD increased from 27.5 +/- 16 to 65.9 +/- 34% (Moderate), and from 0.7 +/- 2 to 31.7 +/- 44% (Slow). CONCLUSIONS: Results of the cold recovery test were related to the occurrence of local cold injury during long-term cold-weather training. Cold training itself improved baseline and cold recovery in moderate and slow rewarmers.
6.	Bäcklund, Tomas, et al. (författare) Novel, clinically applicable method to measure step-width during the swing phase of gait 2020 Ingår i: Physiological Measurement. - : Institute of Physics Publishing (IOPP). - 0967-3334 .- 1361-6579. ; 41:6 Tidskriftsartikel (refereegranskat)abstract Objective: Step-width during walking is an indicator of stability and balance in patients with neurological disorders, and development of objective tools to measure this clinically would be a great advantage. The aim of this study was to validate an in-house-developed gait analysis system (Striton), based on optical and inertial sensors and a novel method for stride detection, for measuring step-width during the swing phase of gait and temporal parameters.Approach: The step-width and stride-time measurements were validated in an experimental setup, against a 3D motion capture system and on an instrumented walkway. Further, test-retest and day-to-day variability were evaluated, and gait parameters were collected from 87 elderly persons (EP) and four individuals with idiopathic normal pressure hydrocephalus (iNPH) before/after surgery.Main results: Accuracy of the step-width measurement was high: in the experimental setup mean error was 0.08 +/- 0.25 cm (R = 1.00) and against the 3D motion capture system 0.04 +/- 1.12 cm (R = 0.98). Test-retest and day-to-day measurements were equal within +/- 0.5 cm. Mean difference in stride time was -0.003 +/- 0.008 s between Striton and the instrumented walkway. The Striton system was successfully applied in the clinical setting on individuals with iNPH, which had larger step-width (6.88 cm, n = 4) compared to EP (5.22 cm, n = 87).Significance: We conclude that Striton is a valid, reliable and wearable system for quantitative assessment of step-width and temporal parameters during gait. Initial measurements indicate that the newly defined step-width parameter differs between EP and patients with iNPH and before/after surgery. Thus, there is potential for clinical applicability in patients with reduced gait stability.
7.	Bäcklund, Tomas, 1958-, et al. (författare) O 035 - A novel method to measure step width during the swing phase of gait 2018 Ingår i: Gait & Posture. - : Elsevier. - 0966-6362 .- 1879-2219. ; 65, s. 71-72 Tidskriftsartikel (refereegranskat)
8.	Bäcklund, Tomas, 1958-, et al. (författare) Single sensor measurement of heel-height during the push-off phase of gait 2021 Ingår i: Physiological Measurement. - : Institute of Physics (IOP). - 0967-3334 .- 1361-6579. ; 42:10 Tidskriftsartikel (refereegranskat)abstract Objective: In healthy gait a forceful push-off is needed to get an efficient leg swing and propulsion, and a high heel lift makes a forceful push-off possible. The power of the push-off is decreased with increased age and in persons with impaired balance and gait. The aim of this study was to evaluate whether a wearable equipment (Striton) and algorithms to estimate vertical heel-height during gait from a single optical distance sensor is reliable and feasible for clinical applications.Approach: To assess heel-height with the Striton system an optical distance sensor was used to measure the distance to the floor along the shank. An algorithm was created to transform this measure to a vertical distance. The heel-height was validated in an experimental setup, against a 3D motion capture system (MCS), and test-retest and day-to-day tests were performed on 10 elderly persons. As a reference material 83 elderly persons were included, and heel-height was measured before and after surgery in four patients with the neurological disorder idiopathic normal pressure hydrocephalus (iNPH).Main results: In the experimental setup the accuracy was high with a maximum error of 2% at all distances, target colours and inclination angles, and the correlation to the MCS was R = 0.94. Test-retest and day-to-day tests were equal within ±1.2 cm. Mean heel-height of the elderly persons was 16.5 ± 0.6 cm and in the patients with iNPH heel-height was increased from 11.2 cm at baseline to 15.3 cm after surgery.Significance: Striton can reliably measure heel-height during gait, with low test-retest and day-to-day variability. The system was easy to attach, and simple to use, which makes it suitable for clinical applications.
9.	Du, Jiaying (författare) Real-time signal processing in MEMS sensor-based motion analysis systems 2019 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract This PhD thesis focuses on real-time signal processing for hardware-limited micro-electro-mechanical system (MEMS) sensor-based human motion analysis systems. The aim of the thesis is to improve the signal quality of MEMS gyroscopes and accelerometers by minimizing the effects of signal errors, considering the hardware limitations and the users' perception.MEMS sensors such as MEMS gyroscopes and MEMS accelerometers are important components in motion analysis systems. They are known for their small size, light weight, low power consumption, low cost, and high sensitivity. This makes them suitable for wearable systems for measuring body movements. The data can further be used as input for advanced human motion analyses. However, MEMS sensors are usually sensitive to environmental disturbances such as shock, vibration, and temperature change. A large portion of the MEMS sensor signals actually originate from error sources such as noise, offset, null drift and temperature drift, as well as integration drift. Signal processing is regarded as the major key solution to reduce these errors. For real-time signal processing, the algorithms need to be executed within a certain specified time limit. Two crucial factors have to be considered when designing real-time signal processing algorithms for wearable embedded sensor systems. One is the hardware limitations leading to a limited calculation capacity, and the other is the user perception of the delay caused by the signal processing.Within this thesis, a systematic review of different signal error reduction algorithms for MEMS gyroscope-based motion analysis systems for human motion analysis is presented. The users’ perceptions of the delay when using different computer input devices were investigated. 50 ms was found as an acceptable delay for the signal processing execution in a real-time motion analysis system. Real-time algorithms for noise reduction, offset/drift estimation and reduction, improvement of position accuracy and system stability considering the above mentioned requirements, are presented in this thesis. The algorithms include a simplified high-pass filter and low-pass filter, a LMS algorithm, a Kalman filter, a WFLC algorithm, two simple novel algorithms (a TWD method and a velocity drift estimation method), and a novel combination method KWT. Kalman filtering was found to be efficient to reduce the problem of temperature drift and the WFLC algorithm was found the most suitable method to reduce human physiological tremor and electrical noise. The TWD method resulted in a signal level around zero without interrupting the continuous movement signal. The combination method improved the static stability and the position accuracy considerably. The computational time for the execution of the algorithms were all perceived as acceptable by users and kept within the specified time limit for real-time performance. Implementations and experiments showed that these algorithms are feasible for establishing high signal quality and good system performance in previously developed systems, and also have the potential to be used in similar systems.
10.	Elmgren Frykberg, Gunilla, 1957-, et al. (författare) How many trials are needed in kinematic analysis of reach-to-grasp? : A study of the drinking task in persons with stroke and non-disabled controls 2021 Ingår i: Journal of NeuroEngineering and Rehabilitation. - : BioMed Central (BMC). - 1743-0003. ; 18:1 Tidskriftsartikel (refereegranskat)abstract Background: Kinematic analysis of the 3D reach-to-grasp drinking task is recommended in stroke rehabilitation research. The number of trials required to reach performance stability, as an important aspect of reliability, has not been investigated for this task. Thus, the aims of this study were to determine the number of trials needed for the drinking task to reach within-session performance stability and to investigate trends in performance over a set of trials in non-disabled people and in a sample of individuals with chronic stroke. In addition, the between-sessions test–retest reliability in persons with stroke was established.Methods: The drinking task was performed at least 10 times, following a standardized protocol, in 44 non-disabled and 8 post-stroke individuals. A marker-based motion capture system registered arm and trunk movements during 5 pre-defined phases of the drinking task. Intra class correlation statistics were used to determine the number of trials needed to reach performance stability as well as to establish test–retest reliability. Systematic within-session trends over multiple trials were analyzed with a paired t-test.Results: For most of the kinematic variables 2 to 3 trials were needed to reach good performance stability in both investigated groups. More trials were needed for movement times in reaching and returning phase, movement smoothness, time to peak velocity and inter-joint-coordination. A small but significant trend of improvement in movement time over multiple trials was demonstrated in the non-disabled group, but not in the stroke group. A mean of 3 trials was sufficient to reach good to excellent test–retest reliability for most of the kinematic variables in the stroke sample.Conclusions: This is the first study that determines the number of trials needed for good performance stability (non-disabled and stroke) and test–retest reliability (stroke) for temporal, endpoint and angular metrics of the drinking task. For most kinematic variables, 3–5 trials are sufficient to reach good reliability. This knowledge can be used to guide future kinematic studies.
11.	Ertzgaard, Per, et al. (författare) A new way of assessing arm function in activity using kinematic Exposure Variation Analysis and portable inertial sensors - A validity study 2016 Ingår i: Manual Therapy. - : Elsevier BV. - 1356-689X .- 1532-2769. ; 21, s. 241-249 Tidskriftsartikel (refereegranskat)abstract Portable motion systems based on inertial motion sensors are promising methods, with the advantage compared to optoelectronic cameras of not being confined to a laboratory setting. A challenge is to develop relevant outcome measures for clinical use. The aim of this study was to characterize elbow and shoulder motion during functional tasks, using portable motion sensors and a modified Exposure Variation Analysis (EVA) and evaluate system accuracy with optoelectronic cameras. Ten healthy volunteers and one participant with sequel after stroke performed standardised functional arm tasks. Motion was registered simultaneously with a custom developed motion sensor system, including gyroscopes and accelerometers, and an optoelectronic camera system. The EVA was applied on elbow and shoulder joints, and angular and angular velocity EVA plots was calculated. The EVA showed characteristic patterns for each arm task in the healthy controls and a distinct difference between the affected and unaffected arm in the participant with sequel after stroke. The accuracy of the portable system was high with a systematic error ranging between -1.2 degrees and 2.0 degrees. The error was direction specific due to a drift component along the gravity vector. Portable motion sensor systems have high potential as clinical tools for evaluation of arm function. EVA effectively illustrates joint angle and joint angle velocity patterns that may capture deficiencies in arm function and movement quality. Next step will be to manage system drift by including magnetometers, to further develop clinically relevant outcome variables and apply this for relevant patient groups.
12.	Ertzgaard, Per, 1958- (författare) Studies on Spasticity from an Interventional Perspective 2018 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract This thesis focuses on interventional aspects of spasticity, but has a very holistic approach, grounded in the specialty of Rehabilitation medicine. This means capturing the effects of spasticity, on such a complex biological system as the human being, living in a psychosocial context affecting the situation. When evaluating spasticity there are a number of levels of evidence. The first of course, understanding what we mean with spasticity, where there unfortunately is no consensus. The second level is to study if our treatments affect spasticity in a positive direction. The third is to grasp if a decrease in spasticity improve or normalize patient’s movement patterns. The fourth level investigates if improvement in movement patterns improve patient’s ability to perform activities; and the fifth level, comprising whether this intervention improves life satisfaction. Finally, on a societal level, we wish to investigate whether the improvement in life satisfaction or health related quality of life would motivate society to fund the intervention.Paper I on Goal Attainment Scaling pointed out necessary aspects to consider when using this instrument. This relates, among other things, to the need of learning (“the art of”) goal setting and deciding the purpose of the measurements. Research and clinical use puts different demands on the instrument, for the latter time-efficiency and simplicity to use being most important. For research, it is important to be able to register deterioration, and this can be achieved using the 6-step version.In paper II, concerning validation of the portable motion system, we showed this system to be valid for short-term measurements and that the use of Exposure Variation Analysis (EVA) seems to be a valuable tool for graphically elucidating different movements. The equipment needs further development in handling long-term measurements (which is effectuated), and norms for normal movements in different activities has to be produced. The discriminative value of EVA needs confirmation in coming studies. For the future, there is the intriguing possibility of long-term measurements in patients’ every-day life, thereby getting objective measures on how our patients use their abilities, thus capturing the difference between what you can do and what you actually do.The results from paper III demonstrated a large inequality in Sweden regarding the accessibility of BoNT-A treatment for spasticity. We could also show that treatment with BoNT-A is sound from a health-economic perspective, accounting for the uncertainty of data via the sensitivity analysis. For the future, we need to explore if this inequality also exists for other modes of spasticity treatments, e.g. multidisciplinary spasticity treatment and ITB pumps, and in other countries.In paper IV evaluating multifocal TES, the results could not confirm efficacy with the treatment according to the protocol of the manufacturer. The results have to be interpreted with care, as low compliance and frequent adverse events made deduction not captured in the RCT study. Further studies are needed in a number of areas, e.g. what is the optimal stimulation frequency, what patients can gain from the treatment and how should adjunct treatment be organized.In this thesis, I have had the privilege to explore different methods of evaluating spasticity interventions from a multimodal perspective as a starting point in an effort to understand more of this intriguing phenomenon. Some of the research questions above are already in the “pipeline” for coming studies; others are to be planned by our research group and others.
13.	Escala-Garcia, Maria, et al. (författare) A network analysis to identify mediators of germline-driven differences in breast cancer prognosis 2020 Ingår i: Nature Communications. - : NATURE PUBLISHING GROUP. - 2041-1723. ; 11:1 Tidskriftsartikel (refereegranskat)abstract Identifying the underlying genetic drivers of the heritability of breast cancer prognosis remains elusive. We adapt a network-based approach to handle underpowered complex datasets to provide new insights into the potential function of germline variants in breast cancer prognosis. This network-based analysis studies similar to 7.3 million variants in 84,457 breast cancer patients in relation to breast cancer survival and confirms the results on 12,381 independent patients. Aggregating the prognostic effects of genetic variants across multiple genes, we identify four gene modules associated with survival in estrogen receptor (ER)-negative and one in ER-positive disease. The modules show biological enrichment for cancer-related processes such as G-alpha signaling, circadian clock, angiogenesis, and Rho-GTPases in apoptosis.
14.	Fjellman-Wiklund, Anncristine, et al. (författare) EMG trapezius muscle activity pattern in string players : Part II - Influences of basic body awareness therapy on the violin playing technique 2004 Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 0169-8141 .- 1872-8219. ; 33:4, s. 357-367 Tidskriftsartikel (refereegranskat)
15.	Fjellman-Wiklund, Anncristine, et al. (författare) EMG trapezius muscle activity pattern in string players : Part I - Is there variability in the playing technique? 2004 Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 0169-8141 .- 1872-8219. ; 33:4, s. 347-356 Tidskriftsartikel (refereegranskat)
16.	Fredrik, Öhberg, et al. (författare) Gait analysis using a portable motion sensor system : measurements in subjects with hip implant as compared with healthy controls 2013 Ingår i: Gait & Posture. - : Elsevier BV. - 0966-6362 .- 1879-2219. ; 38:suppl 1, s. 99-100 Tidskriftsartikel (refereegranskat)abstract Introduction: There is an increase of age related diseases such as hip joint arthritis, something that is often treated with hip replacement surgery. The aim of this study was to quantify movement function and its effect on quality of life in persons treated with hip implant, in comparison to matched asymptomatic controls.Patients/Materials and Methods: This is an ongoing study, and so far, 2 asymptomatic subjects (CTRL, age 50 ± 13 years, BMI 23 ± 2), and 4 subjects with hip implant (HIP, age 51 ± 15 years, BMI 25 ± 3), have been analyzed. The HIP group received their implant 2.6 ± 1.1 years ago and finished their rehabilitation 1.6 ± 1.1 years ago. Hip dysfunction and Osteoarthritis Outcome Score (HOOS) was used to assess the subject's hip function and its associated problems. A functional calibration (flexion/abduction movements) was done and each subject then performed 5 repetitions of gait (approx. 25 left/right gait cycles). Movement was registered with a custom-developed portable motion sensor system, where each sensor consisted of a tri-axial accelerometer and gyroscope. Sensors were placed on pelvis and each thigh and shank. Further calculations were done in MATLAB (v7.12 R2011a, Mathworks). Cosine rotation matrices were extracted by functional sensor-to- segment-calibration and sensor fusion [1], and hip and knee angles were obtained as Euler angles.Results: Preliminary results indicated larger range in hip rotation and smaller range of knee flexion during gait in HIP group than in the CTRL group (Fig. 1). HOOS profile (Fig. 2) indicated that hip function during sports (SP) and the general quality of life (QOL) were lower in the HIP group.Fig. 1. Mean and SD of hip and knee angle over 15 gait cycles in one HIP subject (blue) as compared with the CTRL group (black). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)Figure optionsFig. 2. HOOS profiles in HIP (blue square) and CTRL group (black). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)Figure optionsDiscussion and conclusions: Motion patterns during gait seemed to be negatively affected in subjects with hip implant, even after the rehabilitation program was completed and even though the HOOS profiles indicated a relative good hip function.Reference[1]J. Favre, B.M. Jolles, O. Siegrist, K. AminianQuaternion-based fusion of gyroscopes and accelerometers to improve 3D angle measurement
17.	Frykberg, G., et al. (författare) The “Arm Posture Score” for assessment of arm swing during gait : Evaluation of additional rotational components and different gait speeds 2012 Konferensbidrag (övrigt vetenskapligt/konstnärligt)
18.	Grip, Helena, et al. (författare) A new approach to measure functional stability of the knee based on changes in knee axis orientation 2013 Ingår i: Journal of Biomechanics. - Oxford : Elsevier. - 0021-9290 .- 1873-2380. ; 46:5, s. 855-862 Tidskriftsartikel (refereegranskat)abstract There is a lack of measures that quantify functional knee stability, which is of particular relevance in knee rehabilitation. Therefore, the aim of this study was to investigate the usefulness of knee finite helical axis (FHA) variables in 33 healthy subjects during two different functional tasks; One leg side hop (SH) and Two Leg Squat (TLS), and to investigate correlations of these variables with laxity. Laxity was assessed with a KT-1000 arthrometer and the Beighton Hypermobility Score. Movements were registered with an optical motion capture system. Knee rotation and translation were defined by a six degree of freedom segment model. FHA was calculated for finite steps of 20 degrees knee flexion, based on error simulations. We computed the FHA inclination, the translation along FHA and an FHA Direction Index quantifying directional changes. All variables were repeatable (average ICCs similar to 0.97 during TLS and similar to 0.83 during SH). The lower functional knee stability in SH was reflected by a significantly higher FHA Direction Index and a larger medio-lateral FHA inclination compared to those in TLS. The superior-inferior inclination was smaller during Landing in SH compared to Take-Off and TLS. Translation along FHA was generally small as expected in healthy subjects. Beighton Hypermobility Score and KT-1000 values had weak but significant correlations with FHA Direction Index and FHA translation, which show that laxity influences the functional knee stability. We conclude that FHA measures were sensitive enough to discriminate between SH and TLS. The next step is to investigate the usability of these measures in subjects with knee injury.
19.	Grip, Helena, 1973- (författare) Biomechanical assessment of head and neck movements in neck pain using 3D movement analysis 2008 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Three-dimensional movement analysis was used to evaluate head and neck movement in patients with neck pain and matched controls. The aims were to further develop biomechanical models of head and neck kinematics, to investigate differences between subjects with non-specific neck pain and whiplash associated disorders (WAD), and to evaluate the potential of objective movement analysis as a decision support during diagnosis and follow-up of patients with neck pain. Fast, repetitive head movements (flexion, extension, rotation to the side) were studied in a group of 59 subjects with WAD and 56 controls. A back propagation artificial neural network classified vectors of collected movement variables from each individual according to group membership with a predictivity of 89%. The helical axis for head movement were analyzed in two groups of neck pain patients (21 with non-specific neck pain and 22 with WAD) and 24 matched controls. A moving time window with a cut-off angle of 4° was used to calculate finite helical axes. The centre of rotation of the finite axes (CR) was derived as the 3D intersection point of the finite axes. A downward migration of the axis during flexion/extension and a change of axis direction towards the end of the movements were observed. CR was at its most superior position during side rotations and at its most inferior during ball catching. This could relate to that side rotation was mainly done in the upper spine, while all cervical vertebrae were recruited to stabilize the head in the more complex catching task. Changes in movement strategy were observed in the neck pain groups: Neck pain subjects had lower mean velocities and ranges of movements as compared with controls during ball catching, which could relate to a stiffer body position in neck pain patients in order to stabilize the neck. In addition, the WAD group had a displaced axis position during head repositioning after flexion, while CR was displaced during fast side rotations in the non-specific neck pain group. Pain intensity correlated with axis and CR position, and may be one reason for the movement strategy changes. Increased amount of irregularities in the trajectory of the axis was found in the WAD group during head repositioning, fast repetitive head movements and catching. This together with an increased constant repositioning error during repositioning after flexion indicated motor control disturbances. A higher group standard deviation in neck pain groups indicated heterogeneity among subjects in this disturbance. Wireless motion sensors and electro-oculography was used simultaneously, as an initial step towards a portable system and towards a method to quantify head-eye co-ordination deficits in individuals with WAD. Twenty asymptomatic control subjects and six WAD subjects with eye disturbances (e.g. dizziness and double vision) were studied. The trial-to-trial repeatability was moderate to high for all evaluated variables (single intraclass correlation coefficients >0.4 in 28 of 32 variables). The WAD subjects demonstrated decreased head velocity, decreased range of head movement during gaze fixation and lowered head stability during head-eye co-ordination as possible deficits. In conclusion, kinematical analyses have a potential to be used as a support for physicians and physiotherapists for diagnosis and follow-up of neck pain patients. Specifically, the helical axis method gives information about how the movement is performed. However, a flexible motion capture system (for example based on wireless motion sensors) is needed. Combined analysis of several variables is preferable, as patients with different neck pain disorders seem to be a heterogeneous group.
20.	Grip, Helena, et al. (författare) Cervical helical axis characteristics and its center of rotation during active head and upper arm movements-comparisons of whiplash-associated disorders, non-specific neck pain and asymptomatic individuals. 2008 Ingår i: Journal of Biomechanics. - : Springer. - 0021-9290 .- 1873-2380. ; 41:13, s. 2799-2805 Tidskriftsartikel (refereegranskat)abstract The helical axis model can be used to describe translation and rotation of spine segments. The aim of this study was to investigate the cervical helical axis and its center of rotation during fast head movements (side rotation and flexion/extension) and ball catching in patients with non-specific neck pain or pain due to whiplash injury as compared with matched controls. The aim was also to investigate correlations with neck pain intensity. A finite helical axis model with a time-varying window was used. The intersection point of the axis during different movement conditions was calculated. A repeated-measures ANOVA model was used to investigate the cervical helical axis and its rotation center for consecutive levels of 15 degrees during head movement. Irregularities in axis movement were derived using a zero-crossing approach. In addition, head, arm and upper body range of motion and velocity were observed. A general increase of axis irregularity that correlated to pain intensity was observed in the whiplash group. The rotation center was superiorly displaced in the non-specific neck pain group during side rotation, with the same tendency for the whiplash group. During ball catching, an anterior displacement (and a tendency to an inferior displacement) of the center of rotation and slower and more restricted upper body movements implied a changed movement strategy in neck pain patients, possibly as an attempt to stabilize the cervical spine during head movement.
21.	Grip, Helena, et al. (författare) Cervical helical axis characteristics and its centre of rotation during active head movements : comparisons of whiplash-associated disorders, non-specific neck pain and asymptomatic individuals 2008 Ingår i: Journal of Biomechanics. - : Elsevier. - 0021-9290 .- 1873-2380. ; 41:13, s. 2799-2805 Tidskriftsartikel (refereegranskat)abstract The helical axis model can be used to describe translation and rotation of spine segments. The aim of this study was to investigate the cervical helical axis and its center of rotation during fast head movements (side rotation and flexion/extension) and ball catching in patients with non-specific neck pain or pain due to whiplash injury as compared with matched controls. The aim was also to investigate correlations with neck pain intensity. A finite helical axis model with a time-varying window was used. The intersection point of the axis during different movement conditions was calculated. A repeated-measures ANOVA model was used to investigate the cervical helical axis and its rotation center for consecutive levels of 15° during head movement. Irregularities in axis movement were derived using a zero-crossing approach. In addition, head, arm and upper body range of motion and velocity were observed. A general increase of axis irregularity that correlated to pain intensity was observed in the whiplash group. The rotation center was superiorly displaced in the non-specific neck pain group during side rotation, with the same tendency for the whiplash group. During ball catching, an anterior displacement (and a tendency to an inferior displacement) of the center of rotation and slower and more restricted upper body movements implied a changed movement strategy in neck pain patients, possibly as an attempt to stabilize the cervical spine during head movement.
22.	Grip, Helena, et al. (författare) Classification of Neck Movement Patterns Related to Whiplash-Associated Disorders Using Neural Networks 2003 Ingår i: IEEE transactions on information technology in biomedicine. - : IEEE. - 1089-7771 .- 1558-0032. ; 7:4, s. 412-418 Tidskriftsartikel (refereegranskat)abstract This paper presents a new method for classification of neck movement patterns related to Whiplash-associated disorders (WAD) using a resilient backpropagation neural network (BPNN). WAD are a common diagnosis after neck trauma, typically caused by rear-end car accidents. Since physical injuries seldom are found with present imaging techniques, the diagnosis can be difficult to make. The active range of the neck is often visually inspected in patients with neck pain, but this is a subjective measure, and a more objective decision support system, that gives a reliable and more detailed analysis of neck movement pattern, is needed. The objective of this study was to evaluate the predictive ability of a BPNN, using neck movement variables as input. Three-dimensional (3-D) neck movement data from 59 subjects with WAD and 56 control subjects were collected with a ProReflex system. Rotation angle and angle velocity were calculated using the instantaneous helical axis method and motion variables were extracted. A principal component analysis was performed in order to reduce data and improve the BPNN performance. BPNNs with six hidden nodes had a predictivity of 0.89, a sensitivity of 0.90 and a specificity of 0.88, which are very promising results. This shows that neck movement analysis combined with a neural network could build the basis of a decision support system for classifying suspected WAD, even though further evaluation of the method is needed.
23.	Grip, Helena, et al. (författare) Detection of EGFP Fluorescence : A Low-Cost Device 2003 Ingår i: IFMBE Proceedings WC2003 "World Congress on Medical Physics and Biomedical Engineering", Vol. 4, 2003, Sydney, Australia. Konferensbidrag (refereegranskat)
24.	Grip, Helena, et al. (författare) Does the Femoral Head Size in Hip Arthroplasty Influence Lower Body Movements during Squats, Gait and Stair Walking? : A Clinical Pilot Study Based on Wearable Motion Sensors 2019 Ingår i: Sensors. - : MDPI. - 1424-8220. ; 19:14 Tidskriftsartikel (refereegranskat)abstract A hip prosthesis design with larger femoral head size may improve functional outcomes compared to the conventional total hip arthroplasty (THA) design. Our aim was to compare the range of motion (RoM) in lower body joints during squats, gait and stair walking using a wearable movement analysis system based on inertial measurement units (IMUs) in three age-matched male groups: 6 males with a conventional THA (THAC), 9 with a large femoral head (LFH) design, and 8 hip- and knee-asymptomatic controls (CTRL). We hypothesized that the LFH design would allow a greater hip RoM, providing movement patterns more like CTRL, and a larger side difference in hip RoM in THAC when compared to LFH and controls. IMUs were attached to the pelvis, thighs and shanks during five trials of squats, gait, and stair ascending/descending performed at self-selected speed. THAC and LFH participants completed the Hip dysfunction and Osteoarthritis Outcome Score (HOOS). The results showed a larger hip RoM during squats in LFH compared to THAC. Side differences in LFH and THAC groups (operated vs. non-operated side) indicated that movement function was not fully recovered in either group, further corroborated by non-maximal mean HOOS scores (LFH: 83 +/- 13, THAC: 84 +/- 19 groups, vs. normal function 100). The IMU system may have the potential to enhance clinical movement evaluations as an adjunct to clinical scales.
25.	Grip, Helena, 1973-, et al. (författare) Dynamic knee stability as estimated by finite helical axis methods during drop landing twenty years after anterior cruciate ligament injury 2015 Ingår i: Journal of Biomechanics. - : Elsevier BV. - 0021-9290 .- 1873-2380. ; 48:10, s. 1906-1914 Tidskriftsartikel (refereegranskat)abstract Finite helical axis (FHA) measures of the knee joint during weight-bearing tasks may capture dynamic knee stability following Anterior Cruciate Ligament (ACL) injury. The aim was to investigate dynamic knee stability during two-leg squat (TLS) and one-leg side hop (SH) in a long-term follow-up of ACL injury, and to examine correlations with knee laxity (KT-1000), osteoarthritis (OA, Kellgren–Lawrence) and knee function (Lysholm score). Participants were injured 17–28 years ago and then treated with surgery (n=33, ACLR) or physiotherapy only (n=37, ACLPT) and healthy-knee controls (n=33) were tested. Movements were registered with an optical motion capture system. We computed three FHA inclination angles, its' Anterior–Posterior (A–P) position, and an index quantifying directional changes (DI), during stepwise knee flexion intervals of ∼15°. Injured knees were less stable compared to healthy controls' and to contralateral non-injured knees, regardless of treatment: the A–P intersection was more anterior (indicating a more anterior positioning of tibia relative to femur) positively correlating with high laxity/low knee function, and during SH, the FHA was more inclined relative to the flexion–extension axis, possibly due to reduced rotational stability. During the TLS, A–P intersection was more anterior in the non-injured knee than the injured, and DI was higher, probably related to higher load on the non-injured knee. ACLR had less anterior A–P intersection than ACLPT, suggesting that surgery enhanced stability, although rotational stability may remain reduced. More anterior A–P intersection and greater inclination between the FHA and the knee flexion–extension axis best revealed reduced dynamic stability ∼23 years post-injury.
26.	Grip, Helena, et al. (författare) Dynamic knee stability estimated by finite helical axis methods during functional performance approximately twenty years after anterior cruciate ligament injury 2015 Ingår i: Journal of Biomechanics. - : Elsevier. - 0021-9290 .- 1873-2380. ; 48:10, s. 1906-1914 Tidskriftsartikel (refereegranskat)abstract Finite helical axis (FHA) measures of the knee joint during weight-bearing tasks may capture dynamic knee stability following Anterior Cruciate Ligament (ACL) injury. The aim was to investigate dynamic knee stability during two-leg squat (TLS) and one-leg side hop (SH) in a long-term follow-up of ACL injury, and to examine correlations with knee laxity (KT-1000), osteoarthritis (OA, Kellgren-Lawrence) and knee function (Lysholm score). Participants were injured 17-28 years ago and then treated with surgery (n=33, ACL(R)) or physiotherapy only (n=37, ACL(PT)) and healthy-knee controls (n=33) were tested. Movements were registered with an optical motion capture system. We computed three FHA inclination angles, its' Anterior-Posterior (A-P) position, and an index quantifying directional changes (DI), during stepwise knee flexion intervals of similar to 15 degrees. Injured knees were less stable compared to healthy controls' and to contralateral non-injured knees, regardless of treatment: the A-P intersection was more anterior (indicating a more anterior positioning of tibia relative to femur) positively correlating with high laxity/low knee function, and during SH, the FHA was more inclined relative to the flexion-extension axis, possibly due to reduced rotational stability. During the TLS, A-P intersection was more anterior in the non-injured knee than the injured, and DI was higher, probably related to higher load on the non-injured knee. ACL(R) had less anterior A-P intersection than ACL(PT), suggesting that surgery enhanced stability, although rotational stability may remain reduced. More anterior A-P intersection and greater inclination between the FHA and the knee flexion-extension axis best revealed reduced dynamic stability similar to 23 years post-injury.
27.	Grip, Helena, et al. (författare) Head eye co-ordination using simultaneous measurement of eye in head and head in space movements : potential for use in subjects with a whiplash injury. 2009 Ingår i: Journal of clinical monitoring and computing. - : Springer. - 1387-1307 .- 1573-2614. ; 23:1, s. 31-40 Tidskriftsartikel (refereegranskat)abstract Objective. Describe reproducibility of a measurement method to investigate deficits in eye-head co-ordination. Methods. Combined recordings of head and eye rotation using wireless motion sensors and electro-oculography (EOG) were used as an initial step towards a method to quantify eye-head co-ordination deficits. Head rotation to the side during gaze fixation and sequential head and eye movements were studied on 20 asymptomatic control subjects and six subjects with chronic whiplash disorders. All included whiplash subjects reported eye disturbances according to a vision symptom questionnaire. Results. The trial-to-trial reproducibility was moderate to high for 24 of 28 variables (Intraclass Correlation Coefficient 0.44 to 0.87). Velocity gain (ratio of eye and head velocities) was on average close to unity in both groups. Head stability was high in control subjects, while three of six whiplash subjects demonstrated head instability during eye movement. Whiplash subjects also demonstrated a decreased range of head movement during gaze fixation and lower head velocities as compared with the asymptomatics. Conclusions. The method of combined head and eye motion appears to give accurate, repeatable measurements. Case studies of whiplash subjects indicated deficits in head eye co-ordination. The method could be useful in further clinical research into eye and head movement in those with neck disorders.
28.	Grip, Helena, et al. (författare) Individual finger movement control and association to brain activity in healthy participants 2021 Konferensbidrag (refereegranskat)
29.	Grip, Helena, et al. (författare) Kinematic analyses including finite helical axes of drop jump landings demonstrate decreased knee control long after anterior cruciate ligament injury 2019 Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 14:10 Tidskriftsartikel (refereegranskat)abstract The purpose was to evaluate the dynamic knee control during a drop jump test following injury of the anterior cruciate ligament injury (ACL) using finite helical axes. Persons injured 17-28 years ago, treated with either physiotherapy (ACLPT, n = 23) or reconstruction and physiotherapy (ACLR, n = 28) and asymptomatic controls (CTRL, n = 22) performed a drop jump test, while kinematics were registered by motion capture. We analysed the Preparation phase (from maximal knee extension during flight until 50 ms post-touchdown) followed by an Action phase (until maximal knee flexion post-touchdown). Range of knee motion (RoM), and the length of each phase (Duration) were computed. The finite knee helical axis was analysed for momentary intervals of ~15° of knee motion by its intersection (ΔAP position) and inclination (ΔAP Inclination) with the knee's Anterior-Posterior (AP) axis. Static knee laxity (KT100) and self-reported knee function (Lysholm score) were also assessed. The results showed that both phases were shorter for the ACL groups compared to controls (CTRL-ACLR: Duration 35±8 ms, p = 0.000, CTRL-ACLPT: 33±9 ms, p = 0.000) and involved less knee flexion (CTRL-ACLR: RoM 6.6±1.9°, p = 0.002, CTRL-ACLR: 7.5 ±2.0°, p = 0.001). Low RoM and Duration correlated significantly with worse knee function according to Lysholm and higher knee laxity according to KT-1000. Three finite helical axes were analysed. The ΔAP position for the first axis was most anterior in ACLPT compared to ACLR (ΔAP position -1, ACLPT-ACLR: 13±3 mm, p = 0.004), with correlations to KT-1000 (rho 0.316, p = 0.008), while the ΔAP inclination for the third axis was smaller in the ACLPT group compared to controls (ΔAP inclination -3 ACLPT-CTRL: -13±5°, p = 0.004) and showed a significant side difference in ACL injured groups during Action (Injured-Non-injured: 8±2.7°, p = 0.006). Small ΔAP inclination -3 correlated with low Lysholm (rho 0.391, p = 0.002) and high KT-1000 (rho -0.450, p = 0.001). Conclusions Compensatory movement strategies seem to be used to protect the injured knee during landing. A decreased ΔAP inclination in injured knees during Action suggests that the dynamic knee control may remain compromised even long after injury.
30.	Grip, Helena, 1973-, et al. (författare) Quantifying motor control of the knee during side hops - healthy subjects and subjects ~20 years after anterior cruciate ligament injury 2012 Konferensbidrag (övrigt vetenskapligt/konstnärligt)
31.	Grip, Helena, et al. (författare) Three dimensional kinematic analyses of finger movement control and association to brain activity responses : A pilot study on healthy individuals 2017 Ingår i: Gait & Posture. - : Elsevier BV. - 0966-6362 .- 1879-2219. ; 57, s. 355- Tidskriftsartikel (refereegranskat)abstract Introduction: An increased knowledge of how the brain control finger movements give us keys to understand the recovery of motor function after a brain injury. This knowledge is crucial for the development of reliable and valid assessment methods in the clinical evaluation of hand function.Research question: How are individual finger movements represented in the brain? Investigating the associations between kinematics and brain activity responses in healthy individuals.Methods: Keeping the others still. Finger movements were performed lying in the MR scanner in order to register brain activity response during the task. Optoelectronic cameras simultaneously monitored the positions of reflective markers affixed to each finger. The marker position data were used to calculate each finger's movement frequency (MF), movement independence (“Individuation Index”, II), stationary ability (Stationarity Index, SI)[1][1]. fMRI data was analyzed by contrasting the finger movements against its active rest.Results: Preliminary analyses showed that (1) the finger movements primarily activate sensorimotor areas in the contralateral hemisphere (Fig. 1A), (2) that use of kinematic parameters in the fMRI analyses improved spatial specificity and (3) II engage a number of cortical areas, while MF engage fewer areas (Fig. 1B–D). Further analyses will further explore activations maps for each individual finger.Discussion: The inclusion of movement parameters in the fMRI analyses improves the specificity in the derived activation map, increasing the interpretability of the neural correlates of movement control. This advancement carries the promise for the development of better assessment methods of the recovery of function post-stroke with usability in rehabilitation practices.
32.	Grip, Helena, et al. (författare) Validity and reliability of wearable motion sensors for clinical assessment of shoulder function in brachial plexus birth injury 2022 Ingår i: Sensors. - : MDPI. - 1424-8220. ; 22:23 Tidskriftsartikel (refereegranskat)abstract The modified Mallet scale (MMS) is commonly used to grade shoulder function in brachial plexus birth injury (BPBI) but has limited sensitivity and cannot grade scapulothoracic and glenohumeral mobility. This study aims to evaluate if the addition of a wearable inertial movement unit (IMU) system could improve clinical assessment based on MMS. The system validity was analyzed with simultaneous measurements with the IMU system and an optical camera system in three asymptomatic individuals. Test–retest and interrater reliability were analyzed in nine asymptomatic individuals and six BPBI patients. IMUs were placed on the upper arm, forearm, scapula, and thorax. Peak angles, range of motion, and average joint angular speed in the shoulder, scapulothoracic, glenohumeral, and elbow joints were analyzed during mobility assessments and MMS tasks. In the validity tests, clusters of reflective markers were placed on the sensors. The validity was high with an error standard deviation below 3.6°. Intraclass correlation coefficients showed that 90.3% of the 69 outcome scores showed good-to-excellent test–retest reliability, and 41% of the scores gave significant differences between BPBI patients and controls with good-to-excellent test–retest reliability. The interrater reliability was moderate to excellent, implying that standardization is important if the patient is followed-up longitudinally.
33.	Grip, Helena, et al. (författare) Variations in the axis of motion during head repositioning : a comparison of subjects with whiplash-associated disorders or non-specific neck pain and healthy controls 2007 Ingår i: Clinical Biomechanics. - : Elsevier BV. - 0268-0033 .- 1879-1271. ; 22:8, s. 865-873 Tidskriftsartikel (refereegranskat)
34.	Hellström, Per Anders Rickard, 1975- (författare) Wearable Pedobarography System for Monitoring of Walk Related Parameters 2019 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Health care costs have increased over the last decades due to an ageing population. Therefore, research in personal health monitoring (PHM) has increased in response to this. PHM has advantages such as mobility (monitoring of health at work or at home), early detection of health problems enabling preventive health measures and a reduction of health care cost. Human motion analysis, using for example pedobarography (PBG), is an important subcategory of PHM. PBG is used to study the force fields acting between the plantar surface of the foot and a supporting surface. Gait and posture analysis, prosthetics evaluation and monitoring of recovery from injury or disease are examples of PBG applications. Portable PBG can be performed using force sensing resistors built into the insole inside the shoe. In accordance with this, the research aim for this thesis is to design, build and evaluate a wireless wearable measurement system based on PBG for monitoring of walk related parameters. Monitoring of carried weight and walking speed were chosen as the applications for validation of the system. Motivations for choosing these applications are that there is a lack of a wearable system for monitoring of weight while walking and a possible combination with accelerometers to improve the estimation of walking speed. Both walking speed and weight are important factors for estimating energy expenditure. A portable system, that estimates weight while walking, enables monitoring of heavy working conditions.The main research contributions include design of a PBG measurement system with a sensor implementation resulting in good sensor durability, several novel methods for weight estimation during walk and a novel method for analysing walking intensity and relating it to walking speed. The research results show that the new PBG system, in combination with the novel analysing methods, are suitable for use in wearable systems for monitoring of health related walk parameters.
35.	Hollestelle, Antoinette, et al. (författare) No clinical utility of KRAS variant rs61764370 for ovarian or breast cancer 2016 Ingår i: Gynecologic Oncology. - : Elsevier BV. - 0090-8258 .- 1095-6859. ; 141:2, s. 386-401 Tidskriftsartikel (refereegranskat)abstract Objective Clinical genetic testing is commercially available for rs61764370, an inherited variant residing in a KRAS 3′ UTR microRNA binding site, based on suggested associations with increased ovarian and breast cancer risk as well as with survival time. However, prior studies, emphasizing particular subgroups, were relatively small. Therefore, we comprehensively evaluated ovarian and breast cancer risks as well as clinical outcome associated with rs61764370. Methods Centralized genotyping and analysis were performed for 140,012 women enrolled in the Ovarian Cancer Association Consortium (15,357 ovarian cancer patients; 30,816 controls), the Breast Cancer Association Consortium (33,530 breast cancer patients; 37,640 controls), and the Consortium of Modifiers of BRCA1 and BRCA2 (14,765 BRCA1 and 7904 BRCA2 mutation carriers). Results We found no association with risk of ovarian cancer (OR = 0.99, 95% CI 0.94-1.04, p = 0.74) or breast cancer (OR = 0.98, 95% CI 0.94-1.01, p = 0.19) and results were consistent among mutation carriers (BRCA1, ovarian cancer HR = 1.09, 95% CI 0.97-1.23, p = 0.14, breast cancer HR = 1.04, 95% CI 0.97-1.12, p = 0.27; BRCA2, ovarian cancer HR = 0.89, 95% CI 0.71-1.13, p = 0.34, breast cancer HR = 1.06, 95% CI 0.94-1.19, p = 0.35). Null results were also obtained for associations with overall survival following ovarian cancer (HR = 0.94, 95% CI 0.83-1.07, p = 0.38), breast cancer (HR = 0.96, 95% CI 0.87-1.06, p = 0.38), and all other previously-reported associations. Conclusions rs61764370 is not associated with risk of ovarian or breast cancer nor with clinical outcome for patients with these cancers. Therefore, genotyping this variant has no clinical utility related to the prediction or management of these cancers.
36.	Höglund, Gustav, et al. (författare) The importance of inertial measurement unit placement in assessing upper limb motion 2021 Ingår i: Medical Engineering and Physics. - : Elsevier. - 1350-4533 .- 1873-4030. ; 92, s. 1-9 Tidskriftsartikel (refereegranskat)abstract Motion analysis using inertial measurement units (IMU) has emerged as an alternative to optical motion capture. However, the validity and reliability of upper limb measurements varies significantly between studies. The objective of this study was to determine how sensor placement affects kinematic output in the assessment of motion of the arm, shoulder, and scapula. IMUs were placed proximally/distally on arms, and medially/laterally on the scapula, in a group of eleven healthy participants, while performing nine different motion tasks. Linear regressions and mixed models analysed how these different sensor placements affected the estimated joint motion by establishing the linear relationship between sensors placed on the same body segment. The placement of sensors affected the measured kinematic output considerably, most prominent affect was seen for sensor placement on scapula during flexion and abduction, and on forearm during pronation/supination. The slope of the linear regression lines was 2.5 during flexion, 2.7 during abduction, and 1.8 for forearm pronation/supination. The results of this study suggest that the forearm sensor should be placed on the dorsal side of the forearm, at the distal end; the upper arm sensor should be placed laterally, on the distal part of the arm; and the sensor on the scapula should be placed cranially, along the spine of scapula.
37.	Janols, Helena, et al. (författare) Lymphocyte and monocyte flow cytometry immunophenotyping as a diagnostic tool in uncharacteristic inflammatory disorders. 2010 Ingår i: BMC Infectious Diseases. - : Springer Science and Business Media LLC. - 1471-2334. ; 10 Tidskriftsartikel (refereegranskat)abstract ABSTRACT: BACKGROUND: Patients with uncharacteristic inflammatory symptoms such as long-standing fatigue or pain, or a prolonged fever, constitute a diagnostic and therapeutic challenge. The aim of the present study was to determine if an extended immunophenotyping of lymphocytes and monocytes including activation markers can define disease-specific patterns, and thus provide valuable diagnostic information for these patients. METHODS: Whole blood from patients with gram-negative bacteraemia, neuroborreliosis, tuberculosis, acute mononucleosis, influenza or a mixed connective tissue disorders, as diagnosed by routine culture and serology techniques was analysed for lymphocyte and monocyte cell surface markers using a no-wash, no-lyse protocol for multi-colour flow cytometry method. The immunophenotyping included the activation markers HLA-DR and CD40. Plasma levels of soluble TNF alpha receptors were analysed by ELISA. RESULTS: An informative pattern was obtained by combining two of the analysed parameters: (i), the fractions of HLA-DR-expressing CD4+ T cells and CD8+ T cells, respectively, and (ii), the level of CD40 on CD14+ CD16- monocytes. Patients infected with gram-negative bacteria or EBV showed a marked increase in monocyte CD40, while this effect was less pronounced for tuberculosis, borrelia and influenza. The bacterial agents could be distinguished from the viral agents by the T cell result; CD4+ T cells reacting in bacterial infection, and the CD8+ T cells dominating for the viruses. Patients with mixed connective tissue disorders also showed increased activation, but with similar engagement of CD4+ and CD8+ T cells. Analysis of soluble TNF alpha receptors was less informative due to a large inter-individual variation. CONCLUSION: Immunophenotyping including the combination of the fractions of HLA-DR expressing T cell subpopulations with the level of CD40 on monocytes produces an informative pattern, differentiating between infections of bacterial and viral origin. Furthermore, a quantitative analysis of these parameters revealed the novel finding of characteristic patterns indicating a subacute bacterial infection, such as borreliosis or tuberculosis, or a mixed connective tissue disorder. The employed flow cytometric method is suitable for clinical diagnostic laboratories, and may help in the assessment of patients with uncharacteristic inflammatory symptoms.
38.	Johansson, Anna-Maria, 1981-, et al. (författare) Finger movement control and associated brain activity responses post-stroke 2016 Ingår i: XXI ISEK Congress. Konferensbidrag (refereegranskat)abstract BACKGROUND AND AIM: Impaired finger dexterity is common after stroke, often affecting activities of daily living. Knowledge of kinematic characteristics and of underlying neurological mechanisms of such impairments is important to understand functional recovery. This study aims to investigate finger movement control and related brain activity patterns post-stroke (PS).METHODS: Data from a subsample including 9 participants PS with residual hemiparesis affecting manual dexterity (M age- 66; 3 female) and 12 able-bodied control (C) participants (M age- 65; 3 female) were analyzed. Two series of self-paced cyclic finger extension-flexion movements in random order were performed for each hand (4 series with vision, V, and 4 without vision, NV). Optoelectronic cameras monitored the 3D movement of markers affixed to the fingertips. Motion data was used to calculate each finger's individuation index (II), reflecting movement independence, each finger's Stationarity index (SI), reflecting the ability to keep the finger still while another moves [1] and Movement frequency (MF). Functional magnetic resonance imaging, with simultaneous movement recording, was used to investigate brain activity patterns in relation to the kinematic parameters. II, SI, MF and the effect of vision were analyzed for the 4th digit.RESULTS: A factorial ANOVA 2 [group] x 2 [condition] x 2 [side] x [index type] showed an effect for group (p < .0001; PS < C); condition (p < .01; NV < V); side (p < .0001; affected/non-preferred < non-affected/preferred); and index type (p < .0001; SI < II). An interaction between group and side (p < .01) showed that indices of the affected side were lower compared to the non-affected side within the PS group and compared to both sides in the C group. No significant effects were apparent for MF but significant correlations were found between the indices and MF that were restricted to the PS group alone (over all conditions- r = -0.22; p < .01; within the NV condition- r = -0.19; p < .01; within the affected side r = -0.15; p < .05; and within the SI categorization r = -0.14; p < .05). Furthermore, within NV for the non-affected hand on the SI alone (r = -0.54; p < .05). All indicate that slower movements had higher indices.DISCUSSION: The associations between slower MF and higher index values within the PS group were located to conditions with increased difficulty (NV, affected side, and SI). Thus, reducing speed may be a selected strategy to increase control of finger movements PS when the demand on motor control is high. Further, with the applied calculation of finger movement independence we were able detect group differences, side differences within the PS group, and a positive effect of vision of the hands during performance. This indicates that this calculation is a sensitive measure that could be used to study the effects of stroke and to monitor progression in motor recovery. [1] Häger-Ross & Schieber, 2000, J Neurosci 20:8542-50
39.	Johansson, Anna-Maria, 1981-, et al. (författare) Finger movement control and associated brain activity responses post-stroke 2016 Ingår i: XXI ISEK Congress. Konferensbidrag (refereegranskat)
40.	Johansson, Anna-Maria, 1981-, et al. (författare) Influence of visual feedback, hand dominance and sex on individuated finger movements 2021 Ingår i: Experimental Brain Research. - : Springer. - 0014-4819 .- 1432-1106. ; 239:6, s. 1911-1928 Tidskriftsartikel (refereegranskat)abstract The ability to perform individual finger movements, highly important in daily activities, involves visual monitoring and proprioception. We investigated the influence of vision on the spatial and temporal control of independent finger movements, for the dominant and non-dominant hand and in relation to sex. Twenty-six healthy middle-aged to old adults (M age = 61 years; range 46–79 years; females n = 13) participated. Participants performed cyclic flexion–extension movements at the metacarpophalangeal joint of one finger at a time while keeping the other fingers as still as possible. Movements were recorded using 3D optoelectronic motion technique (120 Hz). The movement trajectory distance; speed peaks (movement smoothness); Individuation Index (II; the degree a finger can move in isolation from the other fingers) and Stationarity Index (SI; how still a finger remains while the other fingers move) were extracted. The main findings were: (1) vision only improved the II and SI marginally; (2) longer trajectories were evident in the no-vision condition for the fingers of the dominant hand in the female group; (3) longer trajectories were specifically evident for the middle and ring fingers within the female group; (4) females had marginally higher II and SI compared with males; and (5) females had fewer speed peaks than males, particularly for the ring finger. Our results suggest that visual monitoring of finger movements marginally improves performance of our non-manipulative finger movement task. A consistent finding was that females showed greater independent finger control compared with males.
41.	Johansson, Anna-Maria, et al. (författare) Three dimensional kinematic analyses of movement control of individual fingers post-stroke 2015 Ingår i: Gait & Posture. - : Elsevier BV. - 0966-6362 .- 1879-2219. ; 42:Supplement 1, s. S33-S33 Tidskriftsartikel (refereegranskat)abstract Research question: Objectives of the present study are: (1) to quantify finger movements in a 3D context and (2) by this method investigate the ability to perform individualized finger movements, with and without vision of the hands, in persons with a chronic stroke diagnosis compared to able-bodied controls.Introduction: Increased knowledge of how fine movement control is affected by stroke is important for the understanding of recovery of function. This is crucial for the development of reliable and valid assessment methods for evaluation of rehabilitation of the upper limbs. This study is part of the MOST project (MOST-MOvement control in STroke) where both clinical tests and 3D movement assessments are performed.Materials and methods: At present, 18 persons post-stroke (M age = 67 years; 6 women) and 26 able-bodied controls (M age = 62 years, 11 women) have participated. The ability to perform uni-manual individualized finger movements and the effect of vison of the hands were evaluated. Participants were instructed to move a specific finger in cyclic extension–flexion movements at the metacarpophalangeal joint, keeping the rest of the finger straight and the other fingers still, at a self-paced speed during 10 s (2 test series for each hand; 8 test series in total). The task was performed seated. The wrists were extended about 10° and fixated to a wooden frame with forearm support. Reflective markers were affixed to each fingertip and movements were recorded by optoelectronic cameras. Based on the positional change of the fingers during task performance, two indices ranging from 0-1 were calculated: (1) Individuation index (II) where the independence of each finger movement is shown and where 1 indicate complete independence, (2) stationary index (SI) where 1 indicate that the finger remains still when the other fingers move [1].Results: Our results show that it is possible to quantify individual finger movements by use of 3D movement analysis addressing the quality of movement performance in stroke survivors: all but 3 persons post-stroke were able to perform the task. Preliminary analyses (based on a subsample constituted of 8 post-stroke and 8 controls) verify that the test discriminated between groups where participants post-stroke had lower values on II and SI as compared to the control persons, the lowest values were observed for the middle and ring fingers. Ongoing analyses will show if vision influences the outcomes.Discussion: A set-up has been tested where individual finger movements can be quantified in 3D, and that discriminates between persons post stroke compared to controls. This advancement carries a promise for development of better assessment methods for recovery of function post-stroke.Reference[1] C. Häger-Ross, M.H. Schieber Quantifying the independence of human finger movements: comparisons of digits, hands and movement frequencies.J Neurosci, 20 (2000), pp. 8542–8550
42.	Johansson, Gudrun M., et al. (författare) Assessment of arm movements during gait in stroke : the Arm Posture Score 2014 Ingår i: Gait & Posture. - : Elsevier BV. - 0966-6362 .- 1879-2219. ; 40:4, s. 549-555 Tidskriftsartikel (refereegranskat)abstract The purpose of the study was to apply the Arm Posture Score (APS) to a stroke population, since comprehensive measures to quantify arm swing in the affected and non-affected arms during gait are lacking. A further aim was to investigate how gait speed and upper limb function estimated by clinical measures are related to the APS in the stroke group. The APS is the summarized root mean square deviation (RMSD) from normal, based on kinematics. Four arm movements (sagittal and frontal planes) as well as six arm movements (incorporating transversal plane) were included in the calculation of APS, referred to as APS4 and APS6, respectively. The study population consisted of 25 persons with stroke and 25 age- and gender-matched controls. The APS measures were significantly different between the affected and non-affected arms, as well as between the affected arm and the non-dominant arm of the controls (p≤0.001). Spasticity significantly influenced both APS measures, while speed only had a significant effect on the APS4. The APS measures correlated significantly to clinical measures of upper limb function. Both APS measures seem to be useful indices to quantify and discriminate between impaired and normal arm swing during gait after stroke. The variability of rotational arm movements needs to be studied further before considering the additional value of the APS6 over the APS4. When interpreting the APS, complementary kinematics should be taken into account, as the single value of the APS gives no information about the direction of the deviation.
43.	Johansson, Gudrun M, 1963- (författare) Clinical and kinematic assessments of upper limb function in persons with post-stroke symptoms 2015 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Stroke is a common and multifaceted disease that often involves motor deficits in the upper limb. This thesis investigated reliability and validity of existing clinical assessments of upper limb function in persons with post-stroke symptoms and in non-disabled controls. Study I was conducted in a clinical setting where the Motor Evaluation Scale of Upper Extremity in Stroke patients (MESUPES) was assessed in persons post-stroke by two physiotherapists selected from a group of four. Study II-IV took place in a motion analysis laboratory with an optoelectronic system. Kinematic measures and clinical measures were used to investigate the validity of the Arm Posture Score (APS), the Finger-to-Nose test (FNT), and the Standardised Nine Hole Peg test (S-NHPT) in persons post-stroke and non-disabled controls. The results showed that the MESUPES had a high inter-rater reliability while the concurrent validity was not fully confirmed. MESUPES has a maximum score of 58 and the minimal detectable change ranged from 5 to 8 for a confidence level of 80% and 95%. The Arm Posture Scores, which include either four or six arm movement variables, were able to distinguish between the affected and non-affected arms, as well as between the affected arm and the non-dominant arm of the controls. The total movement time of the FNT, which is a coordination test, was able to distinguish persons post-stroke from controls, at least at a group level. Movement smoothness, accuracy and compensation, obtained from kinematic analysis, were the most discriminative variables for the FNT. Smoothness was most strongly correlated with the timed FNT and had the greatest association with the variance of the timed FNT. For the S-NHPT, which is a dexterity test involving grasping and reaching, the movement times, smoothness and compensation discriminated between the stroke group and the control group. Persons post-stroke spent considerably more time in the grasp-related parts of the task compared to controls. Smoothness and upper limb impairments had the strongest correlation with the S-NHPT. In conclusion, the clinical measures used within stroke rehabilitation seem valid and reliable, although some limitations are highlighted by the kinematic assessment. MESUPES was shown to be a reliable assessment of upper limb movement quality after stroke. The kinematic analysis revealed that the timed FNT does not have sufficient discriminative validity at an individual level. The timed FNT reflected speed-related aspects of pointing movements such as smoothness and length of the deceleration phase, but should not be used as an overall measure of upper limb coordination after stroke. The timed S-NHPT demonstrated sufficient discriminative validity and reflected smoothness and upper limb impairments. For both the FNT and S-NHPT, kinematic analysis showed that the clinical outcomes of those tests (time of performance) did not adequately detect qualitative aspects of the upper limb movements after stroke such as possible compensatory movements. Therefore, clinical assessments that capture qualitative aspects of upper limb movements would improve the assessment of upper limb coordination and dexterity after stroke. In addition, 3D movement analysis provided unique information about upper limb function after stroke, not least in persons with mild post-stroke impairments. The APS, for instance, which quantifies how much the arm swing during gait deviates from normal, discriminated between persons with stroke and non-disabled persons. Such subtle deviations are not possible to quantify with the human eye.
44.	Johansson, Gudrun M., 1963-, et al. (författare) The added value of kinematic evaluation of the timed finger-to-nose test in persons post-stroke. 2017 Ingår i: Journal of NeuroEngineering and Rehabilitation. - : Springer Science and Business Media LLC. - 1743-0003. ; 14 Tidskriftsartikel (refereegranskat)abstract BACKGROUND: Upper limb coordination in persons post-stroke may be estimated by the commonly used Finger-to-Nose Test (FNT), which is also part of the Fugl-Meyer Assessment. The total movement time (TMT) is used as a clinical outcome measure, while kinematic evaluation also enables an objective quantification of movement quality and motor performance. Our aims were to kinematically characterize FNT performance in persons post-stroke and controls and to investigate the construct validity of the test in persons with varying levels of impairment post-stroke.METHODS: A three-dimensional motion capture system recorded body movements during performance of the FNT in 33 persons post-stroke who had mild or moderate upper limb motor impairments (Fugl-Meyer scores of 50-62 or 32-49, respectively), and 41 non-disabled controls. TMT and kinematic variables of the hand (pointing time, peak speed, time to peak speed, number of movement units, path ratio, and pointing accuracy), elbow/shoulder joints (range of motion, interjoint coordination), and scapular/trunk movement were calculated. Our analysis focused on the pointing phase (knee to nose movement of the FNT). Independent t or Mann-Whitney U tests and effect sizes were used to analyze group differences. Sub-group analyses based on movement time and stroke severity were performed. Within the stroke group, simple and multiple linear regression were used to identify relationships between TMT to kinematic variables.RESULTS: The stroke group had significant slower TMT (mean difference 2.6 s, d = 1.33) than the control group, and six other kinematic variables showed significant group differences. At matched speeds, the stroke group had lower accuracy and excessive scapular and trunk movements compared to controls. Pointing time and elbow flexion during the pointing phase were most related to stroke severity. For the stroke group, the number of movement units during the pointing phase showed the strongest association with the TMT, and explained 60% of the TMT variance.CONCLUSIONS: The timed FNT discriminates between persons with mild and moderate upper limb impairments. However, kinematic analysis to address construct validity highlights differences in pointing movement post-stroke that are not captured in the timed FNT.
45.	Johansson, Gudrun M, et al. (författare) Validity of the timed Finger-to-Nose test as a measure of upper limb coordination in persons post-stroke - a kinematic analysis Annan publikation (övrigt vetenskapligt/konstnärligt)
46.	Johansson, Gudrun, 1963-, et al. (författare) The Arm Posture Score with additional rotational components (APS6) applied to persons with stroke to assess arm movements during gait. 2012 Konferensbidrag (övrigt vetenskapligt/konstnärligt)
47.	Johansson, Gudrun, et al. (författare) Validation and standardisation of the Nine Hole Peg test for kinematic quantification in persons post-stroke Annan publikation (övrigt vetenskapligt/konstnärligt)
48.	Markström, Jonas, 1985-, et al. (författare) Dynamic knee control and movement strategies in athletes and non‐athletes in side hops : implications for knee injury 2019 Ingår i: Scandinavian Journal of Medicine and Science in Sports. - : John Wiley & Sons. - 0905-7188 .- 1600-0838. ; 29:8, s. 1181-1189 Tidskriftsartikel (refereegranskat)abstract Athletes exposed to rapid maneuvers need a high level of dynamic knee stability and robustness, while also controlling whole body movement, to decrease the risk of non‐contact knee injury. The effects of high‐level athletic training on such measures of movement control have not, however, been thoroughly evaluated. This study investigated whether elite athletes (who regularly perform knee‐specific neuromuscular training) show greater dynamic knee robustness and/or different movement strategies than non‐athletic controls, in relation to overall knee function. Thirty‐nine women (19 athletes, 20 controls) performed standardized rebound side hops (SRSH) while a motion capture system synchronized with two force plates registered three‐dimensional trunk, hip, and knee joint angles and moments. Dynamic knee robustness was evaluated using finite helical axis (FHA) inclination angles extracted from knee rotation intervals of 10°, analyzed with independent t tests. Angle and moment curves were analyzed with inferential methods for functional data. Athletes had superior knee function (less laxity, greater hop performances, and strength) but presented similar FHA inclination angles to controls. Movement strategies during the landing phase differed; athletes presented larger (a) hip flexion angles (during 9%‐29% of the phase), (b) hip adduction moments (59%‐99%), (c) hip internal rotation moments (83%‐89%), and (d) knee flexion moments (79%‐93%). Thus, elite athletes may have a greater ability than non‐athletes to keep the knee robust while performing SRSH more efficiently through increased engagement of the hip. However, dynamic knee robustness associated with lower FHA inclination angles still show room for improvement, thus possibly decreasing knee injury risk.
49.	Markström, Jonas, 1985-, et al. (författare) Elite women athletes with superior knee function present similar dynamic knee stability, although different movement strategies, when compared to controls 2018 Ingår i: 23rd annual Congress of the European College of Sport Science: Sport Science at the cutting edge, Dublin, Ireland, July 4-7, 2018. - : European College of Sport Sciences. - 9783981841411 ; , s. 555-555 Konferensbidrag (refereegranskat)abstract INTRODUCTION: Neuromuscular training (NMT) of the lower limb is vital for athletes in learning correct movement technique to avoid risk of injury to the anterior cruciate ligament (ACL). The NMT aims for improved knee control while maintaining dynamic knee stability (DKS; resistance to linear/angular accelerations) during knee-challenging tasks. Assessing DKS is commonly attempted by evaluating discrete values of kinematic and kinetic variables during one-leg hops, but these measures may not sufficiently capture knee dynamics. We aimed to evaluate if elite women athletes who regularly perform NMT have greater DKS and/or different landing technique than normally active women who do not perform NMT, and if there are any correlations of DKS to peak knee extensor or flexor strength.METHODS: A motion capture system (Qualisys) synchronized with two force plates (Kistler) registered hip and knee 3D joint angles and moments during one-leg standardized lateral side hop landings for 39 women (19 athletes, 20 controls). Ten trials were performed for the dominant leg with hands behind their back holding a rope (25 cm), deemed successful following 3 s of single leg stance after landing without putting the contralateral foot on the ground or making major adjustments with the ipsilateral foot. DKS was evaluated using the inclination angle of the knee’s helical axis relative to the flexion-extension axis calculated for rotation intervals of 10 degrees, as has been proven useful (Grip and Häger, 2013), to quantify how much knee joint motion deviated from pure flexion-extension at landing. Hip and knee joint angles were analysed at initial contact (IC), and peak angles and peak moments were analysed during the deceleration phase of landing from IC to peak knee flexion (ind. t-tests, p < 0.05).RESULTS: Athletes had more successful hops, faster task execution, greater knee extension strength, greater hip flexion angle at IC, and higher peak moments of hip adduction and knee flexion than controls. There were however, no group differences in DKS or any significant correlations between DKS and knee extensor or flexor strength for any of the groups (r < absolute values of 0.41).CONCLUSION: Elite women athletes that perform NMT on a regular basis had superior knee function but similar DKS to controls when performing a sport-specific one-leg side hop maneuver. The greater hip flexion at IC for athletes shows a different movement strategy for landing preparation. Potential benefits of NMT in sports contexts, e.g. less ACL injuries (Sugimoto et al., 2016), may be due to movement alterations of the hip to increase landing control to avoid positions that strain the ACL rather than improving DKS. Further emphasis on knee-specific landing control may be important to also improve DKS, which seems unrelated to strength.
50.	Markström, Jonas L., 1985-, et al. (författare) A comparison of knee joint kinematics and kinetics during landings in three one-leg hop tests (hop for distance, vertical hop and side hop) performed by female elite floorball athletes 2016 Ingår i: XXI ISEK Congress. Konferensbidrag (refereegranskat)

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