| 1. |
- Dahlman, Joakim, 1974-
(författare)
-
Psychophysiological and Performance Aspects on Motion Sickness
- 2009
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Motion sickness is not an illness, but rather a natural autonomic response to an unfamiliar or specific stimulus. The bodily responses to motion sickness are highly individual and contextually dependent, making them difficult to predict. The initial autonomic responses are similar to the ones demonstrated when under stress. When under the influence of motion sickness, motivation and ability to perform tasks or duties are limited. However, little is known about how specific cognitive functions are affected. Furthermore, standard mitigation strategies involve medications that induce fatigue or strategies that require cognitive capabilities. Both of them may result in reduced capability to perform assigned tasks or duties. Hence, there is a need for alternative mitigation strategies.The aim of the thesis was to study psychophysiological and performance aspects on motion sickness. The long-term goal is to provide strategies for mitigation and prevention of motion sickness by identifying psychophysiological responses as predictors for both wellbeing and performance. This thesis comprises four studies, in which 91 participants were exposed to two different motion sickness stimuli, either an optokinetic drum or a motion platform. Before the tests, a method for extracting fixations from eye-tracking data was developed as a prerequisite for studying fixations as a possible mitigation strategy for reducing motion sickness. During exposure to stimuli that triggers motion sickness, performance was studied by testing short-term memory and encoding and retrieval. In the final study, the effects of an artificial sound horizon were studied with respect to its potential to subconsciously function as a mitigating source.The results of the measurements of the psychophysiological responses were in accordance with previous research, confirming the ambiguity and high individuality of the responses as well as their contextual dependencies. To study fixations, a centroid mode algorithm proved to be the best way to generate fixations from eye-movement data. In the final study, the effects of the sound horizon were compared to the effects of a non-positioned sound. In the latter condition, both fixation time and the number of fixations increased over time, whereas none of them showed a significant time effect in the sound horizon condition. The fixation time slope was significantly larger in the non-positioned sound condition compared to the sound horizon condition. Number of fixations, heart rate, and skin conductance correlated positively with subjective statements that referred to motion sickness. Among participants that were susceptible to motion sickness symptoms, short-term memory performance was negatively affected. However, no effects of motion sickness on encoding and retrieval were found, regardless of susceptibility.Future studies should continue focusing on autonomic responses and psychological issues of motion sickness. Factors such as motivation, expectancies, and previous experiences play a major and yet relatively unknown role within the motion sickness phenomena.
|
|
| 2. |
- Ahlstrand, Inger
(författare)
-
Pain and its relation to participation in valued activities in rheumatoid arthritis
- 2015
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- There has been a dramatic change over the past two decades for persons with rheumatoid arthritis (RA) not only due to early diagnosis, structured treatment, and aggressive medication but also due to an increased demand of participation in work life and society. Despite these treatment changes, RA continues to impact these individuals’ participation in valued daily activities. Participation in valued daily activities provides wellbeing and the opportunity for engagement and participation. By persons with RA pain has been highlighted as one of the most restrictive symptoms. This thesis uses the International Classification of Functioning, Disability, and Health (ICF) as a conceptual framework to describe disability and how participation is related to pain.Aims: The overall aim of this thesis was to explore and describe the relationship between pain and participation in valued activities, in RA. Paper I compared pain and activity limitations in women and men with contemporary treated early RA with persons who were diagnosed ten years earlier. Paper II described experiences of pain and pain’s relationship with daily activities. Paper III examined difficulties performing valued life activities in relation to pain intensity. Paper IV described personal factors, including self-efficacy and pain acceptance, and studied whether personal factors are mediators of the relationbetween pain and performance of valued life activities.Methods: Different methodological approaches were used to provide a comprehensive understanding of pain and participation in valued activities in persons with RA. A prospective longitudinal cohort study was used to compare women and men treated with contemporary treated RA (n=276) with their counterparts ten years earlier (n=373) (Paper I). This study was followed by a focus group study where 33 persons with RA participated in seven focus groups (Paper II). Subsequently, Papers III and IV were conducted based on data from The Swedish Rheumatology Quality Registry (SRQ) and data from a postal questionnaire that gathered data on demographics, pain, personal factors, and participation in valued life activities (n=737). In addition, these studies used descriptive and analytical statistics with multiple regression and structural equation modelling (SEM).Results: Pain and activity limitations were still pronounced in women and men with RA despite recent treatment advances (Paper I). The relationship between participation and pain was dynamic and is related to fatigue, stress, and mood, factors that generated difficulties finding a suitable level of activity, resulting in difficulties balancing daily activities (Paper II). Both women and men reported restrictions in participation in valued life activities. Pain was identified as having an important relationship to difficulties performing valued life activities (Paper III). Personal factors were found important as mediators for pain in relation to participation (Paper IV).Conclusions: This thesis found a continued need for multidisciplinary interventions despite current treatments. Pain was identified as related to participation restrictions and had an important relationship to difficulties performing valued life activities. Pain and participation in valued activities needs to be comprehensively analysed and treated in the context of the person’s perspective and needs and demands of persons with RA. The subjective experience of participation, the engagement, must be highlighted. Personal factors mediated the relationship between pain and participation and this finding supports the value of self-management interventions to enable participation in valued activities
|
|
| 3. |
- Fristedt, Sofi
(författare)
-
Occupational participation through community mobility among older men and women
- 2012
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The overall aim of the present thesis was to explore and characterise occupational participation and community mobility from an occupational perspective of health and well-being, and to elucidate potential barriers and facilitators for occupational participation and community mobility in older men and women.In Study I, questionnaires were sent to a sample of older citizens (75+) in three Swedish mid-sized municipalities. This survey focused on actual and preferred travel opportunities and was returned by 957 persons (response rate 46%). Although older people appreciated the existing travel opportunities, there was evidence of restricted community mobility for some sub-groups of older people, due to various perceived barriers. More efforts must be put into accessibility improvements including usability from the perspective of older people.In Study II nine focus group interviews with a total of 42 participants (20 men) were conducted, focusing on older peoples’ motives for, and experiences of, community mobility and occupational participation outside the home. The main category “Continuing mobility and occupational participation outside the home in old age is an act of negotiation” summarised the findings. This main category was abstracted from the generic categories “Occupational means and goals”, “Occupational and mobility adaptation” and “Occupational barriers and facilitators”, and their subcategories. Community mobility was identified as an important occupation that in itself also facilitated occupational participation outside the home. Individual community mobility seemed to be influenced by, for example, age and gender, as well as habits acquired over time. Furthermore, community mobility was negatively affected not only by physical barriers, but also by social and attitudinal barriers in the public environment.Study III identified and described older people’s viewpoints on community mobility and occupational participation in older age through a Q-methodology study conducted with 36 participants, including men and women, both drivers and non-drivers. Three viewpoints were found and assigned content-descriptive denominations; viz.: “Prefer being mobile by car”, “Prefer being mobile by public transport” and “Prefer flexible mobility”. Unfortunately, the existing demand-responsive Special Transportation Systems was not considered an attractive enough alternative by any of the participants. Thus, intermediate community mobility options are needed for those who no longer can drive or use public transport. InStudy IV factors associated with community mobility, and decreased community mobility over time, for older men and women were described. Data were based on the Gender study “Aging in men and women: a longitudinal study of gender differences in health behaviour and health among elderly” and collected through surveys in 1994 and 2007. The base-line sample consisted of 605 twin-pairs, i.e., 1,210 individuals, aged 69-88, and the follow-up of 357 individuals (165 men and 192 women), aged 83-97. This surveycovered health and health-related issues including community mobility and occupational participation. Continuing community mobility was cross-sectionally (at follow-up) and prospectively (from baseline to follow-up) associated with better self-reported subjective health rather than self-reported health conditions for both men and women. For men, community mobility was also cross-sectionally associated with few or non-existant depressive symptoms, while reduced community mobility was prospectively associated with higher age for women. Consequently, interventions aiming to enable community mobility must move beyond interventions directed towards health conditions and instead target subjective health and well-being.
|
|
| 4. |
- Sjörs, Anna, 1981-
(författare)
-
I feel terrible! Can you measure that? : Exploring psychophysiological stress responses and their interactions with performance, subjective reports and health status
- 2010
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Despite recent research advances, there are still several common medical conditions whose underlying mechanisms are poorly understood. In conditions with few or diffuse physical findings, it can be difficult to diagnose and determine the state of the condition and its effects on working ability or performance, and the health care practitioners have to rely on the patient’s self-reports. Identification of objective measurements that are sensitive enough to aid in diagnosis or determination of the state of these conditions would thus be valuable. Psychophysiological measurements are generally non-invasive and have the potential to serve as such diagnostic or prognostic tools. In this thesis, psychophysiological reactions to different stressors were recorded in two selected medical conditions; namely motion sickness and chronic trapezius myalgia (musculoskeletal pain). These subjective conditions are unpleasant, unwanted and apparently serve no survival purpose. It is therefore important to elucidate any physical findings associated with them to, eventually, find new means to prevent the development of these conditions or to ameliorate symptoms.The overall aim of the thesis was to explore the development of psychophysiological responses to stressors in relation to performance and subjective reports in healthy individuals and in women with chronic trapezius myalgia. More in detail, the purpose was to identify psychophysiological responses that could provide information about the mechanisms behind, or serve as candidates for characterization of motion sickness and chronic trapezius myalgia, respectively.Responses to motion sickness, triggered by optokinetic stimulation, were studied in healthy individuals, whereas responses to repetitive low-force work and psychosocial stress were studied in women with chronic trapezius myalgia and in pain-free controls. In both medical conditions, the psychophysiological responses were accompanied by subjective reports. The effects of motion sickness on two different aspects of memory performance were tested during exposure to optokinetic stimulation. In the studies of chronic trapezius myalgia, psychophysiological responses were also related to health status, i.e., being a patient or a pain-free control and measurements of pain intensity, psychological symptoms, sleep-related problems and quality of life.The psychophysiological responses to optokinetic stimulation were inconclusive. Moderate levels of motion sickness did not affect memory performance, whereas decreased short term memory performance was seen in subjects reporting high levels of motion sickness. The autonomic responses and stress hormone secretion in response to low-force repetitive work and psychosocial stress in the chronic trapezius myalgia group were similar to those of the pain-free controls. However, muscle activity in the trapezius muscle was generally higher in the chronic trapezius myalgia group. There were indications of negative psychological states being related to a slower response and lower circadian variations of stress hormone secretion.With the present methods, it was possible to measure general stress responses but none of the measurements showed sufficient specificity to serve as predictors or indicators of motion sickness and chronic musculoskeletal pain, respectively. Summarizing, I cannot objectively measure how you feel; I still have to rely on your description of your condition.
|
|
| 5. |
- Albertsson, Pontus, 1958-
(författare)
-
Occupant casualties in bus and coach traffic : injury and crash mechanisms
- 2005
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: The relevance of conducting this thesis is evident by the fact that bus and coach casualties have been “stubbornly stable” in Europe recent years and a need for investigating if a similar trend could be found in Sweden is therefore obvious. It was also important to add new knowledge to the bus and coach research in Sweden, since many areas were scarcely addressed. Aims: To describe bus and coach occupants’ injuries, crash and injury mechanisms generated in a traffic environment based on data from the medical sector. Additional aims were to investigate the injury reducing effect of a 3-point belt, the effect of cross-winds, and crucial factors in the emergency- and rescue response. Material and methods: Injury data analyses were based on a complete ten-year medical data set from a catchment-area with about 130,000 inhabitants. A number of crash studies with the scope in different crash phases were conducted by applying and elaborating the Haddon matrix as a framework. An additional framework, Protocol for Major Incidents was used in order to investi-gate the emergency- and rescue response to a severe coach crash. Results: Between the first and second five-year period, the incidence of injured in non-crash in-cidents was increased by 24%. In non-crash incidents, 54% were injured; 2/3 while alighting from a bus or coach. The pre-crash factor cross-wind, in addition to vehicle design, vehicle speed and road friction, was investigated in ten crashes. It was confirmed that cross-wind, in relation to vehicle speed and slippery road conditions, needs more attention. The importance of goods load-ing and passengers’ position in the bus, was indicated by the fact that a displacement of the cen-tre of mass rearwards with 10% increased the necessary coefficient of friction with, on average 45%, which in many cases corresponded to dry road conditions. Three Swedish rollover crashes were analysed with regard to the injury outcome, mechanisms and the possible injury reduction for occupants using a safety belt. A considerable increase in safety for occupants belted with 3-point belts was shown through limiting interior contacts, occupant interaction and the possibility of ejection. Crucial post-crash factors in the emergency- and rescue response showed that ordi-nary ways of working and equipment are not always useful and proper equipment for lifting a coach body is essential in the case of a rollover. Finally, the communication between the hospitals is important, and the telephone systems may be overloaded by calls from worried relatives and media. Conclusions: In non-crash events: Non-crash events constitute a majority of all bus and coach casualties with a high proportion of elderly female occupants among the MAIS 2+ injury cases. Boarding and, especially alighting causes many injuries to the lower extremities. In the pre-crash phase: Cross-winds do affect the safety of buses and coaches and requires more at-tention. Seat belt usage among bus and coach occupants has to be increased. In the crash phase: Rollover and ejection are the major causes behind serious and fatal injuries to bus and coach occupants, consequently, retentive glazing, pillars or rails need more attention. An upgrade from 2-point seat belts to 3-point seat belts yields an increase in the estimated injury re-duction from approximately 50% up to 80% for the MAIS 2+ casualties in a rollover crash. In the post-crash phase: In order to be able to lift a coach body proper equipment originated from experience and development is essential in a rescue operation of a crashed bus or coach. Fur-thermore, to improve the emergency response inside crashed coaches proper methods originated from experience need to be developed. Euro NBAP: Based on the results and conclusions generated in this thesis, a European New Bus and Coach Assessment Programme is suggested, which would provide bus and coach occupants with a assessment programme similar to the Euro NCAP.
|
|
| 6. |
- Borgestig, Maria
(författare)
-
The impact of gaze-based assistive technology on daily activities in children with severe physical impairments
- 2016
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Aim: The aim of the thesis was to investigate the impact of gaze-based assistive technology on daily activities in children with severe physical impairments and without speech. The objectives were to develop and pilot a gaze-based assistive technology intervention (GAT intervention) at home and in school for these children and to understand its impact on daily activities as experienced by their parents.Methods: Study I was a pilot study in which the basic components that were developed for the intervention were evaluated for students with physical impairments. The study aimed at improving the use of computers as assistive technology (AT) in school. Based on the findings in Study I, the GAT intervention was developed. The GAT intervention aimed at implementing gaze-based AT in daily activities. It consisted of two parts; having access to gaze-based AT and having access to services from a multi professional communication team during nine to ten months. Studies II-IV concerned gazebased AT for children with severe physical impairments without speech who participated in the GAT intervention. The participants were ten children (ages 1-15) (Studies II, III), and their parents (Study IV). Studies II and III had longitudinal designs and children were followed during 15-20 months with repeated measurements before, after and at follow-up. In Study II children’s repertoire of computer activities, extent of use, and goal attainment with gaze-based AT was evaluated, as well as parents’ satisfaction with the AT and with services. In Study III children’s eye gaze performance when using gaze-based AT was examined. In Study IV, parents were interviewed twice with the aim of exploring their experiences of children’s gaze-based AT use in daily life. In Study IV a hermeneutical approach was used.Results: The findings of Study I showed that the basic components of intervention improved the use of computers in school. Study II showed an increased repertoire of computer activities with the gazebased AT, maintained use in daily activities for all at follow up, and that all children attained goals for gaze-based AT use in daily activities. Parents were satisfied with the gaze-based AT, and with the services in the GAT intervention. In study III, nine children improved in eye gaze performance over time when using the gaze-based AT in daily activities. Study IV revealed that children’s gaze-based AT usage in daily activities made a difference to parents since the children demonstrated agency, and showed their personality and competencies by using gaze-based AT, and for the parents this opened up infinite possibilities for the child to do and learn things. Overall, children’s gaze-based AT usage provided parents with hope of a future in which their children could develop and have influence in life.Conclusions: This thesis shows that these children with severe physical impairments and without speech acquired sufficient gaze control skills to use gaze-based AT for daily activities in the home and at school. The gaze-based AT had a positive impact on performing activities, for example, play activities and communication- and interaction-related activities. For the parents, children’s gaze-based AT usage made a difference since it shaped a hope of a better future for their children, where they can develop and gain influence in their future life. Furthermore, the children continued to perform daily activities with gaze-based AT over time. This finding suggests that key persons were provided with sufficient knowledge and skills to support children in maintained use of gaze-based AT after withdrawal of the services provided in the GAT intervention.
|
|
