Change search
Refine search result
1 - 13 of 13
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Jafari, Hedyeh
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Pauelsen, Mascha
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Röijezon, Ulrik
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Nyberg, Lars
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Nikolakopoulos, George
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Gustafsson, Thomas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    A novel data driven model of ageing postural control2019Conference paper (Refereed)
    Abstract [en]

    Background

    Postural control is a complex system. Based on sensorimotor integration, the central nervous system (CNS) maintains balance by sending suitable motor commands to the muscles. Physiological decline due to ageing, affects balance performance through failing postural control – and in turn affects falls self-efficacy and activity participation. Understanding how the CNS adapts to these changes and predicts the appropriate motor commands to stabilize the body, has been a challenge for postural control research the latest years.

    Aims

    To understand and model the performance of the central nervous system as the controller of the human body.

    Methods

    Modelling was based on postural control data from 45 older adults (70 years and older). Ankle, knee and hip joint kinematics were measured during quiet stance using a motion capture system. Principal component analysis was used in order to reduce the measured multidimensional kinematics from a set of correlated discrete time series to a set of principal components. The outcome was utilized to predict the motor commands. The adaptive behaviour of the CNS was modelled by recurrent neural network including the efference copy for rapid predictions. The data from joint kinematics and electromyography (EMG) signals of the lower limb muscles were measured and separated into training and test data sets.

    Results

    The model can predict postural motor commands with very high accuracy regardless of a large physiological variability or balancing strategies. This model has three characteristics: a) presents an adaptive scheme to individual variability, 2) showcases the existence of an efference copy, and 3) is human experimental data driven.

    Conclusion

    The model can adapt to physical body characteristics and individual differences in balancing behaviour, while successfully predict motor commands. It should therefore be utilised in the continued pursuit of a better understanding of ageing postural control.

  • 2.
    Pauelsen, Mascha
    et al.
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Jafari, Hedyeh
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Vikman, Irene
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Nyberg, Lars
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Röijezon, Ulrik
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Using the frequency power spectrum to learn more about aging postural control and fall-related concerns2019Conference paper (Refereed)
    Abstract [en]

    Backgound:

    Posturography is widely used to describe and analyze human postural control. The traditional features of the center of pressure (CoP) trajectory during open eyes quiet standing tests have been used to show the association between declined sensorimotor systems and the variation in fall-related concerns (FrC), but seem to be too crude to separate each sensorimotor system’s contribution. Therefore, research has moved towards analysing the frequency domain of the CoP trajectory.

    Aim:

    To explore the frequency domain of CoP trajectory signals in an effort to learn more about ageing postural control and how it mediates and is mediated by FrC 

    Method:

    We recruited 45 people aged 70 or more. To measure body sway during quiet stance, we registered CoP trajectories using a force plate. A power spectral density analysis was performed on the CoP signal of all participants, from which we then extracted features: peak power, mean power, 50% power and 80% power. Principal component analysis, orthogonal projection to latent structures (OPLS), and OPLS-discriminant analysis were used to explore patterns of explanation of the features by a wide range of sensorimotor variables and FrC measured on the participants. A PLS-tree was used for the initial grouping.

    Results:

    The PLS-tree gave 2 groups. Group 2 had significantly more FrC, lower morale, larger errors in knee proprioception, slower reaction times, and weaker lower limb strength. They also had lower frequencies at all four features (significant at all but peak power).

    Conclusions:

    Under the assumption that the vision feedback loop generates more power in the lower frequencies of quiet stance sway, one explanation of the findings could be that once an individual starts experiencing postural control decline, vision gets weighed heavier in the integration process. More research is needed to find the most accurate ways to investigate postural control changes.

  • 3.
    Pauelsen, Mascha
    et al.
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Nyberg, Lars
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Röijezon, Ulrik
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Vikman, Irene
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Both psychological factors and physical performance are associated with fall-related concerns2018In: Aging Clinical and Experimental Research, ISSN 1594-0667, E-ISSN 1720-8319, Vol. 30, no 9, p. 1079-1085Article in journal (Refereed)
    Abstract [en]

    Background Fall-related concern strongly correlates to activity avoidance in older people.  In this complex phenomenon, different terminology and instruments are often used interchangeably. Three main concepts make up fall-related concerns: fear-of-falling, consequence concern, and falls self-efficacy. It is suggested that fall-related concerns are mediated by psychological and physical factors.

    Aims Our aims were to describe the prevalence of fall-related concerns and find explanatory factors for its most studied concept – falls self-efficacy – in an older population.

    Methods We executed a cross sectional study on a random sample of 153 community dwelling older people (70 years or older). We used validated and reliable instruments as well as structured interviews to gather data on the three concepts of fall-related concerns and possible mediating factors. We then calculated descriptive statistics on prevalence and regression models for the total group, and men and women separately.

    Results 70% of the total sample (80% of women and 53% of men) reported at least one of the three concepts of fall-related concern. For the total sample, fear-of-falling, morale and physical performance were associated factors with falls self-efficacy. For women, number of prescription medications was added. For men, physical performance and concerns for injury were associated.

    Conclusion Fall-related concern is prevalent in large proportions with higher prevalence for women than for men. Important factors are fear of falling, morale, and physical performance. Gender differences in the emergence and variance of fall-related concern and the relation between physical performance and fall-related concern should be targeted in future research endeavors. 

  • 4.
    Pauelsen, Mascha
    et al.
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Vikman, Irene
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Johansson, Viktor
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Larsson, Agneta
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Röijezon, Ulrik
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Decline in sensorimotor systems explains reduced falls self-efficacy2018In: Journal of Electromyography & Kinesiology, ISSN 1050-6411, E-ISSN 1873-5711, Vol. 42, p. 104-110Article in journal (Refereed)
    Abstract [en]

    Physical performance including balance tasks is one of the main factors explaining the variance in falls self-efficacy in older adults. Balance performance is often measured by use of gross assessment scales, which assess the result of integration of all systems involved in postural control. We aimed to investigate which measurements of postural control correlate to falls self-efficacy scores as measured by the FES-I instrument, and which sensory and motor systems best explain them. A cross sectional study was designed, in which 45 older adults performed quiet stance and limits of stability trials during which their center of pressure (CoP) excursion was recorded. Falls self-efficacy was measured using the Falls Efficacy Scale - International. Eyesight, vestibular function, proprioception, reaction time and strength were also measured. Hierarchical orthogonal projection of latent structures was used to model FES-I with the CoP trials and then with the sensory and muscle function data. Fes-I could be explained to 39%, with the eyes open trials and the limits of stability trials loading the heaviest. The base model could be explained to 40% using the sensory and muscle function data, with lower limb strength, leg proprioception, neck proprioception, reaction time and eyesight loading the heaviest.

  • 5.
    Jafari, Hedyeh
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Pauelsen, Mascha
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Röijezon, Ulrik
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Nyberg, Lars
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Nikolakopoulos, George
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Gustafsson, Thomas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    On Internal Modeling of the Upright Postural Control in Elderly2018Conference paper (Refereed)
  • 6.
    Pauelsen, Mascha
    et al.
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Nyberg, Gusten
    Department of Radiology, Linköping University Hospital.
    Tegner, Cecilia
    Swedish University of Agricultural Sciences, Uppsala.
    Tegner, Yelverton
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Concussion in ice hockey: A Cohort Study Across 29 Seasons2017In: Clinical Journal of Sports Medicine, ISSN 1050-642X, E-ISSN 1536-3724, Vol. 27, no 3, p. 283-287Article in journal (Refereed)
    Abstract [en]

    Objective: The aim of this study was to analyse the concussion incidence rate ratios (IRR) across 29 seasons in a Swedish Hockey League team.Design: Cohort study over 29 seasons within one Swedish elite series ice hockey team. Participants: All players who were part of one Swedish elite ice hockey team during the research period gave consent for participation in the study.Independent Variables: Exposure to top level Swedish ice hockey. Main Outcome Measures: Incidence rate ratio for concussion as well as rehabilitation periods due to concussion were calculated and analysed.Results: During the research period, 267 players in total were part of the team. A total of 1638 traumatic injuries were registered of which 162 were concussions. Incidence rates ranged from 0/1,000 games during the first season to 118/1,000 games for the final recorded season. The incidence rate ratio was 1.06 (CI = 1.03-1.10) for the entire research period. A shift towards longer rehabilitation periods was discovered.Conclusions: This study showed a significant increase of concussion incidence rate and a trend towards longer rehabilitation periods due to concussion. Possible risk factors were discussed. Risk behaviour and rehabilitation protocols should be prioritized areas in the research of concussion in ice hockey. 

  • 7. Pauelsen, Mascha
    et al.
    Nyberg, Lars
    Luleå University of Technology, Department of Health Sciences, Health and Rehab.
    Röijezon, Ulrik
    Luleå University of Technology, Department of Health Sciences, Health and Rehab.
    Vikman, Irene
    Luleå University of Technology, Department of Health Sciences, Health and Rehab.
    Fear, morale, and physical performance, not past falls, mediate fallsefficacy in community dwelling older people2017In: WCPT 2017 congress proceedings, 2017Conference paper (Refereed)
    Abstract [en]

    Background: Fallrelatedconcerns have a large impact on wellbeing,balance performance and future falls. Theprimary focus in fallrelatedconcern research has generally been related to physical factors andprevious falls. This is mirrored by the use of the traditional fear avoidance model for falls in clinicalsettings, in which actual falls play a pivotal part in creating and perpetuating the cycle of fear activityavoidance fallsfear.Many researchers and clinicians, however, have started toacknowledge that more factors play a part in this complex issue.

    Purpose: We aimed at investigating fallsefficacyin relation to several psychological, demographic andphysical factors in an effort to discover a more fitting model for explaining fallrelatedconcern.

    Methods: We have visited a random population sample of 115 people, aged 70 or more and living in amunicipality in Northern Sweden. The participants were assessed for falls efficacy by means of theFalls Efficacy Scale International(FESI).We also collected data on selected potential covariatessuch as fear of falling, fall consequence concerns, falls history, physical performance, activity,cognitive performance, morale, medication and selected demographics. We then used multipleregression analyses in order to model covariate associations to prevalence and degree of fallrelatedconcern.

    Results: The analyses show the following: The sample presents a median FESIscore of 21, and 36 % (CI.95limits: 27 %; 44 %) score 22 or higher, indicating poor fallrelatedefficacy. Further, 39% (CI.95 limits:30 %; 48 %) express some degree of fear of falling while 54 % (CI.95 limits: 45 %; 63 %) areconcerned about sustaining injuries from a fall (consequence concern). The correlation betweenfear of falling and falls efficacy seems weak (r = .55), indicating related but separate phenomena.Moreover, data indicate no significant associations between previous falls and falls efficacy, fear offalling, or consequence concern. On the other hand, FESIscores seem to be explained to a degreeof 48 % by the three variables physical performance, fear of falling, and morale (as measured by thePhiladelphia Geriatric Centre Morale scale).

    Conclusion(s): These findings may contribute to a better understanding of fallrelatedconcerns. Perhaps fear,morale, and physical ability are stronger mediators than actual falls experience in itself. If so, thiswould call for the development of a new model which more adequately describes how fallrelatedconcerns are mediated while excluding falls as a cause.

    Implications: The clinical implications of this model would mean a shift to include more psychosocial aspects toreduce fallrelatedconcern and risk of falling. An approach directed more towards morale, as well asincreasing efficacy and improving physical performance.

  • 8.
    Mamikoglu, Umut
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Nikolakopoulos, George
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Pauelsen, Mascha
    Luleå University of Technology, Department of Health Sciences, Health and Rehab.
    Varagnolo, Damiano
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Röijezon, Ulrik
    Luleå University of Technology, Department of Health Sciences, Health and Rehab.
    Gustafsson, Thomas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Elbow Joint Angle Estimation by Using Integrated Surface Electromyography2016In: 24th Mediterranean Conference on Control and Automation (MED): June 21-24, Athens, Greece, 2016, Piscataway, NJ: IEEE Communications Society, 2016, p. 785-790, article id 7535891Conference paper (Refereed)
    Abstract [en]

    Electromyography (EMG) signals represent the electrical activation of skeletal muscles and contain valuable information about muscular activity. Estimation of the joint movements by using surface EMG signals has great importance as a bio-inspired approach for the control of robotic limbs and prosthetics. However interpreting surface EMG measurements is challenging due to the nonlinearity and user dependency of the muscle dynamics. Hence it requires complex computational methods to map the EMG signals and corresponding limb motions. To solve this challenge we here propose to use an integrated EMG signal to identify the EMG-joint angle relation instead of using common EMG processing techniques. Then we estimate the joint angles for elbow flexion-extension movement by using an auto-regressive integrated moving average with exogenous input (ARIMAX) model, which takes integrated EMG measurements as input. The experiments showed that the suggested approach results in a 21.85% average increase in the estimation performance of the elbow joint angle compared to the standard EMG processing and identification.

  • 9.
    Mamikoglu, Umut
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Andrikopoulos, Georgios
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Nikolakopoulos, George
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Röijezon, Ulrik
    Luleå University of Technology, Department of Health Sciences, Health and Rehab.
    Pauelsen, Mascha
    Luleå University of Technology, Department of Health Sciences, Health and Rehab.
    Gustafsson, Thomas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Electromyography Based Joint Angle Estimation and Control of a Robotic Leg2016In: 6th IEEE RAS and EMBS International Conference on Biomedical Robotics and Biomechatronics (BioRob 2016): June 26-29, Singapore, 2016, Piscataway, NJ: IEEE Communications Society, 2016, p. 182-187, article id 7523619Conference paper (Refereed)
    Abstract [en]

    Musculoskeletal modeling based on Electromyography (EMG) has many applications in physiotherapy and biologically-inspired robotics. In this article, a novel methodology for the modeling of the dynamics of an antagonistic muscle pair that actuates the human ankle joint movements will be established. As it will be presented, the musculoskeletal model is based on a multi input single output (MISO) auto-regressive integrated moving average with exogenous input (ARIMAX) model, which takes the integrated EMG measurements as input and estimates the corresponding joint angles. Based on this methodology, a Pneumatic Artificial Muscle (PAM) robotic leg setup that mimics the flexion/extension movement of human ankle joint is controlled to replicate the human movement. The experimental results demonstrate the performance of EMG based joint angle estimation and control of the robotic leg with the proposed model.

  • 10.
    Pauelsen, Mascha
    et al.
    Luleå University of Technology, Department of Health Sciences, Health and Rehab.
    Tegner, Yelverton
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Hjärnskakning i hockey: en studie över 29 säsonger2015Conference paper (Other academic)
    Abstract [sv]

    Hockey är en intensiv sport med en stor risk för commotio. Syftet med studien var att analysera förändring i incidensen av commotio över en 29-års period i ett svenskt elit hockeylag. Under åren 1985-2013 gjordes en prospektiv skaderegistrering i laget. Alla skador som föranledde avbrytande eller bortovaro från match/träning registrerades. skadeorsak, -tidpunkt, -mekanism etc. och närvaro på match/träning registrerades i ett skaderegistreringsprogram (ISIS). Skadedefinitionen på commotio var - förutom under första året - densamma över hela perioden och alla diagnoser ställdes av en och samma läkare. Under studieperioden var 267 spelare med i laget. Totalt registrerades 1628 traumatiska skador och av dessa var 162 (10%) commotio. Incidensen av commotio varierade från 0/1000 matcher under första säsongen till 118/1000 matcher under den sista säsongen. De flesta (85%) av commotio inträffade under match. Bortovaron pga commotio ökade från 0 dagar till 10 dagar per commotio (p<0,001) under studieperioden. Denna kohortstudie visar på en ökning av commotio incidensen över en 29 års period. Vidare ökar bortovaron från match/träning tydande på att skadorna blir allvarligare.

  • 11.
    Pauelsen, Mascha
    et al.
    Luleå University of Technology, Department of Health Sciences, Health and Rehab.
    Jacobson, Inger
    Luleå University of Technology, Department of Health Sciences, Health and Rehab.
    Larsson, Agneta
    Luleå University of Technology, Department of Health Sciences, Health and Rehab.
    Tegner, Yelverton
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Skadepanorama och riskfaktorer inom Flat Track Roller Derby2014In: Svensk idrottsmedicin, ISSN 1103-7652, Vol. 2014, no 1, p. 22-25Article in journal (Other academic)
  • 12.
    Strandkvist, Viktor
    et al.
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation. Norrbotten County Council.
    Pauelsen, Mascha
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Larsson, Agneta
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Nyberg, Lars
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Vikman, Irene
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Lindberg, Anne
    Umeå University.
    Gustafsson, Thomas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Röijezon, Ulrik
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Hand grip strength is strongly associated with lower limb strength but only weakly with postural control in community-dwelling older adultsManuscript (preprint) (Other academic)
  • 13.
    Strandkvist, Viktor
    et al.
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation. Norrbotten County Council.
    Lindberg, Anne
    Umeå University.
    Larsson, Agneta
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Pauelsen, Mascha
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Stridsman, Caroline
    Luleå University of Technology, Department of Health Sciences, Nursing Care.
    Nyberg, Lars
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Backman, Helena
    Umeå University.
    Röijezon, Ulrik
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Postural control among individuals with and without chronic obstructive pulmonary disease: A study of motor and sensory systems.Manuscript (preprint) (Other academic)
1 - 13 of 13
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf