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Publications (10 of 95) Show all publications
Jafari, H., Pauelsen, M., Röijezon, U., Nyberg, L., Nikolakopoulos, G. & Gustafsson, T. (2019). A novel data driven model of ageing postural control. In: : . Paper presented at EU Falls Festival.
Open this publication in new window or tab >>A novel data driven model of ageing postural control
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2019 (English)Conference paper, Poster (with or without abstract) (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.

National Category
Physiotherapy Robotics
Research subject
Physiotherapy; Robotics and Artificial Intelligence
Identifiers
urn:nbn:se:ltu:diva-76838 (URN)
Conference
EU Falls Festival
Available from: 2019-11-25 Created: 2019-11-25 Last updated: 2019-11-25
Sjöholm, H., Hägg, S., Nyberg, L., Rolander, B. & Kammerlind, A.-S. (2019). The Cone Evasion Walk test: Reliability and validity in acute stroke. Physiotherapy Research International, 24(1), Article ID e1744.
Open this publication in new window or tab >>The Cone Evasion Walk test: Reliability and validity in acute stroke
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2019 (English)In: Physiotherapy Research International, ISSN 1358-2267, E-ISSN 1471-2865, Vol. 24, no 1, article id e1744Article in journal (Refereed) Published
Abstract [en]

OBJECTIVETo estimate the reliability and validity of the Cone Evasion Walk test (CEW), a new test assessing the ability to evade obstacles, in people with acute stroke.

METHODSTo estimate the reliability of the CEW, video recordings of 20 people with acute stroke performing the test were assessed by 10 physiotherapists on two occasions, resulting in a total of 400 ratings. Patients performed the CEW (n = 221), functional ambulation classification (FAC; n = 204), Timed Up and Go (TUG; n = 173), TUG cognitive (TUG-cog; n = 139), Serial 7s attention task from the Montreal Cognitive Assessment (MoCA-S7; n = 127), and the Star Cancellation Test (SCT; n = 151). These tests and side of lesion (n = 143) were used to examine construct validity. The predictive validity was evaluated in relation to falls during the following 6 months (n = 203).

RESULTSThe intraclass correlation coefficients for intrarater and interrater reliability were 0.88-0.98. For validity, there were significant correlations between the CEW and FAC (rs  = -0.67), TUG (rs  = 0.45), MoCA-S7 (rs  = -0.36), and SCT total score (rs  = -0.36). There was a significant correlation between the number of cones touched on the left side and the proportion of cancelled stars on the left (rs  = -0.23) and right (rs  = 0.23) side in the SCT. Among right hemisphere stroke participants (n = 79), significantly more persons hit cones on the left side (n = 25) than the right side (n = 8), whereas among those with a left hemisphere stroke (n = 64) significantly more persons hit cones on the right side (n = 11) than the left (n = 3). Cox regression showed that participants who touched four to eight cones had an increased risk of falls over time (hazard ratio 2.11, 95% CI [1.07, 4.17]) compared with those who touched none.

Place, publisher, year, edition, pages
John Wiley & Sons, 2019
National Category
Physiotherapy
Research subject
Physiotherapy
Identifiers
urn:nbn:se:ltu:diva-70874 (URN)10.1002/pri.1744 (DOI)000459566500004 ()30209845 (PubMedID)2-s2.0-85053302585 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-09-17 (svasva)

Available from: 2018-09-17 Created: 2018-09-17 Last updated: 2019-03-27Bibliographically approved
Pauelsen, M., Jafari, H., Vikman, I., Nyberg, L. & Röijezon, U. (2019). Using the frequency power spectrum to learn more about aging postural control and fall-related concerns. In: : . Paper presented at EU Falls Festival.
Open this publication in new window or tab >>Using the frequency power spectrum to learn more about aging postural control and fall-related concerns
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2019 (English)Conference paper, Oral presentation with published abstract (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.

National Category
Physiotherapy
Research subject
Physiotherapy
Identifiers
urn:nbn:se:ltu:diva-76837 (URN)
Conference
EU Falls Festival
Available from: 2019-11-25 Created: 2019-11-25 Last updated: 2019-11-25
Jafari, H., Pauelsen, M., Röijezon, U., Nyberg, L., Nikolakopoulos, G. & Gustafsson, T. (2018). On Internal Modeling of the Upright Postural Control in Elderly. In: : . Paper presented at 2018 IEEE International Conference on Robotics and Biomimetics (IEEE ROBIO 2018), December 12-15, 2018, Kuala Lumpur, Malaysia..
Open this publication in new window or tab >>On Internal Modeling of the Upright Postural Control in Elderly
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2018 (English)Conference paper, Published paper (Refereed)
National Category
Control Engineering Physiotherapy
Research subject
Control Engineering; Physiotherapy
Identifiers
urn:nbn:se:ltu:diva-72472 (URN)
Conference
2018 IEEE International Conference on Robotics and Biomimetics (IEEE ROBIO 2018), December 12-15, 2018, Kuala Lumpur, Malaysia.
Available from: 2019-01-07 Created: 2019-01-07 Last updated: 2019-09-26
Sjöholm, H., Hägg, S., Nyberg, L. & Kammerlind, A.-S. (2018). Reliability of test procedures for postural reactions in people with acute stroke. International Journal of Therapy and Rehabilitation, 25(11), 576-586
Open this publication in new window or tab >>Reliability of test procedures for postural reactions in people with acute stroke
2018 (English)In: International Journal of Therapy and Rehabilitation, ISSN 1741-1645, E-ISSN 1759-779X, Vol. 25, no 11, p. 576-586Article in journal (Refereed) Published
Abstract [en]

Regaining and maintaining balance requires postural reactions such as righting reactions, equilibrium reactions, and protective reactions. There is a lack of uniform, standardised, and reliable testing procedures for postural reactions. The aim of the present study was to examine the intra- And interrater reliability of a newly developed postural reactions assessment for use in people with acute stroke. Methods: The Postural Reactions Test was developed based on the literature, on previous tests, and on input from an expert panel. A total of 10 physiotherapists assessed a total of 20 video recordings of people with acute stroke performing each postural reaction. These assessments were carried out on two occasions at least 2 weeks apart. The study thus included 400 ratings. Findings: For intrarater reliability, the overall proportion of agreement was 86 - 93% for the different postural reactions. For interrater reliability, the most common score for each participant and the number of physiotherapists giving that score were noted. A median of 9-10 out of 10 physiotherapists scored the same value. Conclusions: The results indicate that the Postural Reactions Test can be used to reliably assess function in people with acute stroke and that the test can complement the existing assessments for people with affected postural control

Place, publisher, year, edition, pages
London: Mark Allen Group, 2018
Keywords
Postural reactions, Reliability, Reproducibility of results, Stroke
National Category
Physiotherapy
Research subject
Physiotherapy
Identifiers
urn:nbn:se:ltu:diva-71813 (URN)10.12968/ijtr.2018.25.11.576 (DOI)000449507100003 ()2-s2.0-85056495810 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-11-29 (inah)

Available from: 2018-11-29 Created: 2018-11-29 Last updated: 2019-09-13Bibliographically approved
Calner, T., Nordin, C., Eriksson, M. K., Nyberg, L., Gard, G. & Michaelson, P. (2017). Effects of a self-guided, web-based activity programme for patients with persistent musculoskeletal pain in primary healthcare: A randomized controlled trial (ed.). European Journal of Pain, 21(6), 1110-1120
Open this publication in new window or tab >>Effects of a self-guided, web-based activity programme for patients with persistent musculoskeletal pain in primary healthcare: A randomized controlled trial
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2017 (English)In: European Journal of Pain, ISSN 1090-3801, E-ISSN 1532-2149, Vol. 21, no 6, p. 1110-1120Article in journal (Refereed) Published
Abstract [en]

BACKGROUNDWeb-based interventions for pain management are increasingly used with possible benefits, but never used in addition to multimodal rehabilitation (MMR). MMR is recommended treatment for persistent pain in Sweden. The aim was to evaluate the effects of a self-guided, web-based programme added to MMR for work ability, pain, disability and health-related quality of life.METHODSWe included 99 participants with persistent musculoskeletal pain in a randomized study with two intervention arms: (1) MMR and web-based intervention, and (2) MMR. Data was collected at baseline, 4 and 12 months. Outcome measures were work ability, working percentage, average pain intensity, pain-related disability, and health-related quality of life.RESULTSThere were no significant effects of adding the web-based intervention to MMR regarding any of the outcome variables.CONCLUSIONSThis trial provides no support for adding a self-guided, web-based activity programme to MMR for patients with persistent musculoskeletal pain.SIGNIFICANCEThe comprehensive self-guided, web-based programme for activity, Web-BCPA, added to multimodal treatment in primary health care had no effect on work ability, pain, disability or health-related quality of life. Future web-based interventions should be tailored to patients' individual needs and expectations

Place, publisher, year, edition, pages
John Wiley & Sons, 2017
National Category
Physiotherapy
Research subject
Physiotherapy
Identifiers
urn:nbn:se:ltu:diva-60945 (URN)10.1002/ejp.1012 (DOI)000403249400015 ()28464364 (PubMedID)2-s2.0-85018759209 (Scopus ID)
Note

Validerad; 2017; Nivå 2; 2017-06-15 (inah)

Available from: 2016-12-06 Created: 2016-12-06 Last updated: 2018-09-13Bibliographically approved
Pauelsen, M., Nyberg, L., Röijezon, U. & Vikman, I. (2017). Fear, morale, and physical performance, not past falls, mediate fallsefficacy in community dwelling older people. In: WCPT 2017 congress proceedings: . Paper presented at World Confederation for Physical Therapy Congress 2017, Cape Town, South Africa, 2-4 July 2017.
Open this publication in new window or tab >>Fear, morale, and physical performance, not past falls, mediate fallsefficacy in community dwelling older people
2017 (English)In: WCPT 2017 congress proceedings, 2017Conference paper, Oral presentation with published abstract (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.

Keywords
Aged, Fallrelated Concern, Morale
National Category
Physiotherapy
Research subject
Physiotherapy
Identifiers
urn:nbn:se:ltu:diva-66094 (URN)
Conference
World Confederation for Physical Therapy Congress 2017, Cape Town, South Africa, 2-4 July 2017
Projects
BAHRT
Funder
Swedish Research Council
Available from: 2017-10-12 Created: 2017-10-12 Last updated: 2018-04-24Bibliographically approved
Johansson Strandkvist, V., Nyberg, L., Larsson, A., Röijezon, U., Stridsman, C. & Lindberg, A. (2016). Project: Physical function and postural control among subjects with Chronic Obstructive Pulmonary Disease – epidemiological and laboratory studies. Paper presented at .
Open this publication in new window or tab >>Project: Physical function and postural control among subjects with Chronic Obstructive Pulmonary Disease – epidemiological and laboratory studies
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2016 (English)Other (Other (popular science, discussion, etc.))
National Category
Physiotherapy
Research subject
Physiotherapy
Identifiers
urn:nbn:se:ltu:diva-36074 (URN)5a5a2cc5-876c-40d5-b493-d23e1c49d521 (Local ID)5a5a2cc5-876c-40d5-b493-d23e1c49d521 (Archive number)5a5a2cc5-876c-40d5-b493-d23e1c49d521 (OAI)
Note

Status: Pågående; Period: 01/11/2015 → …

Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-04-24Bibliographically approved
Ahlmark, D. I., Prellwitz, M., Röding, J., Nyberg, L. & Hyyppä, K. (2015). An Initial Field Trial of a Haptic Navigation System for Persons with a Visual Impairment (ed.). Paper presented at . Journal of Assistive Technologies, 9(4), 199-206
Open this publication in new window or tab >>An Initial Field Trial of a Haptic Navigation System for Persons with a Visual Impairment
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2015 (English)In: Journal of Assistive Technologies, ISSN 1754-9450, E-ISSN 2042-8723, Vol. 9, no 4, p. 199-206Article in journal (Refereed) Published
Abstract [en]

Purpose– The purpose of this paper is to describe conceptions of feasibility of a haptic navigation system for persons with a visual impairment (VI). Design/methodology/approach– Six persons with a VI who were white cane users were tasked with traversing a predetermined route in a corridor environment using the haptic navigation system. To see whether white cane experience translated to using the system, the participants received no prior training. The procedures were video-recorded, and the participants were interviewed about their conceptions of using the system. The interviews were analyzed using content analysis, where inductively generated codes that emerged from the data were clustered together and formulated into categories. Findings– The participants quickly figured out how to use the system, and soon adopted their own usage technique. Despite this, locating objects was difficult. The interviews highlighted the desire to be able to feel at a distance, with several scenarios presented to illustrate current problems. The participants noted that their previous white cane experience helped, but that it nevertheless would take a lot of practice to master using this system. The potential for the device to increase security in unfamiliar environments was mentioned. Practical problems with the prototype were also discussed, notably the lack of auditory feedback. Originality/value– One novel aspect of this field trial is the way it was carried out. Prior training was intentionally not provided, which means that the findings reflect immediate user experiences. The findings confirm the value of being able to perceive things beyond the range of the white cane; at the same time, the participants expressed concerns about that ability. Another key feature is that the prototype should be seen as a navigation aid rather than an obstacle avoidance device, despite the interaction similarities with the white cane. As such, the intent is not to replace the white cane as a primary means of detecting obstacles.

Abstract [en]

Purpose: The purpose of the presented field trial was to describe conceptions of feasibility of a haptic navigation system for persons with a visual impairment.Design/methodology/approach: Six persons with a visual impairment who were white cane users were tasked with traversing a predetermined route in a corridor environment using the haptic navigation system. To see whether white cane experience translated to using the system, the participants received no prior training. The procedures were video-recorded, and the participants were interviewed about their conceptions of using the system. The interviews were analyzed using content analysis, where inductively generated codes that emerged from the data were clustered together and formulated into categories.Findings: The participants quickly figured out how to use the system, and soon adopted their own usage technique. Despite this, locating objects was difficult. The interviews highlighted the desire to be able to feel at a distance, with several scenarios presented to illustrate current problems. The participants noted that their previous white cane experience helped, but that it nevertheless would take a lot of practice to master using this system. The potential for the device to increase security in unfamiliar environments was mentioned. Practical problems with the prototype were also discussed, notably the lack of auditory feedback. Originality/value: One novel aspect of this field trial is the way it was carried out. Prior training was intentionally not provided, which means that the findings reflect immediate user experiences. The findings confirm the value of being able to perceive things beyond the range of the white cane; at the same time, the participants expressed concerns about that ability. Another key feature is that the prototype should be seen as a navigation aid rather than an obstacle avoidance device, despite the interaction similarities with the white cane. As such, the intent is not to replace the white cane as a primary means of detecting obstacles.

National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering Occupational Therapy Physiotherapy
Research subject
Industrial Electronics; Occupational therapy; Physiotherapy
Identifiers
urn:nbn:se:ltu:diva-9514 (URN)10.1108/JAT-01-2015-0002 (DOI)2-s2.0-84946825898 (Scopus ID)82b7a0dc-20a7-44fa-9ca3-e4b39bf01ff8 (Local ID)82b7a0dc-20a7-44fa-9ca3-e4b39bf01ff8 (Archive number)82b7a0dc-20a7-44fa-9ca3-e4b39bf01ff8 (OAI)
Projects
Seende rullstol
Note
Validerad; 2015; Nivå 1; 20150520 (danahl)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Kangas, M., Korpelainen, R., Vikman, I., Nyberg, L. & Jämsä, T. (2015). Sensitivity and false alarm rate of a fall sensor in long-term fall detection in the elderly (ed.). Gerontology, 61(1), 61-68
Open this publication in new window or tab >>Sensitivity and false alarm rate of a fall sensor in long-term fall detection in the elderly
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2015 (English)In: Gerontology, ISSN 0304-324X, E-ISSN 1423-0003, ISSN 0304-324x, Vol. 61, no 1, p. 61-68Article in journal (Refereed) Published
Abstract [en]

Background: About a third of home-dwelling older people fall each year, and institutionalized older people even report a two- or threefold higher rate for falling. Automatic fall detection systems have been developed to support the independent and secure living of the elderly. Even though good fall detection sensitivity and specificity in laboratory settings have been reported, knowledge about the sensitivity and specificity of these systems in real-life conditions is still lacking. Objective: The aim of this study was to evaluate the long-term fall detection sensitivity and false alarm rate of a fall detection prototype in real-life use. Methods: A total of 15,500 h of real-life data from 16 older people, including both fallers and nonfallers, were monitored using an accelerometry-based sensor system with an implemented fall detection algorithm. Results: The fall detection system detected 12 out of 15 real-life falls, having a sensitivity of 80.0%, with a false alarm rate of 0.049 alarms per usage hour with the implemented real-time system. With minor modification of data analysis the false alarm rate was reduced to 0.025 false alarms per hour, equating to 1 false fall alarm per 40 usage hours. Conclusion: These data suggest that automatic accelerometric fall detection systems might offer a tool for improving safety among older people.

Keywords
Accelerometer, Fall detector, Frequent faller, Older people, Specificity
National Category
Physiotherapy
Research subject
Physiotherapy; Centre - eHealth Innovation Centre (EIC)
Identifiers
urn:nbn:se:ltu:diva-7740 (URN)10.1159/000362720 (DOI)000346584900008 ()2-s2.0-84919859862 (Scopus ID)62784925-45d7-44b5-858c-ba7342bf0b85 (Local ID)62784925-45d7-44b5-858c-ba7342bf0b85 (Archive number)62784925-45d7-44b5-858c-ba7342bf0b85 (OAI)
Note

Validerad; 2015; Nivå 2; 20150107 (andbra)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2019-08-20Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-9813-2719

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