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  • 1.
    Albinsson, John
    et al.
    Lund University.
    Brorsson, Sofia
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Lindgren, Finn
    Lund University.
    Rydén Ahlgren, Åsa
    Lund University.
    Cinthio, Magnus
    Lund University.
    Combined use of Iteration, Quadratic Interpolation and an Extra Kernel for high-resolution 2D particle tracking: a first evaluation2010In: 2010 ieee international ultrasonics symposium, New York: IEEE Press, 2010, p. 2000-2003Conference paper (Refereed)
    Abstract [en]

    A novel 2D particle tracking method, that uses 1) iteration, 2) fast quadratic sub-pixel estimation (with only 28 multiplications per movement), and 3) a previous kernel, has been evaluated and compared with a full-search block-matching method. The comparison with high-frequency ultrasound data (40 MHz) was conducted in silico and on phantoms, which comprised lateral, diagonal, and ellipsoidal movement patterns with speeds of 0–15 mm/s. The mean tracking error was reduced by 68% in silico and 71% for the phantom measurements. When only sub-pixel estimation was used, the decrease in the tracking error was 61% in silico and 57% for the phantom measurements. As well as decreasing the tracking error, the new method only used 70% of the computational time needed by the full-search block-matching method. With a fast method having good tracking ability for high-frequency ultrasound data, we now have a tool to better investigate tissue movements and its dynamic functionality.

  • 2.
    Albinsson, John
    et al.
    Lund Univ, Dept Biomed Engn, S-22100 Lund, Sweden..
    Brorsson, Sofia
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Rydén Ahlgren, Åsa
    Lund Univ, Dept Clin Sci, Clin Physiol & Nucl Med Unit, Malmo, Sweden..
    Cinthio, Magnus
    Lund Univ, Dept Biomed Engn, S-22100 Lund, Sweden..
    Improved tracking performance of lagrangian block-matching methodologies using block expansion in the time domain: In silico, phantom and invivo evaluations2014In: Ultrasound in Medicine and Biology, ISSN 0301-5629, E-ISSN 1879-291X, Vol. 40, no 10, p. 2508-2520Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to evaluate tracking performance when an extra reference block is added to a basic block-matching method, where the two reference blocks originate from two consecutive ultrasound frames. The use of an extra reference block was evaluated for two putative benefits: (i) an increase in tracking performance while maintaining the size of the reference blocks, evaluated using in silico and phantom cine loops; (ii) a reduction in the size of the reference blocks while maintaining the tracking performance, evaluated using in vivo cine loops of the common carotid artery where the longitudinal movement of the wall was estimated. The results indicated that tracking accuracy improved (mean - 48%, p<0.005 [in silico]; mean - 43%, p<0.01 [phantom]), and there was a reduction in size of the reference blocks while maintaining tracking performance (mean - 19%, p<0.01 [in vivo]). This novel method will facilitate further exploration of the longitudinal movement of the arterial wall. (C) 2014 World Federation for Ultrasound in Medicine & Biology.

  • 3.
    Bergman, Stefan
    et al.
    FoU Spenshult, Halmstad, Sweden; The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden & Lund University, Lund, Sweden.
    Bremander, Ann
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine. FoU Spenshult, Halmstad, Sweden & Lund University, Lund, Sweden.
    Bergman, Anna-Carin
    Sannarpsgymnasiet, Halmstad, Sweden.
    Brorsson, Sofia
    Health and Welfare, Dalarna University, Falun, Sweden.
    Chronic Widespread Pain in Adolescents Is Highly Associated to Stress and Anxiety2015In: Arthritis & Rheumatology, ISSN 2326-5191, E-ISSN 2326-5205, Vol. 67, no Suppl. S10, article id 917Article in journal (Refereed)
    Abstract [en]

    Background/Purpose: Chronic widespread pain (CWP), one of the hallmarks of fibromyalgia, is not uncommon in adolescents and it has previously been shown that adolescents with pain often become young adults with pain. CWP often co-varies with anxiety, depression, and stress symptoms in adults, but the knowledge regarding this is small in youth and young adults.

    The aim was to study the associations between CWP, anxiety, depression and stress in adolescents attending first year of high school.

    Methods: A computerized questionnaire to 296 adolescents attending Swedish high school, with validated questions regarding presence and distribution of pain (Epipain mannequin), stress symptoms (ELO question), anxiety and depression (Hospital Anxiety and Depression Scale – HADS), and health related quality of life (HRQL as measured by EQ5D). Pain was considered chronic when persistent for more than three months, and the subgroup CWP was defined according to the 1990 ACR criteria for fibromyalgia. Statistical analyses in SPSS v21 with comparison of means by Student’s t-test and proportions by chi2-test or Fischer’s exact test.

    Results: 257 (87%) out of 296 eligible students, mean (SD) age 16.1 (0.7) and 65.8% girls, responded to the questionnaire.  Prevalence of chronic pain was 20.8% and that of the subgroup CWP was 4.7%, without any gender differences (boys 18.2% vs girls 22.2%; p=0.224, and 3.4% vs 5.4%; p=0.692). High level (4 or 5 on a 5 point scale) of stress symptoms were less common in boys (16.0% vs 28.2%; p=0.015), as was possible or probable anxiety (17.1% vs 44.4%; p<0.001), but not depression (10.3% vs 12.5%; p=0.764). Students with high level of stress reported CWP five times more often than those with less stress (30.4% vs 5.8%; p=0.001). Students with probable anxiety reported CWP ten times more often than students with no anxiety (17.6% vs 1.8%; p=0.001), and CWP was also more common, but not statistically significant, in students with probable depression (20.0% vs 3.1%; p=0.163). Those reporting CWP had significantly lower HRQL (0.58 vs 0.87; p=0.038) than students with no chronic pain.

    Conclusion: The high prevalence of chronic pain and the strong associations between CWP and reports of stress and anxiety in adolescents highlights that a multifactorial background to chronic pain must be considered early in life. An apparent lower score in EQ5D also indicates that the presence of CWP has an marked impact on HRQL also in adolescents.

  • 4.
    Brorsson, S.
    et al.
    Health and Welfare, Dala Sports Academy, Dalarna University, Falun, Sweden.
    Thorstensson, C.
    Department of Clinical Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden.
    Nilsdotter, A.
    Department of Research and Education, Halmstad County Hospital, Halmstad, Sweden.
    Bremander, Ann
    Department of Clinical Sciences, Lund, Section of Rheumatology, Lund University, Lund, Sweden.
    Two different sets of handexercises improved grip strength after after eight weeks in patients with arthritis2014In: Annals of the Rheumatic Diseases, ISSN 0003-4967, E-ISSN 1468-2060, Vol. 73, no Suppl. 2, p. 1210-1210Article in journal (Refereed)
    Abstract [en]

    Background Hand function measured as grip force and finger extension force is often impaired in patients with rheumatoid arthritis (RA) and hand osteoarthritis (HOA) affecting performance of daily activities why hand exercises are recommended. A number of hand exercises are often used in the clinic but there is little information about “the effects of a minimal set of hand exercises” and if the choice of exercises is important to improve strength and function in the hand.

    Objectives To study the effect on grip- and finger extension strength and patient reported hand function from two different sets of handexercises performed over 8 weeks using a randomized study design.

    Methods Female patients with arthritis (RA and HOA, n=121) were randomly assigned to two different sets of handexercises (HE) for 8 weeks. The four hand exercises applied in the program were exercises commonly used in traditional hand training programs. The exercises were split into two groups depending on if the muscle activation (measured with EMG) were greater in forearm flexor (HE I, n=62) or in extensor muscles (HE II, n=59) (REF). HE I: isolated finger opposition (digits II-V) and rolling the putty with a flat hand, HE II: squeezing the putty and finger extension with putty resistance. The two HE were performed daily and each set was repeated 15 times, training time per day was maximum 5 minutes 7 days/week.

    Grip strength was measured with Grippit and finger extension strength with EX-it both validated instruments (unit: N). Pain was measured with a Visual Analogue Scale (VAS), 0-10 (best to worst). Hand functions were evaluated with the patient reported questionnaire Quick Disability Arm Shoulder and Hand (QuickDASH), 0-100 (best to worst).

    Results Mean grip strength (p=0.01) and mean finger extension force (p=0.004) increased after the training period in the group using HE I. In HE II the mean finger extension force increased (p=0.044), table 1. Hand function was stable over the training period.

    Table 1.

    Descriptive data of finger extension (EXIT) force and grip strength in the right hand, hand function (QuickDASH) and VAS pain presented as mean ± SD (min–max)

    Conclusions Five daily minutes with two hand exercises resulted increased grip strength and finger extension force after eight weeks. We suggest that hand exercises should be combined and selected to improve both flexor and extensor muscle strength of the forearm.

  • 5.
    Brorsson, Sofia
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Biomechanical studies of finger extension function. Analysis with a new force measuring device and ultrasound examination in rheumatoid arthritis and healthy muscles2008Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Aims:

    The overall aim of this thesis was to further our understanding of extensor muscles and their role for hand function.

    The aims of the studies were:

    To develop and evaluate a new device for finger extensor force measurements. To evaluate ultrasound as a tool for assessment of muscle architecture. To determine the correlation between extensor muscle force and hand function. To evaluate the degree of impaired finger extensor force in rheumatoid arthritis (RA) and the correlation to impaired... mer hand function. To analyse the effect of hand exercise in RA patients and healthy subjects with ultrasound and finger extension force measurements.

    Method:

    A new finger extension force measuring device was developed and an ultrasound based method was used to be able to objectively measure the finger extension force and analyze the static and dynamic extensor muscle architectures. Measurements were made of healthy volunteers (n=127) and RA patients (n=77) during uninfluenced and experimental conditions. A hand exercise program was performed and evaluated with hand force measurements, hand function test, patient relevant questionnaires (DASH and SF-36) and ultrasound measurements.

    Results:

    The new finger extension force measurement device was developed and then validated with measurements of accuracy as well as test-retest reliability. The coefficient of variation was 1.8 % of the applied load, and the test-retest reliability showed a coefficient of variation no more than 7.1% for healthy subjects. Ultrasound examination on m. extensor digitorum communis (EDC) showed significant differences between healthy men and healthy women as well as between healthy women and RA patients. The extension and flexion force improved in both groups after six weeks of hand exercise (p<0.01). Hand function improved in both groups (p<0.01). The RA group showed improvement in the results of the DASH questionnaire (p<0.05). The cross-sectional area of the EDC increased significantly in both groups.

    Conclusions:

    A new finger extension force measuring device has been developed which provides objective and reliable data on the extension force capacity of normal and dysfunctional hands and is sufficiently sensitive to evaluate the effects of hand exercise. US provide useful information about muscle architecture. A significant improvement of hand strength and hand function in RA patients was seen after six weeks of hand training, the improvement was even more pronounced after 12 weeks. Hand exercise is thus an effective intervention for RA patients, providing better strength and function.

  • 6.
    Brorsson, Sofia
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS).
    Biomechanical studies on hand function in rehabilitation2012In: Human Musculoskeletal Biomechanics / [ed] Tarun Goswami, New York: InTech, 2012, p. 87-106Chapter in book (Other academic)
  • 7.
    Brorsson, Sofia
    Halmstad University, School of Business and Engineering (SET), PRODEA: Centrum för produktframtagning inom hälsoteknik. Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Extensor muscle force measurements and muscle architecture in rheumatoid arthritis patientsArticle in journal (Refereed)
  • 8.
    Brorsson, Sofia
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Extensor muscle force measurements and muscle architecture in Rheumatoid Arthritis patients2009Conference paper (Refereed)
    Abstract [en]

    Although rheumatoid arthritis (RA) patients frequently experience muscle weakness, limited information exists on disease specific muscle changes. The common hand deformity in RA includes disturbed finger extension with subsequent flexion deformities. The aims of this study were to measure finger extension force and finger flexion force in patients with rheumatoid arthritis and compare them with healthy subjects.  We also wanted to explore the possible causes of impaired finger extension force with the help of ultrasound muscle analyses.

    The study group comprised of 40 women: 20 patients with RA (median disease duration 20 years) and 20 healthy age-matched controls. The finger extension force measurements were performed with a newly developed device (EX-it), finger flexion force was measured with the Grippit. The extensor digitorum communis muscle was examined with ultrasound.

    Significant differences were found between the two groups, concerning extension and flexion force (p<0.001). Ultrasound measurements indicated significant differences in structural parameters (Cross Section Area (p< 0.05), muscle thickness (p < 0.05) and fascicle length (p < 0.05)). Overall changes in muscle architecture during contraction were more pronounced in the control group than in the RA group (p < 0.01).

    The results indicate differences in structural parameters as well as functional tests, i.e. contraction time and extension muscle force capacity, between normal and RA muscles. Whether these differences depend on a disease-specific effect on the muscles in RA, or are secondary to inactivity or hand deformities, remains to be elucidated.

  • 9.
    Brorsson, Sofia
    et al.
    Dalarna University, Falun, Sweden.
    Bremander, Ann
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS). Spenshult Hospital, Oskarström, Sweden.
    Qualitative differences in the muscle activities in the forearm flexor and extensor muscles in healthy men and women in different ages2012In: Annals of the Rheumatic Diseases, ISSN 0003-4967, E-ISSN 1468-2060, Vol. 71, no Suppl. 3, p. 755-755Article in journal (Refereed)
    Abstract [en]

    Background:

    Balance between flexor and extensor muscle activity is essential for optimal function. This has been demonstrated previously for the lower extremity, trunk and shoulder function, but information on the relationship in hand function is lacking.

    Objectives:

    The purpose of this study was to evaluate whether there are qualitative differences in finger extension force, grip force, force duration, force balance and the muscle activities in the forearm flexor and extensor muscles in healthy men and women in different ages.

    Methods:

    Healthy controls (men, n=65, women, n=40) were included. Primary outcome was muscle activity measured with S-EMG and finger flexion- and finger extension force in Newton (N). The maximal force from the first trial was used as reference value (maximal voluntary isometric contraction, MVIC). The S-EMG activity of the m. extensor digitorum communis (EDC) and the m. flexor carpi radialis (FCR) were measured on the dominant hand when performing seven clinically often used hand exercises. Hand function was also evaluated with the self-reported questioner Quick DASH and VAS pain and VAS stiffness.

    Results:

    The force balance between finger extension and flexion force was statistically significant for both men (r=0.51, p=0.000) and women (r=0.78, p=0.000). The finger extension force was not influenced by age, but flexion force was significantly correlated to age. The coefficient of determination showed that age and gender can explain 45-55% of differences in the force measurements. Muscle activity from hand exercises was significant related to gender for EDC and muscle activity in FCR showed significantly relation to age. Only 3 of the 7 hand exercise were adjustable for both men and women unrelatedly to age. Concerning the muscle activation in EDC and FCR in daily activities, the age and gender explain 31% respectively 19% of the differences.

    Conclusions:

    This study shows that there are differences between men and women's hand force capacity and that gender and age can explain 45-55% of the differences. Furthermore this study shows that the EDC muscle is related to gender and FCR is related to age. In a longer perspective this information is useful for designing optimal training program for adjusted for gender and age.

    References:

    Greig M, Wells R. A systematic exploration of distal arm muscle activity and perceived exertion while applying external forces and moments. Ergonomics. [Research Support, Non-U.S. Gov't]. 2008 Aug;51(8):1238-57.

    Nordenskiold U, Grimby G. Assessments of disability in women with rheumatoid arthritis in relation to grip force and pain. Disabil Rehabil. 1997 Jan;19(1):13-9.

    Kapandji I. The physiology of the joints - annotated diagrams of the mechanics of the human joints. Edingburgh London, Melborne and New York: Churchill Livingstone; 1982.

    Brorsson S, Nilsdotter A, Sollerman C, Baerveldt AJ, Hilliges M. A new force measurement device for evaluating finger extension function in the healthy and rheumatoid arthritic hand. Technol Health Care. 2008;16(4):283-92.

    Disclosure of Interest: None Declared

  • 10.
    Brorsson, Sofia
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS).
    Gelzinis, Adas
    Kaunas University of Technology, Kaunas, Lithuania.
    Tonkonogi, Michail
    Dalarna University, Falun, Sweden.
    Verikas, Antanas
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Differences in the muscle activities in the forearm muscles in healthy men and women2012In: Proceedings of the XIXth Congress of the International Society of Electrophysiology & Kinesiology / [ed] Kylie Tucker et al., Brisbane, Australia, 2012, p. 437-437Conference paper (Refereed)
    Abstract [en]

    Balance between flexor and extensor muscle activity is essential for optimal function. This has been demonstrated previously for the lower extremity, trunk and shoulder function, but information on the relationship in hand function is lacking. AIM: Was to evaluate whether there are qualitative differences in finger extension force(fef), grip force, force duration, force balance and the muscle activities in the forearm flexor and extensor muscles in healthy men and women in different ages. 

  • 11.
    Brorsson, Sofia
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS).
    Hilliges, Marita
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS).
    Sollerman, Christer
    R & D centre Spenshult Hospital for Rheumatic Diseases, Halmstad, Sweden.
    Nilsdotter, Anna
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS).
    6 weeks of hand exercise significantly improved the hand-strength and -function in Rheumatoid Arthritis patients2008Conference paper (Refereed)
  • 12.
    Brorsson, Sofia
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS).
    Hilliges, Marita
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS).
    Sollerman, Christer
    Department of Hand Surgery, Sahlgrenska University Hospital, Göteborg.
    Nilsdotter, Anna
    R & D Center, Spenshults Hospital of Rheumatic Diseases .
    A six-week hand exercise programme improves strength and hand function in patients with rheumatoid arthritis2009In: Journal of Rehabilitation Medicine, ISSN 1650-1977, E-ISSN 1651-2081, Vol. 41, no 5, p. 338-342Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE:

    To evaluate the effects of hand exercise in patients with rheumatoid arthritis, and to compare the results with healthy controls.

    METHODS:

    Forty women (20 patients with rheumatoid arthritis and 20 healthy controls) performed a hand exercise programme. The results were evaluated after 6 and 12 weeks with hand force measurements (with a finger extension force measurement device (EX-it) and finger flexion force measurement with Grippit). Hand function was evaluated with the Grip Ability Test (GAT) and with patient relevant questionnaires (Disability of the Arm, Shoulder, and Hand (DASH) and Short Form-36). Ultrasound measurements were performed on m. extensor digitorum communis for analysis of the muscle response to the exercise programme.

    RESULTS:

    The extension and flexion force improved in both groups after 6 weeks (p < 0.01). Hand function (GAT) also improved in both groups (p < 0.01). The rheumatoid arthritis group showed improvement in the results of the DASH questionnaire (p < 0.05). The cross-sectional area of the extensor digitorum communis increased significantly in both groups measured with ultrasound.

    CONCLUSION:

    A significant improvement in hand force and hand function in patients with rheumatoid arthritis was seen after 6 weeks of hand training; the improvement was even more pronounced after 12 weeks. Hand exercise is thus an effective intervention for rheumatoid arthritis patients, leading to better strength and function.

  • 13.
    Brorsson, Sofia
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Lundgren, Lina
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS).
    Olsson, Charlotte
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS).
    Ett fysiologiskt perspektiv på fysisk aktivitet och hälsa2010In: Hälsa & Livsstil: forskning och praktiska tillämpningar / [ed] Lillemor R-M Hallberg, Lund: Studentlitteratur, 2010, 1, p. 87-112Chapter in book (Other academic)
  • 14.
    Brorsson, Sofia
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Nilsdotter, Anna
    R & D centre Spenshult Hospital for Rheumatic Diseases, Oskarström, Sweden.
    Hilliges, Marita
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS).
    Sollerman, Christer
    R & D centre Spenshult Hospital for Rheumatic Diseases, Oskarström, Sweden & Sahlgrenska Academy, Gothenburg, Sweden.
    Aurell, Ylva
    Department of Diagnostic Radiology, Halmstad Central Hospital, Halmstad, Sweden.
    Ultrasound evaluation in combination with finger extension force measurements of the forearm musculus extensor digitorum communis in healthy subjects2008In: BMC Medical Imaging, ISSN 1471-2342, E-ISSN 1471-2342, Vol. 8, article id 6Article in journal (Refereed)
    Abstract [en]

    Background:

    The aim of this study was to evaluate the usefulness of an ultrasound-based method of examining extensor muscle architecture, especially the parameters important for force development. This paper presents the combination of two non-invasive methods for studying the extensor muscle architecture using ultrasound simultaneously with finger extension force measurements.

    Methods:

    M. extensor digitorum communis (EDC) was examined in 40 healthy subjects, 20 women and 20 men, aged 35-73 years. Ultrasound measurements were made in a relaxed position of the hand as well as in full contraction. Muscle cross-sectional area (CSA), pennation angle and contraction patterns were measured with ultrasound, and muscle volume and fascicle length were also estimated. Finger extension force was measured using a newly developed finger force measurement device.

    Results:

    The following muscle parameters were determined: CSA, circumference, thickness, pennation angles and changes in shape of the muscle CSA. The mean EDC volume in men was 28.3 cm3 and in women 16.6 cm3. The mean CSA was 2.54 cm2 for men and 1.84 cm2 for women. The mean pennation angle for men was 6.5° and for women 5.5°. The mean muscle thickness for men was 1.2 cm and for women 0.76 cm. The mean fascicle length for men was 7.3 cm and for women 5.0 cm. Significant differences were found between men and women regarding EDC volume (p < 0.001), CSA (p < 0.001), pennation angle (p < 0.05), muscle thickness (p < 0.001), fascicle length (p < 0.001) and finger force (p < 0.001). Changes in the shape of muscle architecture during contraction were more pronounced in men than women (p < 0.01). The mean finger extension force for men was 96.7 N and for women 39.6 N. Muscle parameters related to the extension force differed between men and women. For men the muscle volume and muscle CSA were related to extension force, while for women muscle thickness was related to the extension force.

    Conclusion:

    Ultrasound is a useful tool for studying muscle architectures in EDC. Muscle parameters of importance for force development were identified. Knowledge concerning the correlation between muscle dynamics and force is of importance for the development of new hand training programmes and rehabilitation after surgery.

    © 2008 Brorsson et al; licensee BioMed Central Ltd.

  • 15.
    Brorsson, Sofia
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS).
    Nilsdotter, Anna
    Department of Research and Education, Halmstad County Hospital, Halmstad, Sweden.
    Pedersen, Eja
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS).
    Bremander, Ann
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS).
    Thorstensson, Carina
    Research and Development Centre, Spenshult Hospital for Rheumatic Diseases, Oskarström, Sweden.
    Relationship between finger flexion and extension force in healthy women and women with rheumatoid arthritis2012In: Journal of Rehabilitation Medicine, ISSN 1650-1977, E-ISSN 1651-2081, Vol. 44, no 7, p. 605-608Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: Balance between flexor and extensor muscle activity is essential for optimal function. The purpose of this pilot study was to compare the relationship between maximum finger flexion force and maximum finger extension force in women with rheumatoid arthritis and healthy women.

    METHODS: Twenty healthy women (median age 61 years) and 20 women with rheumatoid arthritis (median age 59.5 years, median disease duration 16.5 years) were included in the study. Finger extension force was measured with an electronic device, EX-it, and finger flexion force using Grippit. The Grip Ability Test and the score from the patient-reported outcome Disability Arm Shoulder and Hand were used to evaluate activity limitations.

    RESULTS: Patients with rheumatoid arthritis showed significantly decreased hand function compared with healthy controls. A correlation was found between extension force and flexion force in the healthy group (r = 0.65, p = 0.002),but not in the rheumatoid arthritis group (r = 0.25, p = 0.289).

    CONCLUSION: Impaired hand function appears to influence the relationship between maximum finger flexion and extension force. This study showed a difference in the relationship between maximum finger flexion and extension force in healthy controls and those with rheumatoid arthritis. © 2012 Foundation of Rehabilitation Information.

  • 16.
    Brorsson, Sofia
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Nilsdotter, Anna
    R & D Center, Spenshult Hospital of Rheumatic Diseases, Halmstad, Sweden.
    Sollerman, Christer
    Department of Hand Surgery, Sahlgrenska University Hospital, Göteborg, Sweden.
    Baerveldt, Albert-Jan
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Hilliges, Marita
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    A new force measurement device for evaluating finger extension function in the healthy and rheumatoid arthritis hand2008In: Technology and Health Care, ISSN 0928-7329, E-ISSN 1878-7401, Vol. 16, no 4, p. 283-292Article in journal (Refereed)
    Abstract [en]

    Although often neglected, finger extension force is of great importance for developing grip strength. This paper describes the design and evaluation of a new finger extension force measurement device (EX-it) based on the biomechanics of the hand. Measurement accuracy and test-retest reliability were analysed. The device allows measurements on single fingers as well as all the fingers (excluding the thumb) of both healthy and deformed hands. The coefficient of variation in the device was 1.8% of the applied load, and the test-retest reliability showed a coefficient of variation no more than 7.1% for healthy subjects. This study also provides reference values for finger extension force in healthy subjects and patients with rheumatoid arthritis (RA). Significant differences were found in extension strength between healthy subject and RA patients (men, p < 0.05 and women, p < 0.001). EX-it provides objective and reliable data on the extension force capacity of normal and dysfunctional hands and can be used to evaluate the outcome of therapeutic interventions after hand trauma or disease

  • 17.
    Brorsson, Sofia
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS). Health and Welfare, Dala Sports Academy, Dalarna University, Falun, Sweden.
    Nilsdotter, Anna
    Department of Research and Education, Halmstad County Hospital, Halmstad, Sweden.
    Thorstensson, Carina
    Department of Clinical Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden & Department of Medicine, Solna, Karolinska Institutet, Stockholm, Sweden.
    Bremander, Ann
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS). Department of Clinical Sciences, Lund, Section of Rheumatology, Lund University, Lund, Sweden & Research and Development Center, Spenshult, Oskarström, Sweden.
    Differences in muscle activity during hand-dexterity tasks between women with arthritis and a healthy reference group2014In: BMC Musculoskeletal Disorders, ISSN 1471-2474, E-ISSN 1471-2474, Vol. 15, no 1, article id 154Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Impaired hand function is common in patients with arthritis and it affects performance of daily activities; thus, hand exercises are recommended. There is little information on the extent to which the disease affects activation of the flexor and extensor muscles during these hand-dexterity tasks. The purpose of this study was to compare muscle activation during such tasks in subjects with arthritis and in a healthy reference group.

    METHODS: Muscle activation was measured in m. extensor digitorium communis (EDC) and in m. flexor carpi radialis (FCR) with surface electromyography (EMG) in women with rheumatoid arthritis (RA, n = 20), hand osteoarthritis (HOA, n = 16) and in a healthy reference group (n = 20) during the performance of four daily activity tasks and four hand exercises. Maximal voluntary isometric contraction (MVIC) was measured to enable intermuscular comparisons, and muscle activation is presented as %MVIC.

    RESULTS: The arthritis group used a higher %MVIC than the reference group in both FCR and EDC when cutting with a pair of scissors, pulling up a zipper and-for the EDC-also when writing with a pen and using a key (p < 0.02). The exercise "rolling dough with flat hands" required the lowest %MVIC and may be less effective in improving muscle strength.

    CONCLUSIONS: Women with arthritis tend to use higher levels of muscle activation in daily tasks than healthy women, and wrist extensors and flexors appear to be equally affected. It is important that hand training programs reflect real-life situations and focus also on extensor strength. © 2014 Brorsson et al.; licensee BioMed Central Ltd.

  • 18.
    Brorsson, Sofia
    et al.
    Halmstad University, School of Health and Welfare, Centre of Research on Welfare, Health and Sport (CVHI). Lugnet Institute of Sport Science, Dalarna University, Falun, Sweden.
    Nilsdotter, Anna
    Department of Research and Education, Halmstad Central Hospital, Halmstad, Sweden.
    Thorstensson, Carina
    Research and Development Centre, Spenshult, Oskarström, Sweden.
    Bremander, Ann
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS). Research and Development Centre, Spenshult, Oskarström, Sweden.
    Hand flexor and extensor muscle activity in daily activities and hand exercises in women with rheumatoid arthritis or hand osteoarthritis2012In: Annals of the Rheumatic Diseases, ISSN 0003-4967, E-ISSN 1468-2060, Vol. 71, no Suppl. 3, p. 754-754Article in journal (Refereed)
    Abstract [en]

    Background: Impaired hand grip function is common and occurs early in the course of disease in patients with rheumatoid arthritis (RA) and hand osteoarthritis (HOA), affecting daily life activities and quality of life.

    Objectives: To evaluate muscle force and muscle activity in forearm flexors and extensors during daily activities and clinically well-known hand exercises in women with RA and HOA compared with healthy controls

    Methods: The RA group was consecutively included from a specialist clinic and had a disease duration of at least one year.  Women with HOA were allocated from out-patients primary health care clinics in the same area and clinically diagnosed with symptomatic HOA. The age matched control group had no history of hand/arm injuries, inflammatory or muscle disease. Full active finger extension ability was required for all subjects. Hand force (Newton) was measured with EX-it (extension) and Grippit (flexion), both validated instruments. Muscle activity was measured in m. extensor digitorum communis (EDC) and m. flexor carpi radialis (FCR) with surface EMG (S-EMG) on the dominant hand while performing four daily activities (ADL) and four hand exercises and described as percent of maximal voluntary isometric contraction (% MVIC) based on data from EX-it and Grippit. Pain was measured with Visual Analogue Scale (VAS) 0-10 (best to worst). Differences between groups were analyzed and controlled for age.

    Results: Fifty-six women were included; 20 with RA (age mean (SD) 59.2 (10.7) years, VAS pain 2.2 (1.6)), 16 with HOA (age 67.5 (9.3) years, VAS pain 4.1 (1.9)) and 20 healthy controls (age 56.0 (9.7) years). Women with RA and HOA showed decreased extension and flexion force compared with healthy women (p<0.03).There was a tendency towards higher % MVIC in all tests for women with RA or HOA compared with healthy women, with a statistically significant difference between HOA and healthy women for EDC (p<0.05).

    ADL activities “writing with a pen”, and “cutting with scissors” showed the highest % MVIC in both EDC and FCR in all groups. The exercises “isolated opposition”, and “rolling the dough with flat hands”, had high % MVIC in EDC, while “squeezing the dough” and “isolated opposition” had high % MVIC in FCR.

    Conclusions: Women with RA and HOA tend to use a higher % MVIC than healthy women in many daily activities and in hand exercises. Strengthening exercises should include both extensor and flexor specific training.

    Disclosure of Interest: None Declared

  • 19.
    Brorsson, Sofia
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Nordenskiöld, U.
    Section for Clinical Neuroscience and Rehabilitation, The Sahlgrenska Academy University of Gothenburg, Göteborg, Sweden.
    Grip assistive devices studied in women with reumatic diseases2011In: Abstracts EULAR 2011 London, United Kingdom, 25-28 May 2011, 2011Conference paper (Refereed)
    Abstract [en]

    Background:

    Previous studies have shown that persons with reumatoid disease use assistive devices to manage activites of daily living and that loss of grip force and high factors of pain are the main indicator for the use of assitive devices. Furthermore, these studies have pointed out that activities as open and handle bottles, cans are hard items to performe.

    Objectives:

    This pilot project aimed to evaluate grip assistive devices adapted for people with reduced hand function as grip force and pain also disabilities as difficulties in some daily activities. Furthermore, the project aims to evaluate the participants' reflections and advice about the manageability of the products.

    Methods:

    The test group consisted of 14 female patients (mean age 60 years) with rheumatoid diseases (Rheumatoid arthritis (7), Osteoarthritis (5), Fibromyalgia (1), Psoriasis arthritis (1)). Eight different grip assistive devices, developed for opening and handle cans, bottles and canned food, were evaluated. The grip assistive devices was evaluated using a rated scale from 0-10 (0= not useful, 10=very useful) and the cut-off for classification as useful were at least five points.

    Hand activities were evaluated with the Grip Ability Test (GAT) and the questionnaire Quick DASH (Disability of Arm, Shoulder and Hand). The hand function as pain was marked using visual analogue scale (VAS) and grip force was measured using the electronic grip force device Grippit®.

    Results:

    The hand test, GAT, was 34.2 ± 12.0 points and the Quick DASH was 45.5 ± 18.1, VAS was 3.8 ± 3.0 and mean grip force was 76.1 ± 37.2 Newton. The grip force was correlated to pain (r= - 0.581, p=0.029) and also to DASH (r=-0.641, p=0.014). Furthermore there was a correlation between DASH and VAS (r=0.748, p=0.002). There was no correlation between GAT and Grip force, DASH or VAS. Concerning the grip assistive devices five of the eight devices were rated over six points and perceived as functional and useful for open bottles and cans. There was a significant correlation between grip force and the grip device (r=0.557, p=0.039) most useful for the patients and a tendency for correlation between grip force and the other four grip assistive devices that the patients has rated as useful.

    Conclusions:

    This pilot study shows that grip force is one important factor for patients when it comes to chose grip assistive devices. Furthermore, it is individual what grip assistive devices that will be chosen to perform a specific activity. Therefore it is important to measure both hand function and hand activities to maintain good possibilities to perform an active life style with reduced pain and increased grip force in patients with rheumatic diseases.

    References:

    1. Dellhag, B. and A. Bjelle (1995). "A Grip Ability Test for use in rheumatology practice." J Rheumatol 22 (8):1559-65
    2. Gummesson, C., M. M. Ward, et al. (2006). "The shortened disabilities of the arm, shoulder and hand questionnaire (QuickDASH): validity and reliability based on responses within the full-length DASH." BMC Musculoskelet Disord 7: 44.
    3. Nordenskiold, U (1997). “ Daily activities in women with rheumatoid arthritis. Aspects of patients education, assistive devices and methods for disability and impairment assessment.” Scand J Rehabil Med Suppl 37:1-72.
    4. (2003). “Rheumatoid arthritis: hand function, activities of daily living, grip strength and essential assistive devices.” Curationis 26 (3):98-106.
  • 20.
    Brorsson, Sofia
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Olsson, M Charlotte
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Bengtsson, Oscar
    Petersson, Johan
    Maximal strength in one leg squat correlates with acceleration capacity and agility2010Conference paper (Refereed)
    Abstract [en]

    INTRODUCTION: In many intermittent team sports capacities such as speed, agility and explosiveness are important for performance and are evaluated by sprint-, agility- and strength tests. Earlier studies have shown strong correlations between strength in the two leg squat exercise and sprint performance in various distances but not in sprint performance in agility. Studies evaluating squat strength predominantly perform tests on two legs even when they test athletes involved in intermittent sports where sprinting and agility are common features. Thus, the purpose of this study was to investigate the correlation between maximal strength in a one leg squat (Bulgarian split squat) and acceleration capacity in various sprint distances and agility.

    METHODS: The test group consisted of 19 men (mean age 24 ± 2 years ) with experience in intermittent team sports. Acceleration capacity was assessed by sprint tests at 5, 10 and 20 meters and agility was evaluated using the zigzag agility test. The timing was made using photocells (Muscle lab,Ergotest Technology,Norway). The Bulgarian split squat was performed in a smith machine with the barbell on the shoulders to a depth of 110 degrees between tibia and femur.

    RESULTS: The results show significant correlation between maximal strength in the Bulgarian split squat and sprint capacity in the 5 and 10 meter sprint test (Rp= -0,56; p<0.01) as well as the agility test. Maximal strength relative to bodyweight showed significant correlation with the 5 and 20 meter sprint (Rp=-0,62; p< 0,01) as well as the agility test. The zigzag agility test also showed significant correlation between all distances in the sprint tests (p<0.01).

    CONCLUSION: The results from this study show that there maximal strength in one leg correlate significantly with both acceleration capacity and agility. Implementing one leg exercises in the strength and conditioning routine can be useful for athletes in intermittent sports wanting to improve agility and short sprinting capacity. Further implications is that the Bulgarian split squat could be a more functional test for agility performance than the squat on two legs which  predominantly is being used today.

  • 21.
    Brorsson, Sofia
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Olsson, M Charlotte
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Fredriksson, Daniel
    Training program for young female soccer players with focus on increasing the acceleration capacity2010Conference paper (Refereed)
    Abstract [en]

    INTRODUCTION: Soccer is the world’s most popular team sport with over 240 million players around the world. About 20 million of the 240 million players are women and 80% of these women are adolescence or juniors. Acceleration capacity is one of the most important physical qualities for a soccer player. The aim of this study was to design, perform and evaluate a training program for young female soccer players with focus on increasing the acceleration capacity.

    METHODS: There were 22 young females (14,6 ± 1,0 years, 50,3 ± 5,1 kg, 160,2 ± 3,0 cm) from two different soccer teams participating. They were split into two groups, one test group (TG) (n=8) and one control group (CG) (n=14). The training period was 12 weeks, with soccer training 3 times per week for both groups. In the TG one workout per week was specifically designed to increase the acceleration capacity and took about 40 minutes to perform. The acceleration capacity was evaluated by a sprint test of 10-20-30 meter and vertical countermovement jump test using photocells.

    RESULTS: The TG showed a tendency to increased acceleration at the sprint test (p=0,08) and significant improvement at the jump test (p<0.05) after 12 weeks of training. The acceleration training also showed significant correlations between the sprint- and jump test in the TG after completed the 12 week training period (p<0.05). The CG showed decreased acceleration at the sprint test (p<0.05) and the vertical jump height was not significantly different. There were no significant differences between the two groups pre and post training.

    CONCLUSION: A 12 week training program can increase the acceleration capacity and the vertical jump height on young female soccer players. In sport were acceleration capacity is important it seems relevant to specifically train those qualities.

  • 22.
    Brorsson, Sofia
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Olsson, M Charlotte
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Westerberg, Martin
    Maximal multiple repetitions in free weight strength training with different bar sizes2010Conference paper (Refereed)
    Abstract [en]

    INTRODUCTION: An individual’s grip strength is vital for performance of physical demanding tasks such as give some other example here? As well as strength training with free weights. Performing strength training with a thicker grip around the bar may enhance the strength of the grip in the athlete without other special routines for grip strength development. The purpose of this study was a) to examine the difference in performance in multiple repetitions in two strength training exercises using two different sizes on the bar, b) to investigate correlations between hand grip strength and the amount of repetitions performed with two different sizes of the  bar and c) to correlate hand size with the amount of performed repetitions with two different bar sizes.

    METHODS: Fifteen male participants (24 ± 4 years) with at least one year of strength training experience performed bench press and a prone lying rowing exercise with two different bar sizes (normal Olympic lifting bar with and with out Fat Gripz™). The participants performed test of maximal number of repetitions at a level of 80% of one repetition maximum (1RM), hand size was measured as well as maximum grip strength (using JAMAR).

    RESULTS: The use of a thicker diameter bar resulted in 22 % (p<0.01) reduction of weight performance in number of performed repetitions in the bench press compared to the normal diameter of the bar.  When performing lying bench row a 66 % (p<0.01) reduction in number of performed repetitions was seen with the thicker diameter of the bar. There was no significant correlation between hand size and the submaximal strength test (rp = 0,33 ; p = 0,23) or grip strength and submaximal strength test (rp = 0,31 ; p = 0,27).

    CONCLUSION: The results from this study indicated that the size of the bar diameter influences the performance in maximal number of repetitions in a prone lying rowing exercise and bench press.  Further studies have to be done to analyses the effect of strength training with thicker bar.

     

  • 23.
    Brorsson, Sofia
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Pedersen, Eja
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS).
    12-weeks of hand exercise provides better hand function, muscle balance and muscle strength in the rheumatoid arthritis hand2010In: Abstract Archive Sessions Index 2010, EULAR , 2010Conference paper (Refereed)
    Abstract [en]

    Background:

    Impaired grip ability in RA is due to reduced strength in the flexor muscles as well as by dysfunctional extensor muscles leading to inability to open the hand. Furthermore the extensor muscles are important for stabilization during flexion force production and active for developing a controlled grip force. There is today scientific evidence showing that various forms of hand exercise are beneficial for improving hand function and strength in RA patients (Ronningen and Kjeken 2008; Brorsson, Hilliges et al. 2009). However, comparatively little research has evaluated and specific designed hand exercise program for the extensor muscles controlling the hand and fingers (Weiss, Moore et al. 2004; O'Brien, Jones et al. 2006).

    Objectives:

    The objectives for this study were to evaluate the effect of an exercise program on hand strength, hand function and perceived function of daily life activities among RA patients and to explore the possibility to improve the balance between the extensor and flexor muscle forces in the hand.

    Methods:

    The study group comprised of 20 patients with RA (median disease duration 20 years) that performed a hand exercise program for twelve weeks. The finger extension force was measured with a newly developed device (EX-it), finger flexion force was measured with the Grippit. Hand function was evaluated with the Grip Ability Test (GAT) and self reported questionnaire Disability Arm Shoulder and Hand (DASH).

    Results:

    Hand strength (both extension and flexion force) and hand function improved significantly after twelve weeks. The RA group showed improvement in the results of the DASH questionnaire (p < 0.05), but on individual level, the result was partly significant. The relation between extension and flexion force in the hand was not correlated, however, after the exercise there was a strong association between flexion and extension force (p < 0.001). The result on individual level is related to age and duration time.

    Conclusion:

    Twelve weeks of hand exercise significantly improved hand strength, hand function and perceived function for RA patients. Furthermore, exercise improved the relation between the finger extension and flexion force. Hand exercise is thus an effective intervention for RA patients, providing better strength and function.

    References:

    1. Brorsson, S., M. Hilliges, et al. (2009). A six-week hand exercise programme improves strength and hand function in patients with rheumatoid arthritis. J Rehabil Med 41(5): 338-42.
    2. O'Brien, A.V., P. Jones, et al. (2006). Conservative hand therapy treatments in rheumatoid arthritis–a randomized controlled trial. Rheumatology (Oxford) 45(5): 577-83.
    3. Ronningen, A. and I. Kjeken (2008). ffect of an intensive hand exercise programme in patients with rheumatoid arthritis. Scand J Occup Ther: 1-11.
    4. Weiss, A. P., D. C. Moore, et al. (2004). Metacarpophalangeal joint mechanics after 3 different silicone arthroplasties. J Hand Surg [Am] 29(5): 796-803.
  • 24.
    Lundgren, Lina
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Bligård, Lars-Ola
    Division of Design & Human Factors, Chalmers University of Technology, Gothenburg.
    Brorsson, Sofia
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Osvalder, Anna-Lisa
    Division of Design & Human Factors, Chalmers University of Technology, Gothenburg.
    Implementation of usability analysis to detect problems in the management of kitesurfing equipment2011In: Procedia Engineering, ISSN 1877-7058, E-ISSN 1877-7058, Vol. 13, p. 525-530Article in journal (Refereed)
    Abstract [en]

    Equipment used for high-risk sports, such as kitesurfing, needs to be efficient for the intended use and the user, and thus meet the mechanical demands and provide sufficient safety. Accidents related to kitesurfing occur, and the consequences are sometimes catastrophic. One important factor is the equipment design, which can influence the type and number of injuries due to insufficient safety systems. The aim of this study was to investigate how the design of kitesurfing equipment can affect safety issues from a usability perspective in relation to the task of preparation. A focus group of 6 subjects analyzed the task of preparing kitesurfing equipment for riding, using the evaluation methods Enhanced Cognitive Walkthrough (ECW) and Predictive Use Error Analysis (PUEA). From the evaluation, a list of plausible usability problems was identified together with proposed design guidelines. The results showed that usability problems occur during preparation. In total 35 usability problems were found, of which 11 (4 from ECW and 7 from PUEA) have a great impact on safety. These 11 problems were hard to detect for the user and could result in serious consequences for the kitesurfers during rideing. The analysis resulted in some general guidelines that are possible to implement on different types of kites. To conclude, education and improved design of the equipment are essential to increase the safety of the sport.

  • 25.
    Lundgren, Lina
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Brorsson, Sofia
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Observational analysis of body position while kitesurfing2009Conference paper (Refereed)
  • 26.
    Lundgren, Lina
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS).
    Brorsson, Sofia
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS).
    Hilliges, Marita
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS).
    Osvalder, Anna-Lisa
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS). Chalmers University of Technology, Gothenburg, Sweden.
    Sport performance and perceived musculoskeletal stress, pain and discomfort in kitesurfing2011In: International Journal of Performance Analysis in Sport, ISSN 1474-8185, E-ISSN 1474-8185, Vol. 11, no 1, p. 142-158Article in journal (Refereed)
    Abstract [en]

    The purpose of this study was to obtain an overview of the specific movement patterns in kitesurfing, and the participants' perceptions of musculoskeletal stress, pain and discomfort. Task analysis and survey studies were used to provide an overview of the sport, and to identify problematic issues associated with the performance of the tasks. Three different methods were complimentary used for data collection: observations (n=8), a web questionnaire (n=206) and interviews (n=17). Participants were contacted through kitesurfing events and online forums. Their ages ranged from 16-62 years. The results showed that participants experienced high musculoskeletal stress for short times during a session (jumps, tricks and strong winds), and lower, static musculoskeletal stress over a longer time (crossing). High stress was most frequently perceived in abdominal muscles. Knees and feet were the sites most frequently experienced as painful, followed by the shoulders and elbows. This study provides additional information on the performance of kitesurfing and perceived musculoskeletal stress, pain and discomfort. The results can be used as input data to develop training methods and equipment for safe and comfortable performance. © 2017, Routledge. All rights reserved.

  • 27.
    Lundgren, Lina
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Brorsson, Sofia
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Osvalder, Anna-Lisa
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS).
    Comfort aspects important for the performance and safety of kitesurfing2012In: Work: A journal of Prevention, Assesment and rehabilitation, ISSN 1051-9815, E-ISSN 1875-9270, Vol. 41, no Suppl. 1, p. 1221-1225Article in journal (Refereed)
    Abstract [en]

    Equipment used in sports is of great importance, especially when the equipment is in direct contact with the athlete or is important for safety. In the sport kitesurfing environmental factors and the equipment design are crucial for the comfort and safety. The participants’ choice and opinion of equipment can show which factors are considered most important for the performance and to reduce risk for injury. This study has evaluated self-reported information from the participants about what equipment they use, comfort of the equipment and if the equipment has contributed to any injuries. The methods used were questionnaires (n=206) and interviews (n=17), which in combination allows to assess the problem both quantitatively and qualitatively. The results showed that supported leading edge kites are most frequently used, with a waist harness and foot straps to attach the feet. The choice of kite type was mainly based on the discipline of riding for the respondent. Some issues concerning comfort of riding and injury risk the respondents did relate to the design of harness and foot straps. The information from this study can be used for development strategies for industry manufacturers and for further studies in the area of equipment design and biomechanics. © 2012 - IOS Press and the authors. All rights reserved.

  • 28.
    Lundgren, Lina
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Brorsson, Sofia
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Osvalder, Anna-Lisa
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Injuries related to kitesurfing2011In: World Academy of Science, Engineering and Technology, ISSN 2010-3778, no 77, p. 1132-1136Article in journal (Refereed)
    Abstract [en]

    Participation in sporting activities can lead to injury. Sport injuries have been widely studied in many sports including the more extreme categories of aquatic board sports. Kitesurfing is a relatively new water surface action sport, and has not yet been widely studied in terms of injuries and stress on the body. The aim of this study was to get information about which injuries that are most common among kitesurfing practitioners, where they occur, and their causes. Injuries were studied using an international open web questionnaire (n=206). The results showed that many respondents reported injuries, in total 251 injuries to knee (24%), ankle (17%), trunk (16%) and shoulders (10%), often sustained while doing jumps and tricks (40%). Among the reported injuries were joint injuries (n=101), muscle/tendon damages (n=47), wounds and cuts (n=36) and bone fractures (n=28). Also environmental factors and equipment can influence the risk of injury, or the extent of injury in a hazardous situation. Conclusively, the information from this retrospective study supports earlier studies in terms of prevalence and site of injuries. Suggestively, this information should be used for to build a foundation of knowledge about the sport for development of applications for physical training and product development.

  • 29.
    Lundgren, Lina
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS).
    Olandersson, Sofia
    Halmstad University, School of Business and Engineering (SET), PRODEA: Centrum för produktframtagning inom hälsoteknik.
    Hilliges, Marita
    Halmstad University, School of Business and Engineering (SET), PRODEA: Centrum för produktframtagning inom hälsoteknik.
    Osvalder, Anna-Lisa
    Department of Product- and Production Development, Division of Design Chalmers University of Technology.
    Biomechanics of extreme sports - a kite surfing scenario2007In: NES2007 Abstracts / [ed] Cecilia Berlin & Lars-Ola Bligård, Nordic Ergonomics Society , 2007, p. s.169-Conference paper (Refereed)
    Abstract [en]

    Do extreme sports contribute to higher biomechanical stress compared to other sports? Kite surfing is one of the upcoming popular extreme sports,where very few have studied the mechanical forces that act on the body. There are several factors that contribute to mechanical stress. For preventing injuries, it is of high interest to investigate how these forces affect the body and how the equipment can be further developed to prepare the athletes for making the sport as safe as possible. This project will study injury prevalence, motion analysis and mapping of forces and pressure during kite surfing. The outcome will be a better understanding of biomechanics of kite surfing and a construction for testing and training as well as ergonomic design ideas for the equipment.

  • 30.
    Lundgren, Lina
    et al.
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Zügner, Roland
    Gothenburg University, Gothenburg, Sweden.
    Tranberg, Roy
    Gothenburg University, Gothenburg, Sweden.
    Brorsson, Sofia
    Karolinska Institute, Stockholm, Sweden.
    Osvalder, Anna-Lisa
    Chalmers University of Technology, Gothenburg, Sweden.
    Effect of stance width on kinematics of laboratory landings with fixed feet on a kiteboard2017Conference paper (Refereed)
  • 31.
    Lundgren, Lina
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Zügner, Roland
    Sahlgrenska University Hospital, Gothenburg, Sweden.
    Tranberg, Roy
    Sahlgrenska University Hospital, Gothenburg, Sweden.
    Osvalder, Anna-Lisa
    Chalmers University of Technology, Gothenburg, Sweden.
    Brorsson, Sofia
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS).
    Normalizing stance width2012In: Neuroplasticity, Motor control, Cutting-Edge Technology & Rehabilitation: Proceedings of the XIXth Congress of the International Society of Electrophysiology & Kinesiology / [ed] Kylie Tucker, Bianca Butler and Paul W Hodges, Brisbane: NHMRC Centre of Clinical Research Excellence in Spinal Pain, Injury and Health , 2012, p. 221-221Conference paper (Refereed)
    Abstract [en]

    INTRODUCTION: In previous studies, stance widths are most often determined as a percentage of shoulder width, where 70% of shoulder width is considered a narrow stance width and 140% of shoulder width is considered a wide stance width. A few studies have also normalized stance width to the width of the hips (distance between trochanters). However, there are also a possibility to normalize stance width in relation to the length of the lower extremities, since this variable might not change as much in dynamic situations and may correlate higher to the angle of the lower extremity in a frontal plane. AIM: This study aims to compare measurements of stance width when normalized to shoulder width, hip width and leg length for three different stance widths with feet attached to a board. METHOD: Motion capture (Qualisys, 16 Oqus-cameras) was used to measure 7 active male kitesurfers with their feet attached to a kiteboard (136 cm). They were 20-28 years old, in average 180 cm (SD=7 cm) and 78 kg (SD=7 kg). The subjects were standing with three different stance widths, using the same external rotation (20° bilaterally). Markers were attached to shoulders (acromion processes), knee joint lines, hips (trochanter major), heels (mid-posterior of calcaneus) and ankles (lateral and medial malleoli). Stance width was measured as the distance between the two medial ankle markers and normalized towards the distances between (1) the shoulder markers, (2) the hip markers and knee marker plus knee marker and lateral ankle marker and (3) the right and left hip marker. Furthermore, the angle of an extended lower extremity towards a vertical line in the frontal plane was measured. All measurements were done twice, and SPSS 20 was used for data analysis of correlation (Pearson’s r). RESULTS: The measured stance widths between ankles were 39.9 cm, 43.6 cm, and 48 cm (SD=1.2-1.4) for all subjects. The correlations (r) between the angle of the leg towards a vertical line and normalized stance width for the three normalization variables were: (1) 0.79, (2) 0.96 and (3) 0.93. All of the correlations were significant at a level of p>0.01. CONCLUSION: The results show that the variables hip or leg length would be preferred to use when normalizing stance width for young male athletes, standing in wide stance widths. Further studies using a greater number of subjects, more stance widths and a more heterogeneous group are suggested for the future.

  • 32.
    Malmborg, Julia
    et al.
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Bremander, Ann
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Olsson, M. Charlotte
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Bergman, A.-C.
    Spenshult Research and Development Center, Halmstad, Sweden.
    Brorsson, Sofia
    Spenshult Research and Development Center, Halmstad, Sweden.
    Bergman, Stefan
    Primary Health Care Unit, Department of Public Health and Community Medicine, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    Sleeping Problems and Anxiety is Associated to Chronic Multisite Musculoskeletal Pain in Swedish High School Students2018In: Annals of the Rheumatic Diseases, ISSN 0003-4967, E-ISSN 1468-2060, Vol. 77, no Suppl. 2, p. 226-226, article id OP0361-HPRArticle in journal (Refereed)
    Abstract [en]

    Background: The relationship between chronic multisite musculoskeletal pain (CMP) and sleep is complex, where pain can lead to sleeping problems and lack of sleep can intensify the pain perception. Most previous studies relates to adults, but adolescents may also suffer from CMP, and there is a need for more knowledge regarding the relationships between CMP and sleeping problems, stress, anxiety, depression, and health status.

    Objectives: To study background factors associated to CMP in first year Swedish high school students.

    Methods: First year Swedish high school students (n=296) were invited to complete questionnaires on chronic pain (mannequin with 18 body regions), sleeping problems (Uppsala Sleep Inventory, four items scored from 1–5), stress (ELO questions, scored from 1–5), anxiety and depression (Hospital Anxiety and Depression Scale, scored from 0–21), health status (EQ-5D, scored from 0 to 1, worst to best) and physical activity (International Physical Activity Questionnaire, categorised into low, moderate and high levels). Stress and sleeping items were dichotomized into 1–3 points (best) vs 4–5 points (worst). Individuals scoring at least severe problems (4 points) at one or more sleeping items were classified as having severe sleeping problems. HADS were categorised as non-cases (0–7), possible7–10 and probable cases (11–21 points). Students were grouped as having CMP (pain present in ≥3 regions) or not (no chronic pain or chronic pain in 1–2 regions). Multiple logistic regression analyses (adjusted for sex) with CMP as dependent variable were performed in SPSS, version 24.

    Results: 254 students (86% of total sample, 87 boys and 167 girls) with a mean age of 16.1 (SD 0.6) years participated in the study. CMP was present in 25 (9.8%) students with no differences between boys and girls (8.0% vs 10.8%; p=0.488). Having CMP was associated with reporting severe sleeping problems (OR 2.49, 95% CI: 1.06 to 5.81, p=0.035) with initiating sleep, maintaining sleep, early morning awakenings and/or not feeling restored after sleep in comparison to the other students. Students with CMP were more likely to be categorised as probable cases for anxiety (OR 3.06, 95% CI: 1.09 to 8.61, p=0.034), but there were no associations for possible cases for anxiety (OR 1.15, 95% CI: 0.38 to 3.51, p=0.800), possible cases (OR 2.03, 95% CI: 0.63 to 6.54), or probable cases for depression (OR 3.35, 95% CI: 0.33 to 33.83). There was a nearly significant association between stress and belonging to the CMP group (OR 2.31, 95% CI: 0.97 to 5.53, p=0.059). A higher self-reported health status was associated to a lower likelihood for CMP (OR 0.04, 95% CI: 0.01 to 0.27, p=0.001). Distribution of physical activity levels of low, moderate and high was not significantly associated to having CMP in comparison with not having it.

    Conclusions: One in ten high school students fulfilled criteria for having chronic multisite musculoskeletal pain. CMP was associated to sleeping problems, anxiety, and a worse health status. The results from this study may be used by school health-care professionals in their preventive work to promote student’s health.

    Disclosure of Interest: None declared

  • 33.
    Olandersson, Sofia
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS).
    Lundqvist, Helene
    Bengtsson, Martin
    Lundahl, Magnus
    Baerveldt, Albert-Jan
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS).
    Hilliges, Marita
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS).
    Finger-force measurement-device for hand rehabilitation2005In: 2005 IEEE 9th International Conference on Rehabilitation Robotics: Chicago, IL, 28 June - 1 July 2005, Piscataway, N.J.: IEEE Press, 2005, p. 135-138Conference paper (Refereed)
    Abstract [en]

    The purpose was to develop an extension finger-force measurement device, and investigate the intra-individual repeatability. The design of the measuring device allows single finger force and whole hand measurements, and the repeatability error on extension finger forces was measured, both on the whole hand, as well as on individual fingers. The tests showed that a repeatability error of less then 15 % can be achieved for single finger measurements and less then 21 % for whole hand measurements.

  • 34.
    Parker, James
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Olsson, Charlotte
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Brorsson, Sofia
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    A One Year Study on Changes in Flexibility and Stability Characteristics in Elite Golfers2011Other (Other academic)
    Abstract [en]

    The results from this study show that training strategies can lead to improved flexibility and stability in golfers during the off season, however maintaining these improvements, particularly flexibility, during the in-season is not as easy. Decreased flexibility on the left side leads to reduced ROM to manage deceleration of  forces produced in the golf swing that probably lead to an increased risk of injury. Significant improvements can be made after no more than 3 months of  training, including flexibility and stability training. Technique training may be more successful if it follows a period of concentrated physical training.  During the in-season, emphasis ought to be on maintaining ROM by effective implementation of stretching programs.

  • 35.
    Parker, James
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS).
    Olsson, Charlotte
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS).
    Brorsson, Sofia
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS).
    Grip force and muscle activity are associated with kinematics in the golf swing2012In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 44, no Suppl. 2, p. 474-474Article in journal (Refereed)
  • 36.
    Petersson, Johan
    et al.
    Halmstad University, School of Business, Engineering and Science.
    Riggberger, Kenneth
    Stadionkontoret, Malmö Sports Academy, Malmö, Sweden.
    Brorsson, Sofia
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Olsson, Charlotte M.
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Unilateral Strength Training With Maximal Velocity Improves Lower Body Power Outcome And Movement Velocity2012In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 44, no Suppl. 2, p. 671-671Article in journal (Other academic)
  • 37.
    Sundström, Tomas
    et al.
    Halmstad University, School of Business, Engineering and Science.
    Ronkainen, Fanny
    Halmstad University, School of Business, Engineering and Science.
    Brorsson, Sofia
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS).
    Olsson, M. Charlotte
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Five Weeks of Plyometric Training Improve Vertical Jump Height in Female Handball Players During In-Season2010In: Nordic Conference 2010: Abstracts / [ed] Karen Søgaard, Karsten Froberg & Mette Krogh Christensen, Odense: University of Southern Denmark , 2010, p. 112-113Conference paper (Refereed)
    Abstract [en]

    Introduction: Handball is a sport requiring many different physical qualities in order to perform well, one of which is good jumping ability. For handball players available time to enhance power during in-season is often restricted due to an already high training load emphasizing other aspects of the sport than jumping ability. Therefore, one aim of this study was to examine if a small amount of additional plyometric training during in-season, combining drop jumps and box jumps, could give significant improvements in vertical jump height in female handball players after five weeks of training. Generally, vertical jump height is evaluated with two-legged tests, however, the question arises if the tests are relevant in sports that predominantly use several steps and one-leg jumps such as handball. A second aim of this study was thus to develop, evaluate and validate a handball-specific test performed on one leg.

    Methods: Two Swedish female handball-teams playing in the third division were recruited. Players from one team made up the intervention-group (n = 9) and players from the other team functioned as the control-group (n = 4). Plyometric training was added to the regular handball training session twice per week during five weeks, lasting approximately 15 minutes per session, consisting of two sets of eight repetitions of drop jumps and box jumps respectively, while the control-group continued their training as normal. Jumping performance was evaluated through the squat jump test (SJ), countermovement jump test (CMJ) and the handball-specific one leg jump test (OLJ) developed for this study in order to offer a more sport-specific evaluation tool when testing sports that predominantely jump on one leg.

    Results: The intervention-group improved their jumping height significantly with 2,7 cm in the SJ, 3,6cm in the CMJ and 3,6 cm in the OLJ (p < 0,01 for all). The control-group had an opposite trend with diminishing results in all three jumps, -1,5 cm in the SJ (p < 0,05), -1,7 cm in the CMJ (p < 0,05) and -0,9 cm in the OLJ (not significant). The one-legged jump test (OLJ) correlated well with both SJ (r= 0,79, p <0,01 ), and CMJ (r=0,75, p < 0,01).

    Discussion: The present study found significant improvements in jumping height after only five weeks of plyometric training for female handball players. Interestingly, the intervention-group improved to the same extent in both the one and the two-leg jumps test, which might be explained by the accumulation of handball specific training drills performed on one-leg, together with the two-legged plyometric exercises. The same assumption could also explain why the control-group showed no change in the one-leg jump test between the pre and post-tests, but displayed significant lower scores in the two-legged jumping tests after 5 weeks with only regular handball training.

    Conclusion: The improvements seen in this study with a small amount of additional plyometric training is relevant for coaches that need to provide gains in jumping performance during in-season when there is not a lot of time for additional training. Moreover, an evaluation test needs to be as specific as possible to the performance in the sport. The one-leg vertical jump test, developed in this study, could be a first step to a future handball-test that better resembles the jumping performance in handball than already established two-leg jumping tests.

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