| 1. |
- Albinsson, John, et al.
(författare)
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Combined use of Iteration, Quadratic Interpolation and an Extra Kernel for high-resolution 2D particle tracking : a first evaluation
- 2010
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Ingår i: 2010 ieee international ultrasonics symposium. - New York : IEEE Press. - 9781457703829 ; , s. 2000-2003
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Konferensbidrag (refereegranskat)abstract
- 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.
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| 2. |
- Albinsson, John, et al.
(författare)
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Improved tracking performance of lagrangian block-matching methodologies using block expansion in the time domain : In silico, phantom and invivo evaluations
- 2014
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Ingår i: Ultrasound in Medicine and Biology. - : Elsevier. - 0301-5629 .- 1879-291X. ; 40:10, s. 2508-2520
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 3. |
- Brorsson, Sofia, et al.
(författare)
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12-weeks of hand exercise provides better hand function, muscle balance and muscle strength in the rheumatoid arthritis hand
- 2010
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Ingår i: Abstract Archive Sessions Index 2010. - : EULAR.
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Konferensbidrag (refereegranskat)abstract
- 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: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.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.Ronningen, A. and I. Kjeken (2008). ffect of an intensive hand exercise programme in patients with rheumatoid arthritis. Scand J Occup Ther: 1-11.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.
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| 4. |
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| 5. |
- Brorsson, Sofia, et al.
(författare)
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A new electronic grip force measurement device for hand evaluation
- 2013
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Ingår i: Abstracts of the Annual European Congress of Rheumatology EULAR. June 12-15, 2013. Madrid, Spain.
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Konferensbidrag (refereegranskat)abstract
- Background: Hand grip force is a good indicator of general muscle strength and can also be used to predict multiple outcomes such as changes in activities of daily living (ADL), disability, mortality and general upper extremity strength. Hand grip force is often measured as the amount of static grip force a subject can produce when measured with a hydraulic dynamometer such as the Jamar or with an electronic device such as the Grippit. The Grippit device measures an average grip force, a peak grip force and force over a set time period. Grippit has shown good reliability for healthy subjects. Grippit, which was developed over 20 years ago in Gothenburg, Sweden is no longer manufactured. Therefore, the need for anewly developed and modernized measurement instrument for use in evaluating hand rehabilitation has arisen. Objectives: The aim of this study was to evaluate the test-retest reliability of the newly developed instrument GRIP-it and to describe and validate the relationship between grip force measurements from GRIP-it and the original Grippit device. Methods: Healthy controls (n=43) were included in the study. Two devices were used to evaluate grip force (Newton, N), (i) GRIP-it a newly developed device and (ii) Grippit. Both instruments were used to measure mean and maximal force over 10 seconds. Results: GRIP-it displayed a mean measurement error of -1.7 ± 0.5% and the corresponding error for Grippit was -1.6 ± 1.9%. All subjects completed the grip force tests and the results for three attempts for each hand. The test-retest reliability was excellent for both pieces of equipment, with ICCs ranging from 0.963 to 0.947 (CI 95% between 0.103 and 0.041) for GRIP-it and from 0.979 to 0.968 (CI 95% between 0.087 and 0.042) for Grippit. Relationships between Grippit and GRIP-itThere was a significant difference between the measured values derived from Grippit and GRIP-it for both the dominant hand (P < 0.001) and the non-dominant hand (P < 0.01). Grippit gives in general a higher grip force measurement than GRIP-it which is also indicated by the slope (β1) of the regression lines that deviates from 1. However, there were no substantial differences in the grip force when comparing the measurements for the dominant hand with the non-dominant hand for either Grippit (P = 0.071) or GRIP-it (P = 0.404). Based on these non-significant differences between hands and the fact that the model estimates for the intercept (β0) and the slope (β1) are contained within the confidence intervals of the model estimates for the opposite hand, a combined model was derived. The linear regression analysis, with grip force measurements for both hands included, gives: GRIP-it = 49.0 + 0.779 · Grippit. This explains 89.6% of the variance in grip force analyzed by GRIP-it (P < 0.001) see Figure 2. To enable an estimation of grip force measured by Grippit based on GRIP-it values a regression analysis with Grippit as dependent variable gives: Grippit = -18.1 + 1.15 · GRIP-it, which explains 89.6% of the variance in grip force analyzed by Grippit (P < 0.001).Conclusions: This study showed that GRIP-it has excellent test-retest reliability. Measurements of grip force with GRIP-it are strongly related to those from the original Grippit. The newly developed GRIP-it shows great potential for use in the assessment of hand function and the evaluation of hand rehabilitation.
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| 7. |
- Brorsson, Sofia, 1973-, et al.
(författare)
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Differences in muscle activity during hand-dexterity tasks between women with arthritis and a healthy reference group
- 2014
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Ingår i: BMC Musculoskeletal Disorders. - London, England : Springer Science and Business Media LLC. - 1471-2474. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 8. |
- Brorsson, Sofia, 1973-, et al.
(författare)
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Differences in the muscle activities in the forearm muscles in healthy men and women
- 2012
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Ingår i: Proceedings of the XIXth Congress of the International Society of Electrophysiology & Kinesiology. - Brisbane, Australia. - 9780646582283 ; , s. 437-437
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Konferensbidrag (refereegranskat)abstract
- 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.
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| 9. |
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| 10. |
- Brorsson, Sofia, et al.
(författare)
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Grip assistive devices studied in women with reumatic diseases
- 2011
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Ingår i: Abstracts EULAR 2011 London, United Kingdom, 25-28 May 2011.
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Konferensbidrag (refereegranskat)abstract
- 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:Dellhag, B. and A. Bjelle (1995). "A Grip Ability Test for use in rheumatology practice." J Rheumatol 22 (8):1559-65Gummesson, 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.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.(2003). “Rheumatoid arthritis: hand function, activities of daily living, grip strength and essential assistive devices.” Curationis 26 (3):98-106.
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