Kristín Briem

Prof. Kristín Briem

University of Iceland
orcid

Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 May 2011 in Journal of Orthopaedic & Sports Physical Therapy
Verified
Journal Article
Closed access
KBKristín Briem
Kristín Briem
HEHrefna Eythörsdöttir
Hrefna Eythörsdöttir
RMRagnheidur G. Magnúsdóttir
Ragnheidur G. Magnúsdóttir
RPRúnar Pálmarsson
Rúnar Pálmarsson
TRTinna Rúnarsdöttir
Tinna Rúnarsdöttir
TSThorarinn Sveinsson
Thorarinn Sveinsson
Study Design: Controlled laboratory study. Objectives: To examine the effect of 2 adhesive tape conditions compared to a no-tape condition on muscle activity of the fibularis longus during a sudden inversion perturbation in male athletes (soccer, team handball, basketball). Background: Ankle sprains are common in sports, and the fibularis muscles play a role in providing functional stability of the ankle. Prophylactic ankle taping with nonelastic sports tape has been used to restrict ankle inversion. Kinesio Tape, an elastic sports tape, has not been studied for that purpose. Methods: Fifty-one male premier-league athletes were tested for functional stability of both ankles with the Star Excursion Balance Test. Based on the results, those with the 15 highest and those with the 15 lowest stability scores were selected for further testing. Muscle activity of the fibularis longus was recorded with surface electromyography during a sudden inversion perturbation. Each participant was tested under 3 conditions: ankle taped with nonelastic white sports tape, ankle taped with Kinesio Tape, and no ankle taping. Differences in mean muscle activity were evaluated with a 3-way mixed-model analysis of variance (ANOVA) for the 3 conditions, across four 500-millisecond time frames, and between the 2 groups of stable versus unstable participants. Differences in peak muscle activity and in the time to peak muscle activity were evaluated with a 2-way mixed-model ANOVA. Results: Significantly greater mean muscle activity was found when ankles were taped with nonelastic tape compared to no tape, while Kinesio Tape had no significant effect on mean or maximum muscle activity compared to the no-tape condition. Neither stability level nor taping condition had a significant effect on the amount of time from perturbation to maximum activity of the fibularis longus muscle. Conclusion: Nonelastic sports tape may enhance dynamic muscle support of the ankle. The efficacy of Kinesio Tape in preventing ankle sprains via the same mechanism is unlikely, as it had no effect on muscle activation of the fibularis longus. J Orthop Sports Phys Ther 2011;41(5):328–335, Epub 5 January 2011. doi:10.2519/jospt.2011.3501

1 November 2007 in Journal of Bone and Joint Surgery
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Journal Article
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Dan Kenneth RamseyDan Kenneth Ramsey
Dan Kenneth Ramsey
KBKristín Briem
Kristín Briem
MAMichael J. Axe
Michael J. Axe
LSLynn Snyder-Mackler
Lynn Snyder-Mackler
Evidence that knee braces used for the treatment of osteoarthritis mediate pain relief and improve function by unloading the joint (increasing the joint separation) remains inconclusive. Alternatively, valgus-producing braces may mediate pain relief by mechanically stabilizing the joint and reducing muscle cocontractions and joint compression. In this study, therefore, we sought to examine the degree to which so-called unloader braces control knee instability and influence muscle cocontractions during gait. Sixteen subjects with radiographic evidence of knee malalignment and medial compartment osteoarthritis were recruited and fitted with a custom Generation II Unloader brace. Gait analysis was performed without use of the brace and with the brace in neutral alignment and in 4 degrees of valgus alignment. A two-week washout period separated the brace conditions. Muscle cocontraction indices were derived for agonist and antagonist muscle pairings. Pain, instability, and functional status were obtained with use of self-reported questionnaires, and the results were compared. The scores for pain, function, and stability were worst when the knee was unsupported (the baseline and washout conditions). At baseline, nine of the sixteen patients reported knee instability and five of the nine complained that it affected their activities of daily living. Poor knee stability was found to be correlated with low ratings for the activities of daily living, quality of life, and global knee function and with increased pain and symptoms. Knee function and stability scored best with the brace in the neutral setting compared with the brace in the valgus setting. The cocontraction of the vastus lateralis-lateral hamstrings was significantly reduced from baseline in both the neutral (p = 0.014) and valgus conditions (p = 0.023), and the cocontraction of the vastus medialis-medial hamstrings was significantly reduced with the valgus setting (p = 0.068), as a result of bracing. Patients with greater varus alignment had greater decreases in vastus lateralis-lateral hamstring muscle cocontraction. When knees with medial compartment osteoarthritis are braced, neutral alignment performs as well as or better than valgus alignment in reducing pain, disability, muscle cocontraction, and knee adduction excursions. Pain relief may result from diminished muscle cocontractions rather than from so-called medial compartment unloading.

10 April 2012 in The Journals of Gerontology, Series A: Biological Sciences and Medical Sciences
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Journal Article
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OGOlof Gudny Geirsdottir
Olof Gudny Geirsdottir
AAA. Arnarson
A. Arnarson
KBKristín Briem
Kristín Briem
ARA. Ramel
A. Ramel
PJP. V. Jonsson
P. V. Jonsson
ITInga Thorsdottir
Inga Thorsdottir
Insulin is a stimulator of skeletal muscle protein anabolism and insulin resistance might therefore negatively affect muscle protein metabolism. We investigated muscle mass and physical function before and after a resistance exercise program in participants with prediabetes or type 2 diabetes mellitus (T2DM) in comparison to healthy controls. This was a secondary analysis of a randomized controlled intervention designed to investigate resistance training among older adults. Glucose metabolism status was not a selection criteria for the trial, and group designation was done retrospectively. Participants (N = 237, 73.7 ± 5.7 y, 58.2% women) participated in a 12-week resistance exercise program (3 times/week; three sets, six to eight repetitions at 75%–80% of the one-repetition maximum), designed to increase strength and muscle mass of major muscle groups. Body composition, muscular strength, timed up and go test, 6-minute walk for distance, and blood chemical variables were measured at baseline and endpoint. Participants completing the study (n = 213) experienced significant changes in muscle strength or muscle function, which did not differ significantly between healthy (n = 198), prediabetic (n = 20), and T2DM participants (n = 17). Changes in serum glucose during the intervention differed by group: only glucose improved significantly in the prediabetic group, glucose and triacylglycerol improved significantly in the healthy group, whereas no serum parameter improved significantly in the T2DM group. A 12-week resistance exercise program improves muscle strength and muscle function to a similar extent in healthy, prediabetic, and T2DM elderly people. However, according to our data, T2DM participants do not experience favorable changes in fasting glucose or HbA1C.

13 March 2013 in European Journal of Clinical Nutrition
Verified
Journal Article
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AAA Arnarson
A Arnarson
OGO Gudny Geirsdottir
O Gudny Geirsdottir
ARA Ramel
A Ramel
KBKristín Briem
Kristín Briem
PJP V Jonsson
P V Jonsson
ITInga Thorsdottir
Inga Thorsdottir

16 July 2008 in Journal of Orthopaedic Research
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Journal Article
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KBKristín Briem
Kristín Briem
LSLynn Snyder‐Mackler
Lynn Snyder‐Mackler
The purpose of this study was to examine interlimb differences in gait kinematics and kinetics in patients with symptomatic medial knee OA. The main objective was to identify hip joint movement strategies that might lower the knee adduction moment and also compensate for decreased knee flexion during weight acceptance. Gait analysis was performed on 32 patients with moderate medial compartment knee OA. Kinetic and kinematic data were calculated and side‐to‐side comparisons made. Radiographs were used to identify frontal plane alignment. No interlimb difference in the peak knee adduction moment was found (p = 0.512), whereas a greatly reduced hip adduction moment was seen on the involved side (p < 0.001) during the early part of stance. The involved limb flexed significantly less and hip and knee flexion moments were smaller compared to the uninvolved side. Gait adaptations involving a lateral sway of the trunk may successfully lead to relatively lower ipsilateral knee adduction moments, and would further be reflected by a lower adduction moment at the hip. Subjects did not compensate for less knee flexion by any dynamic means, and likely experience a resulting higher joint impact. These gait adaptations may have implications with respect to development of weakness of the ipsilateral hip musculature and progression of multiarticular OA. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:78–83, 2009

13 November 2020 in Frontiers in Robotics and AI
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Journal Article
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DTDiego Torricelli
Diego Torricelli
CRCarlos Rodriguez-Guerrero
Carlos Rodriguez-Guerrero
JVJan F. Veneman
Jan F. Veneman
SCSimona Crea
Simona Crea
KBKristín Briem
Kristín Briem
PBPhilipp Beckerle
Philipp Beckerle
Wearable robots (WRs) are increasingly moving out of the labs toward real-world applications. In order for WRs to be effectively and widely adopted by end-users, a common benchmarking framework needs to be established. In this article, we outline the perspectives that in our opinion are the main determinants of this endeavor, and exemplify the complex landscape into three areas. The first perspective is related to quantifying the technical performance of the device and the physical impact of the device on the user. The second one refers to the understanding of the user's perceptual, emotional, and cognitive experience of (and with) the technology. The third one proposes a strategic path for a global benchmarking methodology, composed by reproducible experimental procedures representing real-life conditions. We hope that this paper can enable developers, researchers, clinicians and end-users to efficiently identify the most promising directions for validating their technology and drive future research efforts in the short and medium term.