Gymnastik- och idrottshögskolan, GIH

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  • 1.
    Alriksson, Anna
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Könsbunden gymkultur?: en kvantitativ studie om hur kvinnor och män väljer att träna på gym.2016Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Syfte och frågeställningar: Syftet med uppsatsen var att undersöka vad och hur vuxna tränade på gym för att se om det fanns några skillnader som gick att relatera till kön. De frågeställningar som användes för att besvara syftet var: Vilken form av träning föredrog vuxna att ägna sig åt på gymmet? I vilken utsträckning styrketränade vuxna i gymmets öppna lokaler? Vilka muskelgrupper och redskap premierades i samband med vuxnas styrketräning? Hur mycket tid lade vuxna på träning? Föredrog vuxna att träna på egen hand eller tillsammans med andra? Samtliga frågeställningar analyserades utifrån om det skiljde sig mellan kvinnor och män.

    Metod: För att besvara studiens frågeställningar som grundade sig i ett allmängiltigt intresse genomfördes en kvantitativ undersökning via ett strukturerat frågeformulär. Det egenkomponerade formuläret baserades på tidigare forskning och innehöll övervägande slutna svarsalternativ. Urvalet resulterade i ett stickprov av totalt 140 deltagare; 86 kvinnor (61,4%) och 54 män (38,6%). Undersökningen genomfördes på en stor träningsanläggning med ett varierande utbud och undertecknad befann sig på platsen under insamlingen av data.

    Resultat: Det fanns könsrelaterade skillnader i hur vuxna tränade på gymmet. Männen tenderade att träna mer och de föredrog individuell styrketräning med fria vikter och maskiner. Kvinnorna deltog oftare i ledarledd gruppaktivitet och/eller använde sig av sin egen kroppsvikt eller övriga redskap så som bollar och gummiband i samband med sin styrketräning. Utöver det lade männen större fokus på att utveckla sin överkropp medan kvinnorna tenderade att prioritera sin underkropp.

    Slutsats: Kvinnor och män tränade olika på gym och med tidigare forskning som stöd kan detta, till viss del, antas bero på yttre faktorer så som normer och kroppsideal. Denna vetskap bidrar till möjligheter att skapa ett gynnande bemötande från träningsbranschens sida som kan neutralisera den, till synes, styrda uppfattningen om träning. Genom att anpassa miljön och bemöta individen på ett sätt som främjar ett könsneutralt beteende i samband med träning ökar chanserna till en hållbar och optimal utveckling på både det fysiska och mentala planet, oavsett om du är kvinna eller man.

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  • 2. Andersson, Ulrika
    et al.
    Leighton, Brendan
    Young, Martin E
    Blomstrand, Eva
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Eva Blomstrands forskningsgrupp.
    Newsholme, Eric A
    Inactivation of aconitase and oxoglutarate dehydrogenase in skeletal muscle in vitro by superoxide anions and/or nitric oxide.1998Ingår i: Biochemical and Biophysical Research Communications - BBRC, ISSN 0006-291X, E-ISSN 1090-2104, Vol. 249, nr 2, s. 512-6Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Strips of rat soleus muscle were incubated in media containing a superoxide generating system and/or the nitric oxide donor sodium nitroprusside (SNP) before the maximal catalytic activities of aconitase, citrate synthase, and oxoglutarate dehydrogenase were measured. The maximal activities of aconitase and oxoglutarate dehydrogenase were both decreased by 25-30% by superoxide anions; however, only the maximal activity of aconitase was decreased, by approximately 50%, by incubation of muscles with SNP. Furthermore, when both superoxide and NO were present in the medium, aconitase activity was decreased by 70%. The maximal activity of citrate synthase was not affected by any of the treatments. This is the first time that superoxide anions or NO has been shown to inactivate aconitase and oxoglutarate dehydrogenase in skeletal muscle. It is suggested that these effects may be responsible for some alterations in skeletal muscle metabolism, and these possibilities are discussed.

  • 3.
    Arndt, Anton
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    Achilles tendon biomechanics and functional anatomy2012Konferensbidrag (Övrigt vetenskapligt)
  • 4.
    Arndt, Anton
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    In vivo, intrinsic kinematics of the foot and ankle2012Konferensbidrag (Övrigt vetenskapligt)
  • 5.
    Arndt, Anton
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    The effects of running in minimalistic shoes on non-uniform displacement in the Achilles tendon2019Konferensbidrag (Refereegranskat)
  • 6.
    Arndt, Anton
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    Bengtsson, Ann-Sophie
    Peolsson, Michael
    Thorstensson, Alf
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    Movin, Tomas
    Non-uniform displacement within the Achilles tendon durig passive ankle joint motion.2012Ingår i: Knee Surgery, Sports Traumatology, Arthroscopy, ISSN 0942-2056, E-ISSN 1433-7347, Vol. 20, nr 9, s. 1868-74Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE:

    An initial step in the understanding of Achilles tendon dynamics is to investigate the effects of passive motion, thereby minimising muscle activation and reducing internal joint forces. Internal tendon dynamics during passive ankle joint motion have direct implications for clinical rehabilitation protocols after Achilles tendon surgery. The aim of this study was to test the hypothesis that tendon tissue displacement is different in different layers of the Achilles tendon during controlled passive ankle joint movements.

    METHODS:

    Ultrasound imaging was conducted on the right Achilles tendon of nine healthy recreationally active males. Standardised isokinetic passive dorsi-plantar-flexion movements were performed with a total range of motion of 35°. The tendon was divided into superficial, central and deep layers in the resulting B-mode ultrasound images viewed in the sagittal plane. A block-matching speckle tracking algorithm was applied post-process, with kernels for the measurement of displacement placed in each of the layers.

    RESULTS:

    The mean (SD) displacement of the Achilles tendon during passive dorsiflexion was 8.4 (1.9) mm in the superficial layer, 9.4 (1.9) mm in the central portion and 10.4 (2.1) mm in the deep layer, respectively. In all cases, the movement of the deep layer of the tendon was greater than that of the superficial one (P < 0.01).

    CONCLUSIONS:

    These results, achieved in vivo with ultrasonographic speckle tracking, indicated complex dynamic differences in different layers of the Achilles tendon, which could have implications for the understanding of healing processes of tendon pathologies and also of normal tendon function.

  • 7.
    Azcarate, Laura
    et al.
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Sandamas, Paul
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    Arndt, Anton
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    Gutierrez-Farewik, Elena M.
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Wang, Ruoli
    KTH, Royal Institute of Technology, Stockholm, Sweden.
    Muscle contributions to body mass centre acceleration during the first stance of sprint running2019Konferensbidrag (Refereegranskat)
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  • 8.
    Dias-Johnson, Georgy
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    The effects of concurrent training on sprint performance in moderately trained cyclists2013Självständigt arbete på avancerad nivå (magisterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Aim: The purpose of the present study was to compare the effects of an 8 week period of combined endurance and resistance training (concurrent training) with that of only endurance training on both maximum strength (1 RM) in the leg press test and performance in the 30 s Anaerobic Wingate Test (WANT) in moderately trained endurance cyclists.

    Method: Twenty male moderately trained cyclists were recruited for the investigation and were assigned to either an Endurance training group (E; n=10) or an Endurance Resistance training group (ER; n=10).  Subjects underwent 8 weeks (2 training sessions per week, 16 sessions in total) of concurrent training (60 min steady state cycling session followed by 6 sets 12 repetitions of leg press) or cycling only. Furthermore the subjects of the intervention completed both Pre and Post intervention testing in the 1RM leg press and the Wingate 30 s cycle test which was conducted twice (SRM cycle sprint 1 and SRM cycle sprint 2) within each testing session.

    Results: The results attained from the intervention were that the ER group demonstrated an increase in concentric leg strength within the one repetition maximum (1 RM) leg press test by 18.7 % from pre-test values 339 ± 42 to post test values 402 ± 59 kg. With regard to the Wingate cycle sprints there was significant improvement from pre to post test results in peak power of cycle sprint 1 from 1019 ± 110 watt to 1077 ± 153 watt 5.7 % and cycle sprint 2 from 1001 ± 131 to 1054 ± 161 watt, 5.3 % (P < 0.05) respectively. The E group showed no significant change in l RM or the Wingate cycle sprints after training.

    Conclusions: The main findings of the study is that an 8-week concurrent training intervention can lead to significant concentric strength gains in 1 RM leg press development and increased peak power within the Wingate 30 s cycle sprint when conducted by moderately trained cyclists.

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    The effects of concurrent training on sprint performance in moderately trained cyclists
  • 9.
    Durrant, Christelle
    et al.
    Université de Paris, France.
    Fuehring, Jana I
    Hannover Medical School, Germany.
    Willemetz, Alexandra
    Université de Paris, France.
    Chrétien, Dominique
    Université Paris Decartes, Sorbonnes Paris Cité, Institut Imagine, France.
    Sala, Giusy
    University of Milan, Italy.
    Ghidoni, Riccardo
    University of Milan, Italy.
    Katz, Abram
    Karolinska institutet, Stockholm, Sweden.
    Rötig, Agnès
    Université Paris Decartes, Sorbonnes Paris Cité, Institut Imagine, France.
    Thelestam, Monica
    Karolinska institutet, Stockholm, Sweden.
    Ermonval, Myriam
    Institut Pasteur, Department of Virology, Paris, France.
    Moore, Stuart E H
    Université de Paris, France.
    Defects in Galactose Metabolism and Glycoconjugate Biosynthesis in a UDP-Glucose Pyrophosphorylase-Deficient Cell Line Are Reversed by Adding Galactose to the Growth Medium.2020Ingår i: International Journal of Molecular Sciences, ISSN 1661-6596, E-ISSN 1422-0067, Vol. 21, nr 6, artikel-id E2028Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    UDP-glucose (UDP-Glc) is synthesized by UGP2-encoded UDP-Glc pyrophosphorylase (UGP) and is required for glycoconjugate biosynthesis and galactose metabolism because it is a uridyl donor for galactose-1-P (Gal1P) uridyltransferase. Chinese hamster lung fibroblasts harboring a hypomrphic UGP(G116D) variant display reduced UDP-Glc levels and cannot grow if galactose is the sole carbon source. Here, these cells were cultivated with glucose in either the absence or presence of galactose in order to investigate glycoconjugate biosynthesis and galactose metabolism. The UGP-deficient cells display < 5% control levels of UDP-Glc/UDP-Gal and > 100-fold reduction of [6-3H]galactose incorporation into UDP-[6-3H]galactose, as well as multiple deficits in glycoconjugate biosynthesis. Cultivation of these cells in the presence of galactose leads to partial restoration of UDP-Glc levels, galactose metabolism and glycoconjugate biosynthesis. The Vmax for recombinant human UGP(G116D) with Glc1P is 2000-fold less than that of the wild-type protein, and UGP(G116D) displayed a mildly elevated Km for Glc1P, but no activity of the mutant enzyme towards Gal1P was detectable. To conclude, although the mechanism behind UDP-Glc/Gal production in the UGP-deficient cells remains to be determined, the capacity of this cell line to change its glycosylation status as a function of extracellular galactose makes it a useful, reversible model with which to study different aspects of galactose metabolism and glycoconjugate biosynthesis.

  • 10.
    Edman, Sebastian
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för fysiologi, nutrition och biomekanik.
    Strömlind, Henrik
    Gymnastik- och idrottshögskolan, GIH, Institutionen för fysiologi, nutrition och biomekanik.
    Horwath, Oscar
    Gymnastik- och idrottshögskolan, GIH, Institutionen för fysiologi, nutrition och biomekanik.
    Apro, William
    Gymnastik- och idrottshögskolan, GIH, Institutionen för fysiologi, nutrition och biomekanik.
    Fiber type-specific signaling responses to nutritional and contractile stimuli in young and aged human skeletal muscleManuskript (preprint) (Övrigt vetenskapligt)
  • 11.
    Ferm, Alexander
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Simon, Galle
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Testing e-sport athletes: A study on competitive gaming2014Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Syfte

    Huvudsyftet med denna studie var att sammansätta och testa validiteten i ett kognitivt testbatteri för att bestämma e-sportatleters styrkor och svagheter. Det andra syftet var att undersöka deras fysiska status. Hypotes1: Elitspelarna kommer att prestera bättre i en rad kognitiva och finmotoriska uppgifter jämfört med rekreationsspelare. Hypotes 2: Elitspelarnas aeroba kapacitet kan inte vara mycket låg (<2,5 VO2 L/min för 20-29åringar) eftersom det skulle påverka deras e–sportprestation negativt. Hypotes 3: Ett stort antal av elitspelarna kommer inte att kunna matcha kraven för en frisk rygg (>193 sekunder) i Biering-Sørensentestet.

    Metod

    25 män delades in i tre grupper, elitspelare (E) [10], rekreationsspelare (R) [10] och icke-spelare (N) [5]. Elitgruppen bestod av två professionella e-sportslag á fem personer och ett Counter Strike: Global Offensivelag (CS) och ett League of Legends-lag (LOL), ålder mellan 17 och 25 år (medelålder 21,5 ). R-gruppen varierade mellan 21 och 29 år (medelvärde 24,9 ) hade alla spelat fightingspel, MOBA, online-FPS, online-3PS eller RTS-spel minst en gång i veckan under en 6 månaders period eller mer men aldrig tävlat i dem. Grupp N varierade mellan 25 och 32 år (medel 28,4) och hade som högst provat dessa typer av spel, men aldrig använt dem i rekreationssyfte. Grupp E, R och N utförde ett testbatteri för reaktionshastighet, strategi, perception, situationsmedvetenhet , tangentbord uthållighet, öga-handkoordination, spatial förmåga och antecipatorisk skicklighet. Grupp E också testades fysiskt genom Ekblom-Bak submaximala cycle ergometertest och ryggstyrka genom Biering-Sørensens (BS) test.

    Resultat

    Grupp E:s beräknade VO2max var 3,83 l/min (SD = 0,38) och elitgruppens medelresultat av BS ryggtest var 133 s (SD=54). E presterade inte signifikant bättre i någon av de kognitiva eller finmotoriska uppgifterna än R.

    Slutsats

    Elitspelarnas resultat från BS-testet bekräftar hypotes 3 och påvisar ohälsosamma ryggar. Den enda signifikanta skillnaden inom de kognitiva testerna mellan E och R är till E-gruppens nackdel, överraskande visade de sämre resultat i det antecipatoriska skicklighetstestet . Deras aeroba kapacitet bekräftar hypotes 2, elitspelarnas VO2max var inte mycket låg, E-gruppen placerade sig i den övre hälften av genomsnittet för sin åldersgrupp. Testbatteriet kan inte användas för talangscouting men eventuellt för att upptäcka kognitiva svagheter.

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  • 12.
    Flockhart, Mikael
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Åstrandlaboratoriet.
    Nilsson, Lina
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Åstrandlaboratoriet, Forskningsgruppen Mitokondriell funktion och metabolisk kontroll.
    Apro, William
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Åstrandlaboratoriet, Björn Ekbloms forskningsgrupp.
    Ekblom, Björn
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Åstrandlaboratoriet, Björn Ekbloms forskningsgrupp.
    Larsen, Filip J
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Åstrandlaboratoriet, Forskningsgruppen Mitokondriell funktion och metabolisk kontroll.
    Dose-response relationship between exercise load and mitochondrial function2019Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Dose-response relationship between exercise load and mitochondrial function

    Flockhart M, Nilsson L, Bergman K, Apro W, Ekblom B, Larsen FJ

    A dose-dependent relationship exists between exercise load and muscular adaptation. Mitochondria adapt to the increased ATP-demand by alterations in mass and/or quality. How mitochondrial mass and quality changes as a function of exercise load is not well investigated and we have previously found mitochondrial dysfunction after short-term intensive exercise. We therefore aimed to study mitochondrial function by altering exercise load during a three week interval training regimen to understand the dose-response relationship between exercise load and mitochondrial function. We took four muscle biopsies throughout the study, and as expected, mitochondrial function was positively affected during the first two weeks. After the third week, a dramatic mitochondrial dysfunction was evident as mitochondrial intrinsic respiration was reduced by 26% despite a 32% increase in mitochondrial yield. We hereby present evidence of a striking exercise-induced reduction in mitochondrial function after a period of very intense interval training.

  • 13. Gullstrand, Lennart
    et al.
    Nilsson, Johnny
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    A new method for recording the temporal pattern of stride during treadmill running2009Ingår i: Sports Engineering, ISSN 1369-7072, E-ISSN 1460-2687, nr 11, s. 195-200Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of this study was to investigate the reliability of a new infrared light based method (IR40) for recording temporal stride patterns during treadmill running. The IR40 device, emitting a tight web of 40 infrared light beams 10 mm above the treadmill running surface, was compared to a previously validated electro-pneumatic contact shoe (CS) method while nine well-trained athletes ran at 2.8, 3.3, 3.9, 4.4, 5.0, and 5.6 m s−1. Disconnection and reconnection of the IR beams marked the stance phase. The sampling rate was 500 Hz for both methods. The stance phase duration was on average 11.5 (±8.4) ms longer with the IR40 than with the CS depending on earlier touch down (8.3 ± 6.2 ms) and delayed toe off (3.2 ± 5.3 ms) registrations. Significantly different stance phases were recorded between all velocities and for both methods. Thus, despite the fact that the IR40 systematically measured a somewhat longer stance phase duration than CS, the IR40 is nonetheless useful for temporal stride analysis during treadmill running.      

  • 14.
    Hedlund, Martin
    et al.
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Jonsson, Adam
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Bogdan, Christian
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Meixner, Gerrit
    Heilbronn University, Heilbronn, Germany.
    Ekblom Bak, Elin
    Gymnastik- och idrottshögskolan, GIH, Institutionen för fysisk aktivitet och hälsa.
    Matviienko, Andrii
    KTH Royal Institute of Technology, Stockholm, Sweden.
    BlocklyVR: Exploring Block-based Programming in Virtual Reality2023Ingår i: MUM'23: Proceedings of the 22nd International Conference on Mobile and Ubiquitous Multimedia / [ed] Florian Michahelles, Pascal Knierim, Jonna Häkkilä, Association for Computing Machinery , 2023, s. 251-263Konferensbidrag (Refereegranskat)
    Abstract [en]

    As programming is typically a static activity in front of a screen, we perform an initial exploration around the capabilities of block-based programming in the immersive space using Virtual Reality (VR) to make an early charting on how programming could involve moving the programmer's body. We created a block-based programming interface in a VR space called BlocklyVR based on the existing Blockly programming environment. To investigate programmer performance and experience in BlocklyVR, we conducted a controlled lab experiment (N = 20) with eight programming tasks that covered mathematical operations, if-statements, and function creation. Our initial exploration contributes by classifying movement types made by BlocklyVR programmers and reflecting on how these movements are related to the programming tasks. Additionally, our data suggests that participant performance in BlocklyVR was not affected compared to the 2D Blockly, even if participants were physically moving in VR space. We also found that the virtual reality sickness was marginal. Lastly, we identified four types of interaction that can potentially be employed by VR designers and developers aiming to convert a static task, like programming at a desk, into a "mobile"immersive experience. © 2023 Owner/Author.

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  • 15.
    Hegyi, Andras
    et al.
    University of Jyväskylä, Finland.
    Peter, Annamaria
    University of Jyväskylä, Finland.
    Andersson, Eva
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    Arndt, Anton
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    Finni, Taija
    University of Jyväskylä, Finland.
    Tarassova, Olga
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    Cronin, Neil J.
    University of Jyväskylä, Finland.
    Ankle joint angle influences hamstring fine-wire and high-density electromyography activity in ramp isometric knee flexions2019Konferensbidrag (Refereegranskat)
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  • 16. Holmberg, Hans-Christer
    et al.
    Nilsson, Johnny
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    Reliabilty and validity of new double poling ergometer for cross-country skiers2008Ingår i: Journal of Sports Sciences, ISSN 0264-0414, E-ISSN 1466-447X, Vol. 26, nr 2, s. 171-179Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Thirty-eight competitive cross-country skiers were divided into three groups to assess the reliability and validity of a new double poling ergometer. Group A (n = 22) performed two maximal 60-s tests, Group B (n = 8) repeated peak oxygen uptake tests on the double poling ergometer, and Group C (n = 8) performed a maximal 6-min test on the double poling ergometer and a double poling time-trial on snow. The correlation between the power calculated at the flywheel and the power applied at the base of the poles was r = 0.99 (P < 0.05). The power at the poles was 50 – 70% higher than that at the flywheel. There was a high test – retest reliability in the two 60-s power output tests (coefficient of variation = 3.0%) and no significant difference in peak oxygen uptake in the two 6-min all-out tests (coefficient of variation = 2.4%). There was a strong correlation between the absolute (W) and relative power (W · kg−1) output in the 6-min double poling ergometer test and the double poling performance on snow (r = 0.86 and 0.89 respectively; both P < 0.05). In conclusion, our results show that the double poling ergometer has both high reliability and validity. However, the power calculated at the flywheel underestimated the total power produced and needs to be corrected for in ergonomic estimations.

  • 17.
    Holmberg, Joakim
    et al.
    Linköpings Universitet.
    Lund, Marie
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling (-2013).
    A Musculoskeletal Full‐body Simulation of Cross‐Country Skiing2008Ingår i: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, ISSN 1754-3371, Vol. 222, nr P1, s. 11-22Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents a measurement-driven, musculoskeletal, full-body simulation model for biomechanical analysis of the double-poling (DP) technique in cross-country skiing. DP is a fast and powerful full-body movement; therefore, it is interesting to examine whether inverse dynamics using static optimization is working for a musculoskeletal full-body model with high accelerations, a large range of motion, and realistic loads. An experiment was carried out to measure motion and pole force of a skier on a double-poling ergometer. Using the measurement data, a simulation model was implemented in the AnyBody Modeling System (AnyBody Technology A/S, Denmark). Experimental results of motion and pole force from the DP ergometer, and also simulation results of relative muscle force profiles, are presented. These results agree with results found in literature when the kinematics and external kinetics are similar. Consequently, it should be possible to use computer simulations of this type for cross-country skiing simulations. With a simulation model, it is possible to perform optimization studies and to ask and answer ‘what if’ questions. Solutions to such problems are not easy to obtain by traditional testing alone.

  • 18.
    Holmberg, Joakim
    et al.
    Linköpings Universitet.
    Lund, Marie
    Mittuniversitetet, Institutionen för teknik, fysik och matematik (-2008).
    Using Double‐Poling Simulations to Study the Load Distribution between Teres Major and Latissimus Dorsi2007Ingår i: Science and Nordic Skiing, Oxford: Meyer & Meyer Sport , 2007, s. 81-89Konferensbidrag (Refereegranskat)
  • 19.
    Johansson, Christer
    et al.
    Department of Environmental Science and Analytical Chemistry, Stockholm University, SE-10691 Stockholm, Sweden.
    Lövenheim, Boel
    Environment and Health Administration, SLB, Stockholm, Sweden.
    Schantz, Peter
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Åstrandlaboratoriet, FoU-gruppen för rörelse, hälsa och miljö.
    Wahlgren, Lina
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Åstrandlaboratoriet, FoU-gruppen för rörelse, hälsa och miljö.
    Almström, Peter
    WSP Civils, Stockholm, Sweden.
    Markstedt, Anders
    WSP Civils, Stockholm, Sweden.
    Strömgren, Magnus
    Department of Geography and Economic History, Umeå University, Umeå, Sweden .
    Forsberg, Bertil
    Division of Occupational and Environmental Medicine, Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.
    Nilsson Sommar, Johan
    Division of Occupational and Environmental Medicine, Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.
    Impacts of air pollution and health by changing commuting from car to bicycle2017Ingår i: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 584-585, s. 55-63Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Our study is based on individual data on people’s home and work addresses, as well as their age, sex and physical capacity, in order to establish realistic bicycle-travel distances. A transport model is used to single out data on commuting preferences in the County Stockholm. Our analysis shows there is a very large potential for reducing emissions and exposure if all car drivers living within a distance corresponding to a maximum of a 30 minute bicycle ride to work would change to commuting by bicycle. It would result in more than 111 000 new cyclists, corresponding to an increase of 209% compared to the current situation.

    Mean population exposure would be reduced by about 7% for both NOx and black carbon (BC) in the most densely populated area of the inner city of Stockholm. Applying a relative risk for NOx of 8% decrease in all-cause mortality associated with a 10 µg m-3 decrease in NOx, this corresponds to more than 449 (95% CI: 340 - 558) years of life saved annually for the Stockholm county area with 2.1 million inhabitants. This is more than double the effect of the reduced mortality estimated for the introduction of congestion charge in Stockholm in 2006. Using NO2 or BC as indicator of health impacts, we obtain 395 (95% CI: 172 - 617) and 185 (95% CI: 158 - 209) years of life saved for the population, respectively. The calculated exposure of BC and its corresponding impacts on mortality are likely underestimated. With this in mind the estimates using NOx, NO2 and BC show quite similar health impacts considering the 95% confidence intervals.

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  • 20. Karlsen, Jon
    et al.
    Nilsson, Johnny
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    A new method to record aiming in golf putting  -  applied to elite players2008Ingår i: Science and Golf V: proceedings of the World Scientific Congress of Golf / [ed] D. Crews and R. Lutz, Energy in Motion , 2008, s. 395-401Konferensbidrag (Refereegranskat)
  • 21. Karlsen, Jon
    et al.
    Nilsson, Johnny
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    Club shaft weight in putting accuracy and perception of swingparameters in golf putting2007Ingår i: Perceptual and Motor Skills, ISSN 0031-5125, E-ISSN 1558-688X, Vol. 105, nr 1, s. 29-38Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study assessed how shaft weight influenced golf putting accuracy and subjective perception of swing parameters. Three putters of different shaft weight (100, 420, and 610 gm) were tested by 24 club players. Distance and deviation in direction were measured, and subjective ratings of the putters recorded. Subjects hit the ball further with lighter shafts. The mean distance hit was 100.2, 99.3, and 98.1% of the target distance for the normal, medium, and heavy putter shafts, respectively. Subjectively, the medium heavy putter was rated best on "overall feeling" and it was also rated better than the normal on"feeling of stability in the downswing." The heaviest putter was rated as too heavy by 23 of 24 subjects. There were no significant differences between the putter clubs in distance and directional putting accuracy. The major findings are that the golfers putted 2.1% longer with the 100 gm shaft than with the 610 gm shaft and that the perception of overall feeling of the putter club was not related to performance.

  • 22. Karlsen, Jon
    et al.
    Nilsson, Johnny
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    Distance variability in golf putting among highly skilled players: the role of green reading2008Ingår i: Annual Review of Golf Coaching, Multi-Science Publishing, 2008Kapitel i bok, del av antologi (Refereegranskat)
  • 23. Karlsen, Jon
    et al.
    Nilsson, Johnny
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    Golf players prefer mallet putters for aiming, but aim more consistent with blade putters2008Ingår i: Science and Golf V: proceedings of the World Scientific Congress of Golf Science and Golf V / [ed] D. Crews and R. Lutz, Energy in Motion , 2008, s. 402-407Konferensbidrag (Refereegranskat)
  • 24. Karlsen, Jon
    et al.
    Smith, Gerald
    Nilsson, Johnny
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    The stroke has a minor influence on direction consistencyin golf putting among elite players2008Ingår i: Journal of Sports Sciences, ISSN 0264-0414, E-ISSN 1466-447X, Vol. 3, s. 243-250Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In the golf instructional literature, the putting stroke is typically given higher priority than green reading and aiming. The main purpose of this study was to assess the importance of the putting stroke for direction consistency in golf putting. Kinematic stroke parameters were recorded from 71 elite golf players (mean handicap = 1.8, s = 4.2) on 1301 putts from about 4 m. Of the different factors deciding stroke direction consistency, face angle was found to be the most important (80%), followed by putter path (17%) and impact point (3%). This suggests that improvements in consistency of putter path and impact point will have very little effect on overall putting direction consistency and should not be prioritized in the training of elite players. In addition, mean stroke direction variability for an elite player (European Tour) was found to be 0.39°, which is good enough to hole about 95% of all 4-m putts. In practice, however, top professionals in tournaments only hole about 17% of 4-m putts. We conclude that the putting stroke of elite golfers has a relatively minor influence on direction consistency.

  • 25.
    Katarina, Löfvenhaft
    Stockholms universitet.
    Biologisk mångfald i urban miljö: Exempel från nationalstadsparken2002Ingår i: Nationalstadsparken – ett experiment i hållbar utveckling.: Studier av värdefrågor, lagtillämpning och utvecklingslinjer. / [ed] Lennart Holm, Peter Schantz, Stockholm: Forskningsrådet Formas, 2002, s. 31-47Kapitel i bok, del av antologi (Övrigt vetenskapligt)
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  • 26. Korten, Slobodanka
    et al.
    Albet-Torres, Nuria
    Paderi, Francesca
    ten Siethoff, Lasse
    Linneuniversitetet.
    Diez, Stefan
    Korten, Till
    te Kronnie, Geertruy
    Månsson, Alf
    Sample solution constraints on motor-driven diagnostic nanodevices2013Ingår i: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 13, nr 5, s. 866-876Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The last decade has seen appreciable advancements in efforts towards increased portability of lab-on-a-chip devices by substituting microfluidics with molecular motor-based transportation. As of now, first proof-of-principle devices have analyzed protein mixtures of low complexity, such as target protein molecules in buffer solutions optimized for molecular motor performance. However, in a diagnostic workup, lab-on-a-chip devices need to be compatible with complex biological samples. While it has been shown that such samples do not interfere with crucial steps in molecular diagnostics (for example antibody-antigen recognition), their effect on molecular motors is unknown. This critical and long overlooked issue is addressed here. In particular, we studied the effects of blood, cell lysates and solutions containing genomic DNA extracts on actomyosin and kinesin-microtubule-based transport, the two biomolecular motor systems that are most promising for lab-on-a-chip applications. We found that motor function is well preserved at defined dilutions of most of the investigated biological samples and demonstrated a molecular motor-driven label-free blood type test. Our results support the feasibility of molecular-motor driven nanodevices for diagnostic point-of-care applications and also demonstrate important constraints imposed by sample composition and device design that apply both to kinesin-microtubule and actomyosin driven applications.

  • 27. Kumar, Saroj
    et al.
    ten Siethoff, Lasse
    Linnéuniversitetet.
    Persson, Malin
    Lard, Mercy
    Kronnie, Geertruy Te
    Linke, Heiner
    Månsson, Alf
    Antibodies Covalently Immobilized on Actin Filaments for Fast Myosin Driven Analyte Transport2012Ingår i: PLOS ONE, E-ISSN 1932-6203, Vol. 7, nr 10, artikel-id e46298Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Biosensors would benefit from further miniaturization, increased detection rate and independence from external pumps and other bulky equipment. Whereas transportation systems built around molecular motors and cytoskeletal filaments hold significant promise in the latter regard, recent proof-of-principle devices based on the microtubule-kinesin motor system have not matched the speed of existing methods. An attractive solution to overcome this limitation would be the use of myosin driven propulsion of actin filaments which offers motility one order of magnitude faster than the kinesin-microtubule system. Here, we realized a necessary requirement for the use of the actomyosin system in biosensing devices, namely covalent attachment of antibodies to actin filaments using heterobifunctional cross-linkers. We also demonstrated consistent and rapid myosin II driven transport where velocity and the fraction of motile actin filaments was negligibly affected by the presence of antibody-antigen complexes at rather high density (&gt;20 mu m(-1)). The results, however, also demonstrated that it was challenging to consistently achieve high density of functional antibodies along the actin filament, and optimization of the covalent coupling procedure to increase labeling density should be a major focus for future work. Despite the remaining challenges, the reported advances are important steps towards considerably faster nanoseparation than shown for previous molecular motor based devices, and enhanced miniaturization because of high bending flexibility of actin filaments.

  • 28. Lard, Mercy
    et al.
    ten Siethoff, Lasse
    Linneuniversitetet.
    Generosi, Johanna
    Månsson, Alf
    Linke, Heiner
    Molecular Motor Transport through Hollow Nanowires2014Ingår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 14, nr 6, s. 3041-3046Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Biomolecular motors offer self-propelled, directed transport in designed microscale networks and can potentially replace pump-driven nanofluidics. However, in existing systems, transportation is limited to the two-dimensional plane. Here we demonstrate fully one-dimensional (1D) myosin-driven motion of fluorescent probes (actin filaments) through 80 nm wide, Al2O3 hollow nanowires of micrometer length. The motor-driven transport is orders of magnitude faster than would be possible by passive diffusion. The system represents a necessary element for advanced devices based on gliding assays, for example, in lab-on-a-chip systems with channel crossings and in pumpless nanosyringes. It may also serve as a scaffold for bottom-up assembly of muscle proteins into actin ordered contractile units, mimicking the muscle sarcomere.

  • 29. Lard, Mercy
    et al.
    ten Siethoff, Lasse
    Linneuniversitetet.
    Generosi, Johanna
    Persson, Malin
    Linke, Heiner
    Månsson, Alf
    Nanowire-Imposed Geometrical Control in Studies of Actomyosin Motor Function2015Ingår i: IEEE Transactions on Nanobioscience, ISSN 1536-1241, E-ISSN 1558-2639, Vol. 14, nr 3, s. 289-297Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Recently, molecular motor gliding assays with actin and myosin from muscle have been realized on semiconductor nanowires coated with Al2O3. This opens for unique nanotechnological applications and novel fundamental studies of actomyosin motor function. Here, we provide a comparison of myosin-driven actin filament motility on Al2O3 to both nitrocellulose and trimethylchlorosilane derivatized surfaces. We also show that actomyosin motility on the less than 200 nm wide tips of arrays of Al2O3-coated nanowires can be used to control the number, and density, of myosin-actin attachment points. Results obtained using nanowire arrays with different inter-wire spacing are consistent with the idea that the actin filament sliding velocity is determined both by the total number and the average density of attached myosin heads along the actin filament. Further, the results are consistent with buckling of long myosin-free segments of the filaments as a factor underlying reduced velocity. On the other hand, the findings do not support a mechanistic role in decreasing velocity, of increased nearest neighbor distance between available myosin heads. Our results open up for more advanced studies that may use nanowire-based structures for fundamental investigations of molecular motors, including the possibility to create a nanowire-templated bottom-up assembly of 3D, muscle-like structures.

  • 30. Lard, Mercy
    et al.
    ten Siethoff, Lasse
    Linneuniversitetet.
    Kumar, Saroj
    Persson, Malin
    te Kronnie, Geertruy
    Linke, Heiner
    Månsson, Alf
    Ultrafast molecular motor driven nanoseparation and biosensing2013Ingår i: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 48, s. 145-152Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Portable biosensor systems would benefit from reduced dependency on external power supplies as well as from further miniaturization and increased detection rate. Systems built around self-propelled biological molecular motors and cytoskeletal filaments hold significant promise in these regards as they are built from nanoscale components that enable nanoseparation independent of fluidic pumping. Previously reported microtubule-kinesin based devices are slow, however, compared to several existing biosensor systems. Here we demonstrate that this speed limitation can be overcome by using the faster actomyosin motor system. Moreover, due to lower flexural rigidity of the actin filaments, smaller features can be achieved compared to microtubule-based systems, enabling further miniaturization. Using a device designed through optimization by Monte Carlo simulations, we demonstrate extensive myosin driven enrichment of actin filaments on a detector area of less than 10 μm2, with a concentration half-time of approximately 40 s. We also show accumulation of model analyte (streptavidin at nanomolar concentration in nanoliter effective volume) detecting increased fluorescence intensity within seconds after initiation of motor-driven transportation from capture regions. We discuss further optimizations of the system and incorporation into a complete biosensing workflow.

  • 31. Lard, Mercy
    et al.
    ten Siethoff, Lasse
    Linneuniversitetet.
    Månsson, Alf
    Linke, Heiner
    Tracking Actomyosin at Fluorescence Check Points2013Ingår i: Scientific Reports, E-ISSN 2045-2322, Vol. 3, artikel-id 1092Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Emerging concepts for on-chip biotechnologies aim to replace microfluidic flow by active, molecular-motor driven transport of cytoskeletal filaments, including applications in bio-simulation, biocomputation, diagnostics, and drug screening. Many of these applications require reliable detection, with minimal data acquisition, of filaments at many, local checkpoints in a device consisting of a potentially complex network of channels that guide filament motion. Here we develop such a detection system using actomyosin motility. Detection points consist of pairs of gold lines running perpendicular to nanochannels that guide motion of fluorescent actin filaments. Fluorescence interference contrast (FLIC) is used to locally enhance the signal at the gold lines. A cross-correlation method is used to suppress errors, allowing reliable detection of single or multiple filaments. Optimal device design parameters are discussed. The results open for automatic read-out of filament count and velocity in high-throughput motility assays, helping establish the viability of active, motor-driven on-chip applications.

  • 32.
    Lund, Marie
    et al.
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling (-2013).
    Holmberg, Joakim
    Linköpings Universitet.
    Which are the Antagonists to the Pectoralis MajorMuscle in 4th Gear, Free‐style Technique, Cross‐Country Skiing?2008Ingår i: Science and Nordic Skiing, Oxford: Meyer & Meyer Sport , 2008, s. 110-118Konferensbidrag (Refereegranskat)
  • 33.
    Lund, Marie
    et al.
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling (-2013).
    Ståhl, Fredrik
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling (-2013).
    Gulliksson, Mårten
    Mittuniversitetet, Institutionen för naturvetenskap, teknik och matematik (-2012).
    Regularity Aspects in Inverse Musculoskeletal Biomechanics2008Ingår i: NUMERICAL ANALYSIS AND APPLIED MATHEMATICS / [ed] Simos, TE; Psihoyios, G; Tsitouras, C, American Institute of Physics (AIP) , 2008, s. 368-371Konferensbidrag (Refereegranskat)
    Abstract [en]

    Inverse simulations of musculoskeletal models computes the internal forces such as muscle and joint reaction forces, which are hard to measure, using the more easily measured motion and external forces as input data. Because of the difficulties of measuring muscle forces and joint reactions, simulations are hard to validate. One way of reducing errors for the simulations is to ensure that the mathematical problem is well-posed. This paper presents a study of regularity aspects for an inverse simulation method, often called forward dynamics or dynamical optimization, that takes into account both measurement errors and muscle dynamics. Regularity is examined for a test problem around the optimum using the approximated quadratic problem. The results shows improved rank by including a regularization term in the objective that handles the mechanical over-determinancy. Using the 3-element Hill muscle model the chosen regularization term is the norm of the activation. To make the problem full-rank only the excitation bounds should be included in the constraints. However, this results in small negative values of the activation which indicates that muscles are pushing and not pulling, which is unrealistic but the error maybe small enough to be accepted for specific applications. These results are a start to ensure better results of inverse musculoskeletal simulations from a numerical point of view.

  • 34.
    Lund Ohlsson, Marie
    Mittuniversitetet, Institutionen för naturvetenskap, teknik och matematik (-2012).
    New methods for movement technique development in cross-country skiing using mathematical models and simulation2009Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    This Licentiate Thesis is devoted to the presentation and discussion of some new contributions in applied mathematics directed towards scientific computing in sports engineering. It considers inverse problems of biomechanical simulations with rigid body musculoskeletal systems especially in cross-country skiing. This is a contrast to the main research on cross-country skiing biomechanics, which is based mainly on experimental testing alone. The thesis consists of an introduction and five papers. The introduction motivates the context of the papers and puts them into a more general framework. Two papers (D and E) consider studies of real questions in cross-country skiing, which are modelled and simulated. The results give some interesting indications, concerning these challenging questions, which can be used as a basis for further research. However, the measurements are not accurate enough to give the final answers. Paper C is a simulation study which is more extensive than paper D and E, and is compared to electromyography measurements in the literature. Validation in biomechanical simulations is difficult and reducing mathematical errors is one way of reaching closer to more realistic results. Paper A examines well-posedness for forward dynamics with full muscle dynamics. Moreover, paper B is a technical report which describes the problem formulation and mathematical models and simulation from paper A in more detail. Our new modelling together with the simulations enable new possibilities. This is similar to simulations of applications in other engineering fields, and need in the same way be handled with care in order to achieve reliable results. The results in this thesis indicate that it can be very useful to use mathematical modelling and numerical simulations when describing cross-country skiing biomechanics. Hence, this thesis contributes to the possibility of beginning to use and develop such modelling and simulation techniques also in this context.

  • 35.
    Lund Ohlsson, Marie
    et al.
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling (-2013).
    Gulliksson, Mårten
    Mittuniversitetet, Institutionen för naturvetenskap, teknik och matematik (-2012).
    Least Squares Approach to Inverse Problems in Musculoskeletal Biomechanics2009Rapport (Övrigt vetenskapligt)
    Abstract [en]

    Inverse simulations of musculoskeletal models computes the internal forces such as muscle and joint reaction forces, which are hard to measure, using the more easily measured motion and external forces as input data. Because of the difficulties of measuring muscle forces and joint reactions, simulations are hard to validate. One way of reducing errors for the simulations is to ensure that the mathematical problem is well-posed. This paper presents a study of regularity aspects for an inverse simulation method, often called forward dynamics or dynamical optimization, that takes into account both measurement errors and muscle dynamics. The simulation method is explained in detail. Regularity is examined for a test problem around the optimum using the approximated quadratic problem. The results shows improved rank by including a regularization term in the objective that handles the mechanical over-determinancy. Using the 3-element Hill muscle model the chosen regularization term is the norm of the activation. To make the problem full-rank only the excitation bounds should be included in the constraints. However, this results in small negative values of the activation which indicates that muscles are pushing and not pulling. Despite this unrealistic behavior the error maybe small enough to be accepted for specific applications. These results is a starting point start for achieving better results of inverse musculoskeletal simulations from a numerical point of view.

  • 36.
    Moberg, Marcus
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Åstrandlaboratoriet, Eva Blomstrands forskningsgrupp.
    Apró, William
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Åstrandlaboratoriet, Eva Blomstrands forskningsgrupp.
    Ekblom, Björn
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Åstrandlaboratoriet, Björn Ekbloms och Mats Börjessons forskningsgrupp.
    Blomstrand, Eva
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Åstrandlaboratoriet, Eva Blomstrands forskningsgrupp.
    High-intensity cycling performed prior to resistance exercise does not influence mTORC1-signaling and the rate of muscle protein synthesis in the triceps brachii2014Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Introduction

    Endurance exercise can influence strength training adaptations when performed concurrently, with both inhibition (Kreamer 1995) and augmentation (Lundberg 2012) of muscular hypertrophy being reported. Our lab has set out to conduct a series of studies to examine the influence of endurance exercise on the acute stimulatory effect of resistance exercise on anabolic processes. In the present study, the effect of endurance exercise on a previously inactive muscle was investigated. The aim was to examine the influence of resistance exercise on mTORC1-signaling and rate of protein synthesis in the triceps brachii muscle with or without preceding intervals of high-intensity cycling. 

     

    Methods

    Eight trained males performed, in a randomized fashion, two sessions of heavy resistance exercise (RE) with the triceps muscles, where one session was preceded by intervals of high-intensity cycling (E+RE), 5 x 4 min at 85% of VO2 peak. Mixed muscle protein fractional synthetic rate (FSR) was measured at rest, prior to exercise, and during a 3 hour recovery period following exercise by continuous infusion of L-[ring-13C6] phenylalanine. Muscle biopsies from the triceps brachii was collected twice at rest separated by three hours, directly after resistance exercise and following 90 and 180 min of recovery. Signalling in the mTORC1-and AMPK-pathway was assessed using western blot technique.

     

    Results

    The same amount of work with regard to load, total number of repetitions and total time under tension was performed in the two trials. Muscle protein FSR increased from 0.050 ± 0.006 %/h at rest to 0.078 ± 0.008 and 0.082 ± 0.0016 %/h following E+RE and RE, respectively, with no difference between trials. Phosphorylation (P) of AMPKT172 was increased by 45-65% directly after exercise, similarly in both conditions, and regressed to a level approx. 20% lower than baseline following 180 min of recovery. P-mTORS2448 was increased 76 and 108% above rest directly after the E+RE and RE, respectively, and remained elevated in both trials during the entire recovery period. P-eEF2T56 was 20-36% higher directly after exercise but fell to a level that was 30-36% lower than pre-exercise and remained reduced during the entire recovery, with no difference between trials.

     

    Conclusion

    High-intensity endurance cycling does not influence the acute stimulation of anabolic signalling and muscle protein synthesis in the triceps brachii following resistance exercise.

     

     

    References

    Kreamer WJ et al. (1995) J Appl Physiol 78(3):976-989

    Lundberg T et al. (2013) J Appl Physiol 114: 81-89

  • 37.
    Moretti, Chiara H
    et al.
    Karolinska Institutet, Stockholm, Sweden..
    Schiffer, Tomas A
    Karolinska Institutet, Stockholm, Sweden..
    Montenegro, Marcelo F
    Karolinska Institutet, Stockholm, Sweden..
    Larsen, Filip J
    Gymnastik- och idrottshögskolan, GIH, Institutionen för fysiologi, nutrition och biomekanik.
    Tsarouhas, Vasilios
    The Wenner-Gren Institute, Stockholm, Sweden.
    Carlström, Mattias
    Karolinska Institutet, Stockholm, Sweden..
    Samakovlis, Christos
    The Wenner-Gren Institute, Stockholm.
    Weitzberg, Eddie
    Karolinska Institutet, Stockholm, Sweden..
    Lundberg, Jon O
    Karolinska Institutet, Stockholm, Sweden..
    Dietary nitrite extends lifespan and prevents age-related locomotor decline in the fruit fly.2020Ingår i: Free Radical Biology & Medicine, ISSN 0891-5849, E-ISSN 1873-4596, Vol. 160, s. 860-870, artikel-id S0891-5849(20)31255-7Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Aging is associated with decreased nitric oxide (NO) bioavailability and signalling. Boosting of a dietary nitrate-nitrite-NO pathway e.g. by ingestion of leafy green vegetables, improves cardiometabolic function, mitochondrial efficiency and reduces oxidative stress in humans and rodents, making dietary nitrate and nitrite an appealing intervention to address age-related disorders. On the other hand, these anions have long been implicated in detrimental health effects of our diet, particularly in formation of carcinogenic nitrosamines. The aim of this study was to assess whether inorganic nitrite affects lifespan in Drosophila melanogaster and investigate possible mechanisms underlying any such effect. In a survival assay, female flies fed a nitrite supplemented diet showed lifespan extension by 9 and 15% with 0.1 and 1 μM nitrite respectively, with no impact of nitrite on reproductive output. Interestingly, nitrite could also protect female flies from age-dependent locomotor decline, indicating a protective effect on healthspan. NO generation from nitrite involved Drosophila commensal bacteria and was indicated by a fluorescent probe as well as direct measurements of NO gas formation with chemiluminescence. Nutrient sensing pathways such as TOR and sirtuins, have been strongly implicated in lifespan extension. In aged flies, nitrite supplementation significantly downregulated dTOR and upregulated dSir2 gene expression. Total triglycerides and glucose were decreased, a described downstream effect of both TOR and sirtuin pathways. In conclusion, we demonstrate that very low doses of dietary nitrite extend lifespan and favour healthspan in female flies. We propose modulation of nutrient sensing pathways as driving mechanisms for such effects.

  • 38. Månsson, Alf
    et al.
    ten Siethoff, Lasse
    Linneuniversitetet.
    Lard, Mercy
    Generosi, Johanna
    Andersson, Håkan S.
    Linke, Heiner
    Three-Dimensionally Constrained Actomyosin Motility on Oxide Coated Semiconductor Nanowires2014Ingår i: Biophysical Journal, ISSN 0006-3495, E-ISSN 1542-0086, Vol. 106, nr 2, s. 453A-453AArtikel i tidskrift (Övrigt vetenskapligt)
  • 39.
    Nilsson, Johnny
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    Tinmark, Fredrik
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    Halvorsen, Kjartan
    Arndt, Anton
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    Kinematic, kinetic and electromyographic adaptation to speed and resistance in double poling cross country skiing2013Ingår i: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 113, nr 6, s. 1385-1394Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study incorporated variations in speed and the horizontal resistance acting upon elite female skiers during double poling (DP) on a treadmill and specifically analyzed biomechanical adaptations to these variations. Whole body kinematics and pole force data were recorded and used to calculate the moment of force acting on the shoulder and elbow joints. Data were obtained with a 3D optoelectronic system using reflective markers at given anatomical landmarks. Forces along the long axis of the right pole were measured with a piezoelectric force transducer. Surface electrodes were used to record EMG activity in the rectus femoris, rectus abdominis, latissimus dorsi and triceps brachii muscles. In a first set of recordings, the participants double poled with zero elevation at five different speeds from 8 to 17 km h−1. In a second set of recordings, horizontal resistance was added by weights (0.4–1.9 kg) attached to a pulley system pulling the skier posteriorly during DP at 14 km h−1. Results showed increasing relative duration of the thrust phase with increasing resistance, but not with speed. Significant kinematic differences occurred with increase in both speed and resistance. The mean (±SD) horizontal force components ranged between 1.7 (±1.3) and 2.8 (±1.1) percent (%) bodyweight (BW) in the speed adaptation and 3.1 (±0.6) and 4.0 (±1.3) % BW in the adaptation to horizontal resistance. Peak muscle activity showed a central to peripheral (proximo-distal) activation sequence. The temporal cycle phase pattern in the adaptation to speed and horizontal resistance differed.

  • 40.
    Nilsson, Lina
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Åstrandlaboratoriet.
    Flockhart, Mikael
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Åstrandlaboratoriet.
    Apro, William
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Åstrandlaboratoriet, Eva Blomstrands forskningsgrupp.
    Ekblom, Björn
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Åstrandlaboratoriet, Björn Ekbloms forskningsgrupp.
    Larsen, Filip J
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Åstrandlaboratoriet, Forskningsgruppen Mitokondriell funktion och metabolisk kontroll.
    Biphasic relationship between training load and glucose tolerance2019Konferensbidrag (Övrigt vetenskapligt)
    Abstract [sv]

    Biphasic relationship between training load and glucose tolerance

    Nilsson, L, Flockhart M, Bergman K, Apro W, Ekblom B, Larsen FJ

     

    There is a well-established construct regarding the positive effects of exercise on glucose tolerance and insulin sensitivity, as well as muscle glycogen storage. In insulin resistance, physical activity is an essential part of the treatment. However, the optimal dose is unknown. Reduced muscular glycogen stores, resulting from exercise, should stimulate an increased uptake of blood glucose. In this study we investigated the relation between training load, glucose tolerance and insulin sensitivity during three weeks of increasing interval training. Three times during the intervention, oral glucose tests were conducted to investigate the rate of glucose uptake. We found a biphasic dose-response relationship between training load and glucose tolerance, where an excessive training load led to a paradoxical reduction in glucose tolerance and impaired insulin release despite an unchanged amount of muscle glycogen. In light of these results, an upper limit of physical exercise exist where the negative effects overpowers the positive.

  • 41.
    Niotis, Dimitrios
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    IT i skolan: en studie av hur datorer används i skolan2007Studentarbete andra termin, 5 poäng / 7,5 hpStudentuppsats
    Abstract [sv]

    SAMMANFATTNING

    Syfte och frågeställningar

    Syftet med denna uppsats är att ta reda på hur datorerna som finns i skolan används.

    * Kan man se några tydliga skillnader mellan en innerstadsskola och en förortsskola?

    * Hur ser elevernas datavanor ut?

    Metod

    Min uppsats är en kvantitativ studie. För att besvara mina frågeställningar har jag använt mig av en enkät. Enkäten som jag har gjort är till stora delar hämtad från examensarbetet Datorer i skolan som skrevs på Idrottshögskolan för 10 år sedan. Jag tyckte att många av deras frågor var intressanta och fortfarande aktuella.

    Resultat

    Svaren från enkäten visade att datorn används mest i ämnen som matematik, svenska och engelska i förortsskolan medan i innerstadsskolan har man använt datorn i svenska, engelska och bild. I innerstaden använder man ofta datorn till att hämta information från Internet och göra presentationer i t.ex. PowerPoint. Förortseleverna använder också datorn till att hämta information från Internet. En annan skillnad mellan de två skolorna är att man i förorten låter eleverna i högre grad använda datorn även till annat än skolarbete medan det sällan händer i innerstaden.

    Det fanns många fler likheter än olikheter mellan skolorna. Alla barnen i båda skolorna tyckte om att arbeta med datorer vilket inte är så förvånande i dessa tider då datorerna har blivit så vanliga.

    Slutsats

    Datorn har blivit en naturlig del i elevernas sökning efter information. Datorn används också mycket till att jobba med skolans kärnämnen som t.ex. matematik, svenska och engelska vilket är bra för den ökade måluppfyllelsen som det ofta pratas om i dagens skola. Mycket hänger dock på lärarens datautbildning och inställning till att integrera datorn i undervisningen.

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    FULLTEXT01
  • 42.
    Olsson, Gustav
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Enkät för skattning av 8-åriga barns fysiska aktivitet: En valideringsstudie. Frågor ur SIH-enkäten jämförda med referensmetoden accelerometri2011Självständigt arbete på avancerad nivå (magisterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Syfte och frågeställningar

    Att validera STOPP-8-enkäten (S8Q), som innehåller frågor ur SIH-enkäten, mot kriteriemetoden accelerometri för att pröva dess förmåga att skatta 8-åriga svenska barns fysiska aktivitet (FA). Kan S8Q skatta barns grad av FA? Kan S8Q skilja de aktiva barnen från de stillasittande? Om svaren på dessa frågor blir ja, hur väl gör den det?

    Metod

    Data samlades in hösten och vintern skolåret 2008 - 2009 via projektet STOPP-8. Av 676 barn vid 12 skolor i Stockholmsområdet, lämnade 155 (pojkar n = 72, flickor n = 83) ifyllda enkäter samt bar en accelerometer (Actiwatch 4) under 7 dagar i följd. Accelerometern genererade data för medel och median FA, tid stillasittande, i måttlig till intensiv FA och i intensiv FA. Kriterium för att accelerometerdata skulle användas i analysen var åtminstone 4 giltiga dagar där mätaren burits minst 10 timmar per dag mellan klockan 08:00 och 21:00. Ett t-test användes för att jämföra data från pojkar respektive flickor. Alla frågor från enkäten och specialkonstruerade derivat baserade på dem jämfördes med accelerometri med hjälp av Spearmans korrelationskoefficient, ANOVA och Receiver Operating Characteristic analys (en metod för att illustrera sensitivitet och specificitet samt beräkna effektivast gränsvärden).

    Resultat

    Resultatet från S8Q visade sig vara beroende av kön i sådan omfattning att pojk- och flickdata behövde analyseras separat. Hos flickor var starkaste korrelaten frågan ”Hur tar du dig till dina kompisar?” som gav r = 0,37 och p = 0,05 när ställd mot andel FA i intensitet mellan 1,5 till 3 METs. Bland pojkarna visade frågan ”Hur tar du dig till dina fritidsaktiviteter?” starkast samband om r = - 0,33 och p = 0,05 när ställd mot andel mättid stillasittande. I de fall där S8Q visade starkast klassificeringskapacitet kunde den korrekt identifiera 75 % av de sant fysiskt aktiva barnen på bekostnad av att 60 % av dem som i själva verket var stillasittande felklassificerades, vilket får anses vara låg specificitet.

    Slutsats

    Enkätens förmåga att skatta 8-åriga barns FA är i linje med flera andra etablerade självskattningsmetoder men är inget pålitligt verktyg för detta ändamål. Möjligen kan den användas för att jämföra större populationer såsom kommuner, städer och länder. Dock kan andelen felklassificering på individnivå ändå bli stor. S8Q visade sig ha svagt samband med objektivt uppmätt FA.

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  • 43. Persson, Malin
    et al.
    Bengtsson, Elina
    ten Siethoff, Lasse
    Linneuniversitetet.
    Månsson, Alf
    Nonlinear Cross-Bridge Elasticity and Post-Power-Stroke Events in Fast Skeletal Muscle Actomyosin2013Ingår i: Biophysical Journal, ISSN 0006-3495, E-ISSN 1542-0086, Vol. 105, nr 8, s. 1871-1881Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Generation-of force and movement by actomyosin cross-bridges is the molecular basis of muscle contraction, but generally accepted ideas about cross-bridge properties have recently been questioned. Of the utmost significance, evidence for nonlinear cross-bridge elasticity has been presented. We here investigate how this and other newly discovered or postulated phenomena would modify cross-bridge operation, with focus on post-power-stroke events. First, as an experimental basis, we present evidence for a hyperbolic [MgATP]-velocity relationship of heavy-meromyosin-propelled actin filaments in the in vitro motility assay using fast rabbit skeletal muscle myosin (28-29 degrees C). As the hyperbolic [MgATP]-velocity relationship was not consistent with interhead cooperativity, we developed a cross-bridge model with independent myosin heads and strain-dependent interstate transition rates. The model, implemented with inclusion of MgATP-independent detachment from the rigor state, as suggested by previous single-molecule mechanics experiments, accounts well for the [MgATP]-velocity relationship if nonlinear cross-bridge elasticity is assumed, but not if linear cross-bridge elasticity is assumed. In addition, a better fit is obtained with load-independent than with load-dependent MgATP-induced detachment rate. We discuss our results in relation to previous data showing a nonhyperbolic [MgATP1-velocity relationship when actin filaments are propelled by myosin subfragment 1 or full-length myosin. We also consider the implications of our results for characterization of the cross-bridge elasticity in the filament lattice of muscle.

  • 44. Persson, Malin
    et al.
    Bengtsson, Elina
    ten Siethoff, Lasse
    Linneuniversitetet.
    Månsson, Alf
    Non-Linear Cross-Bridge Elasticity, ATP-Independent Detachment and ATP-Velocity Relationships for Skeletal Muscle Actomyosin2014Ingår i: Biophysical Journal, ISSN 0006-3495, E-ISSN 1542-0086, Vol. 106, nr 2, s. 158A-158AArtikel i tidskrift (Övrigt vetenskapligt)
  • 45.
    Põlajeva, Jelena
    et al.
    Uppsala universitet, Cancer och vaskulärbiologi.
    Swartling, Fredrik
    Uppsala universitet, Cancer och vaskulärbiologi.
    Jiang, Yiwen
    Uppsala universitet, Cancer och vaskulärbiologi.
    Singh, Umashankar
    Uppsala universitet, Cancer och vaskulärbiologi.
    Pietras, Kristian
    Department of Medical Biochemistry and Biophysics, Karolinska Institutet.
    Uhrbom, Lene
    Uppsala universitet, Cancer och vaskulärbiologi.
    Westermark, Bengt
    Uppsala universitet, Cancer och vaskulärbiologi.
    Roswall, Pernilla
    Uppsala universitet, Institutionen för immunologi, genetik och patologi.
    miRNA-21 is developmentally regulated in mouse brain and is co-expressed with SOX2 in glioma2012Ingår i: BMC Cancer, ISSN 1471-2407, E-ISSN 1471-2407, Vol. 12, s. 378-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background

    MicroRNAs (miRNAs) and their role during tumor development have been studied in greatdetail during the last decade, albeit their expression pattern and regulation during normaldevelopment are however not so well established. Previous studies have shown that miRNAsare differentially expressed in solid human tumors. Platelet-derived growth factor (PDGF)signaling is known to be involved in normal development of the brain as well as in malignantprimary brain tumors, gliomas, but the complete mechanism is still lacking. We decided toinvestigate the expression of the oncogenic miR-21 during normal mouse development andglioma, focusing on PDGF signaling as a potential regulator of miR-21.

    Methods

    We generated mouse glioma using the RCAS/tv-a system for driving PDGF-BB expression ina cell-specific manner. Expression of miR-21 in mouse cell cultures and mouse brain wereassessed using Northern blot analysis and in situ hybridization. Immunohistochemistry andWestern blot analysis were used to investigate SOX2 expression. LNA-modified siRNA wasused for irreversible depletion of miR-21. For inhibition of PDGF signaling Gleevec(imatinib mesylate), Rapamycin and U0126, as well as siRNA were used. Statisticalsignificance was calculated using double-sided unpaired Student´s t-test.

    Results

    We identified miR-21 to be highly expressed during embryonic and newborn braindevelopment followed by a gradual decrease until undetectable at postnatal day 7 (P7), thiscorrelated with SOX2 expression. Furthermore, miR-21 and SOX2 showed up-regulation andoverlapping expression pattern in RCAS/tv-a generated mouse brain tumor specimens. Uponirreversible depletion of miR-21 the expression of SOX2 was strongly diminished in bothmouse primary glioma cultures and human glioma cell lines. Interestingly, in normalfibroblasts the expression of miR-21 was induced by PDGF-BB, and inhibition of PDGFsignaling in mouse glioma primary cultures resulted in suppression of miR-21 suggesting thatmiR-21 is indeed regulated by PDGF signaling.

    Conclusions

    Our data show that miR-21 and SOX2 are tightly regulated already during embryogenesisand define a distinct population with putative tumor cell of origin characteristics. We believethat miR-21 is a mediator of PDGF-driven brain tumors, which suggests miR-21 as apromising target for treatment of glioma.

  • 46.
    Rosdahl, Hans
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    Lindberg, Thomas
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för tillämpad idrottsvetenskap (LTIV).
    Edin, Fredrik
    Nilsson, Johnny
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    The Moxus Modular metabolic sustem evaluated with two sensors for ventilation against the Douglas bag method2013Ingår i: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 113, nr 5, s. 1353-1367Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study evaluated the Moxus metabolic system with the Douglas bag method (DBM) as criterion. Reliability and validity were investigated in a wide range of ventilation and oxygen uptake and two sensors for determining ventilation were included. Thirteen well-trained athletes participated in one pre-test and four tests for data collection, exercising on a cycle ergometer at five submaximal powers (50-263 W) and at [Formula: see text]. Gas exchange variables were measured simultaneously using a serial setup with data collected on different days in an order randomized between Moxus with pneumotachometer (MP) and turbine flowmeter (MT) sensors for ventilation. Reliability with both sensors was comparable to the DBM. Average CV (%) of all exercise intensities were with MP: 3.0 ± 1.3 for VO(2), 3.8 ± 1.5 for VCO(2), 3.1 ± 1.2 for the respiratory exchange ratio (RER) and 4.2 ± 0.8 for V (E). The corresponding values with MT were: 2.7 ± 0.3 for VO(2), 4.7 ± 0.4 for VCO(2), 3.3 ± 0.9 for RER and 4.8 ± 1.4 for V (E). Validity was acceptable except for small differences related to the determination of ventilation. The relative differences in relation to DBM at the powers including [Formula: see text] were similar for both sensors with the ranges being: +4 to -2 % for V (E), +5 to -3 % for VO(2) and +5 to -4 % for VCO(2) while RER did not differ at any power. The Moxus metabolic system shows high and adequate reliability and reasonable validity over a wide measurement range. At a few exercise levels, V (E) differed slightly from DBM, resulting in concomitant changes in VO(2) and VCO(2).

  • 47.
    Ryhed, Anna
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Syreupptagningsförmåga vid fem-minuterspyramidtest gentemot maximalt test på löpband: en valideringsstudie hos äldre och yngre vuxna2017Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Syfte och frågeställningar. Syftet med studien är att, hos äldre personer, över 65 år, samt hos yngre vuxna, mellan 20-30 år, jämföra syreupptagningsförmågan med två olika metoder, fem-minuterspyramidtest (5MPT) samt VO2max-test på löpband. Vid båda mätmetoderna används direkt syrgasmätning.

    Metod. Totalt deltog 36 personer i studien, varav 17 äldre personer 65 till 85 år (9 kvinnor och 8 män) samt 19 yngre med en ålder mellan 20 till 35 år (10 kvinnor och 9 män). Deltagarnas syreupptagningsförmåga mättes under 5MPT vid två tillfällen som sedan jämfördes med VO2max mätt via ett maximalt test på löpband vid ett tillfälle. Således utfördes sammanlagt tre mätningar med direkt syrgasmätning, via andningsmask, under ett maximalt löpbandstest samt under två separata tester av 5MPT med minst 48 timmar mellan varje testtillfälle. Utandningsluften analyserades sedan, vid 5MPT för alla, via det trådlösa portabla systemet Jaeger Oxycon Mobile och vid test på löpband för testgruppen med yngre deltagare. För den testgrupp med äldre deltagare användes, vid testet på löpband, den fasta on-line-utrustningen Jaeger Oxycon Pro som är en liknande mätmetod för syreupptag. 5MPT är ett fem minuter långt test där individen från golvnivå, med högsta möjliga tempo, förflyttar sig fram och tillbaka på en 5,50 meter lång sträcka med en centralt placerad trappramp som är pyramidformad och med en högsta central höjd på 0,62 meter.

    Resultat. Det primära fyndet i studien var att en stark signifikant korrelation (r = 0,99) visade sig mellan direkt uppmätt VO2max under maximalt test på löpband gentemot syreupptagningsförmågan vid 5MPT då båda åldersgrupperna var sammanslagna, uppmätt i l·min–1.

    Slutsats. Då det i undersökningen visades en stark signifikant korrelation mellan direkt uppmätt VO2max vid 5MPT och ett maximalt test på löpband i l·min–1 för äldre och yngre vuxna ger det indikationer på att 5MPT kan används som en tillförlitlig metod vid undersökning och uppföljning av en persons aeroba förmåga. Fyndet kan vara av värde då det genom mindre kostsamma och enklare metoder går att få ett mått på en persons hälsa i form av aerob kapacitet, vilket är betydelsefullt ur flera hälsoaspekter på individ- och samhällsnivå.

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    A Ryhed masteruppsats
  • 48.
    Salier Eriksson, Jane
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Åstrandlaboratoriet, FoU-gruppen för rörelse, hälsa och miljö.
    The heart rate method for estimating oxygen uptake in walking and cycle commuting: Evaluations based on reproducibility and validity studies of the heart rate method and a portable metabolic system2018Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Walking and cycling to work can contribute to population health, but more objective knowledge concerning exercise intensities, oxygen uptake and the metabolic demands of this physical activity is needed for this and other evaluations. To attain this, valid and reliable instruments are a requirement. The focus of this thesis was to evaluate whether the heart rate method can be used for this purpose. It involves establishing the relation between heart rate and oxygen uptake during ergometer cycling in laboratory conditions, and thereafter checking if the same relation exists during cycle or walking commuting in a metropolitan area.

    To accomplish this, a portable metabolic system was tested for validity and reliability in laboratory and field conditions and the reproducibility of the heart rate and oxygen uptake relation in the laboratory was evaluated. Furthermore, the heart rate and oxygen uptake relations during cycle and walking commuting was compared with those attained in the laboratory.

    The first two studies showed that a portable metabolic system is valid during laboratory and sustained field conditions. Studies 3 and 4 showed that the heart rate method with respect to the heart rate-oxygen uptake relationship is reliable on the group level for both walking and cycling commuters during repeated measures in the laboratory. The last two studies showed that applying the heart rate method during cycle commuting leads to valid levels of oxygen uptake on the group level for both males and females. Contrary to that, the measured levels of oxygen uptake in the field during walking commuting were on average 17% higher for males, and 13% higher for females than the values obtained with the heart rate method. For both walking and cycling commuters, the individual spread around the mean values was rather high, creating somewhat wide confidence intervals for the mean values.

    In summary, the heart rate method can be used for cycle commuters during their normal commuting conditions, while for pedestrians it is necessary to take into account that oxygen uptake per heart rate is higher while walking than that estimated from ergometer cycling in the laboratory.

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  • 49.
    Schantz, Peter
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Åstrandlaboratoriet, FoU-gruppen för rörelse, hälsa och miljö.
    Nilsson, Johnny
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Exempel på integrering av idrott och biologi1986Ingår i: Tidskrift i gymnastik och idrott : officiellt organ för Svenska g, ISSN 0281-5338, nr 4, s. 29-35Artikel i tidskrift (Övrigt vetenskapligt)
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  • 50.
    Schyberg, Jonas
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Palm, Johan
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Bedömning av beslutsfattande och utförande av fotbollsaktioner: Utvärdering av Game Performance Evaluation Tool (GPET) i ett Allsvenskt U17-lag2018Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Sammanfattning

    Syfte och frågeställningar

    Syftet med studien var att undersöka om Game Performance Evaluation Tool (GPET) kan särskilja fotbollsprestation hos spelare på junior-elit nivå. Som tillförlitlig utgångspunkt för jämförelse används en samlad subjektiv bedömning av fotbollsförmåga utifrån två oberoende erfarna och kunniga tränare. Frågeställningarna var: (1) Korrelerar den subjektiva bedömningen av fotbollsprestation med GPET-verktygets resultat? (2) Korrelerar den subjektiva bedömningen med GPET-verktygets resultat gällande spelarnas utförande, beslutsfattande och agerande utifrån taktisk kontext?

    Metod Studien har genom en kvantitativ ansats genomförts med blind observation vid ett tillfälle, vilket har lagrats och i efterhand kodats med GPET. Juniorelit-spelare (n=12, 17,3 ± 0,5 år), har valts ut och delats upp i två grupper av deras två tränare. (n=6) spelare, representerar enligt tränarna de som har kommit längst i sin fotbollskunskap (bra) och (n=6) spelare, representerar de som inom samma lag ansetts svagast sett till deras fotbollskunskap (sämre).

    Resultat

    Totalt har 96 minuter film kodats och analyserats. 649 aktioner har registrerats (utan boll 60,3%, med boll 26,5%, och “andra” 13,2%). 32% i taktisk kontext 1A; 65% i kontext 2A samt 3% i kontext 3A. I den totala sammanställningen, medelvärdet av poängen på alla aktioner spelarna lyckats med, nådde grupp “bra” ett resultat av 94,4 ± 3,5 medan grupp “sämre” fick medelvärde 89,7 ± 4,2. Ett oberoende t-test visade en trend mot skillnad mellan grupperna (p < 0,065).  

    Slutsats

    GPET verkar kunna särskilja grupperna då resultatet visar en procentuell skillnad på samtliga kodade delar samt den totala sammanställningen vilket är resultatet av spelarnas fotbollsprestation. Verktyget verkar även vara praktiskt tillämpbart då kodningen är relativt tidseffektiv och ger möjlighet att skapa en mer samlad och objektiv bild av fotbollsspelares prestation. Studiens resultat bör tolkas kritiskt på grund av det begränsade urvalet samt det limiterade antal spelsituationer spelarna ställdes inför.   

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