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  • 1.
    Holmberg, Joakim
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik och hållfasthetslära. Linköpings universitet, Tekniska fakulteten.
    Classification of Paralympic Athletes using Musculoskeletal Simulations2016Konferansepaper (Annet vitenskapelig)
  • 2.
    Holmberg, Joakim
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik. Linköpings universitet, Tekniska högskolan.
    Cross-country Skiing Biomechanics using the AnyBody Modeling System2007Konferansepaper (Annet vitenskapelig)
  • 3.
    Holmberg, Joakim
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik. Linköpings universitet, Tekniska högskolan.
    Simulera med mera2008Inngår i: CAD & ritnytt, ISSN 0282-5708, nr 4, s. 27-28Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
    Abstract [sv]

    Varför tillverkar man produkter utan att ta hänsyn till människan som ska använda dem? Är det inte konstigt att det nästan inte finns någon egenskap hos tekniska produkter som inte går att simulera, men ingen vet belastningen på din ryggrad när du sitter i din kontorsstol?

  • 4.
    Holmberg, Joakim
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik och hållfasthetslära. Linköpings universitet, Tekniska fakulteten.
    Skiers’ summer training – to bike or not to bike?2015Konferansepaper (Annet vitenskapelig)
  • 5.
    Holmberg, Joakim L.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik. Linköpings universitet, Tekniska högskolan.
    Computational Biomechanics in Cross-country Skiing2008Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Traditionally, research on cross‐country skiing biomechanics is based mainly on experimental testing alone. Trying a different approach, this thesis explores the possibilities of using computational musculoskeletal biomechanics for cross‐country skiing. As far as the author knows, this has not been done before.

    Cross‐country skiing is both fast and powerful, and the whole body is used to generate movement. Consequently, the computational method used needs to be able to handle a full‐body model with lots of muscles. This thesis presents several simulation models created in the AnyBody Modeling System, which is based on inverse dynamics and static optimization. This method allows for measurementdriven full‐body models with hundreds of muscles and rigid body segments of all major body parts.

    A major result shown in the thesis is that with a good simulation model it is possible to predict muscle activation. Even though there is no claim of full validity of the simulation models, this result opens up a wide range of possibilities for computational musculoskeletal biomechanics in cross‐country skiing. Two example of new possibilities are shown in the thesis, finding antagonistic muscle pairs and muscle load distribution differences in different skiing styles. Being able to perform optimization studies and asking and answering “what if”‐questions really gives computational methods an edge compared to traditional testing.

    To conclude, a combination of computational and experimental methods seems to be the next logical step to increase the understanding of the biomechanics of crosscountry skiing.

    Delarbeid
    1. Versatile Optimization
    Åpne denne publikasjonen i ny fane eller vindu >>Versatile Optimization
    2001 (engelsk)Inngår i: Nordic MATLAB Conference Proceedings Oslo, Norway, October 17‐18, 2001, s. 207‐212-Konferansepaper, Publicerat paper (Fagfellevurdert)
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-12908 (URN)
    Tilgjengelig fra: 2008-01-28 Laget: 2008-01-28 Sist oppdatert: 2015-01-14
    2. A biomechanical model of a double‐poling skier
    Åpne denne publikasjonen i ny fane eller vindu >>A biomechanical model of a double‐poling skier
    2003 (engelsk)Inngår i: In International Society of Biomechanics XIXth Congress on The human body in motion, CD Rom Abstracts and Proceedings, Milburn, P. (Ed.), University of Otago, Dunedin, New Zealand, 6‐11 July, 2003Konferansepaper, Publicerat paper (Annet vitenskapelig)
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-12909 (URN)
    Konferanse
    International Society of Biomechanics XIXth Congress
    Tilgjengelig fra: 2008-01-28 Laget: 2008-01-28 Sist oppdatert: 2015-01-14
    3. Which are the antagonists to the pectoralis major muscle in 4th gear free‐style technique, cross‐country skiing?
    Åpne denne publikasjonen i ny fane eller vindu >>Which are the antagonists to the pectoralis major muscle in 4th gear free‐style technique, cross‐country skiing?
    2007 (engelsk)Inngår i: Science and Nordic Skiing, Linnamo, V., Komi, P.V. and Müller, E. (Eds.), Meyer and Meyer Sport, Oxford, UK / [ed] Vesa Linnamo, Paavo V. Komi, Erich Müller, Meyer and Meyer Sport, Oxford, UK , 2007, s. 112-118Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    Between June 18-20 2006, the Vuokatti Sports Institute in Finland - arguably the world's finest ski training facility - played host to the International Congress on Science and Nordic Skiing."Science and Nordic Skiing" brings together the very latest in cutting edge research and developments into Nordic Skiing - ski jumping and cross-country skiing to biomechanics and the effects of cold weather on exercise - presented by some of the world's foremost experts in the field."Science and Nordic Skiing" is destined to become an invaluable and practical reference for sports scientists, coaches, skiers and anyone involved in this exciting area of winter sports.It presents the very latest research and development in the world of science and Nordic skiing.

    sted, utgiver, år, opplag, sider
    Meyer and Meyer Sport, Oxford, UK, 2007
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-12910 (URN)978-1-84126-229-1 (ISBN)1-841-26-229-3 (ISBN)
    Tilgjengelig fra: 2008-01-28 Laget: 2008-01-28 Sist oppdatert: 2015-01-14bibliografisk kontrollert
    4. Using double‐poling simulations to study the load distribution between teres major and latissimus dorsi
    Åpne denne publikasjonen i ny fane eller vindu >>Using double‐poling simulations to study the load distribution between teres major and latissimus dorsi
    2007 (engelsk)Inngår i: In Science and Nordic Skiing, Linnamo, V., Komi, P.V. and Müller, E. (Eds.), Meyer and Meyer Sport, Oxford, UK / [ed] Vesa Linnamo, Paavo V. Komi, Erich Müller, Meyer and Meyer Sport, Oxford, UK , 2007, s. 81-89Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    Between June 18-20 2006, the Vuokatti Sports Institute in Finland - arguably the world's finest ski training facility - played host to the International Congress on Science and Nordic Skiing."Science and Nordic Skiing" brings together the very latest in cutting edge research and developments into Nordic Skiing - ski jumping and cross-country skiing to biomechanics and the effects of cold weather on exercise - presented by some of the world's foremost experts in the field."Science and Nordic Skiing" is destined to become an invaluable and practical reference for sports scientists, coaches, skiers and anyone involved in this exciting area of winter sports.It presents the very latest research and development in the world of science and Nordic skiing.

    sted, utgiver, år, opplag, sider
    Meyer and Meyer Sport, Oxford, UK, 2007
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-12911 (URN)978-1-84126-229-1 (ISBN)184-12-62-29-3 (ISBN)
    Tilgjengelig fra: 2008-01-28 Laget: 2008-01-28 Sist oppdatert: 2015-01-14bibliografisk kontrollert
    5. A musculoskeletal full‐body simulation of cross‐country skiing
    Åpne denne publikasjonen i ny fane eller vindu >>A musculoskeletal full‐body simulation of cross‐country skiing
    2008 (engelsk)Inngår i: Proc. IMechE Vol. 222 Part P: J. Sports Engineering and Technology, ISSN 1754-3371, Vol. 222, nr 1, s. 11-22Artikkel i tidsskrift (Fagfellevurdert) Published
    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.

    Emneord
    biomechanics, double poling, ergometer, inverse dynamics
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-12912 (URN)10.1243/17543371JSET10 (DOI)
    Tilgjengelig fra: 2008-01-28 Laget: 2008-01-28 Sist oppdatert: 2015-01-14
  • 6.
    Holmberg, Joakim
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik. Linköpings universitet, Tekniska högskolan.
    Lund Ohlsson, Marie
    MittUniversitet.
    Biomekaniska simuleringar adderar insikt om längdskidåkning2010Inngår i: Svensk Idrottsforskning: Organ för Centrum för Idrottsforskning, ISSN 1103-4629, Vol. 19, nr 1, s. 38-40Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
    Abstract [sv]

    Varför ska man kopiera de som är bäst? När man väl lärt sig deras teknik så har de bästa kanske redan gått vidare och utvecklat ännu bättre tekniker? Med biomekaniska simuleringar adderas insikt så att man kan utveckla sin teknik och ligga i framkant, istället för i svallvågorna.

  • 7.
    Holmberg, Joakim
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik. Linköpings universitet, Tekniska högskolan.
    Lund Ohlsson, Marie
    Department of Engineering and Sustainable Development, Mid Sweden University, Sweden .
    Danvind, Jonas
    Department of Engineering and Sustainable Development, Mid Sweden University, Sweden .
    Letter: Musculoskeletal simulations: a complementary tool for classification of athletes with physical impairments2012Inngår i: Prosthetics and orthotics international, ISSN 0309-3646, E-ISSN 1746-1553, Vol. 36, nr 3, s. 396-397Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    n/a

  • 8.
    Holmberg, Joakim
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik. Linköpings universitet, Tekniska högskolan.
    Rännar, L-E
    Mid Sweden University.
    Versatile Optimization2001Inngår i: Nordic MATLAB Conference Proceedings Oslo, Norway, October 17‐18, 2001, s. 207‐212-Konferansepaper (Fagfellevurdert)
  • 9.
    Holmberg, Joakim
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik. Linköpings universitet, Tekniska högskolan.
    Wagenius, P.
    Mid Sweden University.
    A biomechanical model of a double‐poling skier2003Inngår i: In International Society of Biomechanics XIXth Congress on The human body in motion, CD Rom Abstracts and Proceedings, Milburn, P. (Ed.), University of Otago, Dunedin, New Zealand, 6‐11 July, 2003Konferansepaper (Annet vitenskapelig)
  • 10.
    Holmberg, L. Joakim
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik. Linköpings universitet, Tekniska högskolan.
    A simulation study on the necessity of muscle contraction dynamics in cross-country skiingManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Competitive cross-country skiing is considered to be a fast and powerful dynamic movement. It is unknown what level of complexity that is needed in a musculoskeletal model of a skiing movement, e.g. double-poling. Therefore, a simulation study is carried out to explore the influence of muscle model choice. The theoretical framework of two types of muscle models and their respective implementations are given. These models are a Hill-type model with contraction dynamics and a constant force model, respectively. Results show that it is necessary to incorporate muscle contraction dynamics to estimate individual muscle behaviour in double-poling. Moreover, it may be bad practice to model different body parts with different muscle models; the musculoskeletal system is not a collection of discrete uncoupled body parts and kinetic effects will propagate through the system.

  • 11.
    Holmberg, L. Joakim
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik. Linköpings universitet, Tekniska högskolan.
    Biomekanisk simulering av längdskidåkning2012Inngår i: Svensk idrottsmedicin, ISSN 1103-7652, Vol. 31, nr 3, s. 11-13Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
  • 12.
    Holmberg, L. Joakim
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik. Linköpings universitet, Tekniska högskolan.
    Musculoskeletal Biomechanics for Paralympic Classification2013Konferansepaper (Annet vitenskapelig)
  • 13.
    Holmberg, L. Joakim
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik. Linköpings universitet, Tekniska högskolan.
    Musculoskeletal Biomechanics in Cross-country Skiing2012Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Why copy the best athletes? When you finally learn their technique, they may have already moved on. Using muscluloskeletal biomechanics you might be able to add the "know-why" so that you can lead, instead of being left in the swells.

    This dissertation presents the theoretical framework of musculoskeletal modeling using inverse dynamics with static optimization. It explores some of the possibilities and limitations of musculoskeletal biomechanics in cross-country skiing, especially double-poling. The basic path of the implementation is shown and discussed, e.g. the issue of muscle model choice. From that discussion it is concluded that muscle contraction dynamics is needed to estimate individual muscle function in double-poling. Several computer simulation models, using The Anybody Modeling System™, have been created to study different cross-country skiing applications. One of the applied studies showed that the musculoskeletal system is not a collection of discrete uncoupled parts because kinematic differences in the lower leg region caused kinetic differences in the other end of the body. An implication of the results is that the kinematics and kinetics of the whole body probably are important when studying skill and performance in sports. Another one of the applied studies showed how leg utilisation may affect skiing efficiency and performance in double-poling ergometry. Skiing efficiency was defined as skiing work divided by metabolic muscle work, performance was defined as forward impulse. A higher utilization of the lower-body increased the performance, but decreased the skiing efficiency. The results display the potential of musculoskeletal biomechanics for skiing efficiency estimations. The subject of muscle decomposition is also studied. It is shown both analytically and with numerical simulations that muscle force estimates may be affected by muscle decomposition depending on the muscle recruitment criteria. Moreover, it is shown that proper choices of force normalization factors may overcome this issue. Such factors are presented for two types of muscle recruitment criteria.

    To sum up, there are still much to do regarding both the theoretical aspects as well as the practical implementations before predictions on one individual skier can be made with any certainty. But hopefully, this disseration somewhat furthers the fundamental mechanistic understanding of cross-country skiing, and shows that musculoskeletal biomechanics will be a useful complement to existing experimental methods in sports biomechanics.

    Delarbeid
    1. A musculoskeletal full‐body simulation of cross‐country skiing
    Åpne denne publikasjonen i ny fane eller vindu >>A musculoskeletal full‐body simulation of cross‐country skiing
    2008 (engelsk)Inngår i: Proc. IMechE Vol. 222 Part P: J. Sports Engineering and Technology, ISSN 1754-3371, Vol. 222, nr 1, s. 11-22Artikkel i tidsskrift (Fagfellevurdert) Published
    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.

    Emneord
    biomechanics, double poling, ergometer, inverse dynamics
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-12912 (URN)10.1243/17543371JSET10 (DOI)
    Tilgjengelig fra: 2008-01-28 Laget: 2008-01-28 Sist oppdatert: 2015-01-14
    2. Performance optimization by musculoskeletal simulation
    Åpne denne publikasjonen i ny fane eller vindu >>Performance optimization by musculoskeletal simulation
    Vise andre…
    2012 (engelsk)Inngår i: Movement & Sport Sciences – Science & Motricité, ISSN 2118-5735, Vol. 75, s. 73-83Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    This paper uses two examples, from cross country skiing and badminton, to illustrate the idea of using musculoskeletal simulation as a tool to understand and ultimately optimize sports performance. The results show that the analysis provides insight into the performances that cannot be obtained by other means, and it is advocated that this insight ultimately can lead to better coaching. The importance of “know-why” over “know-how” is stressed, and it is hypothesized that this may enable athletes to learn difficult techniques faster.

    Abstract [fr]

    Cet article s’appuie sur deux exemples, ski de fond et badminton, pour illustrer l’utilisation de la simulation musculo-squelettique comme un outil pour comprendre et finalement optimiser les performances sportives. Les r ́sultats montrent que l’analyse donne un aper ̧u des performances qui ne peuvent pas ˆtre obtenues par d’autres moyens, et il est pr ́conis ́ que cette id ́e peut finalement conduire ` un meilleur entraˆaınement. L’importance du (( savoir-pourquoi )) en plus du (( savoir-faire )) est soulign ́, et il est suppos ́ que cela pourrait permettre aux athl`tes d’apprendre plus rapidement des techniques difficiles.

    sted, utgiver, år, opplag, sider
    Les Ulis, France: EDP Sciences, 2012
    Emneord
    Simulation, musculoskeletal model, sport, optimization
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-71022 (URN)10.1051/sm/2011122 (DOI)
    Prosjekter
    Beräkningsbaserad biomekanik inom längdskidåkning - möjligheter och begränsningar
    Merknad
    This study has received support from the following sources: The Danish Advanced Technology Foundation, The Swedish National Centre for Research in Sports (Grant No. 168/09) and Active Sportswear A/S. The authors wish to thank the Swedish Winter Sports Research Centre for providing laboratory resources.Tilgjengelig fra: 2011-09-27 Laget: 2011-09-27 Sist oppdatert: 2015-01-14
    3. Skiing efficiency versus performance in double-poling ergometry
    Åpne denne publikasjonen i ny fane eller vindu >>Skiing efficiency versus performance in double-poling ergometry
    2013 (engelsk)Inngår i: Computer Methods in Biomechanics and Biomedical Engineering, ISSN 1025-5842, E-ISSN 1476-8259, Vol. 16, nr 9, s. 987-992Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    This study is on how leg utilisation may affect skiing efficiency and performance in double-poling ergometry. Three experiments were conducted, each with a different style of the double-poling technique: traditional with small knee range-of-motion and fixed heels (TRAD); modern with large knee range-of-motion and fixed heels (MOD1) and modern with large knee range-of-motion and free heels (MOD2). For each style, motion data were extracted with automatic marker recognition of reflective markers and applied to a 3D full-body musculoskeletal simulation model. Skiing efficiency (skiing work divided by metabolic muscle work) and performance (forward impulse) were computed from the simulation output. Skiing efficiency was 4.5%, 4.1% and 4.1% for TRAD, MOD1 and MOD2, respectively. Performance was 111, 143 and 149Ns for TRAD, MOD1 and MOD2, respectively. Thus, higher lower body utilisation increased the performance but decreased the skiing efficiency. These results demonstrate the potential of musculoskeletal simulations for skiing efficiency estimations.

    sted, utgiver, år, opplag, sider
    Taylor & Francis, 2013
    Emneord
    AnyBody Modeling System; AviMes AD; biomechanics; cross-country skiing; impulse; musculoskeletal simulation
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-71027 (URN)10.1080/10255842.2011.648376 (DOI)000324612300008 ()
    Prosjekter
    Beräkningsbaserad biomekanik inom längdskidåkning - möjligheter och begränsningar
    Merknad

    This study was sponsored in part by the Swedish National Centre for Research in Sports (Grant No. 168/09). The Swedish Winter Sports Research Centre provided laboratory resources.

    Tilgjengelig fra: 2011-09-27 Laget: 2011-09-27 Sist oppdatert: 2017-12-08bibliografisk kontrollert
    4. Muscle decomposition and recruitment criteria influence muscle force estimates
    Åpne denne publikasjonen i ny fane eller vindu >>Muscle decomposition and recruitment criteria influence muscle force estimates
    2012 (engelsk)Inngår i: Multibody system dynamics, ISSN 1384-5640, E-ISSN 1573-272X, Vol. 28, nr 3, s. 283-289Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    It has recently been pointed out that muscle decomposition influence muscle force estimates in musculoskeletal simulations. We show analytically and with numerical simulations that this influence depends on the recruitment criteria. Moreover, we also show that the proper choices of force normalization factors may overcome the issue. Such factors for the minmax and the polynomial criteria are presented.

    sted, utgiver, år, opplag, sider
    Springer, 2012
    Emneord
    force normalization factor, minmax optimization criteria, musculoskeletal simulation, polynomial optimization criteria
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-71021 (URN)10.1007/s11044-011-9277-4 (DOI)000306734500005 ()
    Prosjekter
    Beräkningsbaserad biomekanik inom längdskidåkning - möjligheter och begränsningar
    Merknad

    This study was sponsored in part by the Swedish National Centre for Research in Sports (Grant No. 168/09). The authors wish to thank the Swedish Winter Sports Research Centre for providing laboratory resources.

    Tilgjengelig fra: 2011-09-27 Laget: 2011-09-27 Sist oppdatert: 2017-12-08bibliografisk kontrollert
    5. A simulation study on the necessity of muscle contraction dynamics in cross-country skiing
    Åpne denne publikasjonen i ny fane eller vindu >>A simulation study on the necessity of muscle contraction dynamics in cross-country skiing
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Competitive cross-country skiing is considered to be a fast and powerful dynamic movement. It is unknown what level of complexity that is needed in a musculoskeletal model of a skiing movement, e.g. double-poling. Therefore, a simulation study is carried out to explore the influence of muscle model choice. The theoretical framework of two types of muscle models and their respective implementations are given. These models are a Hill-type model with contraction dynamics and a constant force model, respectively. Results show that it is necessary to incorporate muscle contraction dynamics to estimate individual muscle behaviour in double-poling. Moreover, it may be bad practice to model different body parts with different muscle models; the musculoskeletal system is not a collection of discrete uncoupled body parts and kinetic effects will propagate through the system.

    Emneord
    Double-poling, fast movements, Hill-type muscle, musculoskeletal model
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-75335 (URN)
    Prosjekter
    Beräkningsbaserad biomekanik inom längdskidåkningen - möjligheter och begränsningar
    Tilgjengelig fra: 2012-02-26 Laget: 2012-02-26 Sist oppdatert: 2015-01-14bibliografisk kontrollert
  • 14.
    Holmberg, L. Joakim
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik. Linköpings universitet, Tekniska högskolan.
    Holmberg, Hans-Christer
    Mittuniversitetet.
    The role of triceps in double-poling biomechanics, an introductory study2007Inngår i: 4th International Congress on Science and Skiing: Book of Abstracts / [ed] E. Müller, S. Lindinger, T. Stöggl & V. Fastenbauer, Salzburg, 2007, s. 184-Konferansepaper (Annet vitenskapelig)
  • 15.
    Holmberg, L. Joakim
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik. Linköpings universitet, Tekniska högskolan.
    Klarbring, Anders
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik. Linköpings universitet, Tekniska högskolan.
    Muscle decomposition and recruitment criteria influence muscle force estimates2012Inngår i: Multibody system dynamics, ISSN 1384-5640, E-ISSN 1573-272X, Vol. 28, nr 3, s. 283-289Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    It has recently been pointed out that muscle decomposition influence muscle force estimates in musculoskeletal simulations. We show analytically and with numerical simulations that this influence depends on the recruitment criteria. Moreover, we also show that the proper choices of force normalization factors may overcome the issue. Such factors for the minmax and the polynomial criteria are presented.

  • 16.
    Holmberg, L. Joakim
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik. Linköpings universitet, Tekniska högskolan.
    Lund, A. M.
    Mid Sweden University.
    A musculoskeletal full‐body simulation of cross‐country skiing2008Inngår i: Proc. IMechE Vol. 222 Part P: J. Sports Engineering and Technology, ISSN 1754-3371, Vol. 222, nr 1, s. 11-22Artikkel i tidsskrift (Fagfellevurdert)
    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.

  • 17.
    Holmberg, L. Joakim
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik. Linköpings universitet, Tekniska högskolan.
    Lund, A. M.
    Using double‐poling simulations to study the load distribution between teres major and latissimus dorsi2007Inngår i: In Science and Nordic Skiing, Linnamo, V., Komi, P.V. and Müller, E. (Eds.), Meyer and Meyer Sport, Oxford, UK / [ed] Vesa Linnamo, Paavo V. Komi, Erich Müller, Meyer and Meyer Sport, Oxford, UK , 2007, s. 81-89Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    Between June 18-20 2006, the Vuokatti Sports Institute in Finland - arguably the world's finest ski training facility - played host to the International Congress on Science and Nordic Skiing."Science and Nordic Skiing" brings together the very latest in cutting edge research and developments into Nordic Skiing - ski jumping and cross-country skiing to biomechanics and the effects of cold weather on exercise - presented by some of the world's foremost experts in the field."Science and Nordic Skiing" is destined to become an invaluable and practical reference for sports scientists, coaches, skiers and anyone involved in this exciting area of winter sports.It presents the very latest research and development in the world of science and Nordic skiing.

  • 18.
    Holmberg, L. Joakim
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik.
    Lund Ohlsson, Marie
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik.
    Danvind, Jonas
    Mittuniversitetet.
    Can Simulations Assist in Classification Development?2013Inngår i: Equipment and Technology in Paralympic Sports, International Paralympic Committee , 2013Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    There is a critical need for research that describes the extent to which impairments of varying type, severity and distribution impact performance in Paralympic sports. It is important with evidence-based judgment on how the impairments aect performance. In the following, we present a complementary evidence-based tool for classication.

    Let us start with an example. We recently presented a study (Holmberg et al., 2012)1 that utilized two full-body musculoskeletal simulation models of cross-country skiing (double-poling). The models were identical except that one carried no muscles in the right lower leg and foot; thus mimicking a lower leg prosthesis. It was hypothesized that a lower leg prosthesis would inuence muscular work throughout the whole body. Results showed that to generate the same motion and external work, an able-bodied skier only had to produce about 80% metabolic muscle work compared to a disabled skier (with a non-active right lower leg prosthesis).

    In reality there is always psychological factors present and it is probably not possible to nd two human beings (one fully functional and one impaired) with the same tness, size, strength and technique. Thus, it is hard to nd the unbiased eect of an impairment on performance in a speci c sport. The example above shows the strength of using simulations because a  musculoskeletal model yields quantitative data on the unbiased eect of dierent functional impairments.

    In cross-country skiing, athletes with functional impairments are, in 'competition format' classification, assigned to dierent categories with weight factors. Athletes perform their race and the result list is presented as race time multiplied by weight factor. In the future, musculoskeletal simulations may assist in answering how a specic functional impairment aects performance and thereby improve the fairness in assigning weight factors for classication.

  • 19.
    Holmberg, L. Joakim
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik. Linköpings universitet, Tekniska högskolan.
    Lund Ohlsson, Marie
    Department of Engineering and Sustainable Development, Mid Sweden University, Östersund, Sweden.
    Supej, Matej
    Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia.
    Holmberg, Hans-Christer
    Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, Östersund.
    Skiing efficiency versus performance in double-poling ergometry2013Inngår i: Computer Methods in Biomechanics and Biomedical Engineering, ISSN 1025-5842, E-ISSN 1476-8259, Vol. 16, nr 9, s. 987-992Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This study is on how leg utilisation may affect skiing efficiency and performance in double-poling ergometry. Three experiments were conducted, each with a different style of the double-poling technique: traditional with small knee range-of-motion and fixed heels (TRAD); modern with large knee range-of-motion and fixed heels (MOD1) and modern with large knee range-of-motion and free heels (MOD2). For each style, motion data were extracted with automatic marker recognition of reflective markers and applied to a 3D full-body musculoskeletal simulation model. Skiing efficiency (skiing work divided by metabolic muscle work) and performance (forward impulse) were computed from the simulation output. Skiing efficiency was 4.5%, 4.1% and 4.1% for TRAD, MOD1 and MOD2, respectively. Performance was 111, 143 and 149Ns for TRAD, MOD1 and MOD2, respectively. Thus, higher lower body utilisation increased the performance but decreased the skiing efficiency. These results demonstrate the potential of musculoskeletal simulations for skiing efficiency estimations.

  • 20.
    Lund, A. M.
    et al.
    Mid Sweden University.
    Holmberg, Joakim L.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik. Linköpings universitet, Tekniska högskolan.
    Which are the antagonists to the pectoralis major muscle in 4th gear free‐style technique, cross‐country skiing?2007Inngår i: Science and Nordic Skiing, Linnamo, V., Komi, P.V. and Müller, E. (Eds.), Meyer and Meyer Sport, Oxford, UK / [ed] Vesa Linnamo, Paavo V. Komi, Erich Müller, Meyer and Meyer Sport, Oxford, UK , 2007, s. 112-118Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    Between June 18-20 2006, the Vuokatti Sports Institute in Finland - arguably the world's finest ski training facility - played host to the International Congress on Science and Nordic Skiing."Science and Nordic Skiing" brings together the very latest in cutting edge research and developments into Nordic Skiing - ski jumping and cross-country skiing to biomechanics and the effects of cold weather on exercise - presented by some of the world's foremost experts in the field."Science and Nordic Skiing" is destined to become an invaluable and practical reference for sports scientists, coaches, skiers and anyone involved in this exciting area of winter sports.It presents the very latest research and development in the world of science and Nordic skiing.

  • 21.
    Lund Ohlsson, Marie
    et al.
    Mid Sweden Univ, Sweden.
    Danvind, Jonas
    Mid Sweden Univ, Sweden.
    Holmberg, Joakim
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik och hållfasthetslära. Linköpings universitet, Tekniska fakulteten.
    Shoulder and Lower Back Joint Reaction Forces in Seated Double Poling2018Inngår i: Journal of Applied Biomechanics, ISSN 1065-8483, E-ISSN 1543-2688, Vol. 34, nr 5, s. 369-376Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Overuse injuries in the shoulders and lower back are hypothesized to be common in cross-country sit-skiing. Athletes with reduced trunk muscle control mainly sit with the knees higher than the hips (KH). To reduce spinal flexion, a position with the knees below the hips (KL) was enabled for these athletes using a frontal trunk support. The aim of the study was to compare the shoulder joint (glenohumeral joint) and L4-L5 joint reactions of the KL and KH sitting positions. Five able-bodied female athletes performed submaximal and maximal exercise tests in the sitting positions KL and KH on a ski ergometer. Measured pole forces and 3-dimensional kinematics served as input for inverse-dynamics simulations to compute the muscle forces and joint reactions in the shoulder and L4-L5 joint. This was the first musculoskeletal simulation study of seated double poling. The results showed that the KH position was favorable for higher performance and decreased values of the shoulder joint reactions for female able-bodied athletes with full trunk control. The KL position was favorable for lower L4-L5 joint reactions and might therefore reduce the risk of lower back injuries. These results indicate that it is hard to optimize both performance and safety in the same sit-ski.

  • 22.
    Lund Ohlsson, Marie
    et al.
    Mid Sweden University, Sundsvall, Sweden.
    Laaksonen, Marko S.
    Mid Sweden University, Östersund.Sweden.
    Holmberg, Joakim
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik och hållfasthetslära. Linköpings universitet, Tekniska fakulteten.
    Evaulation of two sitting positions in Cross-Country Sit-Skiing2016Inngår i: Abstract book of the 7th International Congress on Science and skiing, 2016Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    INTRODUCTION In cross-country sit-skiing (CCSS) athletes with reduced trunk control mainly sit with their knees higher than the hips (KH) to increase trunk stability. To improve the spine curvature by reducing kyphosis a new sitting position was created where the knees are lower than the hips by help of a forward trunk support (KL). The aim of this study was to evaluate the new KL position and compare it to KH in terms of physiological and biomechanical measurements as well as musculoskeletal simulations. METHODS Five abled-bodied female cross-country skiers (62.6±8.1kg, 1.67±0.05m) performed two sets of tests; one in each sitting position on a skiing ergometer (ThoraxTrainer A/S, Denmark). Each test comprised a 30s all-out test (AO), an incremental submaximal test (4 to 6 x 3 min, SUB1-SUB6) and a maximal time-trial test of 3 min (MAX). During SUB and MAX external power and kinematics were measured. Metabolic rates (MR) were calculated from oxygen consumption and lactate concentrations. The AnyBody Modelling system (AMS 6.0, Anybody Technology A/S, Denmark) were used to simulate full-body musculoskeletal models over 4 poling cycles of SUB2, SUB4 and MAX. From the simulations muscular metabolic rate (mMR) and musculo-skeletal efficiency (ME) were computed (Holmberg et al., 2013). RESULTS & DISCUSSION The performance (W/kg) was higher in KH (p < 0.01) in both AO (24%) and MAX (32%). KL had more flexed knee, more extended hip and less kyphosis in trunk, while KH had larger range of motion (ROM) in hip and larger flexion and ROM in spine at SUB4 and MAX. Gross efficiency (GE) was higher in KH than KL. The total MR and ratio of anaerobic MR to total MR were higher in KL at SUB3 and SUB4. Simulations showed that 4 subjects had higher ME in KH for both SUB4 and MAX, though no statistical significance were observed. mMR were higher for KL at SUB2 and SUB4 but it was higher for KH at MAX. The ratio of mMR in body parts to total mMR showed higher ratio for KL in arm-shoulders (6.7-9.1%) and higher ratio for KH in trunk (3.7-4.6%) and hip-legs (3.0-4.6%). CONCLUSION The physiological results were comparable to others (Lajunen, 2014 & Verellen et al, 2012) and the simulation results were novel by showing how the motion of the trunk contributes to the total metabolic rate. KH position showed higher performance and GE while the KL position indicated higher mMR for arm-shoulders, and had also higher anaerobic MR. Therefore the KH position is favorable for abled-bodied athletes because KL limits trunk motion. REFERENCES Holmberg, L. J. et al. (2013). Comput Methods Biomech Biomed Engin, 16(9), 987-992. Lajunen, K. (2014). Effect of sitting posture on sit-skiing economy. Bachelor’s thesis, University of Jyväskylä.Verellen, J. et al. (2012). Eur J Appl Physiol, 112(3), 983-989.

  • 23.
    Pannetier, Romain
    et al.
    Renault SAS, Service Facteur Humain, Conduite et Vie Abord, 1 avenue du Golf, Guyancourt, France.
    Robert, Thomas
    Université de Lyon, F-69622, Lyon, France, Ifsttar, UMR_T9406, LBMC, Université Lyon1, France.
    Holmberg, Joakim
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik. Linköpings universitet, Tekniska högskolan.
    Wang, Xuguang
    Université de Lyon, F-69622, Lyon, France, Ifsttar, UMR_T9406, LBMC, Université Lyon1, France.
    Optimization-based muscle force scaling for subject specific maximum isometric torque estimation2011Inngår i: Proceedings of the XXIIIth Congress of the International Society of Biomechanics, 2011Konferansepaper (Fagfellevurdert)
  • 24.
    Rasmussen, John
    et al.
    M-Tech, Aalborg University, Denmark.
    Holmberg, L. Joakim
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik. Linköpings universitet, Tekniska högskolan.
    Sörensen, K.
    M-Tech, Aalborg University, Denmark.
    Kwan, M.
    M-Tech, Aalborg University, Denmark.
    Andersen, M.S.
    M-Tech, Aalborg University, Denmark.
    de Zee, M.
    Department of Health Science and Technology, Aalborg University, Denmark.
    Performance optimization by musculoskeletal simulation2012Inngår i: Movement & Sport Sciences – Science & Motricité, ISSN 2118-5735, Vol. 75, s. 73-83Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper uses two examples, from cross country skiing and badminton, to illustrate the idea of using musculoskeletal simulation as a tool to understand and ultimately optimize sports performance. The results show that the analysis provides insight into the performances that cannot be obtained by other means, and it is advocated that this insight ultimately can lead to better coaching. The importance of “know-why” over “know-how” is stressed, and it is hypothesized that this may enable athletes to learn difficult techniques faster.

  • 25.
    Rasmussen, John
    et al.
    M-Tech, Aalborg University, Denmark.
    Holmberg, L. Joakim
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik. Linköpings universitet, Tekniska högskolan.
    Sørensen, K.
    M-Tech, Aalborg University, Denmark.
    Kwan, M.
    M-Tech, Aalborg University, Denmark.
    Andersen, M.S.
    M-Tech, Aalborg University, Denmark.
    de Zee, Mark
    Department of Health Science and Technology, Aalborg University, Denmark.
    Performance optimization by musculoskeletal simulation: Erratum2012Inngår i: Movement & sport sciences, ISSN 2118-5735, Vol. 76, s. 75-75Artikkel i tidsskrift (Annet vitenskapelig)
  • 26.
    Rovan, Klemen
    et al.
    University of Ljubljana, Faculty of Sport, Ljubljana, Slovenia.
    Kugovnik, Otmar
    University of Ljubljana, Faculty of Sport, Ljubljana, Slovenia.
    Holmberg, L. Joakim
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik. Linköpings universitet, Tekniska högskolan.
    Supej, Matej
    University of Ljubljana, Faculty of Sport, Ljubljana, Slovenia.
    The steps needed to perform acceleration and turning at different approach speeds2014Inngår i: Kinesiologia Slovenica, ISSN 1318-2269, E-ISSN 2232-4062, Vol. 20, nr 1, s. 38-50Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The aims of the study were to examine: how many and which steps are needed to initiate and complete accelerations and turnings at different angles at different approach speeds; and how an intended turning angle and approach speed influence the magnitude of the actual turning angle in each step. Eight soccer players participated in the study. They performed acceleration and turnings: 1) from a standstill; 2) while already jogging; and 3) while already running on an outdoor soccer field. The speeds and angles were calculated from the data obtained from the high-end Global Navigation Satellite System. The high correlation between the intended turning angle and actual turning angle indicated the major turning steps during a turn. The intended turning angle revealed a large effect on the magnitude of the turning angle during the side-step (r = 0.995, p < 0.01) and the following step (r = 0.950, p < 0.01) for acceleration and turning from a standstill, and during the first two steps following the side-step for starts made while already jogging (r= 0.919, p < 0.01; r = 0.952, p < 0.01) and running (r = 0.897, p < 0.01; r = 0.881, p < 0.01). Further, a major part of the turning began earlier at a lower approach speed, which allowed the turning to be more quickly completed. In conclusion, the effect of acceleration with turning on the turning angle could already be seen two steps before and up to two steps after the major turning steps during a turn.

  • 27.
    Tinnsten, Mats
    et al.
    Mittuniversitetet, Institutionen för teknik, fysik och matematik.
    Dahlén, Leon
    Mittuniversitetet, Institutionen för teknik, fysik och matematik.
    Holmberg, Joakim
    Mittuniversitetet, Institutionen för teknik, fysik och matematik.
    Holmberg, Hans Christer
    Mittuniversitetet, Institutionen för hälsovetenskap.
    Projekt Davos: hjälper längdlandslaget att åka fortare2004Inngår i: Svensk Idrottsforskning: Organ för Centrum för Idrottsforskning, ISSN 1103-4629, Vol. 13, nr 1, s. 25-27Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [sv]

    DAVOS – Datorbaserade verktyg för optimering och simulering är ett EU fi nansierat (Mål 1) projekt som handlar om tillämpad teknik och tilllämpad optimering. Projektet omfattar ca 10 personer, ca 20 miljoner kr och kommer att pågå fram till 2004. Projektet drivs av institutionen för informationsteknologi och medier vid Mitthögskolan i Östersund men även personal från institutionen för teknik, fysik och matematik ingår och projektledare är docent Mats Tinnsten. I projektet ingår sex delprojekt varav två har en inriktning mot sport och sportrel aterad utrustning. DAVOS har goda kontakter med den regionala industrin, internationella universitet och forskargrupper, nationella universitet, forskargrupper och projekt. Särskilt goda och givande kontakter har projektet med Nationellt Vintersportcentrum och längdskidlandslaget samt ett antal elitskidåkare som har varit eller är studenter vid någon av teknikinstitutionerna vid campus Östersund. DAVOS handlar alltså om tillämpad teknik och optimering och verksamheten är inriktad på numeriska simuleringar och analyser av tekniska tillämpningar vilket närmast faller inom området maskinteknik och man kan ju fråga sig hur detta kan kopplas till området sport och sportutrustning. På ett alldeles naturligt sätt anser deltagarna i projektet och förhoppningsvis ska detta klarna vid genomläsning av den resterande texten.

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