| 1. |
- Karczewska-Lindinger, Magdalena, et al.
(författare)
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Force Generation Profiles of Para-Nordic Sit-Skiers Representing Different Physical Impairments
- 2021
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Ingår i: Journal of Science in Sport and Exercise. - : Springer Science and Business Media LLC. - 2662-1371 .- 2096-6709. ; 3, s. 281-291
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Tidskriftsartikel (refereegranskat)abstract
- PurposeTo biomechanically profile force generation connected to the complex role of the trunk in double poling in a representative sample of Para-Nordic sit-skiers.MethodsTwelve male World Cup Para-Nordic sit-skiers (sport classes: LW10–12) were skiing on flat snow terrain at submaximal speed of 4.5 m/s (~ 73% maximum speed). 2D video (50 Hz) and pole force analyses (1000 Hz) were performed synchronously, examining angle, force and cycle characteristics to analyse the role of the trunk in generating propulsion.ResultsLW10–11.5 skiers lost between 21% and 4% propulsive force versus LW12 athletes only due to different geometrics of the trunk and pole angle at an equal axial pole force. While LW10–11 skiers indicated trunk extension or position maintenance during pole thrust, LW11.5–12 skiers showed strong trunk flexion combined with smaller pole angles to the ground. Hence, LW11.5–12 skiers could create larger propulsive forces and therefore greater cycle lengths at lower cycle rates at the same speed. Maximum speed increased from LW10 to LW12 and was significantly correlated to trunk flexion range of motion (r = 0.63) and cycle length (r = 0.59). Trunk flexion ROM showed a significant relationship to the impulse of propulsive force (r = 0.63) and pole angle to the ground (r = − 0.76) (all P < 0.05).ConclusionThe impact of impairment on the force production profiles and its physiological-biomechanical consequences need further investigation also in other terrains and at wider spectrums of skiing speeds. The evident problem of low numbers of LW10–11 skiers in World Cup needs creative future solutions for research.
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| 2. |
- Karczewska-Lindinger, Magdalena, 1986, et al.
(författare)
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Race and split time analysis in para nordic sit-skiing
- 2019
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Ingår i: 8th International Congress on Science and Skiing (ICSS) - Abstract book. Vuokatti, Finland, March 11th - 15th, 2019, s. 69. - 9789513976835
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Konferensbidrag (refereegranskat)
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| 3. |
- Lindinger, Stefan, 1968, et al.
(författare)
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Quantification methods of spinal and supraspinal excitability during cross-country skiing: a pilot study on skiing-specific motor control measurements
- 2022
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Ingår i: Abstract Book of the 9th Congress on Science and Skiing 2023. - Salzburg, Austria : University of Salzburg, Austria.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- INTRODUCTION: Motor control is an essential part of athlete’s efficient performances. The motor control can be divided to spinal and supraspinal components, which’s contribution can be quantified using Hoffmann-reflex (H-reflex) and volitional wave (V-wave) methods, respectively, during both isometric (Aagaard et al. 2002) and dynamic conditions (Alkjaer et al. 2013). However, it is unknown how feasible these responses would be to study more challenging multi-joint dynamic tasks like cross-country skiing. Purpose was to develop this methodology for complex skiing techniques for future examination of spinal and supraspinal control mechanisms during specific phases (e.g. gliding/balance control) related to performance level, fatigue status or other factors. METHODS: A former male Elite skier performed numerous trials using V2 skating technique on roller skies at treadmill (2° incline) velocities of 12 (slow) and 18 km/h (fast). H-reflex (m. soleus; conditioned with 15% Maximal M-wave [Mmax]) was measured 30, 70, 110 and 580 ms after the ground contact of the roller ski to get the H-reflex responses during short-latency reflex (SLR), medium-latency reflex (MLR), highest force production and mid-glide phases, respectively. V-wave responses were measured with identical delays, but with supramaximal stimulation intensity (125% Mmax). Both H-reflex and V-wave were normalized to Mmax. RESULTS: H/Mmax ratio was reduced from SLR to MLR (Slow -16.7%; Fast -31.1%) and highest force (Slow -33.3%; Fast -19.8%) while being similar or elevated during mid-glide phase (Slow 3.8%; Fast 67.0%) compared to SLR. Opposite to H-reflex, V/Mmax increased from SLR to MLR in slow (19.1%) and fast (22.1%) velocities. However, velocity related differences were observed at highest forces (Slow 64.7%; Fast -19.8%) and mid-glide phase (Slow 53.0%; Fast 5.8%) compared to SLR. DISCUSSION/CONCLUSION: Similar pattern of H-reflex has been observed previously during drop jumps (Taube et al. 2008), where H-reflex was reduced, and cortical activation enhanced from ground contact toward voluntary activation. H-reflex and V-wave methods seem to be potential tools to investigate motor control during skiing which could be utilized for example to examine training and fatigue related changes in motor control of Nordic skiing and possibly other skiing disciplines.
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| 4. |
- Rosso, V, et al.
(författare)
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Measures of impairment in cross-country sit skiing
- 2019
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Ingår i: 8th International Congress on Science and Skiing (ICSS) - Abstract book. Vuokatti, Finland, March 11th - 15th, 2019. - 9789513976835
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Konferensbidrag (refereegranskat)
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| 5. |
- Rosso, V., et al.
(författare)
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Simulated skiing as a measurement tool for performance in cross-country sit-skiing
- 2019
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Ingår i: Proceedings of the Institution of Mechanical Engineers Part P-Journal of Sports Engineering and Technology. - : SAGE Publications. - 1754-3371 .- 1754-338X. ; 233:4, s. 455-466
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Tidskriftsartikel (refereegranskat)abstract
- The International Paralympic Committee mandates the development of an evidence-based classification system, which requires a measure of performance. Performance in cross-country sit-skiing is mainly dependent on force generated during the poling phase and is enhanced by trunk flexion-extension movements. Since all sit-skiers have neuromuscular impairment, but different ability to control the trunk, this study aimed to verify if simulated action of poling on an adapted ergometer, together with a cluster analysis, could be used for grouping participants with different impairments according to their performance. On the ergometer, eight male and five female participants performed seven poling cycles at maximal speed, while sitting on personal sit-ski. Based on maximal speed, generated force, cycle characteristics, and trunk kinematics, cluster analysis divided participants into three groups showing good accuracy, sensitivity, and precision. Although a validation of this exploratory study is necessary, skiing on the ergometer could be considered as sport-specific measure of performance and may become an interesting tool in the development of an evidence-based classification system for cross-country sit-skiing.
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| 6. |
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Science and Skiing VIII
- 2020
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Samlingsverk (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
- The 8th International Congress on Science and Skiing was held at the Vuokatti Sport Resort located in the North-East of Finland, March 11‒15, 2019. The congress was hosted by the Vuokatti Sports Technology Unit of the Faculty of Sport and Health Sciences, University of Jyväskylä, Finland. The congress program offered a comprehensive overview of current research in Alpine and Nordic Skiing. The scientific event involved research in topics such as Biomechanics in Alpine Skiing, Physiology and Training in Cross-Country Skiing & Biathlon, Talent and Injury in Skiing, Paralympic Skiing, Cross-country Skiing, Ski Jumping, Air Drag and Aerodynamics in Skiing and Methodology and Technology in Skiing. The Young Investigator Award competition provided scientific competition among young fellows. The Congress Proceedings with all Congress abstracts can be downloaded from www.icss2019.fi Altogether 62 oral presentations, of which five were keynotes, 13 were invited and 10 were in the Young Investigator Award Competition, and 19 poster presentations represented 16 different countries around the world. In this Congress Book, selected keynotes, oral and poster presentations are published. The manuscripts went through a peer review and editorial judgment process prior to acceptance. On behalf of the organizers we are honored to present this Congress Book with interesting research papers, which we hope will encourage further challenging research in this fascinating field of Skiing. Magdalena Karczewska-Lindinger Anni Hakkarainen Vesa Linnamo Stefan Lindinger
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| 7. |
- Ainegren, Mats, 1963-, et al.
(författare)
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Effects of Aerodynamic Drag and Drafting on Propulsive Force and Oxygen Consumption in Double Poling Cross-Country Skiing
- 2022
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Ingår i: Medicine & Science in Sports & Exercise. - 0195-9131 .- 1530-0315. ; 54:7, s. 1058-1065
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Tidskriftsartikel (refereegranskat)abstract
- Purpose This study aimed to investigate the effects of aerodynamic drag and drafting on propulsive force (FPROP), drag area (CDA), oxygen cost (V˙O2), metabolic rate (Ė), and heart rate (HR) during roller skiing on a treadmill in a wind tunnel using the double poling technique. A secondary aim was to investigate the effects of wind versus no-wind test conditions on the same physiological parameters. Methods Ten subjects of each gender participated in the experiments. One pair of skiers of the same gender roller skied simultaneously in line with the air flow; the distance between the skiers was 2.05 m. Each pair was tested as follows: I) with wind, leading; II) with wind, drafting; and III) without wind. The treadmill inclination was 0° throughout the tests. For the wind conditions, the air velocity was similar to the treadmill belt speed: 3 to 7 m·s-1 for men and 3 to 6 m·s-1 for women. Results Drafting resulted in significantly (P < 0.05) lower FPROP,CDA, V˙O2, and Ė, compared with leading, for both genders at racing speed but not at lower speeds, whereas HR was only affected for the male skiers at racing speed. The test without wind resulted in significantly lower FPROP, V˙O2, and Ė at all tested speeds compared with the tests with wind present, whereas HR was lower only at higher speeds. Conclusions At racing speed, but not at lower speeds, the positive effects of drafting behind a skier during double poling were obvious and resulted in a lower FPROP, CDA, V˙O2, Ė, and HR. Tests without wind present put even lower demands on the skiers' physiology, which was also evident at lower speeds.
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| 8. |
- Ainegren, M, et al.
(författare)
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Effects of drafting on VO2 in double poling XC-skiing
- 2019
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Ingår i: 8th International Congress on Science and Skiing (ICSS) - Abstract book. Vuokatti, Finland, March 11th - 15th, 2019, s. 41. - 9789513976835
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Konferensbidrag (refereegranskat)
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| 9. |
- Allen, T., et al.
(författare)
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Winter sports special issue
- 2017
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Ingår i: Sports Engineering. - : Springer Science and Business Media LLC. - 1369-7072 .- 1460-2687. ; 20:4, s. 243-244
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 10. |
- Canclini, A., et al.
(författare)
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HISTORICAL ANALYSIS OF DOUBLE POLING IN HIGH-LEVEL CROSS COUNTRY SKIING (XCS)
- 2020
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Ingår i: Karczewska-Lindinger, M., Hakkarainen, A., Linnamo, V., Lindinger, S. (2020) (Eds), Science and Skiing VIII, University of Jyväskylä (publisher), Jyväskylä, Finland, ISBN 978-951-39-8077-1, pp 202. - Jyväskylä, Finland : University of Jyväskylä. - 9789513980771
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Bokkapitel (refereegranskat)
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