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[{"key": "dc.contributor.author", "value": "Nieminen, Veli-Matti", "language": null, "element": "contributor", "qualifier": "author", "schema": "dc"}, {"key": "dc.date.accessioned", "value": "2013-02-20T15:28:58Z", "language": null, "element": "date", "qualifier": "accessioned", "schema": "dc"}, {"key": "dc.date.available", "value": "2013-02-20T15:28:58Z", "language": null, "element": "date", "qualifier": "available", "schema": "dc"}, {"key": "dc.date.issued", "value": "2013", "language": null, "element": "date", "qualifier": "issued", "schema": "dc"}, {"key": "dc.identifier.other", "value": "oai:jykdok.linneanet.fi:1254037", "language": null, "element": "identifier", "qualifier": "other", "schema": "dc"}, {"key": "dc.identifier.uri", "value": "https://jyx.jyu.fi/handle/123456789/40969", "language": null, "element": "identifier", "qualifier": "uri", "schema": "dc"}, {"key": "dc.description.abstract", "value": "Tutkimuksen tarkoitus oli selvitt\u00e4\u00e4 erilaisten voiteluiden vaikutusta lihasten voimantuoton ja lihasaktiivisuuden muutoksiin maksimaalisen pitk\u00e4kestoisen perinteisen tyylin murtomaahiihtosuorituksen aikana. Samalla pyrittiin l\u00f6yt\u00e4m\u00e4\u00e4n uusia tekniikoita suksen luisto- ja pito-ominaisuuksien mittaamiseen. Tutkimuksessa pyrittiin selvitt\u00e4m\u00e4\u00e4n, miten suksen luisto- ja pito-ominaisuuksien heikentyminen pitk\u00e4kestoisen hiihtosuorituksen aikana vaikuttaa hiihdon biomekaanisiin ominaisuuksiin. Samalla seurattiin my\u00f6s fysiologisten muuttujien eli syd\u00e4men sykkeen ja veren laktaattipitoisuuden muuttumista suorituksen aikana.\nTutkimus suoritettiin Jyv\u00e4skyl\u00e4n yliopiston Vuokatin toimipisteen biomekaniikan laboratoriossa ja Vuokatin hiihtoputkessa. Tutkimukseen osallistui 9 vapaaehtoista, aktiivisesti murtomaahiihtoa harrastavaa mieshenkil\u00f6\u00e4, joidenka taso vaihteli kansallisesta huipputasosta aktiiviseen kuntohiiht\u00e4j\u00e4\u00e4n. Jokainen koehenkil\u00f6 suoritti kaksi eri 20.7 km:n kilpavauhtista perinteisen tyylin hiihtosuoritusta, joissa k\u00e4ytettiin erilaista suksien voitelua. Toisessa voitelussa pyrittiin siihen, ett\u00e4 suksen luisto- ja pito-ominaisuudet s\u00e4ilyv\u00e4t hyvin\u00e4 koko hiihtosuorituksen ajan ja toisessa siihen, ett\u00e4 luisto- ja pito-ominaisuudet heikkenev\u00e4t huomattavasti hiihdon kuluessa. Testien v\u00e4liksi m\u00e4\u00e4riteltiin v\u00e4hint\u00e4\u00e4n viikon palautusaika, koska testisuoritus oli kilpavauhtinen pitk\u00e4kestoinen hiihto. Koehenkil\u00f6t hiihtiv\u00e4t testin Vuokatin hiihtoputken 2.3 km:n ladulla, jonka he kiersiv\u00e4t 9 kertaa. Jokaisella kierroksella hiihdettiin yli 20 m pitk\u00e4n\nvoimalevyj\u00e4rjestelm\u00e4n, parittomilla kierroksilla vuorotahtia ja parillisilla kierroksilla tasatahtia. Hiihdon aikana koehenkil\u00f6ilt\u00e4 mitattiin potkun ja sauvan ty\u00f6nn\u00f6n horisontaalisia ja vertikaalisia voimia voimalevyill\u00e4, lihasten aktiivisuutta EMG-laitteella, syd\u00e4men sykett\u00e4 ja veren laktaattipitoisuutta. Lis\u00e4ksi voimalevyjen ylihiihto kuvattiin mahdollisesti my\u00f6hemp\u00e4\u00e4 liikeanalyysi\u00e4 varten. Ennen ja j\u00e4lkeen hiihtosuorituksen koehenkil\u00f6t suorittivat maksimaalisen isometrisen voimatestin polven ojentajille ja kyyn\u00e4rvarren ojentajille. Lis\u00e4ksi koehenkil\u00f6iden suksien luisto- ja pito-ominaisuutta mitattiin suksen liikutuslaitteella ennen ja j\u00e4lkeen hiihtosuorituksen sek\u00e4 4 hiihdetyn kierroksen j\u00e4lkeen. Samalla suksista mitattiin my\u00f6s voiteiden kulumista kahdella eri mittalaitteella, fluoresenssi-mittarilla ja mittakellolla.\nTutkimuksen p\u00e4\u00e4tulokset olivat seuraavat:\n1) Hiihtoajassa ja maksiminopeudessa ei havaittu tilastollisesti merkitsevi\u00e4 eroja eri voiteluiden v\u00e4lill\u00e4 2) Jalan tuottamat voimat pieneniv\u00e4t enemm\u00e4n paremmin pit\u00e4vill\u00e4 suksilla (jalan suhteellinen horisontaalinen huippuvoima (p_HLF_r) laski paremmalla pidolla 21 % (p<0.01) ja huonommalla 4 % (n.s.)), mutta ero voiteluiden v\u00e4lill\u00e4 ei ollut tilastollisesti merkitsev\u00e4, 3) sauvaty\u00f6nn\u00f6n horisontaaliset voimat pieneniv\u00e4t huonommin pit\u00e4vill\u00e4 suksilla hiihdett\u00e4ess\u00e4 enemm\u00e4n (vuorohiihdossa suhteellinen horisontaalinen huippuvoima (H_rPPF) laski paremmalla pidolla 3.0\u00b10.9 % (p<0.05) ja huonommalla 3.7\u00b11.9 % (p<0.05). Huonommalla pidolla lasku oli tilastollisesti merkitsev\u00e4sti suurempi. Tasaty\u00f6nn\u00f6ss\u00e4 suhteellinen horisontaalinen huippuvoima (H_PPF_r) laski huonommalla pidolla 7 % (p<0.01), mutta paremmalla pidolla havaittiin jopa pieni voimatason nousu 4) lihasten RMS aktiivisuus pieneni paremmin pit\u00e4vill\u00e4 suksilla hiihdett\u00e4ess\u00e4 tilastollisesti merkitsev\u00e4sti polven ojentaja lihaksissa (Vastus Medialis: 0.64\u00b10.38 mV -> 0.34\u00b10.20 mV. p<0.05), kun taas huonommin pit\u00e4vill\u00e4 suksilla hiihdett\u00e4ess\u00e4 RMS aktiivisuuden pieneneminen oli tilastollisesti merkitsev\u00e4\u00e4 kaikissa mitatuissa lihaksissa (Vastus Medialis: 0.43\u00b10.22 mV -> 0.23\u00b10.12 mV. p<0.05, Biceps femouris: (0.15\u00b10.13 mV -> 0.06\u00b10.02 mV. p<0.05), Rectus Femoris: (0.24\u00b10.13 mV -> 0.16\u00b10.08 mV. p<0.01), Gastrocnemius: (0.33\u00b10.09 mV -> 018\u00b10.07 mV. p<0.01) ja Triceps Brachii: (0.95\u00b1028 mV -> 0.78\u00b10.27 mV. p<0.05, 5) vuorohiihdon potkuaika piteni huonommin pit\u00e4vill\u00e4 suksilla hiihdett\u00e4ess\u00e4 enemm\u00e4n, mutta ero voiteluiden v\u00e4lill\u00e4 ei ollut tilastollisesti merkitsev\u00e4\u00e4, 6) sauvan ty\u00f6nt\u00f6sykliin suhteutettu ty\u00f6nt\u00f6aika piteni huonommin pit\u00e4vill\u00e4 suksilla hiihdett\u00e4ess\u00e4\ntilastollisesti merkitsev\u00e4sti (43.1\u00b13.9 % -> 46.5\u00b14.2 %. p<0.01), kun taas paremmalla pidolla muutosta ei havaittu, 7) Uusien voidem\u00e4\u00e4r\u00e4n mittauslaitteiden (mittakello ja fluoresenssi-mittari) tulokset olivat tilastollisesti merkitsev\u00e4sti samansuuntaisia kuin liikutuslaitteen kitkanmittaustulokset ja 8) hiiht\u00e4j\u00e4n keskim\u00e4\u00e4r\u00e4inen syke oli hieman (1.8 %) korkeampi hiihdett\u00e4ess\u00e4 huonommin pit\u00e4vill\u00e4 suksilla.\nTutkimustulosten ja aikaisempien tutkimusten perusteella voidaan olettaa, ett\u00e4 hiihdett\u00e4ess\u00e4 huonosti pit\u00e4vill\u00e4 suksilla voimantuotto siirtyy enemm\u00e4n k\u00e4sille, jolloin pitk\u00e4kestoisen suorituksen aikana k\u00e4det v\u00e4syv\u00e4t suhteessa enemm\u00e4n. Huonosti pit\u00e4v\u00e4 suksi ei kuitenkaan n\u00e4yt\u00e4 t\u00e4m\u00e4n tutkimuksen perusteella vaikuttavan hiihdon loppuaikaan eik\u00e4 hiiht\u00e4j\u00e4n maksiminopeuteen, ainakaan kohtuullisen helpossa ja loivapiirteisess\u00e4 maastossa. Pitovoiteiden m\u00e4\u00e4r\u00e4\u00e4 ja kulumista on kohtuullisen helppo analysoida, mutta luistovoiteen tapauksessa analysointi onkin jo huomattavasti vaativampaa. Tutkimuksessa k\u00e4ytetyt uudet voidem\u00e4\u00e4r\u00e4n mittausmenetelm\u00e4t (fluoresenssi ja mittakello) osoittautuivat kehityskelpoisiksi mittausmenetelmiksi varsinkin pitovoiteen mittaamiseen.", "language": "fi", "element": "description", "qualifier": "abstract", "schema": "dc"}, {"key": "dc.description.abstract", "value": "The aim of this study was to investigate the influence of different kind of waxing for force production and electrical activity (EMG) of muscles in maximal long distance classic style XC-skiing. Also new technics for measuring glide- and grip features of skies were explored. The study attempted to determine, how decline of glide- and grip features in maximal long distance skiing exercise influence biomechanics features of XC-skiing as well as changes of some physiological features; blood lactate and heart rate.\nThe study was conducted at Vuokatti ski-tunnel and biomechanics laboratory of University of Jyv\u00e4skyl\u00e4, Vuokatti campus. The study involved 9 active male skiers, from national top-level to active fitness skier. Each volunteer performed two different 20.7 km's maximal classic style skiing performance, using two different types of ski waxing. In one attempt the waxing was made so that the glide and grip properties would remain good throughout the execution of the ski and in the other one so that the glide and grip properties would deteriorate considerably during skiing. There was at least one week recovery time between test sessions, because the test performance was maximal (=competition speed) long-term cross-country skiing. Ski track in ski-tunnel is 2.3 km long and skiers toured it nine times. In each round they skied over 20 m long force platform system. During the skiing test subjects was measured horizontal and vertical forces of kick and poling in the force plates, EMG activity in six different muscles, heart rate and blood lactate (before, after, and halfway). Before and after the skiing, the\nsubjects performed maximal isometric strength test of the knee extensors and forearm extensors. Furthermore, the subjects' skis glide and grip properties (coefficient of friction) were measured with ski moving machine before, after and during the skiing test. At the same time skis were also measured with two different wax wear measuring device, a fluorescence indicator and a dial gauge.\nMain results of the study were as follows:\n1) there were no statistically significant differences in skiing time and maximum speed between different types of waxing, 2) the leg forces decreased more with better grip skis (relative horizontal peak force (p_HLF_r) decreased with better grip by 21% (p <0.01) and a worse 4% (n.s.) but this difference between grips was not statistically significant), 3) horizontal forces of poling decreased more with worse grip (in diagonal stride relative horizontal peak force (H_rPPF) decreased with better grip 3.0 \u00b1 0.9% (p <0.05) and with worse 3.7 \u00b1 1.9% (p <0.05). With worse grip the decline was statistically significantly higher. In double poling relative horizontal peak force (H_PPF_r) decreased with worse grip by 7% (p <0.01), but with a better grip even a small power increase was observed (n.s.), 4) muscle RMS activity decreased statistically significantly in knee extensor muscles with better grip while RMS activity reduction was significant in all measured muscles with worse grip skis, 5) In diagonal stride the kick time prolonged more with worse grip, but difference between waxes was not statistically significant, 6) the relative poling time prolonged with worse grip (43.1\u00b13.9 % -> 46.5\u00b14.2 %. p<0.01), while a change with better grip was not observed, 7) the results of new measuring methods of waxing wear (dial gauge and fluorescence indicator) were statistically significantly in the same direction as the friction measurements of the ski moving machine and 8) the average heart rate of skier\u00b4s was slightly (1.8 %) higher with worse grip.\nResearch and previous studies suggest that when skiing with bad grip, power generation moves more to hands and cause relative more fatigue in long-term performance. Poor grip did not seem to affect skiing time or maximum speed, at least in an easy and relatively gently sloping terrain. It is relatively easy to analyze the amount and wearing of kick waxes, but not so easy to analyze glide waxes. The study used new methods of measurement of the amount of ski-wax (fluorescence indicator (UV-meter) and dial\ngauge) proved to be an evolutionary measuring system, particularly the measurement of grip wax.", "language": "en", "element": "description", "qualifier": "abstract", "schema": "dc"}, {"key": "dc.description.provenance", "value": "Submitted using Plone Publishing form by Veli-Matti Nieminen (veanniem) on 2013-02-20 15:28:57.406878. Form: Pro gradu -lomake (1 tekij\u00e4) (https://kirjasto.jyu.fi/julkaisut/julkaisulomakkeet/pro-gradu-lomake-1-tekijae). 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pito- ja luisto-ominaisuuksien muutoksen vaikutus voimantuottoon ja lihasaktiivisuuteen maksimaalisessa pitk\u00e4kestoisessa hiihtosuorituksessa perinteisell\u00e4 hiihtotavalla", "language": null, "element": "title", "qualifier": null, "schema": "dc"}, {"key": "dc.type", "value": "master thesis", "language": null, "element": "type", "qualifier": null, "schema": "dc"}, {"key": "dc.identifier.urn", "value": "URN:NBN:fi:jyu-201302201250", "language": null, "element": "identifier", "qualifier": "urn", "schema": "dc"}, {"key": "dc.type.dcmitype", "value": "Text", "language": "en", "element": "type", "qualifier": "dcmitype", "schema": "dc"}, {"key": "dc.type.ontasot", "value": "Pro gradu -tutkielma", "language": "fi", "element": "type", "qualifier": "ontasot", "schema": "dc"}, {"key": "dc.type.ontasot", "value": "Master\u2019s thesis", "language": "en", "element": "type", "qualifier": "ontasot", "schema": "dc"}, {"key": "dc.contributor.faculty", "value": "Liikuntatieteellinen tiedekunta", "language": "fi", "element": "contributor", "qualifier": "faculty", "schema": "dc"}, {"key": "dc.contributor.faculty", "value": "Faculty of Sport and Health Sciences", "language": "en", "element": "contributor", "qualifier": "faculty", "schema": "dc"}, {"key": "dc.contributor.department", "value": "Liikuntabiologian laitos", "language": "fi", "element": "contributor", "qualifier": "department", "schema": "dc"}, {"key": "dc.contributor.department", "value": "Department of Biology of Physical Activity", "language": "en", "element": "contributor", "qualifier": "department", "schema": "dc"}, {"key": "dc.contributor.organization", "value": "University of Jyv\u00e4skyl\u00e4", "language": "en", "element": "contributor", "qualifier": "organization", "schema": "dc"}, {"key": "dc.contributor.organization", "value": "Jyv\u00e4skyl\u00e4n yliopisto", "language": "fi", "element": "contributor", "qualifier": "organization", "schema": "dc"}, {"key": "dc.subject.discipline", "value": "Biomekaniikka", 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