It is a challenge to collect data on visitors' movement patterns via a mobile app for an alpine ski resort. Because gathering of location information is based on voluntariness. One way to motivate more people to share their location information is to offer the features that users expects or want in such a mobile app. This study aims to investigate what features a mobile app should include in order for users to share their location information. The research strategy used is case study and the data collection method is interviews. 22 alpine skiers were interviewed and in addition, an expert on the topic of mobile solutions with experience of leading development of location-based mobile apps has been interviewed. The interviews generated qualitative data that was analyzed thematically. The results presented by the study show that users are positive about sharing their location information if they receive something significant in return. The results are presented in two parts, one with general needs that the overwhelming majority desired, and one with interest-driven needs. / Det är en utmaning att samla in data om besökarnas rörelsemönster via en mobilapp för en alpin skidanläggning eftersom insamlingen av platsinformation baseras på frivillighet. Ett sätt att motivera fler att dela sin platsinformation är att erbjuda de funktioner användarna förväntar sig eller önskar i en sådan mobilapp. Denna studie syftar till att undersöka vilka funktioner en mobilapp bör innehålla för att användare ska dela med sig av sin platsinformation. Forskningsstrategin som tillämpas är fallstudie. Fallstudien baseras på intervjuer som datainsamlingsmetod. Intervjuer har genomförts med 22 alpinåkare samt en expert med erfarenhet inom att leda utveckling av platsbaserade mobila lösningar. Intervjuerna har genererat kvalitativ data som analyserats tematiskt. Resultaten som studien presenterar visar att användarna är positivt inställda till att dela sin platsinformation om de får något signifikant i gengäld. Resultaten presenteras i två delar. En del med allmänna behov vilka en övervägande majoritet önskade samt en del med intressestyrda behov.

Product testing and development are essential parts in sports and for the athletes in their quest to reach the podium. Manufacturers of sports equipment often use basic test methods which do not test the equipment in a sports specific way. Much of the equipment used by world-class athletes is chosen based only on subjective tests and the athletes’ feelings. One short term aim was therefore to develop test methods for objective tests of sports equipment that also tested the equipment in a sports  specific  way.  Another  aim  was  to  integrate  mechanics  and  simulations  to  enhance  the understanding of the test results. The more long term aims are to contribute to increased theoretical knowledge regarding test methods for sports equipment and to contribute to the development of test  methods  to  create  new  and  better  sports  equipment.  Experimental  tests  combined  with simulations  can  give  valuable  information  to  improve  the  performance  and  safety  of  sports equipment. Three studies dealt with the issue of objective yet sport specific test methods for sports equipment. The main methodological advancement is the modification of established test methods together  with  conventional  mechanics  calculations.  New  test  devices  and  methodologies  are proposed for alpine ski helmets and cross-country ski poles. Suggestions are given for improved test setups as well as theoretical simulation are introduced for glide tests of skis. The results show how sport   specific   test   methodologies   together   with   theoretical   calculations   can   improve   the objectiveness and relevance when testing sports equipment. However, the collected and used data require high precision to obtain high accuracy in the simulations. High data accuracy can be an issue in field measurements but also due to manufacturers not disclosing key material data. Still, the used methods  and  calculations  in  this  thesis  produce  relevant  and  reliable  results  which  can  be implemented to accurate evaluations of different sports equipment. Even though it has not been a first priority aim in this work, the results from the alpine helmet study have been used by helmet manufacturers to design new helmets with increased safety properties. This further show how an objective and sport specific test approach together with theoretical simulation can improve sports equipment and in the longer perspective, also the athletes’ performances. / <p>QC 20140423</p>

Forskning och karakterisering av alpinskidors belag kräver mycket tid och resurser att utföra därav försvinner informationsmängd inom området, då de tester som görs inte delas offentligt. Idag användsuteslutningsmetoden mycket och inte mätvärden som testats fram. Idenna rapport undersöks varför den ena skidan är snabbare än den andra med hjälp av teknisk information i form av data.Arbetet kring studien introducerades med en förstudie. I förstudien identifierades problem, analys av artiklar samt förberedelse kring intervju. Under arbetet har större del av tiden arbetats kring glidtester och uppsikt av strukturen samt att undersöka strukturer på belaget med mikroskop på ett laboratorium i Uppsala.Resultatet omfattar teoretiskt bevis grundat på mätdata som arbetats fram vid Ångströms laboratorium. Med hjälp av tre skilda strukturer som syftar till varierande karaktär, visar resultaten hur olika strukturer ger utslag i glid mellan snö och belag. Strukturerna som användes var helbäddsstruktur, kryss-struktur med släppta kanter samt fiskbensstruktur.Slutsatser kring projektet är att det glidtest som utfördes inte höll tillräckligt hög standard. För att kunna styrka att någon av strukturerna var snabbare än den andra behöver man utveckla glidtestet. Tiderna indikerar på skillnad i strukturerna, men på grund av de brister i testet som uppkom kan man inte med säkerhet fastställa att det är enbart strukturen som gör att tiden påverkas.Det går inte hitta någon korrelation mellan mikroskopsbilderna och de resultat man fick från glidtesterna, vilket ledet till att målet inte uppnåttsmed att hitta de parametrar som påverkar friktionen mellan skida ochsnö / In this study, the characteristics of an alpine ski’s base structure arepresented. The goal is to identify which parameters on the surface control the friction between the ski and the snow. The project is based on selfstudies through laboratory experiments and tests has been completed with facts from scientific reports and articles. This thesis is written for Sports Technology - Bachelor of Science in Product Development at Mid Sweden University Spring term 2022.Research and characterization of the alpine ski base require a lot of time and resources. As a result, the amount of information in the area disappears, as the tests performed are not shared publicly. Exclusion methods is the most common method used today and not measured values that have been tested. This report examines why one ski is faster than the other using technical data.The pilot study identified problems-, analyzed articles, and made the necessary preparations for the interviews. During the rest of the study, the main part of the time has been put into glide testing, an inspection of the structure and also observing the base of the ski with a microscope at the laboratory in Uppsala.The result covers theoretical evidence based on the measurement data that has been subtracted at the Ångstöms laboratory. With the help of three different structures aiming for varying characters, the result shows how these different structured bases interact with the snow. The structures used were full bed Cross structure, Cross structure withshaped edges and fishbone structure.Conclusions about the project are that the ski test that was performed did not maintain a sufficiently high standard. To be able to prove that one of the structures was faster than the other you need to develop the ski test. The times indicate a difference in the structures, but due to the shortcomings in the test that arose, it cannot be established with certainty that it is only the structure that causes the time to be affected.Karakterisering av ytstrukturen på en alpinskidas belagMittuniversitetet2022-05-25Based on the Mid Sweden University template for technical reports, written by Magnus Eriksson, Kenneth Berg and MivIt is not possible to find any correlation between the microscope images and the results obtained from the tests, which led to the goal not being achieved by finding the parameters that affect the friction between skisand snow / <p>2022-07-01</p>

Mittuniversitetets forskningsavdelning Sports Tech Research Centre (STRC) driver sedan en tid tillbaka ett projekt i samarbete med Svenska Skidförbundet. Syftet med projektet är att bidra till det alpina landslagets framgång genom att utveckla fartdräkterna som åkarna använder, främst genom att minska fartdräktens påverkan av luftmotståndet. En del av projektet innefattar vindtunneltester av dessa fartdräkter för att mäta dess luftmotstånd. Syftet med detta examensarbete är att bidra till fortsatt utveckling genom att underlätta dessa tester. Syftet är även att undersöka och utvärdera en ny tillverkningsmetod för att designa och tillverka testdockor avsedda att använda i vindtunneltester. Målet var att designa och tillverka en testdocka utifrån en alpinskidåkare på elitnivå. Dockan skulle kunna kläs i en fartdräkt och användas i en vindtunnel, och där visa likvärdiga mätvärden för luftmotståndet som för testpersonen och en lägre standardavvikelse. Arbetet började med att skanna testpersonen som testdockan skulle skapas utifrån. Fotogrammetri användes som skanningsmetod. Därefter följde 3D-modellering och beredning inför tillverkningen. Testdockan tillverkades av horisontella spånskivelager sammanfogade med varandra. Jämförande vindtunneltester utfördes sedan på testdockan och testpersonen den är skapad utefter, i syfte att validera dockan och uppnå liknande mätvärden. Den resulterande 3D-modellen från skanning och 3D-modellering kunde valideras mot testpersonens verkliga mått och var därför användbar för att tillverka den fysiska testdockan. Resultatet efter montering och ytbehandling var en fysisk testdocka som kunde kläs med fartdräkt och tillhörande utrustning. Dockans dimensioner stämde överens tillräckligt bra med testpersonens dimensioner. Vindtunneltesterna visade på ett luftmotstånd på ca 19,8N för testpersonen och ca 28,1N för testdockan. Detta beror troligtvis på skillnader mellan deras positionering. Standardavvikelsen av luftmotståndet för testpersonen och testdockan var ca 3,76N respektive ca 4,33N. Fotogrammetri följt av 3D-modellering i Rhino lämpade sig för denna typ av modell med organiska former. Tillverkningsmetoden krävde mycket efterarbete men gav ett bra resultat i just detta arbete, där de minsta detaljerna som t. ex ansikte och händer inte var av största vikt. Målet att tillverka en testdocka med fungerande funktioner uppfylldes. Ökningen av standardavvikelsen för testdockans luftmotstånd gör att den delen av målet inte uppfylldes, men ytterligare undersökningar behöver utföras innan slutsatser kan dras om dockans användbarhet. / Mid Sweden University's research department Sports Tech Research Center has been running a project in collaboration with the Swedish Ski Association for some time. The purpose of the project is to contribute to the success of the Swedish alpine national team by developing the race suits that the riders use, mainly by reducing the race suit's impact on air resistance. Part of the project includes wind tunnel tests of these race suits to measure its air resistance. The purpose of this thesis is to contribute to further development by facilitating these tests. The purpose is also to investigate and evaluate a new manufacturing method for designing and manufacturing test dummies intended for use in wind tunnel tests. The goal was to design and manufacture a test dummy based on an alpine skier at an elite level. The dummy was to be dressed in a race suit and used in a wind tunnel, and there show equivalent measured values for the air resistance of the test person and a lower standard deviation. The work began with scanning the test person from whom the test dummy was to be created. Photogrammetry was used as the scanning method. This was followed by 3D modulation and preparation for production. The test dummy was made of horizontal chipboard layers joined together. Comparative wind tunnel tests were then performed on the test dummy and the test person it is created from, in order to validate the dummy and achieve similar measurement values. The resulting 3D model from scanning and 3D modulation could be validated against the test person's actual measurements and was therefore useful for manufacturing the physical test dummy. The result after assembly and surface treatment was a physical test dummy that could be dressed in a speed suit and associated equipment. The dimensions of the dummy matched well enough with the dimensions of the test person. The wind tunnel tests showed an air resistance of about 19.8N for the test person and about 28.1N for the test dummy. This is probably due to differences between their positioning. The standard deviation of the air resistance for the test person and the test dummy was about 3.76N and about 4.33N, respectively. Photogrammetry followed by 3D modulation in Rhino was suitable for this type of model with organic shapes. The manufacturing method required a lot of finishing work but gave a good result in this particular work, where the smallest details such as the face and hands were not of the utmost importance. The goal of manufacturing a test dummy with needed functions was met. The increase in the standard deviation of the test dummy's air resistance means that part of the goal was not met, but further investigations need to be carried out before conclusions can be drawn about the dummy´s usefulness / <p>2022-07-01</p>

This thesis is about selection processes and processes of measuring and judging athletes in competitions in top-level sport. The purpose was to increase the knowledge of these processes and to analyse them from a validity perspective in order to contribute to the discussion of whether the “right” athletes are selected to participate in teams, competitions and games and whether the “right” athletes win. The rule and judging systems were investigated in the judged sports acroski and rhythmic gymnastics. Information was gathered through individual interviews with two judges, two coaches, and four elite athletes from each of the sports, and in addition to this the respective sport’s rule systems, judging manuals, meeting protocols and historical documents were studied. Selections to top-level sport teams were investigated by individual interviews with 14 top-level coaches (selectors) from the national league in soccer and a national team and from national teams in alpine skiing. The results from the judging study showed that both studied sports had undergone major changes in their rule and judging regulations, changes that had a considerable impact on the sports and the judgements. The level of definition of the rules and regulations was raised to increase the opportunities for clear and reliable judgements, but this became problematic for the overall validity of the judgements. The reason for this was that the new rules and regulations did not clearly correspond to the original idea of the sport, since the specified and detailed regulations lead to less originality and freedom in the performances. In the selection study, the results pointed to great differences in how precisely defined the selection criteria were among the teams. The selectors stated that well-defined selection criteria or grounds could be helpful in many ways, but they also emphasised how important it was for them that some parts of the selections were based on their subjective valuations of the athletes. Quite a few coaches from both sports argued that they would choose an athlete with good behaviour and favourable personality over an athlete with better sports skills, if they had an opportunity to do that depending on the selection system that was used. Overall, this research displays how validity issues connected to the selection and judging criteria and these processes might affect the outcome of the processes. It is notable that high reliability is in the main focus of the measuring and judging processes, while considerably vaguer and more subjective assessments are considered important in the selection process. The thesis points to the importance of discussing and understanding the consequences of rules, rule changes, selection and judging criteria as well as how these processes are performed, if the desired outcomes and consequences of the selection and judging processes are to be reached.

No description available.

Fusion Motion Capture (FMC), a wearable motion capture system was developed, and applied to the optimisation of athlete performance in alpine ski racing. In what may be a world first, the three-dimensional movements of a skilled athlete (with less than 20 FIS1 points) skiing through a complete training giant slalom racecourse were analysed. FMC consists of multiple light weight sensors attached to the athlete including inertial measurement units (IMUs), pressure sensitive insoles and a global position system (GPS) receiver. The IMUs contain accelerometers, gyroscopes, and magnetometers. Limb orientation and location are obtained by mathematically combining the most reliable data from each sensor using fusion algorithms developed by the author. FMC fuses the signals from the IMUs and GPS without the need for the post filtering, usually applied to motion capture data, and therefore, maintains maximum bandwidth. The FMC results were stable and relatively independent of motion type and duration unlike other inertial systems available in 2005, when the research was initiated. Analysis of data collected from an athlete skiing giant slalom contradict the traditional „going straight turning short? race strategy. The shortest path may not always be the fastest. Instead each gate has a different optimum approach arc. Optimum turn radius increases with both increasing speed and increasing terrain slope. The results also contradict laboratory measurements of ski/snow sliding friction and suggest that snow resistance in giant slalom is of similar importance to wind drag. In addition to gravity, the athlete increased speed using the techniques of „lateral projection? and „pumping?. Race performance was determined from the analysis of the athlete skiing through the entire course. FMC proved, therefore, to be more suitable than traditional optical systems that are practically limited to capturing small sections of a race course. The athlete experienced high and rapidly fluctuating torques about all three axes of the lower joints. This information could be useful in designing training programmes racecourses and equipment to reduce knee injuries. Data driven animations and colour coded force vector diagrams were developed to enhance athlete feedback. Inline skating data was also analysed.

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal.

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

Head injuries caused by impacts are among the most critical and dangerous types of accidents that can occur while practising sports. Alpine skiing is one of the activities with the highest incidence of head injuries. Over the years, specific regulations have been introduced to protect athletes where possible, but the perception is that the level of protection needed to manage the forces to which they are exposed has yet to be achieved. This thesis project aims to examine video sequences of accidents in alpine ski competitions (Giant Slalom, Super-G, Downhill, Ski Cross) to better understand the translational violence exerted on the head during impacts. After an in-depth analysis, it was shown that, in at least 41% of the videos investigated, the translational impact speeds exceeded the standards adopted in helmet certifications by 44.3% and 52.2%, respectively. Besides, in 60% of these accidents, the blow was located on the upper semicircle of the helmet, which is believed to be due to the ever-increasing use of airbags for the torso. / Huvudskador orsakade av slag är bland den alvarligaste typen av olyckor som kan inträffa vid utövande av idrott. Alpin skidåkning är en av de sporter med den högsta förekomsten av skador på huvudet. Under årens lopp har särskilda regler införts för att skydda atleterna där så är möjligt, men uppfattningen är att den skyddsnivå som krävs för att hantera de krafter åkarna utsätts för ännu inte har uppnåtts. Detta examensarbete syftar göra videoanalys på olyckor vid alpina skidtävlingar (Storslalom, Super-G, Störtlopp, Ski Cross) för att bättre förstå translationsvåldet mot huvudet vid olyckor. Efter en djupgående analys visades att i minst 41% av de undersökta fallen översteg translationshastigheten de hastigheter som används vid hjälmcertifieringar med 44.3% respektive 52.2%. För 60% av olyckorna skedde slaget högt upp på bakre delen av hjälmen, något som tros bero på den ökande användningen av krockkuddar för torso.