Nearly 3.5 million kids play youth football every year in the United States, many in independent organizations with few or no rules for limiting head impact exposure in practices or competition. Studies have found potential long-term effects of repetitive head impact exposure from a young age, even in the absence of concussion. The best methods for reducing head impact exposure include a multi-pronged approach: limiting contact through rules changes, teaching proper technique for contact when it does occur, and designing equipment with better protective capabilities. Four youth football teams were studied for one season each using helmet mounted accelerometer arrays. Head acceleration data indicated that youth teams often have a small subset of players who account for a disproportionately large number of high-risk head impacts. As few as six players (6%) accounted for over 50% of all high-risk impacts seen in practice sessions. Technique used during tackling and tackle-absorption had considerable effect on head acceleration. Both the tackler and ball carrier were found to be at greater risk for high magnitude head impacts when exhibiting poor form as defined by specific tackling recommendation criteria. These data suggest that individualized interventions encouraging proper form, especially for a subset of impact-prone players, may be beneficial in reducing high magnitude head impact exposure for an entire youth football team. This is especially critical because a majority of high-risk impacts are experienced in practice at the youth level. Results from this work could be applied by coaching staffs in youth football leagues to increase the safety of their athletes. / MS

Concussion rates and head injuries for football players have been on the rise and there is a need for further research in football to increase skills and decrease injuries. Behavioral skills training has been proven to be effective in teaching a wide variety of skills but has yet to be studied in the sports setting. We evaluated behavioral skills training to teach safer tackling techniques among six participants from a local Pop Warner football team. Results show safer tackling techniques increased substantially during practice and generalized to games among all six participants.

本文研究者採取合作原則與符擔性理論的觀點，以在台灣特有的徵兵制度下形成的「站崗的女人」版面為田野，探究其使用者面對衝突事件時採取高度合作溝通行為的原因，其中特別關注在使用者最後決定採取高度合作溝通行為之前，她們如何思考自己與環境（社群／介面）以及她們與其他社群成員的關係。研究發現，「站崗的女人」版成員面對衝突時，並不尋求長足的討論並推衍出結論以解決該衝突凸顯的問題，而是採取情感取向的方式，求急切、快速地平息衝突；採取此溝通模式的過程中，她們透過文章與推文的文字感知到社群的溫馨氛圍，並修正自身的溝通方式，集體追求在短時間內平抑衝突以確保個人層次與社群層次溝通目的的存續。本研究並且發現，在她們的思考過程中，人際的因素比介面的物理因素影響其溝通行為更甚。 / This research aimed at taking an affordance perspective on the collective cooperative communication behavior of members of the GFonGuard discussion board amid conflicts in one of Taiwan’s most popular bulletin board systems (BBS). The researcher was most interested in the reasons behind the conflict tackling mode of members of the GFonGuard – an online community whose spaciotemporal peculiarity results from Taiwan’s compulsory military service – and how members of the community deliberate over their relations with the community/text-only medium and with other participants of the communication while deciding on how to tackle conflicts. The research found that members of the community sought to immediately quell the conflicts instead of seeking a lengthy discussion and a final resolution to the problems the conflicts highlighted. Throughout the deliberation process, the members perceived an amicable atmosphere via the choice of words and tone of articles on the discussion board. They modified their own communication style and pursued immediate appeasement of conflicts in an attempt to ensure the survival of their communication goals on the individual and community levels. The research also found that they were more concerned about “interpersonal” factors than about “medium” factors during their deliberation.

Head injuries in American football is a serious issue regarding player health which is highly affected by velocity and its direction. Impact location can affect the severity of the head injury in both helmet-to-helmet impacts and helmet-to-ground impacts hence the understanding of concussive outcome from velocities and impact locations must be improved. In this thesis a video analysis resulted in simulation of five helmet-to-helmet impacts and two helmet-to-ground impacts, where velocity in each impact also was approximated with the method of least squares to avoid extreme values. The average velocity in helmet-to-helmet impacts was 5.1728 m/s for tackler player and 4.4766 m/s for tackled player and in helmet-to-ground impacts it instead was 6.1975 m/s. With the regression method an average velocity of 4.3982 m/s for tackler player and 5.3854 m/s for the tackled player in helmet-to-helmet impacts and 5.874 m/s in helmet-to-ground impacts. The simulations were performed with LS-DYNA and examined in LS-PrePost where head kinematics and the strain of brain tissue or more specific the maximum principal strain (MPS) was of interest. Further the MPS was scaled to its 95th percentile which determined the concussive likelihood for each impact scenario. The highest concussive outcome for an impact scenario was 100% and the lowest was 15%. The head kinematics of interest was linear acceleration, angular acceleration and angular velocity which in high risk for concussive outcome wasn't dominated by a single head kinematic. Impacts locations in helmet-to-helmet impacts didn't show any connection between impact location and high concussive risk. In helmet-to-ground impacts a connection between impact location at the back of the head and high concussive risk was observed. / Huvudskador inom Amerikansk fotboll är ett återkommande problem när det gäller spelarnas hälsa. Hastigheten och vart tacklingen träffar är starkt kopplat till hur allvarlig en huvudskada kan bli i både hjälm-mot-hjälm tacklingarn och hjälm-mot-mark. För att förhindra huvudskador måste förståelsen om kinematiken och vart tacklingen träffar förbättras.  I detta examensarbete gjordes en videoanalys vilket resulterade i fem hjälm-mot-hjälm simuleringar och två hjälm-mot-mark. Hastigheten approximerades också genom att använda uppskattnings metoden minsta kvadratmetoden. Medel-värdet av hastigheterna från videoanalysen blev 5.1728 m/s för spelaren som utförde tacklingen och 4.4766 m/s för spelaren som blev tacklad i hjälm-mot-hjälm tacklingar. I hjälm-mot-mark blev det istället ett medelvärde på 6.1975 m/s. Med uppskattnings metoden blev hastigheterna istället 4.3982 m/s för den tacklande spelaren och 5.3854 m/s för den tacklade spelaren i hjälm-mot-hjälm tacklingar. För hjälm-mot-mark blev medelvärdet av hastigheten 5.874 m/s med uppskattnings metoden. Simuleringarna av tacklings fallen gjordes med LS-DYNA och analyserades i LS-PrePost där huvudets kinematik och töjningen av hjärnvävnad är av intresse. Töjningen mättes av maximum principal strain (MPS) och den 95:e percentilen av MPS för att bestämma risken för hjärnskakning där den största risken för hjärnskakning var 100% och den minsta 15%. För huvudets kinematik var det linjär acceleration, vinkelacceleration och vinkelhastighet som var av intresse. Det fanns ingen koppling mellan endast en av kinematikerna och hög risk för hjärnskakning. Gällande vart tacklingen träffar fanns det ingen koppling mellan vart den träffar och hög risk för hjärnskakning i hjälm-mot-hjälm tacklingar. För hjälm-mot-mark tacklingar fanns det ett samband mellan att bakre delen av huvudet träffar marken och hög risk för hjärnskakning.

The purpose of this research study was to explore the effectiveness of the KiVa anti-bullying programme with Grade 4 learners in a primary school, located in the Eden Central Karoo District of the Western Cape. Since bullying is a worldwide phenomenon, it is important to explore to what extent it is an issue in South Africa. International anti-bullying programmes, which are well researched and highly recommended, are described with an overview of the integration of systems theory with the practicalities of this research project. A mixed methods intervention design was used to collect data. Grade four learners completed questionnaires prior to and after implementation of the intervention programme, which comprised the quantitative data. The experiment schools Grade 4 Life Skills teachers led the implementation of the programme. Qualitative data were collected through semi-structured interviews with the Grade 4 teachers and the principal of the experiment school. The findings demonstrate that the implementation process over less than a year, did raise awareness and certain skills were developed and practised by learners. The effectiveness of the KiVa anti-bullying programme during a short period of six months, did establish consciousness and a change in attitude and behaviour. A statistically significant difference for two of the three categories, experiences at school (bullying) and about your life (well-being), of the questionnaire from before the implementation to after the implementation of the intervention programme was indicated at the experiment school. Thus, implications for future research regarding the implementation of the KiVa school-based programme are suggested. / Psychology of Education / M. Ed. (Psychology of Education)