Repository of Faculty of Kinesiology, University of Zagreb - KIFoREP
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PARENTAL CHARACTERISTICS AND BEHAVIORS AS PREDICTORS OF SPORTS PARTICIPATION IN YOUNG SCHOOL-AGED CHILDREN
No full textOvaj diplomski rad istražuje doprinos karakteristika i ponašanja roditelja u bavljenju sportom djece mlađe školske dobi, a poseban je naglasak stavljen na važnost roditeljske podrške kao ključnog čimbenika u poticanju djece na sportske aktivnosti. Problematika rada odnosi se na nedovoljnu uključenost djece mlađe školske dobi u sportske aktivnosti unatoč prepoznatoj važnosti tjelesne aktivnosti za njihov fizički, emocionalni i socijalni razvoj. Roditelji su često najvažniji promicatelji sportskih aktivnosti.
Cilj istraživanja je istražiti povezanost sportskog iskustva roditelja, njihove razine bavljenja sportom, njihove uključenosti i podrške s razinom bavljenja sportskim aktivnostima njihove djece mlađe školske dobi, kao i ispitati razlike u tim varijablama između majki i očeva.
Istraživanjem je utvrđeno da djeca čiji se roditelji bave rekreativnim aktivnostima dobivaju manju razinu emocionalne podrške nego djeca čiji se roditelji bave sportom na natjecateljskoj razini. Također je utvrđeno da su majke u većoj mjeri uključene u sportske aktivnosti djece nego očevi i to na svima ispitanim razinama – emocionalno, materijalno i operativno.This thesis explores the contribution of parental characteristics and behaviors to the sports participation of younger school-age children, with a particular emphasis on the importance of parental support as a key-factor in encouraging children to engage in sports activities. The issue addressed in the paper concerns the insufficient involvement of younger school-age children in sports activities, despite the recognized importance of physical activity for their physical, emotional, and social development. Parents are often the most important promoters of sports activities.
The aim of the research is to examine the connection between parents' sports experience, their level of sports involvement, their engagement and support, and the level of sports activities of their younger school-age children, as well as to investigate the differences in these variables between mothers and fathers.
The research found that children whose parents engage in recreational activities receive less emotional support than children whose parents participate in competitive sports. It was also found that mothers are more involved in their children's sports activities than fathers, on all examined levels – emotionally, materially, and operationally
Physical education teacher and peer violence
No full textOvaj diplomski rad istražuje ključnu ulogu nastavnika tjelesne i zdravstvene kulture (TZK) u sprječavanju i rješavanju vršnjačkog nasilja u školskom okruženju. Vršnjačko nasilje može biti fizičko, verbalno, emocionalno ili kibernetičko. Ono predstavlja ozbiljan problem s dugoročnim posljedicama na tjelesno i mentalno zdravlje učenika. Zbog prirode njihovog rada, učitelji TZK
često su u poziciji da prvi prepoznaju nasilje među učenicima s obzirom na to da njihove aktivnosti uključuju intenzivnu interakciju i fizičku prisutnost. Analizom različitih stilova poučavanja rad pokazuje kako natjecateljski pristupi mogu potaknuti sukobe i nasilničko ponašanje među učenicima. S druge strane, suradničke metode koje potiču timski rad i međusobnu podršku smanjuju rizik od nasilja. Uvođenje i promicanje pozitivne školske klime u kojoj se njeguju vrijednosti poput fair playa, međusobnog poštovanja i inkluzivnosti ključno je za stvaranje sigurnog i podržavajućeg okruženja za sve učenike. Posebno se razmatra utjecaj individualnih karakteristika učenika poput tjelesnih sposobnosti, izgleda i motoričkih vještina koje često imaju ulogu u nasilničkom ponašanju. Učenici s lošijim tjelesnim vještinama ili nižim statusom među vršnjacima mogu biti podložniji zadirkivanju i isključivanju tijekom satova TZK. Također, učenici s invaliditetom i specifičnim razvojnim poremećajem školskih vještina češće postaju žrtve nasilja, što naglašava važnost prilagodbe nastavnih sadržaja kako bi se osigurala inkluzija svih učenika. Rad zaključuje da učitelji TZK kroz promicanje pozitivnih socijalnih vrijednosti i socijalnoemocionalno učenje imaju jedinstvenu priliku doprinijeti smanjenju nasilja u školama. Inkluzivni pristupi i osnaživanje učenika kroz tjelesne aktivnosti mogu značajno doprinijeti jačanju socijalne kohezije i stvaranju sigurnijeg školskog okruženja za sve.This thesis explores the key role of physical education (PE) teachers in preventing and addressing peer violence in the school environment. Peer violence can be physical, verbal, emotional, or cyberbullying. It represents a serious issue with long-term consequences for the physical and mental health of students. Due to the nature of their work, PE teachers are often in a position to be the first to recognize violence among students, as their activities involve intense interaction and
physical presence. By analyzing different teaching styles, the thesis shows how competitive approaches can encourage conflicts and bullying behaviors among students. On the other hand, cooperative methods that foster teamwork and mutual support reduce the risk of violence. The
introduction and promotion of a positive school climate, where values such as fair play, mutual respect, and inclusivity are nurtured, are essential for creating a safe and supportive environment for all students. The thesis also examines how individual characteristics of students, such as physical abilities, appearance, and motor skills, often play a role in bullying behavior. Students with poorer physical skills or lower status among peers may be more susceptible to teasing and exclusion during PE classes. Furthermore, students with disabilities and specific developmental disorders of scholastic skills (SDDSS) are more likely to become victims of violence, highlighting the importance of adapting teaching content to ensure the inclusion of all students. The thesis
concludes that PE teachers, by promoting positive social values and social-emotional learning, have a unique opportunity to contribute to reducing violence in schools. Inclusive approaches and empowering students through physical activities can significantly contribute to strengthening social cohesion and creating a safer school environment for everyone
ANATOMICAL AND KINEMATIC ANALYSIS OF SHOTS IN HANDBALL
No full textRazvojem rukometne igre i tehnologije u području sportskih znanosti dolazi se do novih spoznaja u pogledu kinematičkih parametara i aktivacije mišića kinematičkog lanca pri specifičnim dinamičko-motoričkim obrascima pokreta, u ovom slučaju šuta u rukometu. Cilj ovog rada je dati pregledi kritički osvrt na dostupna istraživanja koja obrađuju tehniku šuta u rukometu s naglaskom na anatomsku analizu i mišićnu aktivaciju sastavnica kinematičkog lanca prilikom izvođenja samog šuta. Navedene analize bitne su za informiranje trenera o tome što čini dobru tehničku izvedbu, prema kojima je moguće sastaviti individualan plan treninga, kako za poboljšanje tehnike, tako i za prevenciju ozljeda. Rad također identificira ograničenja dosadašnjih istraživanja, te predlaže neke smjernice za buduće analize koje bi mogle pridonijeti daljnjem unaprjeđenju šuterske tehnike u rukometu.With the development of handball as a sport and advancements in sports science technology, new insights are being gained regarding kinematic parameters and muscle activation within the kinematic chain during specific dynamic-motor movement patterns, such as the handball shot. The aim of this thesis is to provide a review and critical analysis of the available research that examines the technique of shooting in handball, with an emphasis on anatomical analysis and muscle activation within the kinematic chain components during the execution of the shot. These analyses are crucial for informing coaches about the elements that constitute good technical performance, enabling the creation of individualized training plans aimed at both technique improvement and injury prevention. The thesis also identifies the limitations of existing research and proposes some guidelines for future analyses that could further contribute to the enhancement of shooting techniques in handball
Proposal of some urban solutions for the expansion of outdoor sports and recreational facilities
No full textVeliki broj ljudi preferira vježbanje na otvorenom prostoru što posebno dolazi do izražaja tijekom perioda godišnjih odmora. Stoga većina turističkih destinacija već ima određenu ponudu sportsko rekreacijskih sadržaja na otvorenom prostoru ali i teži ka proširenju iste. U nastojanju da što brže i sa što manjim troškovima unaprijede svoju ponudu turističke destinacije često odabiru manjkava urbanistička rješenja. Cilj ovoga rada bio je izraditi prijedlog nekih urbanističkih rješenja za proširenje sportsko rekreacijskih sadržaja na otvorenom. Stoga je u radu, na primjeru Supetra na Braču, prikazana trenutna ponuda sportsko rekreacijskih sadržaja na otvorenom te izrađeno nekoliko urbanističkih rješenja za poboljšanje postojećih sadržaja kao i implementiranje novih aktivnosti. U ovom radu razrađene su teme razvoja sportske rekreacije u turizmu, njezina povijest te suvremeni kontekst. Prikazano je i kako urbanizam utječe na razvoj sportsko rekreacijskih sadržaja u turističkom mjestu te sami sadržaji i aktivnosti koji se mogu primijeniti kako uz samu obalu mora tako i u moru. Potrebno je trenutnu ponudu poboljšati i upotpuniti kako bi gosti, kao i lokalno stanovništvo, imali mogućnost biti tjelesno aktivni u vrijeme godišnjeg odmora u proljetnim i ljetnim mjesecima ili slobodno vrijeme za mještane tijekom cijele godine.A large number of people prefer to exercise outdoors, which is especially evident during the holiday period. Therefore, most tourist destinations already have a certain offer of sports and recreational facilities in the open space, but they are also striving to expand it. In an effort to improve their offer as quickly as possible and at the lowest possible cost, tourist destinations often choose flawed urban solutions. The aim of this paper is to make a proposal for some urban solutions for the expansion of outdoor sports and recreational facilities. Therefore, on the example of Supetar on Brač, the current offer of outdoor sports and recreational facilities is shown and several urban solutions have been developed to improve the existing facilities as well as implement new activities. This paper elaborates the topics of the development of sports recreation in tourism, its history and contemporary context. Also, how urbanism affects the development of sports and recreational facilities in a tourist place, as well as the facilities and activities that can be applied along the seashore and in the sea. It is necessary to improve and complete the current offer so that guests, as well as the local population, have the opportunity to fully enjoy their vacation in the spring and summer months or free time for locals throughout the year
Influence of physical actvity and sleep hygiene on sleep quality in elderly people
No full textCilj istraživanja: Starije osobe su skupina povećanog rizika od smrtnosti zbog visoke prevalencije poremećaja spavanja. Tjelesna aktivnost, kao nefarmakološka intervencija, može imati blagotvorne učinke na kvalitetu spavanja, no mehanizmi njezina utjecaja kod starije populacije nisu u potpunosti razjašnjeni. S toga je cilj ovog istraživanja bio utvrditi utjecaj intervencije tjelesne aktivnosti provedene u jutarnjim i popodnevnim satima te higijene spavanja, na kvalitetu spavanja kod osoba starije životne dobi.
Metode istraživanja: U ovom istraživanju, 76 ispitanika starijih od 65 godina (prosječna dob: 72.6 ± 1.2 godina) je slučajno bilo raspodijeljeno u tri grupe ispitanika: 1) jutarnja grupa (N = 30), koja je provodila tjelesnu aktivnost u jutarnjim satima; 2) popodnevna grupa (N = 23), koja je provodila istu aktivnost u popodnevnim satima; i 3) grupa higijene spavanja (N = 23), koja je provodila intervenciju higijene spavanja. Intervencija je trajala četiri tjedna, a korištene su slijedeće metode: i) dnevnik spavanja (odlazak na spavanje i buđenje); ii) subjektivna procjena kvalitete spavanja mjerene Pittsburgh upitnikom kvalitete spavanja; iii) objektivna procjena tjelesne aktivnosti i kvalitete spavanja kod jutarnje i popodnevne grupe mjerena GENEActive akcelerometrijom. Prije testiranja, svi su ispitanici ispunili Montrealsku ljestvicu kognitivne procjene, te su ispitanici s rezultatom ≥ 27 bili uključeni u istraživanje. Inicijane razlike između grupa testirane su Kruskal-Wallis testom za nezavisne uzorke, dok su se vremenske promjene unutar pojedine grupe izračunale Wilcoxonovim rank testom za zavisne uzorke.
Rezultati istraživanja: Nakon intervencije u trajanju od četiri tjedna, komponente mjerene subjektivnom metodom Pittsburgh upitnika kvalitete spavanja su pokazale značajne vremenske promjene i poboljšanja u kvaliteti, latenciji, trajanju, učinkovitosti i cjelokupnoj kvaliteti spavanja, dok su se poremećaji i disfunkcije spavanja značajno smanjile. Grupa higijene spavanja pokazala je najveće promjene tijekom primjene intervencije spavanja u cjelokupnoj kvaliteti spavanja (82.6%, Z – vrijednost = -4.359, p – vrijednost < 0.001) nasuprot jutarnje (66.1%, Z – vrijednost = -4.264, p – vrijednost < 0.001) i popodnevne grupe (66.9%, Z – vrijednost = -4.000, p – vrijednost < 0.001), te u trajanju spavanja (90.8%, Z – vrijednost = -4.221, p – vrijednost < 0.001), nasuprot popodnevne grupe (60.9%, Z – vrijednost = -3.742, p – vrijednost < 0.001), dok je jutarnja grupa pokazala najmanje vremenske promjene u trajanju spavanja (23.3%, Z – vrijednost = -2.111, p – vrijednost = 0.035). U drugim parametrima kvalitete spavanja (osim konzumacije lijekova), iako je došlo do značajnih vremenskih
promjena primjenom intervencije (p – vrijednost < 0.05), nije došlo do značajnih interakcija vremena i tipa intervencije. Kod komponenata spavanja mjerenih objektivnom metodom akcelerometrije, rezultati istraživanja su pokazali značajno vremensko smanjenje spavanja kod jutarnje grupe za 8.3%, dok je popodnevna grupa smanjila isto trajanje spavanja za 7.2%, proteklog vremena spavanja kod jutarnje (7.7%) i popodnevne (19.4%) grupe, smanjenje ukupnog vremena spavanja tijekom vikenda za 10.0% kod jutarnje i 18.5% za popodnevnu grupu, povećano ukupno vrijeme budnosti tijekom vikenda kod jutarnje za 1.2%, dok je smanjenje zamijećeno kod popodnevne grupe za 21.2% dok u istim varijablama tijekom dana tjedna nije bilo značajnih promjena. Na prosječnoj tjednoj razini, nije došlo do značajnih promjena u obje grupe ispitanika. Konačno, učinci broja koraka, različitih intenziteta tjelesne aktivnosti i sedentarnog ponašanja na karakteristike spavanja mjerenih objektivnom metodom akcelerometrije su pokazali, kako su generalno intenziteti tjelesne aktivnosti i veći broj koraka značajno pozitivno povezani s kvalitetom i arhitekturom spavanja, dok je veća razina sedentarnih ponašanja bila povezana s nižom razinom učinkovitosti spavanja i višim brojem aktivnih razdoblja kod jutarnje i popodnevne grupe ispitanika. Globalne razlike su utvrđene Friedmanovim testom.
Zaključak istraživanja: Ovo je istraživanje pokazalo kako intervencija tjelesne aktivnosti i higijene spavanja u trajanju od četiri tjedna može pozitivno utjecati na komponente spavanja mjerenih subjektivnom metodom u jutarnjoj i popodnevnoj grupi tjelesne aktivnosti i grupi higijene spavanja dok se prosječne tjedne vrijednosti parametara spavanja mjerenih objektivnom metodom nisu značajno promijenili u istom razdoblju. S druge strane, veći broj koraka i različiti intenziteti tjelesne aktivnosti imaju tendenciju poboljšanja trajanja, ukupnog vremena i učinkovitosti spavanja, dok smanjuju razinu budnosti i broj aktivnih razdoblja. Iako vremenskih promjena kod korištenja objektivnih metoda nije bilo, subjektivna procjena kvalitete spavanja se pokazuje dovoljno osjetljivom prilikom primjene intervencija i tendencija prema poboljšanjima u sve tri grupe ispitanika može pomoći u implementaciji strategija tjelesne aktivnosti za poboljšanje samo procijenjenog spavanja kod osoba starije životne dobi.Research goal: Older adults are a group who are at increased risk of mortality due to the high prevalence of sleep disorders. Physical activity, as a non-pharmacological intervention, can have beneficial effects on sleep quality, but the mechanisms of its influence in older adults have not been fully elucidated. Therefore, the aim of this research was to determine the influence of physical activity intervention carried out in the morning and afternoon hours, and sleep hygiene on the quality of sleep in older adults.
Research methods: In this study, 76 subjects older than 65 years (average age: 72.6 ± 1.2 years) were randomly divided into three groups of subjects: 1) morning group (N = 30), which performed physical activity in the morning hours; 2) afternoon group (N = 23), which carried out the same activity in the afternoon; and 3) the sleep hygiene group (N = 23), which had a sleep hygiene intervention and was without a physical activity intervention. The intervention lasted four weeks with the measurement of the following variables: i) sleep diary (going to sleep and waking up); ii) subjective assessment of sleep quality measured by the Pittsburgh Sleep Quality Index questionnaire (PSQI); iii) objective assessment of physical activity and sleep quality in the morning and afternoon groups measured by the GENEActive accelerometry method. Before testing, all subjects completed the Montreal Cognitive Assessment Scale (MOCA), and subjects with a score ≥ 27 were included in the study. Initial differences between groups were analyzed using Krukal-Wallis test for indepenent samples and time changes within each group were calculated using Wilcoxon rank test. Global changes were identified using Friedman test.
Research results: After a four-week intervention, components measured by the subjective method of the PSQI showed significant temporal changes and improvements in quality, latency, duration, efficiency, and overall sleep quality, while sleep disturbances and dysfunctions significantly decreased. The sleep hygiene group showed the greatest changes during the implementation of the sleep intervention in the overall quality of sleep (82.6%, Z-value = -4.359, p-value < 0.001) compared to morning sleep (66.1%, Z-value = -4.264, p-value < 0.001 ) and the afternoon group (66.9%, Z - value = -4.000, p - value < 0.001), and in sleep duration (90.8%, Z - value = -4.221, p - value < 0.001), in contrast to the afternoon group (60.9% , Z-value = -3.742, p-value < 0.001), while the morning group showed the least temporal changes (23.3%, Z-value = -2.111, p-value = 0.035). In other parameters of sleep quality (except medication consumption), although there were significant time changes with the application of
the intervention (p - value < 0.05), there were no significant interactions between time and type of intervention. In terms of sleep components measured by the objective method of accelerometry, the research results showed a significant decrease in sleep time in the morning group by 8.3%, while the afternoon group decreased the same duration of sleep by 7.2%. Moreover, the elapsed sleep time in the morning (7.7%) and afternoon (19.4%) groups decreased, along with the total sleep time during the weekend by 10.0% in the morning group and by 18.5% in the afternoon group. Finally, a increased total wake time during the weekend in the morning group by 1.2% was shown, while a more pronounced decrease in the afternoon group was by 21.2%. At the average weekly level, there were no significant changes in both groups of subjects. Finally, the effects of the number of steps, different intensities of physical activity and sedentary behavior on sleep characteristics measured by the objective method of accelerometers showed that, in general, the intensity of physical activity and a greater number of steps were significantly positively related to the quality and architecture of sleep, while a higher level of sedentary behaviors was related with a lower level of sleep efficiency and a higher number of active periods in the morning and afternoon group of subjects.
Research conclusion: This research shows how a four-week physical activity and sleep hygiene intervention can have a positive effect on sleep components measured by the subjective method in the morning and afternoon physical activity and sleep hygiene groups. The average weekly values of the sleep parameters measured by the objective method do not change significantly in the final, with regard to the initial measurement, except for some parameters during the weekend. On the other hand, a greater number of steps and different intensities of physical activity tend to improve the duration, total time and efficiency of sleep, while reducing the level of alertness and the number of active periods. Although there were no temporal changes when using objective methods, the subjective assessment of sleep quality proves to be sensitive enough when applying interventions and the tendency towards improvements in all three groups of subjects can help in the implementation of physical activity strategies to improve self-perceived sleep quality in older adults
determinants of ground reaction forces in the first phase of racewalking stride
No full textSvrha provedenog istraživanja bila je unaprijediti znanstvenu osnovu treninga sportskog hodanja, temeljem biomehaničke analize kretanja na uzorku od 26 ispitanika – aktivnih natjecatelja i početnika u različitim disciplinama sportskog hodanja, u dobi od 13 do 37 godina, iz četiriju zemalja. Cilj istraživanja bio je utvrditi utjecaje odabranih kinetičkih i kinematičkih varijabli na maksimalnu silu reakcije podloge u prvoj fazi koraka te temeljem toga definirati indikatore kvalitetne tehnike sportskog hodanja. Provedeno je mjerenje odabranih morfoloških karakteristika prema IBP protokolu te raspona pokreta prema standardnom goniometrijskom protokolu zbog prikupljanja osnovnih podataka važnih za analizu kinetičkih i kinematičkih varijabli. Mjerenjem pri pojedinačno specifičnoj natjecateljskoj brzini kretanja tehnikom sportskog hodanja, prikupljeni su kinetički podaci pomoću platforme za mjerenje sila reakcije podloge Kistler, model 9286 i kinematički podaci pomoću triju kamera Panasonic DMC-FZ200 te sustava Optojump Next.
U fokusu analize bila je maksimalna sila reakcije podloge u prvoj fazi koraka te identifikacija sastavnica koje na nju imaju znatan utjecaj. Ne temelju prikupljenih podataka provedeno je testiranje regresijskog utjecaja 48 prediktorskih varijabli na navedenu kriterijsku varijablu te je za 13 varijabli provedena detaljnija analiza. Za 6 najznačajnijih varijabli provedena je višestruka regresijska analiza utjecaja, u zajedničkom djelovanju s relevantnim varijablama koje su s njima imale zadovoljavajuće malu kolinearnost.
U okviru disertacije testirane su dvije osnovne hipoteze. Prva hipoteza - kako postoji statistički značajna povezanost između sile reakcije podloge u drugoj fazi koraka i sile reakcije podloge u prvoj fazi koraka sportskog hodanja - prihvaćena je u potpunosti. U okvirima ograničenja uzorka i primjenjenih analitičkih metoda utvrđeno je da varijabla omjera prosječne relativne sile reakcije podloge u intervalu 70 % - 80 % i prosječne relativne sile reakcije podloge u cjelokupnom trajanju faze kontakta samostalno objašnjava 55 % varijance kriterijske varijable, a u zajedničkom djelovanju s varijablom torakolumbalne ekstenzije objašnjava 66 % varijance kriterijske varijable. Bitan je utjecaj nagiba krivulje relativne sile reakcije podloge u fazi odraza u istom intervalu 70 % do 80 % trajanja kontakta, jer ova varijabla u zajedničkom djelovanju s varijablama zbroja kutova rotacije zdjelice i torakolumbalne lateralne fleksije i pretklona/zaklona trupa objašnjava 71 % varijance kriterijske varijable.
Druga hipoteza - kako postoji statistički značajna povezanost promatranih kinematičkih varijabli i sile reakcije podloge u prvoj fazi koraka sportskog hodanja - prihvaćena je
djelomično s obzirom na to da za kutove stopala prema podlozi fleksiju i ekstenziju kuka i koljena, kao niti za zamah rukama i torakalnu rotaciju nisu nađene značajne statističke veze s maksimalnom silom reakcije podloge u prvoj fazi koraka.
U okvirima ograničenja uzorka i primijenjenih analitičkih metoda utvrđeno je da na sile reakcije podloge u prvoj fazi koraka sportskog hodanja značajno utječe duljinski i vremenski omjer druge i prve faze koraka, ukupna duljina koraka, trajanje faze leta, rotacija zdjelice, torakolumbalna lateralna fleksija i torakolumbalna ekstenzija. Ukupna duljina koraka u zajedničkom djelovanju s varijablama rotacije zdjelice, torakolumbalne lateralne fleksije te pretklona/zaklona zdjelice objašnjava 73 % varijance kriterijske varijable. Trajanje faze leta u zajedničkom djelovanju s varijablama torakolumbalne ekstenzije i rotacije objašnjava 75 % varijance kriterijske varijable. Omjer trajanja dviju faza koraka u zajedničkom djelovanju s varijablama duljine koraka, torakolumbalne ekstenzije i torakolubalne lateralne fleksije objašnjava 64 % varijance kriterijske varijable.
Osnovni je nalaz i znanstveni doprinos istraživanja (u okviru ograničenja veličine i strukture uzorka i metoda istraživanja) da je za smanjenje maksimalne sile u prvoj fazi koraka sportskog hodanja osobito važno smanjiti trajanje faze leta, smanjiti torakolumbalnu ekstenziju, a povećati rotaciju zdjelice i torakolumbalnu lateralnu fleksiju, kao i silu prema podlozi u drugoj fazi koraka. Nužno je osigurati da je brzina kretanja sportaša u granicama u kojima razvoj njihovih motoričkih sposobnosti omogućava način kretanja koji uključuje opisani raspon pokreta.Racewalking is an integral part of athletics with competitions at the Olympic Games and World Championships, defined by two basic rules: athletes must maintain contact with the ground in such a way that there is no loss of contact (visible to the human eye), and the legs must be straightened (i.e. not bent at the knee) from first contact with the ground to the vertical upright position. For this reason, racewalking coaches consider the extended knee phase as critical in teaching a compliant technique while avoiding excessive ground reaction forces (GRF) that lead to the most common overuse injuries in racewalking (hamstring tears, shin splints and knee problems), as the knees are extended in the first phase of the stride when the peak forces occur. The main problem addressed by this dissertation is therefore how racewalking can be performed without generating excessive forces that can lead to injury. The main objective of the analyses conducted was to identify the main biomechanical indicators that show a statistically significant relationship with the peak GRF immediately after initial ground contact. There are few studies dealing with young and inexperienced novice racewalkers and no scientific recommendations have been defined on the key indicators for high-quality and low-impact racewalking training. Therefore, the scientific contribution of this doctorate is the improvement of the knowledge base of racewalking training by defining the key performance indicators that address the main research problem – the control of excessive ground reaction force in the first phase of the racewalking stride.
The dissertation consists of eight chapters. The first chapter contains an introduction to the research problem, which is based on a descriptive analysis of the kinematics of racewalking in comparison to running over a marathon distance. The main characteristics of racewalking are knee extension in the first phase of the stride, greater pelvic rotation and a smaller range of hip motion with a flight phase of much shorter duration than in running. Hanley et al. (2019) concluded that even at low speeds in racewalking (3.0 ms-1), a short flight phase occurs, while the speed in racewalking at which the visible flight phase occurs (about 0.04 seconds) is about 3.9 ms-1 for male athletes and 3.6 ms-1 for female athletes. The kinetic model of racewalking describes the ground reaction forces with a significantly lower peak than in running and a difference between "N" and "M" shapes of the (vertical) GRF curve. The results of studies on injuries in racewalking are presented, showing that injuries are relatively common and specific,
with the overuse injuries to the hamstrings, shins and knees being attributable to the forces towards the ground in the first phase of the stride.
The second chapter describes the main objective of the study, which is to assess the impact of kinetic variables (GRF in the second phase of the stride) and kinematic variables (stride length, ratio of stride phases, ankle, knee and hip flexion and extension, pelvic and thoracic flexion and rotation, and arm swing) on peak GRF in the first phase of the racewalking gait. In the third chapter, two basic research hypotheses are put forward, namely that in racewalking there is a statistically significant influence of the GRF in the second phase of the stride on the peak GRF in the first phase of the stride (H01) and that there is a statistically significant influence of the observed kinematic variables on the peak GRF in the first phase of the stride (H02).
The research methods used are presented in the fourth chapter. The laboratory tests were conducted with 33 participants, of which the results of 26 participants were used for the detailed analyses, while the research protocol could not determine representative GRF curves for 7 participants. The 26 participants were 16 women and 10 men aged 13 to 37 years from 4 different countries. Seven participants were elite senior athletes, another 3 participants were junior elite athletes, 8 were national competitive athletes, and 8 participants were novices who had competed in racewalking. All tests were conducted bilaterally, increasing the sample size to 52. The athletes racewalked within +/- 5% of their individually determined pace, which was based on the previous season's best competition results at the distances at which the athletes primarily compete. Each participant had to perform at least 12 correct trials by positioning each foot six times on the Kistler force plate (model 9286, Winthertur, Switzerland) with a recording frequency of 1,000 Hz. Of these 6 trials, 3 were selected as representative using the least squares method. The problem of different speeds of the participants was solved by defining speed as one of the independent variables in the regressions. Kinematic data were collected with Panasonic cameras (DMC-FZ200, Japan) in all three planes and with the Optojump Next system. A total of 10 kinetic and 38 kinematic variables were analysed in a simple linear regression with peak GRF as the dependent variable. As the coefficients of determination were below 0.20, 29 variables were excluded, while a further 6 variables were not included due to redundancy. The remaining 3 kinetic and 10 kinematic variables were considered relevant for the detailed analyses. Of these 13 variables, 6 were selected as the most important, i.e. as leading variables with coefficients of determination greater than 0.40. For these variables, 6 multiple regression models were tested linking the leading variables to the variables that were not highly
correlated with them. The multicollinearity test was performed based on the variance inflation factor, while the G*Power programme was used to calculate the adequacy of the effect size and the statistical significance of the variables in the multiple regressions, considering the number of independent variables.
The fifth chapter presents the most important results of the analyses conducted. Of the 26 participants, 15 participants had predominantly M-shaped GRF curves with two distinct maxima, while 7 participants had N-shaped GRF curves with a single maximum and 4 participants had atypical curve shapes. The regression analysis showed that the variance of the peak GRF in the first phase of the stride can be explained by the indicators of GRF before toe-off in the interval 70-90% of the contact phase with a large coefficient of determination (R2 = 0.56). Racewalking speed is also an important factor in explaining the variance of the peak GRF (R2 = 0.59). Among the kinematic variables not included in a more detailed analysis due to low value of coefficient of determination in a simple regression were the indicators of arm swing, thoracic rotation, hip and knee flexion and foot angle to the ground. Of the remaining indicators, the highest coefficients of determination were calculated in a simple regression for the duration of the flight phase (R2 = 0.64), stride length (R2 = 0.59), the sum of pelvic rotation and lateral thoracolumbar flexion (R2 = 0.42) and thoracolumbar extension (R2 = 0.40). Multiple regression analysis was performed for these 6 leading variables to evaluate the combined influence with other relevant variables on the peak GRF in the first phase of the stride, to address the basic problem and test the hypotheses of this dissertation. The results of this analysis represent important scientific contributions of this dissertation. Namely, they show that a reduction of the GRF in the first phase of the racewalking stride is possible due to the simultaneous influence of the following variables:
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by reducing the duration of the flight phase as well as the thoracolumbar extension, with greater pelvic rotation (R2 = 0.75);
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by shortening the stride and reducing the forward tilt of the pelvis, with a greater sum of the angles of pelvic rotation and thoracolumbar lateral flexion (R2 = 0.73);
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by reducing the racewalking speed as well as the backward tilt of the trunk, with increased pelvic rotation (R2 = 0.72);
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by increasing the sum of the angles of pelvic rotation and thoracolumbar lateral flexion, with decreased backward trunk tilt and decreased slope of the GRF curve in the second phase of the stride (R2 = 0.71);
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by increasing the GRF in the second phase of the stride, with decreased thoracolumbar extension (R2 = 0.66);
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by decreasing the ratio between the second and first phase of the stride and shortening the stride, with decreased thoracolumbar extension and increased thoracolumbar lateral flexion (R2 = 0.64).
The sixth chapter contains the discussion. The results of the conducted research indicate that the peak GRF in the first phase of the stride is smaller when the mode of locomotion is more similar to normal walking than to running, i.e. when the shape of the GRF curve is of the "M" type rather than the "N" type, which is consistent with the results of previously published research (Pavei et al., 2019). The research conducted confirmed that speed is a significant factor in the regression with GRF, confirming previously published research findings. When a racewalker retains a significant percentage of force towards the ground prior to toe-off, the contralateral leg is less loaded at anterior contact, which has also been found in previous research (Hanley and Bissas, 2013), but without formal evaluation of the effects, which is one of the scientific contributions of this dissertation. The analysis conducted also found that the peak GRF is smaller when the stride is shorter and when the ratio between the duration of the second and first phases of the stride is smaller, which is also one of the scientific contributions of this dissertation. Published research did not address the effects of stride length on GRF, but indicated that stride length and the ratio between the duration of the second and first phases of the stride are related to pelvic rotation (Gravestock, Tucker, & Hanley, 2019). The study conducted showed a significant influence of the duration of the flight phase on the peak GRF (R2 = 0.64), confirming the results of a previous study (Hanley and Bissas, 2016), which also found a strong regression between the two variables (R2 = 0.47). Due to ground contact rules, pelvic rotation is a very important way to increase stride length (Cairns et al., 1986; Murray et al., 1983). This dissertation formally demonstrated that peak GRF is significantly dependent on the sum of the angles of pelvic rotation and thoracolumbar lateral flexion. Previous research (Gravestock et al., 2019) indicated a large thoracolumbar extension with 11 degrees of anterior pelvic tilt and posterior thoracic tilt. This dissertation found similar angles with an average pelvic tilt of 7.4 degrees and an average thoracic tilt of 10.2 degrees, while the sum of these two angles (thoracolumbar extension) is a strong predictor of peak GRF, which is also the scientific contribution of this dissertation.
The seventh chapter contains conclusions on the acceptance or rejection of the hypotheses put forward. The first hypothesis on the statistically significant relationship between
the GRF in the second phase of the stride and the peak GRF in the first phase is fully accepted, since the indicator of the average GRF in the interval of 70 % - 80 % of the duration of ground contact in multiple correlation with the thoracolumbar extension explains 66 % of the variance of the dependent variable, while there is also a significant influence of the slope of the GRF curve in the same interval. The second hypothesis about the statistically significant relationship between the observed kinematic variables and the ground reaction force in the first phase of the racewalking stride was partially accepted, as the influence of the indicators of stride length, duration of the flight phase, ratio of the two stride phases, thoracolumbar lateral flexion and extension, as well as pelvic rotation on the peak GRF in the first stride was demonstrated. This hypothesis is only partially accepted due to no significant statistical relationships found between the peak GRF in the first phase of the stride and the arm swing, thoracic rotation, flexion and extension of the hips and knees as well as the angles of the feet to the ground.
The eighth chapter contains a description of the scientific contribution and the possible practical use of the research. The scientific contribution of the research carried out is demonstrated by the identification of indicators of racewalking technique that significantly influence the peak GRF in the first phase of the racewalking stride. The research conducted also has a pragmatic benefit for racewalking training as it defines technical elements for smooth and low impact racewalking while providing tools for risk assessment of the occurrence of the overuse injuries. However, given the size and structure of the sample and the limitations of the analytical methods used, the research findings should be viewed with caution and the author therefore urges further analysis on these research topics.
In conclusion, the research conducted has formally demonstrated that the reduction in peak ground reaction force in racewalking can be achieved by increasing the force towards the ground in the second phase of the stride, reducing the duration of the flight phase, reducing thoracolumbar extension while increasing thoracolumbar lateral flexion and pelvic rotation, and reducing racewalking speed in accordance with the athletes' fitness level and their technical ability to sustain the movement described by the aforementioned variables
ISOMETRICAL MUSCLE CONTRACTIONS AS A METHOD OF STRENGTH DEVELOPMENT AND PREVENTION OF LOWER MUSCLE INJURIES
No full textIzometrijske mišićne kontrakcije predstavljaju važnu komponentu u razvoju mišićne jakosti i snage i efikasnu strategiju za prevenciju ozljeda. Ovaj diplomski rad temelji se na detaljnoj analizi anatomije potkoljenice, uključujući pregled kostiju, mišića, i njihovih funkcija te istražuje ulogu izometrijskih vježbi u kondicijskoj pripremi. U radu su proučeni pristupi izometrijskom treningu, njegovoj primjenjivosti u sportskoj praksi te važnosti za prevenciju ozljeda. Poseban naglasak stavljen je na pregled postojećih istraživanja koja potvrđuju pozitivne učinke izometrijskog treninga na povećanje jakosti, snage i elastičnosti tetiva te otpornosti mišićno-tetivnog sustava na ozljede. Osim toga, rad obuhvaća i praktične smjernice za implementaciju izometrijskih vježbi u trenažne procese s ciljem maksimiziranja njihove efektivnosti i sigurnosti za sportaše i osobe uključene u redovite fitness programe. Kroz multidisciplinarni pristup, diplomski rad ističe značaj izometrijskih kontrakcija u modernom treningu jakosti i snage, naglašavajući potrebu za daljnjim istraživanjima i razvojem specijaliziranih programa treninga koji bi koristili ovu metodu za unapređenje fizičkih performansi i prevenciju ozljeda. Nadalje, ovim radom istraživani su i složeni biomehanički procesi koji su uključeni u izometrijske kontrakcije i način na koji doprinose strukturalnom i funkcionalnom integritetu mišićno-koštanog sustava. Konačno, ovim radom pokušalo se i odgovoriti na pitanje kako pravilna primjena izometrijskih vježbi može pomoći u prevenciji nastanka ozljeda potkoljenice, ističući pritom važnost individualiziranog pristupa i prilagodbe treninga specifičnim potrebama i ograničenjima sportaša. Kroz kombinaciju teorijskog uvida i praktičnih primjera ovo istraživanje pruža uvid u razumijevanje prednosti izometrijskog treninga, pružajući temelj za razvoj efektivnijih i sigurnijih programa treninga.Isometric muscle contractions represent an important component in the development of muscle strength and power and an effective strategy for injury prevention. This thesis is based on a detailed analysis of the anatomy of the lower leg, including an overview of the bones, muscles, and their functions, and explores the role of isometric exercises in conditioning. The paper examines approaches to isometric training, its applicability in sports practice, and its importance for injury prevention. Special emphasis is placed on the review of existing research that confirms the positive effects of isometric training on increasing the strength, power and elasticity of tendons and the resistance of the muscle-tendon system to injuries. In addition, the work includes practical guidelines for the implementation of isometric exercises in training processes with the aim of maximizing their effectiveness and safety for athletes and people involved in regular fitness programs. Through a multidisciplinary approach, the thesis highlights the importance of isometric contractions in modern strength and power training, emphasizing the need for further research and development of specialized training programs that would use this method to improve physical performance and prevent injuries. Furthermore, this work investigated the complex biomechanical processes involved in isometric contractions and how they contribute to the structural and functional integrity of the musculoskeletal system. Finally, this paper tried to answer the question of how the correct application of isometric exercises can help in the prevention of lower leg injuries, emphasizing the importance of an individualized approach and adaptation of training to the specific needs and limitations of athletes. Through a combination of theoretical insight and practical examples, this research provides insight into understanding the benefits of isometric training, providing a foundation for developing more effective and safer training programs
THE INFLUENCE OF TRAINING IN THE PREPARATORY PERIOD ON THE SITUATIONAL MOTOR SKILLS OF FOOTBALL PLAYERS IN THE U-16 CATEGORY
No full textJedni od glavnih elemenata uspješne izvedbe u nogometnoj utakmici su motoričke sposobnosti te situacijska uspješnost sportaša u fazi napada i obrane. Primarni cilj diplomskog rada je utvrditi utjecaj pripremnog perioda na situacijsko-motoričke sposobnosti nogometaša kategorije U-16. U ovom istraživanju sudjelovalo je 12 ispitanika muške populacije u 5 testova: vijugavo trčanje (slalom), brzina vođenja s promjenom pravca pod pravim kutem, brzina vođenja (slalom), udarci u stijenu poslije odbijene lopte od podloge i pravolinijska preciznost nogom-vertikalni cilj. Testiranje je provedeno u dobnoj skupini U-16 (uzrast kadeti) s igračima kluba NK „Sloga“ Gredelj. Provedena su 2 testiranja, prvo početkom pripremnog perioda (inicijalno) te drugo na kraju pripremnog perioda (finalno). Prikupljeni podaci nakon testiranja analizirali su se u računalnom programu „Statistica“ t-testom za zavisne uzorke. Za opis dobivenih rezultata provedeni su određeni deskriptivni pokazatelji kao što su: aritmetička sredina (AS), totalni raspon (MAX i MIN), standardna devijacija (SD) te pokazatelji zakrivljenosti distribucije (skewness i kurtosis). Na temelju provedenog istraživanja može se zaključiti kako su nogometaši kadetskog uzrasta U-16, nakon provedenog pripremnog perioda, u većini odabranih testova, ostvarili slične rezultate situacijsko-motoričkih pokazatelja iz čega se može zaključiti kako je mladom sportašu potreban dugoročno sustavno isplanirani trenažni proces po točno određenom planu i programu.One of the main elements of a successful performance in a football match is the motor skills and situational performance of the athlete in the attack and defense phase. The primary goal of the thesis is to determine the influence of the preparatory period on the situational motor skills of football players in the U-16 category. In this research, 12 male respondents participated in 5 tests: winding running (slalom), speed of leading with a change of direction at a right angle, speed of leading (slalom), hitting the rock after the ball bounced off the surface and straight-line accuracy with the foot - vertical target. Testing was conducted in the U-16 age group (cadet age) with players from the Nk “Sloga” Gredelj club. 2 tests were conducted, first at the beginning of the preparatory period (initial) and second at the end of the preparatory period (final). Collected data after the test were analyzed in the “Statistica” computer program with a t-test for dependent samples. Certain descriptive indicators were also used to describe the obtained results, such as: arithmetic mean (AS), total range (MAX and MIN), standard deviation (SD) and indicators of the curvature of the distribution (skewness and kurtosis). Based on the conducted research, it can be concluded that, after the preparation period, U-16 soccer players achieved similar results of situational motor indicators in the majority of selected tests, from which it can be concluded that a young athlete needs a long-term systematic training process under a precisely defined plan and program
RECOVERY METHOD IN FOOTBALL
No full textOporavak nakon intenzivne tjelesne aktivnosti, poput nogometa, ključan je za održavanje aktivnosti i smanjenje rizika od ozljeda. Metode oporavka u nogometu obuhvaćaju niz strategija i tehnika koje se koriste kako bi se ublažili umor mišića, obnovili resursi tijela te kako bi se povećala otpornost na daljnje opterećenje. Cilj ovog rada je pobliže objasniti koje su najučinkovitije metode oporavka u nogometu, uključujući hidrataciju, prehranu, san – odnosno upravljanje odmorom te disanje. Ovaj rad prikazat će koji su sve ciljevi poboljšanja strategije oporavka u nogometu te doprinijeti boljem razumijevanju važnosti oporavka u sportu općenito.Recovery after intense physical activity such as football is key to maintaining activity and reducing the risk of injury. Soccer recovery methods include various strategies and techniques designed to relieve muscle fatigue, restore the body's resources, and increase resistance to further stress. This article aims to explain the most effective recovery methods in football, including hydration, nutrition, and sleep - i.e. rest management and breathing. This article highlights the goals of improving recovery strategy in football and contributes to a better understanding of the importance of recovery in sports in general
KINESIOTHERAPEUTIC APPROACH TO EXERCISING DURING PREGNANCY AND THE POSTPARTUM PERIOD
No full textDiplomski rad pod nazivom "Kineziterapijski pristup u provođenju vježbi u trudnoći i postpartalnom razdoblju" istražuje važnost tjelesne aktivnosti tijekom trudnoće i nakon poroda. Rad se temelji na sve većoj potražnji za kineziološkim pristupom u ginekologiji, gdje vježbe imaju ključnu ulogu u očuvanju zdravlja trudnica, pripremi za porod i oporavku nakon njega.
U radu su analizirane anatomske i fiziološke promjene u trudnoći te prednosti vježbanja u tom periodu, koje uključuju smanjenje rizika od komplikacija poput gestacijskog dijabetesa i preeklampsije. Također se naglašava važnost prilagođenih vježbi tijekom postpartalnog razdoblja, uključujući jačanje mišića zdjeličnog dna i trbuha, kako bi se smanjio rizik od inkontinencije i olakšao oporavak.The thesis titled "Kinesiotherapeutic Approach to Exercising During Pregnancy and the Postpartum Period" examines the significance of physical activity during pregnancy and after childbirth. The paper emphasizes the growing demand for a kinesiological approach in gynecology, where exercises play a crucial role in maintaining the health of pregnant women, preparing for childbirth, and facilitating postpartum recovery.
The study analyzes the anatomical and physiological changes during pregnancy and highlights the benefits of exercising, such as reducing the risk of complications like gestational diabetes and preeclampsia. It also underscores the importance of tailored postpartum exercises, including pelvic floor and abdominal strengthening, to reduce the risk of incontinence and aid recovery