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STRETCH-SHORTENING CYCLE AS A BASIS OF PLYOMETRIC TRAINING
No full textPliometrijski trening oblik je treninga u kojem dominiraju skakački ili bacački pokreti, odnosno balistički pokreti koji u svojoj izvedbi sadrže tzv. ekscentrično-koncentrični mišićni režim rada. Ciklus istezanja i skraćivanja, kao jedinstvena kontrakcija mišića, u stranoj i znanstvenoj literaturi označava naziv „stretch-shortening cycle“ – SSC. Pliometrijske aktivnosti uslijed ekscentrične kontrakcije pohranjuju elastičnu potencijalnu energiju u mišićno-tetivnom sustavu te se oslobađanjem te energije tijekom koncentrične kontrakcije maksimizira mišićna sila. Skeletni mišić čovjeka ne sadrži isključivo mišić nego i elemente tetiva. Mišićno- tetivna mehanika, u kojoj tetive svojim specifičnim svojstvima uvelike doprinose ovom kompleksnom fenomenu, utječe na maksimalno generiranje sile, rada i snage. Ako se želi proizvesti što veća sila u što kraćoj jedinici vremena onda je iznimno važno da pasivne strukture sadrže dostatnu krutost. Njeno svojstvo elastičnosti, odnosno krutosti, uvelike će ovisiti o vrsti primijenjenog treninga. U svrhu što boljeg opisa i shvaćanja SSC-a, funkcija skeletnih mišića je objašnjena u sinergiji s radom ostalih sustava lokomocije. Cilj ovog rada bio je detaljno opisati i objasniti – s anatomskog, fiziološkog i biomehaničkog stajališta – ciklus istezanja i skraćivanja mišića i njegov značaj za izvedbu balističkih vježbi koje se tipično provode u kontekstu pliometrijskog treninga.Plyometric training is a form of training that involves jumping or throwing movements, i.e. ballistic movements that contain the so-called eccentric-concentric muscle regime of work. The cycle of stretching and shortening, as a unique muscle contraction, is reffered to in foreign and scientific literature as the „stretch-shortening cycle“ – SSC. Plyometric activities due to eccentric contraction store elastic potential energy in the muscle-tendon system and by releasing this energy during concentric contraction muscle force is maximized. Human skeletal muscle does not only contain muscle, but also elements of tendons. Muscle-tendon mechanics, in which the tendons with their specific properties greatly contribute to this complex phenomenon, affect the maximum generation of force, work and power. If one wants to produce as much force as possible in the shortest unit of time, then passive structures must contain sufficient stiffness. Its property of elasticity and stifness will largely depend on the type of training applied. To better describe and understand SSC, the function of skeletal muscles is explained in synergy with the work of other locomotion systems. This paper aimed to describe and explain in detail – from an anatomical, physiological and biomechanical point of view – the muscle stretch-shortening cycle and its significance for the performance of ballistic exercises that are typically performed in the context of plyometric training
INJURY PREVENTION PROGRAMS IN BASKETBALL: A SYSTEMATIC REVIEW
No full textKošarka je dinamičan sport koji zahtijeva brzinu i eksplozivnost, ali isto tako nosi značajan rizik od ozljeđivanja, posebice donjih ekstremiteti koje obuhvaćaju ozljede gležnja i koljena. Stoga, očuvanje zdravlja sportaša mora biti prioritet u svakom trenažnom programu, koji treba pažljivo uzeti u obzir potencijalne rizike. Cilj ovog preglednog rada bio je sustavnim pregledom literature utvrditi koji su prevencijski programi efikasni u suzbijanju prevalentnih ozljeda u košarci. U pregledu dostupne znanstvene literature, korištene su baze podataka: Pubmed, Scopus, Web of Science i Cochrane database. Od ukupno 313 prikupljenih radova, 84 istraživanja bile su randomizirane kontrolne studije od kojih je 8 bilo duplikat. Zatim je uslijedio pregled naslova i sažetaka nakon čega je još 65 radova eliminirano jer nisu zadovoljavali postavljene kriterije. U zadnjem koraku selekcije u cijelosti je pregledano 15 radova, a 7 + 1 članak su zadovoljili kriterij selekcije. Uzrak ispitanika činili su košarkaši dobnih skupina od kadeta do seniora. Rezultati preglednog rada upućuju na to da je proprioceptivni trening efikasan u sprječavanju svih oblika uganuća gležnja u populaciji seniora, juniora i kadeta kod muškaraca i žena. Neuromuskularni trening potencijalno može smanjiti incidenciju generalnih ozljeda donjih ekstremiteta kod muških košarkaša seniora.Basketball is a dynamic sport that requires speed and explosiveness but also carries a significant risk of injury, especially to the lower extremities, including ankle and knee injuries. Therefore, preserving the health of athletes must be a priority in every training program, which should carefully consider potential risks. The aim of this review was to systematically review the literature to determine which preventive programs are effective in reducing prevalent injuries in basketball. The review utilized the following scientific databases: PubMed, Scopus, Web of Science, and the Cochrane database. Out of a total of 313 collected studies, 84 were randomized controlled trials, of which 8 were duplicates. Subsequently, a review of titles and abstracts followed, eliminating 65 studies that did not meet the specified criteria. In the final step of selection, 15 studies were fully reviewed, and 7 + 1 articles met the selection criteria. The study participants consisted of basketball players of various age groups, ranging from cadets to seniors. The results of the review suggest that proprioceptive training is effective in preventing all forms of ankle sprains in senior, junior, and cadet populations among both men and women. Neuromuscular training potentially can reduce the incidence of general lower extremity injuries in male senior basketball players
Prevention of ACL injuries in handball player
No full textRukomet je timski sport koji zahtjeva velike fizičke napore od igrača u kojima dolazi do različitih ozljeda velikog broja. Rukomet kao sport karakteriziraju različiti oblici kretnji, kao što su: kontrolirani i nekontrolirani skokovi, iznenadne promjene smjera, trčanje te bacanja. Ozljede su česte, no ipak ozljede koljena (ruptura ACL-a) predstavlja područje najčešćeg ozljeđivanja. Svrha i cilj ovog diplomskog rada je pregled relevantne dostupne literature o prevenciji ozljeda ACL-a i implementaciji u rukometu. Prikazana je anatomija i biomehanika zgloba koljena, njihove karakteristike te višekomponentni program preventivnog treninga. Integracija navedenih komponenti i neuromuskularnog treninga pokazuju se najučinkovitijom metodom. Neophodna je važnost uzimanja u obzir specifičnih karakteristika sportaša u dizajniranju trenažnog procesa. Preventivni trening bi trebao biti implementiran kao dio sportaševog predsezonskog i sezonskog treninga. Provedba programa se preporučuje od najranije dobi i osobito je korisna ukoliko želimo optimizirati čimbenike motoričkog učenja i zadržati poboljšanu neuromuskularnu kontrolu s naglaskom na smanjenje rizika od ozljeda.Handball is a team sport that requires great physical demands from the players, in which a large number of different injuries occur. Handball as a sport is characterized by different forms of movements, such as: controlled and uncontrolled jumps, running, throwing and sudden changes of direction. Injuries are common, but knee injuries (ACL rupture) are the area of most frequent injuries. The purpose and goal of this thesis is to review relevant available literature on ACL injury prevention and implementation in handball. Numerous risk factors and the specific mechanism of injury are described. The anatomy and biomechanics of the knee joint are presented together with the functional characteristics of certain structures in the knee. A multi-component preventive training program is presented that includes (feedback on technique and quality of movement in combination with exercises from the following categories: strength, flexibility, mobility, plyometrics, agility and proprioception). The integration of the mentioned components and neuromuscular training prove to be the most effective method. It is crucial to take into account the specific characteristics of athletes in designing the training process. Preventive training should be implemented as part of the athlete's preseason and season training. Implementation of the program is recommended from an early age and is particularly useful if we want to optimize motor learning factors and maintain improved neuromuscular control with the aim of reducing the risk of injury
THE INFLUENCE OF DIFFERENT TYPES OF STRETCHING ON EXPLOSIVE POWER
No full textCILJ
Temeljni cilj ovog istraživanja bio je utvrditi koja je od četiri različite metode istezanja najefikasnija kod pripreme košarkaša za određenu sportsku aktivnost ili izvedbu u kojoj je eksplozivna snaga nogu od primarne važnosti.
METODA
72 košarkaša juniora (dob 16,9 ± 1,19 god.; visina 190,2 ± 10,04 cm; masa 79,1 ± 12,69 kg) iz tri različita košarkaška kluba napravili su četiri različite metode istezanja na način da su se ispitanici u svakoj sljedećoj točci mjerenja istezali na drugačiji način: 1) Statičko istezanje (SS); 2) Dinamičko istezanje (DS); 3) Kombinacija statičkog i dinamičkog istezanja (SS+DS); 4) Kombinacija dinamičkog i statičkog istezanja (DS+SS). Nakon kontinuiranog aerobnog trčanja malog do srednjeg intenziteta u trajanju od 3 min uslijedilo je inicijalno testiranje ispitanika testovima eksplozivne snage tipa vertikalnog skoka: a) Statički vertikalni skok iz čučnja (SJ); b) Dinamički vertikalni skok (CMJ). Testovi za eksplozivnu snagu izmjereni su pomoću prenosive kontaktne ploče Just Jump System (Probotics, Inc., USA). Zatim je uslijedila jedna od četiri metode istezanja u trajanju od 12 min, te pasivni odmor u trajanju od 2 min. Nakon toga ispitanici su bili podvrgnuti finalnom testiranju na identičan način i sa istim testovima kao u inicijalnom testiranju prije tretmana istezanja.
REZULTATI
Rezultati ANOVE ukazali su na statistički značajan efekt vrste istezanja na promjenu visine skoka prilikom testiranja SJ testom (ANOVA za ponovljena mjerenja; p < 0,001) i CMJ testom (ANOVA za ponovljena mjerenja; p = 0,001). DS ostvaren je značajno bolji efekt u odnosu na sve ostale vrste istezanja, a najviše u odnosu na SS (ANOVA za ponovljena mjerenja; p < 0,001). Rezultati istraživanja su pokazali da je nakon DS promjena u prosjeku bila veća u testovima vertikalnog skoka (SJ = 2,79 cm; CMJ = 1,49 cm) uspoređujući sa SS. Upravo suprotno, SS pokazalo je statistički značajno lošije rezultate u prosječnoj promjeni visine skoka kod oba testa (SJ = -1,83 cm, p < 0,001; CMJ = -1,28 cm, p < 0,001) i u odnosu na obje kombinacije istezanja (SS+DS, DS+SS). Nakon primjene kombiniranih metoda istezanja (SS+DS, DS+SS) također je primjećen pad u visini vertikalnog skoka. Između SS+DS i DS+SS nije opažena statistički značajna razlika, a jedino značajno prosječno smanjenje bilo je vidljivo upotrebom DS+SS u CMJ testu (-0,89 cm, p = 0,008).
ZAKLJUČAK
Rezultati ovog istraživanja pokazali su da se korištenjem DS prije testova eksplozivne snage postižu bolji rezultati u odnosu na SS, kombinaciju DS+SS te kombinaciju SS+DS. Možemo konstatirati da će primjena DS kao komponente zagrijavanja poboljšati izvedbu u eksplozivnim aktivnostima vertikalnog skoka (SJ i CMJ), za razliku od uporabe i negativnih efekata SS i kombiniranih načina istezanja (SS+DS, DS+SS) na eksplozivnu snagu.OBJECTIVE
The basic aim of this research was to determine which of the four different stretching methods is most effective in preparing a basketball player for a particular sporting activity or performance in which explosive leg strength is of primary importance.
METHOD
72 junior basketball players (age 16,9 ± 1,19 years; height 190,2 ± 10,04 cm; weight 79,1 ± 12,69 kg) from three different basketball clubs conducted four different stretching methods in such a way that the subjects stretched differently at each of the following measuring points: 1) Static stretching (SS); 2) Dynamic Stretching (DS); 3) Combination of static and dynamic stretching (SS+DS); 4) Combination of dynamic and static stretching (DS+SS). Continuous low to medium intensity aerobic running for 3 min was followed by initial testing of subjects with vertical jump type explosive power tests: a) Squat jump (SJ); b) Countermovement jump (CMJ). Tests for explosive power were measured using the portable Just Jump System contact mat (Probotics, Inc., USA). This was followed by one of four stretching methods for 12 min duration and a 2 min passive rest. Subsequently, subjects were exposed to final testing in the same manner and with the same tests as in the initial testing prior to stretching treatment.
RESULTS
ANOVA results indicated a statistically significant effect of type of stretching on the change in jump height when tested with the SJ test (ANOVA for repeated measurements; p < 0,001) and the CMJ test (ANOVA for repeated measurements; p = 0,001). DS had a significantly better effect compared to all other types of stretching, and most to SS (ANOVA for repeated measurements; p < 0.001). The results of the study showed that after DS the changes were on average greater in the vertical jump tests (SJ = 2,79 cm; CMJ = 1,49 cm) compared with the SS. On the contrary, SS showed statistically significantly poorer results in the average change in jump height in both tests (SJ = -1,83 cm, p < 0,001; CMJ = -1,28 cm, p < 0,001) and in relation to both stretching combinations (SS+DS, DS+SS). After the application of combined stretching methods (SS+DS, DS+SS), a decrease in the height of the vertical jump was also observed. No statistically significant difference was observed between
SS + DS and DS + SS, and the only significant mean decrease was seen using DS+SS in the CMJ test (−0,89 cm, p = 0,008).
CONCLUSION
The results of this study showed that using DS prior to explosive power tests achieves better results than SS, DS+SS and SS+DS. We can conclude that the use of DS as a warming component will improve performance in explosive vertical jump activities (SJ and CMJ), as opposed to the use and negative effects of SS and combined stretching protocols (SS+DS,
DS+SS) on explosive power
HOW TO AVOID THE EARLY END OF THE SPORTS CAREER OF YOUNG SAILING MEN?
No full textCilj ovoga rada bio je utvrditi najčešće razloge zbog kojih mladi jedriličari odustaju od jedrenja. Uzorak je činilo 73 bivša jedriličara i 28 bivših jedriličarki. Za utvrđivanje najčešćih razloga odustajanja od jedrenja korišten je upitnik kreiran u svrhu istraživanja. Rezultati pokazuju da su ispitanici odustali od jedrenja najčešće u dobi od 19. do 22. godine te od 16. do 18. godine. Nedostatak vremena zbog školskih ili akademskih obaveza primarni je razlog prestanka treniranja jedrenja koji navodi 27,7 % ispitanika. Nedovoljna financijska sredstva glavni su razlog odustajanja od jedrenja kod 18,8 % ispitanika dok je nekompetentnost trenerskog kadra utjecala na odustajanje od jedrenja kod 10,9 % ispitanika. Ozljeda ili bolest, nezainteresiranost, promjena klase u jedrenju i utjecaj drugih sportova su preostali najčešći razlozi zbog kojih su ispitanici odustali od jedrenja. Aktivno treniranje jedrenja u kombinaciji sa školovanjem oduzima ogromnu količinu vremena sportašu i otežava sudjelovanje u bilo kojim drugim aktivnostima. Kako bi sportaši imali mogućnost za socijaliziranje izvan sportskih i obrazovnih obaveza potrebno ih je naučiti na koji način kvalitetno upravljati vremenom. Uz to, i obrazovne institucije bi sportašima trebale pružiti fleksibilniji raspored pohađanja škole ili fakulteta. Sportaše je potrebno podržati i financijski na način da klubovi ili sponzori financiraju odlaske na natjecanje te nabavu i održavanje opreme. Jedriličare je potrebno uključiti u procese donošenja odluka i postavljanja ciljeva te ih uskladiti s željama i potrebama sportaša. Podržavanjem mladih jedriličara sa više strana omogućuje im se daljnje sudjelovanje u sportu te ostvarivanje ne samo sportskih već i drugih ciljeva. U budućnosti, potrebno je mladim jedriličarima omogućiti ostvarivanje sportske karijere uz redovno školovanje umjesto česte prakse u kojoj jedriličari moraju odabrati jedno, a od drugoga potpuno odustati.The aim of this paper was to determine the most common reasons why young sailors give up sailing. The sample consists of 73 former sailors and 28 former sailors. A questionnaire created for the purpose of research was used to determine the most common reasons for giving up sailing. The results show that the respondents gave up sailing most often between the ages of 19 and 22 and between 16 and 18. The results show that the most common reasons why respondents gave up sailing training were the lack of time due to school or academic obligations, cited by 27.7% of respondents. Insufficient financial resources are the main reason for giving up sailing in the case of 18.8% of respondents, while the incompetence of the coaching staff influenced the giving up of sailing in 10.9% of respondents. Injury or illness, lack of interest, a change in sailing class and the influence of other sports are the remaining most common reasons why respondents gave up sailing. Active sailing training combined with schooling takes a huge amount of time for the athlete and makes it difficult to participate in any other activities. In order for athletes to have the opportunity to socialize outside of sports and educational obligations, it is necessary to teach them how to manage their time well. In addition, educational institutions should provide athletes with a more flexible schedule of attending school or college. Athletes need to be supported financially, in such a way that clubs or sponsors finance trips to the competition and purchase and maintenance of equipment. Sailors need to be included in the decision-making and goal-setting processes and aligned with the wishes and needs of the athletes. By supporting young sailors from several sides, it is possible for them to further participate in sports and achieve not only sporting but also other goals. In the future, it is necessary to enable young sailors to pursue a sports career with regular education instead of the frequent practice in which sailors have to choose one and give up the other completely
Satisfaction of elementary school students with different teaching methods in physical education classes
No full textCilj ovog rada bio je utvrditi zadovoljstvo i motiviranost učenika različitim načinima provedbe nastave Tjelesne i zdravstvene kulture (TZK-e) kod osnovnoškolaca. Provedena su dva različita tipa nastave: individualni i grupni način vježbanja. Učenici petih i šestih razreda provodili su sadržaje iz odbojke, dok su učenici sedmih i osmih razreda proveli programske sadržaje usmjerene ka razvoju jakosti i snage putem kružne postave vježbanja. Oba programska sadržaja su provedena kroz individualni i grupni pristup. Učenici su slučajnim odabirom raspoređeni u grupe, te su razlike između grupa utvrđene Studentovim t-testom za nezavisne uzorke. Generalno, nisu utvrđene statistički značajne razlike između dva načina provedbe nastave TZK-e, no važno je istaknuti veće zadovoljstvo učenika provedbom grupnog načina vježbanja. Utvrđene su razlike u zadovoljstvu i motiviranošću prema spolu tijekom provedbe različitih načina nastave TZK-e. Učenice su izrazile veće zadovljstvo i motiviranost individualnim pristupom naspram učenika. Može se zaključiti kako izbor nastavnoga sadržaja koji se provodi u skupinama ima utjecaj na povećanje motivacije i zadovoljstva učenika.The aim of this master’s thesis was to determine student satisfaction and motivation with different teaching of Physical and health education (PHE) for elementary school students. Two different types of classes were conducted: individual and group mode of exercise. Fifth and sixth grade students conducted volleyball content, while seventh and eighth grade students conducted program content aimed at developing strength and power through a circular exercise method. Both program contents were implemented through an individual and group approach. Students were randomly assigned to groups, and differences between groups were determined by Student's t-test for independent samples. In general, no statistically significant differences were found between the two methods of teaching PHE, but it is important to highlight the greater satisfaction of students with the implementation of the group method of exercise. Differences in satisfaction and motivation according to gender were determined during the implementation of different methods of teaching PHE. Female students expressed greater satisfaction and motivation with an individual approach to students. It can be concluded that the choice of teaching content that is carried out in groups has an impact on increasing the motivation and satisfaction of students
The importance of Kegel exercises for preventing postpartum incontinence
No full textPostporođajna inkontinencija je stanje u kojem žene iskuse nekontrolirani gubitak mokraće nakon što su rodile. Predstavlja relativno čestu pojavu uzrokovanu oslabljenim mišićima dna zdjelice i mokraćnog mjehura tijekom trudnoće i porođaja.
Kegelove vježbe su ključan i učinkovit način prevencije postporođajne inkontinencije kod žena. Nakon porođaja, mnoge žene suočavaju se s problemom inkontinencije, što može značajno utjecati na njihovu kvalitetu života. Kegelove vježbe se sastoje od ciljanog jačanja mišića zdjelice, posebno mišića koji podržavaju mokraćni mjehur i rektum. Ove vježbe pomažu u poboljšanju tonusa mišića zdjelice, čime se smanjuje rizik od nekontroliranog mokrenja i inkontinencije.
Tijekom trudnoće i porođaja, mišići zdjelice podvrgavaju se stresu i opterećenju, što može oslabiti njihovu funkciju. Međutim, redovito izvođenje Kegelovih vježbi, prije i nakon porođaja, pomaže u jačanju tih mišića i vraćanju njihove funkcije. Preporučuje se da žene započnu s Kegelovim vježbama tijekom trudnoće te ih nastave redovito izvoditi i nakon porođaja.
Jedna od ključnih prednosti Kegelovih vježbi je njihova jednostavnost i diskretnost jer se mogu obavljati gotovo bilo gdje i bilo kada. Važno je da se pravilno izvode kako bi bile učinkovite. Žene koje redovito prakticiraju Kegelove vježbe mogu ojačati mišiće zdjelice, poboljšati kontrolu mokrenja i smanjiti rizik od postporođajne inkontinencije.
U većini slučajeva, postporođajna inkontinencija je privremena i može se poboljšati s vremenom i redovitim vježbanjem Kegelovih vježbi. Uz redovitu praksu, one mogu biti izuzetno korisne u održavanju zdravlja zdjeličnih mišića te prevenciji postporođajne inkontinencije.Postpartum incontinence is a condition in which women experience involuntary loss of urine after giving birth. It is a relatively common occurrence caused by weakened pelvic floor muscles and bladder during pregnancy and childbirth.
Kegel exercises are a key and effective way to prevent postpartum incontinence in women. After childbirth, many women face the issue of incontinence, which can significantly impact their quality of life. Kegel exercises involve targeted strengthening of the pelvic muscles, especially those that support the bladder and rectum. These exercises help improve the tone of the pelvic muscles, thereby reducing the risk of uncontrolled urination and incontinence.
During pregnancy and childbirth, the pelvic muscles undergo stress and strain, which can weaken their function. However, regular practice of Kegel exercises before and after childbirth helps strengthen these muscles and restore their function. It is recommended that women start doing Kegel exercises during pregnancy and continue them regularly after childbirth.
One of the key advantages of Kegel exercises is their simplicity and discreteness, as they can be performed almost anywhere and anytime. It is important to perform them correctly to make them effective. Women who regularly practice Kegel exercises can strengthen their pelvic muscles, improve urinary control, and reduce the risk of postpartum incontinence.
In most cases, postpartum incontinence is temporary and can improve over time with regular practice of Kegel exercises. With consistent practice, they can be extremely beneficial in maintaining pelvic muscle health and preventing postpartum incontinence
THE INFLUENCE OF SKI HELMET AND GOGGLES ON VISUAL FIELD AND REACTION TIME
No full textProblem ovog doktorskog rada leži u činjenici da je naglasak kod testiranja zaštitne uloge skijaške kacige uglavnom bio na smanjenju sila koje djeluju na glavu s ciljem smanjenja rizika od ozljeđivanja. No, pritom se ne uzimaju u obzir potencijalna ograničenja vida koja mogu značajno utjecati na smanjenu reakciju na podražaj u situacijskim uvjetima alpskog skijanja. Iako se broj korisnika skijaških kaciga povećava iz godine u godinu, nije poznato kako se proporcionalno tome smanjuje broj ozljeda glave. Jedan od razloga može biti i činjenica da skijaške kacige u kombinaciji sa skijaškim naočalama utječu na smanjenje širine vidnog polja te smanjenu brzinu reakcije skijaša na vizualne podražaje iz okoline.
Kako bi se istražio navedeni problem, proveli su se integrirani laboratorijski i terenski protokoli mjerenja na istoj skupini ispitanika. U istraživanju su sudjelovali studenti Kineziološkog fakulteta u sklopu nastave redovnog predmeta „Skijanje“ i usmjerenja „Skijanje“ (n=45) koji su završili minimalno osnovnu školu alpskog skijanja. Također, istraživanjem su obuhvaćeni ispitanici koji imaju stečenu naviku nošenja skijaške kacige (n=22) i oni koji nemaju razvijenu naviku (n=23) kako bi se utvrdile potencijalne razlike između njih u rezulatima mjerenja. Testirano je 5 kombinacija nošenja zaštitne opreme za glavu (kontrolno stanje – skijaška kapa, skijaška kapa i sunčane naočale, skijaška kapa i skijaške naočale, skijaška kaciga i sunčane naočale, skijaška kaciga i skijaške naočale). Za potrebe laboratorijskog istraživanja koristio se ortoreter uređaj za mjerenje vidnog polja temeljem provedenog testa „Perimetrija 28 točaka“ te WITTY sustav fotoćelija za mjerenje brzine reakcije izravno na terenu, tj. na skijaškoj stazi.
Na temelju dobivenih rezultata laboratorijskog mjerenja veličine vidnog polja može se zaključiti da navika nošenja kacige ne utječe na smanjenje vidnog polja skijaša, no postoje značajne razlike između pojedinih uvjeta nošenja zaštitne opreme za glavu u smetnji koje predstavljaju za periferni vid skijaša rekreativne razine. Rezultati terenskog dijela istraživanja na skijaškoj stazi usmjerenog na utvrđivanje vremena potrebnog za reakciju na vizualni podražaj pokazuju da postoje statistički značajne razlike između grupe ispitanika koji imaju naviku nošenja kacige i grupe ispitanika koji nemaju stečenu naviku nošenja skijaške kacige. Također, dobivena je statistički značajna razlika između testiranih uvjeta nošenja zaštitne
opreme za glavu. Kada se promatraju rezultati kombiniranog utjecaja zaštitne opreme za glavu i navike nošenja skijaške kacige, utvrdilo se da postoji statistički značajna interakcija između skupine ispitanika i testiranih uvjeta. Naime, statistički značajna razlika utvrđena je između rezultata nenositelja kacige i nositelja kacige u uvjetima nošenja skijaške kacige i skijaških naočala, u korist boljeg rezultata, tj. brže reakcije kod ispitanika koji uobičajeno koriste skijašku kacigu.
Prikazom svih navedenih rezultata može se zaključiti kako postoji značajan utjecaj pojedinih kombinacija nošenja zaštitne opreme za glavu (kontrolno stanje u odnosu na 4 eksperimentalna uvjeta te između pojedinih eksperimentalnih uvjeta) na utvrđenu veličinu vidnog polja, tj. uočavanje podražaja u perifernom vidnom polju te na vrijeme reakcije na vizualni podražaj. Ovisno o pojedinoj kombinaciji nošenja zaštitne opreme, utjecaj je manje ili više izražen u smislu negativnog trenda kretanja rezultata u odnosu na kontrolno stanje. Također, skijaške naočale pokazale su se većim limitirajućim čimbenikom u odnosu na samu skijašku kacigu, u oba dijela istraživanja vizualne percepcije – lokalizaciji podražaja u vidnom polju i vremenu potrebnom za reakciju na periferne vizualne podražaje.
Dobiveni rezultati donose nove znanstvene i praktične spoznaje koje se odnose na potencijalne rizike vezane uz vid i vrijeme reakcije pri nošenju zaštitne opreme u alpskom skijanju unatoč njenim neprijepornim brojnim korisnicima. Iako se nošenje kacige općenito preporučuje iz sigurnosnih razloga, skijaši također trebaju biti svjesni mogućeg utjecaja na vrijeme reakcije i vidno polje te moraju prilagoditi svoju tehniku i opremu u skladu s tim kako bi se osigurala optimizacija vidljivosti i sigurnosti na padinama.The problem of this doctoral thesis lies in the fact that the emphasis in testing the protective role of the ski helmet was mainly on reducing the impact of the forces on the head with the aim of minimizing the risk of injury. However, this does not take into account potential vision limitations that can significantly affect the reduced response to visual stimuli in the situational conditions of alpine skiing. Despite the fact that the usage of ski helmets increases, it is still elusive if the frequency of head injuries decreased significantly. One of the reasons may be in the fact that ski helmets in combination with ski goggles influence the width of the visual field and potentially decrease the speed of the skier's reaction to external visual stimuli.
In order to investigate this problem, integrated laboratory and field testing protocols were conducted on the same group of participants. The students of the Faculty of Kinesiology (n=45) who completed at least the elementary school of alpine skiing participated in the study as part of the regular course "Skiing" and the specialization "Skiing". Also, the research included respondents who have developed a habit of wearing a ski helmet (n=22) and those who have not developed this habit (n=23) in order to determine potential differences between them in the test results. Five combinations of wearing head protective equipment were tested (control condition – ski cap, ski cap and sunglasses, ski cap and ski goggles, ski helmet and sunglasses, ski helmet and ski goggles). For the purposes of laboratory research, an orthoreter device was used to test the visual field based on the 28-point Perimetry test, and the WITTY photocell system was used to measure reaction speed directly on the field, i.e. on the ski slope.
Based on the obtained results of laboratory testing of the visual field size, it can be concluded that the habit of wearing a helmet does not affect the reduction of the skier's visual field, but there are significant differences between the each condition of wearing head protective equipment in the interference they represent for the peripheral vision of recreational skiers. The results of the on-the-field part of the research on the ski slope aimed at determining the time required to react to a visual stimulus show that there are statistically significant differences between the group of respondents who have the habit of wearing a helmet and the group of respondents who have not acquired the habit of wearing a ski helmet. Furthermore, statistically significant difference was obtained between the tested conditions of wearing protective head
equipment. When observing the results of the combined influence of protective headgear and the habit of wearing a ski helmet, it was found that there is a statistically significant interaction between the group of respondents and the tested conditions. Namely, a statistically significant difference was found between the results of helmet non-users and users in the condition of wearing a ski helmet and ski goggles, in favor of a better result, i.e. faster reactions in respondents who usually wear a ski helmet.
Presented results suggest a significant influence of certain combinations of wearing head protective equipment (control condition vs. 4 experimental conditions and between individual experimental conditions) on the determined size of the visual field, i.e. the perception of stimuli in the peripheral visual field and on the reaction time to visual stimulus. Depending on the particular combination of wearing protective equipment, the influence is more or less pronounced in terms of a negative trend in the results compared to the control condition. Also, ski goggles proved to be a greater limiting factor compared to the ski helmet itself, in both parts of visual perception research - stimulus localization in the visual field and the time required to react to peripheral visual stimuli.
The obtained results bring new scientific and practical knowledge related to potential risks related to vision and reaction time when wearing protective equipment in alpine skiing despite its undisputed numerous users. Although wearing a helmet is generally recommended for safety reasons, skiers should also be aware of the potential impact on reaction time and visual field and have to adjust their technique and equipment accordingly to ensure optimized visibility and safety on the slopes
Differences between some indicators of the situational efficency of women handball teams and final result on the Olympic tournament in Tokyo
No full textCilj ovog diplomskog rada bio je utvrditi razlike u pokazateljima situacijske efikasnosti pobjedničkih i poraženih ekipa u odnosu na konačni ishod utakmice, odnosno pobjedu ili poraz ženskih rukometnih ekipa na Olimpijskom turniru u Tokyu 2020. godine. Pratilo se 12 reprezentacija koje su bile raspoređene u dvije skupine (6 ekipa u skupini A i 6 u skupini B), a koje su kasnije igrale utakmice četvrtfinala, polufinala, utakmicu za treće mjesto te finale. Uzorak je činilo 35 odigranih utakmica (70 suprostavljenih ekipa). Za potrebe istraživanja koristilo se 18 varijabli, od čega ih je 16 bilo za fazu napada i 2 za fazu obrane. Bilježena je frekvencija uspješno i neuspješno izvedenih tehničko-taktičkih elemenata koje su činile varijable u radu, a putem notacijske analize za svaki odigrani susret. Za utvrđivanje razlika između pobjedničkih i poraženih ekipu koristila se regresijska analiza. Utvrđene su značajne statističke razlike promatranih varijabli i to: šut sa sedam metara neuspješno - 7M_NE (p=0,00); neuspješan šut s krila - W_NE (p=0,00); izgubljene lopte - TO (p=0,01); šut s devet metara neuspješno - 9M_NE (p=0,02) te neuspješan šut sa šest metara - 6M_NE (p=0,03).
Pobjedničke ekipe imale su značajno nižu frekvenciju neuspjelih pokušaja u šutiranjima s crte 7M te s krilnih pozicija. Isto tako su činile manje tehničkih grešaka te gubile manje lopti u fazi napada, a napadačke akcije su završavale iz bolje izrađenih prilika za vanjske pucačice s 9 metara i koncentriranijom realizacijom izglednih šansi sa šest metara čemu u prilog govori značajno veći broj promašenih šuteva s 9 i 6 metara kod ekipa koje su gubile utakmice u odnosu na pobjedničke ekipe.
Analize ovog tipa potrebno je provoditi učestalije jer se zahtjevi i dinamika modernog vrhunskog sporta mijenja iz dana u dan.The goal of this study was to establish the difference of indicator of the situationaly effciency of the game result, ie winning and defeated female handball teams in Olympic tournament in Tokyo 2020. 12 national teams were separated in 2 groups ( 6 teams in group A and 6 in group B) and after the first stage they played quarterfinals, semifinals, game for third place and finals.
The sample was consisted of 35 matches (70 opponents). For sample of variables were used 18 variables, 16 of them were elements during attacking phase of the game and 2 were defending.
Frequency of successfuly and unsuccessfully executed elements of handball were noted during the every match of the tournament and they were taken as a varibales. To determine the difference between winning and defeated teams was used regression analysis. Statistically significant differences showed up in following variables: seven meter throw unsuccessfully – 7M_NE (p=0.00); wing shot unsuccessfully – W_NE (p=0.00); turnovers – TO (p=0.01); shot from 9 meter distance unsuccessfully – 6M_NE (p=0.02); shot from 6 meter distance unseccessfully – 6M_NE (p=0.03).
Winning teams had significantly lower frequency of unsuccessfully executed shots from seven meter line and from the wing positions, they were making less turnovers in the attacking phase of the game and they put themselves in better situtation to shot from 9 and 6 meter distance which resulted with less unsuccessfully shots from both distances in the winning teams in regards to defeted teams.
Handball game requires an engagement on year base and it is necessary to pursue this kind of reseach in future due to modern sport requierments are changing daily
Anatomical and kinematic analysis of tennis serve
No full textServis je najkopompleksniji udarac u tenisu koji zahtijeva pravovovremenost mišićne aktivacije i tehnike udarca. Tri su glavne vrste servisa: " flat ", slice " i topspin kick "". K roz 3 glavne faze , koje obuhvaćaju pohranjivanje energije (faza pripreme), oslobađanje energije (faza ubrzanja) i usporavanje (faza završetka analiziran je svaki pojedini stupanj servisa 8 stupanjsk i model , prema Kovacs i Ellenbecker 2011): pozicioniranje, bacanje loptice, ekscentrično punjenje (‘ loading ’), rotacija, ubrzanje, kontakt, deceleracija i završni dio. U fazi pripreme o pisane su značajke 2 glavne tehnike servisa:“ Foot up “ i Foot back “ tehnika početnog udarca . Anatomska i kinematička analiza servisa u tenisu omogućuje dublje razumijevanje biomehanike pokreta i svakog pojedinog stupnja. U radu su istaknute glavne mišićne skupine koje su aktivne u pojedinim fazama servisa. To uključuje mišiće donjih ekstremiteta , trupa i ramenog pojasa koji omogućuju generiranje snage i stabilnost tijekom udarca. Kinematička analiza pomaže u identifikaciji ključnih parametara koji utječu na snagu i preciznost servisa, i omogućuju optimalnu brzinu, rotaciju i amplitude pokreta u pojedinim zglobovima. U konačnici, anatomska i kinematička analiza servisa omogućuje tenisačima da poboljšaju izvedbu svog početnog udarca, povećaju snagu i precizno st udarca te smanje rizik od ozljeda. Cilj ovog rada je dati pregled i kritički osvrt na istraživanja koja obrađuju tehniku servisa u tenisu s naglaskom na anatomsku analizu i mišićnu aktivaciju sastavnica kinematičkog lanca pri izvođenju početnog udarca.Tennis serve is the most complex stroke in tennis, requiring precise timing of muscle activation and hitting technique. The three main types of serves - "flat," "slice," and "topspin kick". The three main phases of the serve, that include the storage of energy (preparation phase), energy release (acceleration phase) and deceleration (follow-through phase) are analysed through the 8-stage model (Kovacs, Ellenbecker 2011). Each individual stage of the serve is described: positioning, ball toss, loading, rotation, acceleration, contact, deceleration, and completion. Within the loading stage, two main serve techniques are described: the "Foot up" and "Foot back" techniques. The anatomical and kinematic analysis of the tennis serve enables a deeper understanding of the stroke biomechanics involved in the motion within each individual stage. Throughout the study, it is important to highlight the main muscle groups that are active during the service motion. This includes muscles of the lower extremities, core, and shoulder complex that enable generation of power and stability during the stroke. The kinematic analysis assists in identifying key parameters such as speed, rotation, and joint angles that influence the power and precision of the serve. Ultimately, the combination of anatomical and kinematic analysis allows tennis players to improve their technical skills, increase power and accuracy in their strokes, and reduce the risk of injuries. The main aim of this Master's Thesis is to provide an overview and critical review of research addressing the tennis serve technique, with a focus on anatomical analysis and muscle activation of components of the kinematic chain in execution of the stroke