Die Variabilität von den kinematischen Parametern des Hochsprungs in einer longitudinalen Forschung

The aim of this research was to determine the basic kinematic parameters of the high jump as well as the impact of changes in kinematic parameters on the height of the jump, and finally to determine the variability of kinematic parameters in longitudinal research. By means of kinematic analysis 25 kinematic parameters were acquired for seven jumps performed in the time span of three years by an elite Croatian female high jumper. By analysis of the kinematic parameters and the height of the jump the parameters which correlated the most with the height of the jump were acquired. Those were: height of the flight of CG (H2), vertical velocity of CG at the end of the take-off (VVETO), height of the hips above the bar (HHIP), take-off angle (ANTO), take-off duration (DTO), angle at the moment of entering the take-off (ANETO), maximal height of CG at the moment of crossing the bar (CGMAX), horizontal velocity of CG in the penultimate stride in the run-up (HV2RU). The values of certain kinematic parameters increased with the increase in the height of the jump, while values of other kinematic parameters decreased with the increase in the height of the jump. Basic kinematic parameters that increased with the height of the jump were height of the flight of CG (H2), vertical velocity of CG at the end of the take-off (VVETO), height of the hips above the bar (HHIP), take-off angle (ANTO), maximal height of CG at the moment of crossing the bar (CGMAX) as well as horizontal velocity of CG in the penultimate stride in the run-up (HV2RU), while the values of kinematic parameters take-off duration (DTO) and angle at the moment of entering the take-off (ANETO) decreased with the increase in the height of the jump. By analyzing the kinematic parameters of all the observed jumps it was determined that all the parameters varied with the increase in the height of the jump. Parameters that had the highest variability with regard to the height of the jump were: length of the penultimate stride in the run-up (SD = 18.90), distance between CG and bar projection at the moment of the take-off leg positioning (SD = 15.24), distance between take-off point and the bar projection (SD = 11.78) and the length of the last stride during the run-up (SD = 11.11). The lowest variability was observed in the parameter take-off duration, which is the duration of contact between the take-off leg and the surface, indicated by the 0.007 value of standard deviation.Uvod Primjena kinematičkih mjernih sustava u atleti-ci nezaobilazna je metoda dijagnostike treniranosti sportaša koja omogućuje dobivanje relevantnih informacija o stanju sportaša i tehnici izvođenja sportskih gibanja. Izračunavanjem linearnih i kutnih pomaka te brzina i ubrzanja moguće je dobiti detaljan uvid u tehniku gibanja, što može biti značajna komponenta praćenja, programiranja i kontrole procesa treninga u različitim atletskim disciplinama. Skok u vis može se strukturalno podijeliti na fazu zaleta, odraza, leta i doskoka, a u okviru tih faza analiziraju se kinematičke veličine i parametri koji su bitni za efikasnost gibanja. U posljednjih nekoliko godina jedna vrhunska hrvatska skakačica u vis postigla je zapažene rezultate na svjetskoj razini, a kako bi se istražila pozadina postignuća uspješnih rezultata sustavno je promatrano sedam skokova na različitim visinama skoka u vis u razdoblju od tri godine. Stoga se ovo istraživanje temelji na longitudinalnom praćenju kinematičkih parametara i njihovih promjena u analiziranim skokovima, pri čemu se nisu uzele u obzir promjene antropoloških obilježja (osim tjelesne visine i mase tijela) ni ostali aspekti trenažnog procesa koji, zasigurno, utječu na ukupnu motoričku efikasnost skoka. Cilj ovog longitudinalnog istraživanja bio je utvrditi osnovne kinematičke parametre skoka u vis, kao i utjecaj promjena osnovnih kinematičkih parametara na visinu skoka te utvrditi varijabilitet kinematičkih parametara u promatranom razdoblju. Metode Subjekt ovog istraživanja jedna je vrhunska hrvatska skakačica u vis. Za potrebe ovog istraživanja analizirano je sedam skokova snimljenih u razdoblju od 19. veljače 2000. godine do 7. ožujka 2003. godine. Video zapisi, potrebni za kinematičke analize, prikupljeni su i zaprimljeni pomoću dvije digitalne video kamere JVS DVL 9800, frekvencije 60 Hz, na šest natjecanja i trening natjecanja. Istraživanje je obuhvatilo analizu 25 kinematičkih parametara koji se najčešće koriste u istraživanjima tehnike skoka u vis. Kinematički podaci su prikupljeni i izračunati prema standardima procedure APAS (Ariel Performance Analysis System). Podaci su obrađeni programskim paketom Statistica for Windows 7.0. Rezultati U radu su prikazani osnovni deskriptivni parametri 25 kinematičkih parametara sedam analiziranih skokova u vis, vrijednosti visine i mase tijela pri svakom mjerenju, korelacije svih kinematičkih parametara s visinom skoka te vrijednosti osnovnih kinematičkih parametara u svim analiziranim skokovima. Da bi se utvrdili osnovni kinematički parametri skoka u vis, odnosno kinematički parametri koji imaju najveću povezanost s visinom skoka, izračunate su korelacije prosječnih vrijednosti kinematičkih parametara iz svih mjerenja s visinom skoka. Osnovni kinematički parametri jesu: visina leta težišta tijela (H2), vertikalna brzina težišta tijela na kraju odraza (VVETO), visina kukova iznad letvice (HHIP), kut odraza (ANTO), trajanje odraza (DTO), kut ulaska u odraz (ANETO), maksimalna visina težišta tijela u trenutku prelaska preko letvice (CGMAX), horizontalna brzina težišta tijela pretposljednjeg (drugog) koraka zaleta (HV2RU). Rasprava i zaključak Dobiveni rezultati potvrđuju dosadašnje spoznaje o povezanosti dobivenih osnovnih kinematičkih parametara s visinom skoka te ukazuju na to kako uspješnost skakača u vis nedvojbeno ovisi o brzini zaleta, izvođenju odraza te optimalnoj trajektoriji leta. Vrijednosti rezultata nekih kinematičkih parametara povećavaju se s povećanjem visine skoka, dok se vrijednosti rezultata drugih kinematičkih parametara smanjuju s povećanjem visine skoka. Osnovni kinematički parametri koji se povećavaju s povećanjem visine skoka jesu: visina leta težišta tijela (H2), vertikalna brzina težišta tijela na kraju odraza (VVETO), visina kukova iznad letvice (HHIP), kut odraza (ANTO), maksimalna visina težišta tijela u trenutku prelaska preko letvice (CGMAX) i horizontalna brzina težišta tijela pretposljednjeg (drugog) koraka zaleta (HV2RU), dok se vrijednosti kinematičkih parametara trajanje odraza (DTO) i kut ulaska u odraz (ANETO) smanjuju s povećanjem visine skoka. Analizom kinematičkih parametara svih skokova utvrđeno je da vrijednosti rezultata svih kinematičkih parametara variraju s povećanjem visine skoka. Kinematički parametri koji imaju najveći varijabilitet rezultata s obzirom na visinu skoka jesu: duljina drugog (pretposljednjeg) koraka zaleta (SD=18,90), udaljenost težišta tijela od ravnine letvice pri postavljanju odrazne noge (SD=15,24), udaljenost odra-za (prstiju) od ravnine letvice (SD=11,78) i dužina posljednjeg koraka zaleta (SD=11,11). Najmanji varijabilitet rezultata ima kinematički parametar trajanje odraza, odnosno vrijeme kontakta odrazne noge s podlogom, na što ukazuje vrijednost standardne devijacije koja iznosi tek 0,007. U razdoblju tijekom kojega su prikupljeni analizirani skokovi, ispitanica je izvela veliki broj iteracija skoka u vis u trenažnom procesu, kao i velik broj skokova u natjecateljskim uvjetima, što je zasigurno utjecalo na razvoj tehnike skoka u vis. U tom razdoblju došlo je do promjene tjelesne mase i visine tijela, što je vjerojatno utjecalo i na promjene ostalih antropoloških karakteristika. S obzirom na dobivene rezultate, istraživanje bi bilo dobro ponoviti na većem uzorku ispitanika i većem broju skokova na različitim visinama.Das Ziel dieser Forschung war, sowohl die basischen kinematischen Parameter des Hochsprungs als auchden Einfluss deren Änderungen auf die Höhe des Sprunges zu bestimmen, zusammen mit der Variabilität von kinematischen Parametern in einer longitudinalen Forschung. Mittels einer kinematischen Analyse wurden 25 kinematischen Parametern für sieben Hochsprünge, die in einer Zeitspanne von drei Jahren von einer kroatischen Spitzenhochspringerin ausgeführt wurden, analysiert. Die Analyse von kinematischen Parametern und der Höhe des Sprunges resultierte mit den Parametern, die mit der Sprunghöhe am meisten korrelieren. Diese Parameter waren: Flughöhe des Schwerpunktes (H2), vertikale Schnelligkeit des Schwerpunktes am Ende des Absprungs (VVETO), die Höhe von Hüften über der Latte (HHIP), Absprungwinkel (ANTO), Absprungdauer (DTO), der Winkel im Moment des Hineingehens in den Absprung (ANETO), maximale Höhe des Schwerpunktes beim Überspringen der Latte (CGMAX), horizontale Schnelligkeit des Schwerpunktes des vorletzten Schrittes während des Anlaufs (HV2RU). Die Werte von einigen kinematischen Parametern steigern mit der Steigerung der Sprunghöhe, während die Werte von anderen kinematischen Parametern senken mit der Steigerung der Sprunghöhe. Die basischen kinematischen Parameter, die mit der Sprunghöhe steigern, sind: Flughöhe des Schwerpunktes (H2), vertikale Schnelligkeit des Schwerpunktes am Ende des Absprungs (VVETO), die Höhe von Hüften über der Latte (HHIP), Absprungwinkel (ANTO), maximale Höhe des Schwerpunktes beim Überspringen der Latte (CGMAX) und horizontale Schnelligkeit des Schwerpunktes des vorletzten Schrittes während des Anlaufs (HV2RU). Die Werte von kinematischen Parametern Absprungdauer (DTO) und der Winkel im Moment des Hineingehens in den Absprung (ANETO) senken mit der Steigerung der Sprunghöhe. Mittels der Analyse von kinematischen Parametern von allen Sprüngen, die beobachtet wurden, wurde festgestellt, dass alle Parameter im Zusammenhang mit der Sprunghöhe variieren. Die Parameter mit der höchsten Variabilität waren: die Länge des zweiten (vorletzten) Schrittes während des Anlaufs (SD = 18,90), die Distanz zwischen dem Schwerpunkt und der Lattenprojektion im Moment der Positionierung des Absprungbeines (SD = 15,24), die Distanz zwischen dem Absprungspunkt und der Lattenprojektion (SD = 11,78) und die Länge des letzten Schrittes während des Anlaufs (SD = 11,11). Die niedrigste Variabilität zeigte sich in dem Parameter: Dauer des Absprungs, die die Dauer des Kontaktes zwischen dem Absprungbein und dem Boden darstellt (SD = 0,007)

BIOMECHANICAL EVALUATION OF THE DROP JUMP EXERCISES IMPLEMENTED IN PREPARATION OF LONG JUMPERS

Cilj ovog istraživanja je opis i standardiziranje postupka korištenja osnovnih biomehaničkih tehnika za istovremeno dobivanje kinematičkih, kinetičkih i EMG podataka kod vježbi dubinskih skokova. Mjerenje dubinskih skokova izvršeno je korištenjem piezoelektrične platforme za mjerenje sile reakcije podloge, uređaja za mjerenje EMG aktivnosti muskulature i akvizicijom video signala na temelju kojih je kasnije učinjena kinematička analiza.Dubinske skokove izvodilo je pet ispitanika, skakača u dalj, koji su vrhunski natjecatelji, a analizirane vježbe često su primjenjivane u tehnologiji atletskog treninga.Analizirane biomehaničke varijable iskazuju visoku zahtjevnost izvođenih zadataka na lokomotorni sustav ispitanika. Rezultati ukazuju na veliku vertikalnu silu reakcije podloge na svim razinama opterećenja (visinama saskoka), što je pokazatelj da se korištenim vježbama dubinskih skokova uspješno može ostvariti opterećenje kao i kod skokova u dalj (vrijednosti vertikalne sile rakcije podloge kreću se od 3500 do 6300N). Rezultati horizontalne sile reakcije podloge očekivano su niži zbog znatno manje horizontalne brzine kretanja skakača i ne prelaze 1500N. Prema rezultatima EMG aktivnosti muskulature odrazne noge moguće je zaključiti kako je priprema u smislu predaktivacije muskulature neposredno prije doskoka izuzetno važna kako bi se izveo dobar skok. Maksimalne vrijednosti EMG aktivnosti muskulature postizane su, najčešće u trenutku kontakta s podlogom. Analiziranim vježbama dubinskih skokova uspješno se može simulirati kretna struktura odraza koja se pojavljuje kod skoka u dalj iz zaleta, i jednako tako izazvati zadovoljavajuće opterećenje neuromuskularnog sustava.The goal of the research was to give a description and to standardize implementation procedures of the basic biomechanical techniques for simultaneous acquisition of kinematic, kinetic and EMG data on the drop jump exercises. Data collection was done by simultaneous employment of piezoelectric platform, used for measuring ground reaction force, an EMG device for measuring muscular activity and video signal acquisition, on the basis of which the kinematic analysis was later performed. Then the signals were used to interpreting and describing the drop jump exercises. Five top-quality long jumpers performed the drop jump exercises, which were frequently used in the technology of the athletics training. The EMG results of the take-off leg muscle activity indicated that the voluntary preparation in terms of muscle preactivation just prior to landing is crucial for a good jump performance. The maximum values of EMG activity were most frequently achieved in the very moment of establishing contact with the ground. The analysed biomechanical variables set high demands on the locomotor system of the examinees. The results indicated the high vertical ground reaction force at all levels, suggesting that the applied exercises generated loads equal to the long jump specific loads in actual performance (values of the vertical ground reaction force ranged from 3500 to 6300N). The obtained horizontal ground reaction force was expectedly lower (not exceeding 1500N) due to the lower horizontal speed of movement

ANTHROPOLOGICAL CHARACTERISTICS OF NOVICE AND TRAINED VOLLEYBALL PLAYERS

Antropološke karakteristike odbojkaša istraživane su uglavnom na seniorskim uzrastima, dok je mali broj istraživača radio s juniorima. Cilj ovog istraživanja je utvrditi antropološki profil igrača uzrasta 15 do 18 godina i pri tome analizirati razlike između početnika i igrača iste dobi ali koji su podvrgnuti trenažnom procesu najmanje tri godine. Istraživanje je provedeno na uzorku skupine od 24 odbojkaša mlađih uzrasta od 15-18 godina odbojkaškog kluba „Mladost“ iz Zagreba. Ispitanici su podijeljeni u dvije podskupine po 12 igrača. Prvu skupinu činili su odbojkaši istog kluba koji su trenirali odbojku više od tri godine (tri do sedam godina), a drugu skupinu činili su odbojkaši koji su trenirali odbojku manje od godinu dana. Obje skupine ispitanika imale su prosječno oko 16 godina ( kupina 16,75 : kupina 16,25). Ispitanicima su izmjerene masa i visina tijela, postotak masnog tkiva metodom bioelektrične impedancije, frekvencija srca i arterijski krvni tlak u mirovanju, spirometrijski parametri (vitalni kapacitet, Tiffeneauov indeks), dinamometrijski pokazatelji (stisak šake, fleksija podlaktica, ekstenzija trupa i ekstenzija nogu), volumen srca, te pri testu maksimalnog opterećenja na pokretnom sagu maksimalni primitak kisika, puls kisika i maksimalna frekvencija srca. Obrada podataka izvršena je primjenom programskog paketa STATISTICA, ver 8. Mladi odbojkaši višlji su i teži od svojih vršnjaka koji se ne bave sportom i imaju manju količinu masnog tkiva, no niži su od odbojkaša seniora. Može se zaključiti da su odbojkaši početnici sličnog antropološkog profila kao i trenirani odbojkaši istog uzrasta. Međutim već trogodišnji trening ostavlja trag na karakteristike i sposobnosti odbojkaša što je vidljivo u ukupnoj masi tijela, jakosti nogu i trupa te volumenu srca.Several studies investigated anthropological characteristics of senior volleyball players, while young players were studied rarely. The aim of this investigation was to evaluate the anthropological profile of volleyball players aged 15 to 18 years with special attention to differences between novice players and those who were involved in volleyball training for three or more years. The sample consisted of 24 volleyball players from AŠK Mladost, Zagreb, 12 of them novice and 12 who were training three or more years. The examinees underwent measurement of standard anthropometric variables (body mass and height, percent of fat), spirometry, spiroergometry, lower body muscular strength and arm strength, and heart volumetry. Standard statistical procedures were used to calculate descriptive statistical parameters and t-test was used to analyze differences between two groups. The average body measures of young volleyball players, as expected, greatly exceeded those reported for nonathletic population of the same age in Croatia. On the other hand, these measures were lower than in senior volleyball players in Croatia or in the world. Their functional abilities were on high level and similar to those of elite players. It can be concluded that the anthropological profile of novice and trained volleyball players of the same age is similar. But volleyball training after only three years made some differences and they were present in body mass, leg and body strength and heart volume

Učestalost i vrste ozljeda u karateu

Istraživanje je provedeno na uzorku od 84 ispitanika (42 karataša i 42 karatašice) na području Republike Hrvatske. Cilj ovog rada bio je utvrditi vrstu i učestalost sportskih ozljeda, stupanj težine kao i mjesto njihovog nastanka. Također, rezultati istraživanja trebali bi pružati glavne smjernice trenerima prilikom izrade kvalitetnih prevencijskih i kondicijskih programa. Zabilježene su ukupno 184 ozljede, iz čega proizlazi da se u prosjeku svaki karataš ozlijedio 2,19 puta. Ozljede su bile učestalije na treninzima (110), nego na natjecanjima (74). Karataši su se češće ozljeđivali od karatašica. Karataši su najčešće ozljeđivali ruke, šake i prste, a karatašice gležanj, stopalo i prste. Najčešća vrsta ozljeda je uganuće zgloba (11,41%). Prema stupnju težine, najviše je zabilježeno srednje teških ozljeda (42%)

TYPES AND MANIFESTATION OF INJURIES IN ATHLETICS

Razumijevanje mehanizama nastanka sportskih ozljeda te poznavanje utjecaja i interakcije unutarnjih i vanjskih rizičnih faktora temelj su za preventivno djelovanje u svrhu smanjenja broja i ozbiljnosti sportskih ozljeda. Cilj ovog rada je utvrđivanje vrste i učestalosti pojavljivanja ozljeda u atletici te identificiranje uzroka njihovog nastanka s obzirom na atletsku disciplinu. Istraživanje je provedeno na uzorku od 84 aktivnih atletičara (45 atletičara i 39 atletičarki) iz 14 klubova prosječne dobi 23,44 godine uz prosječno 10,58 godina aktivnog treninga u atletici ispunjavanjem anonimnog anketnog upitnika koji je sadržavao 16 općenitih i 9 specifičnih čestica. Rezultati istraživanja ukazuju kako je ruptura mišića (17%) najučestalija ozljeda, a zatim slijede sindrom prenaprezanja (14%) i istegnuće mišića (13%) dok su mišići stražnje strane natkoljenice (20%) i stopalo (19%) najčešći zahvaćeni anatomski lokaliteti. Rupture i istegnuća mišića stražnje skupine mišića natkoljenice najčešće su u sprinterskim disciplinama, dok su u skakačkim disciplinama najzastupljenije distorzije skočnih zglobova, sindrom prenaprezanja te rupture i istegnuća mišića. U bacačkim disciplinama dominiraju sindrom prenaprezanja, uklještenja živca te istegnuća i rupture mišića. Najučestaliji uzroci nastanka ozljeda su niska razina tehnike izvođenja, loši uvjeti treniranja, vlastita neopreznost atletičara i visoka razina umora, a najveći broj ozljeda dogodio za vrijeme ljetnog natjecateljskog perioda i pripremnog perioda za ljetni natjecateljski period. Rezultati istraživanja bi trebali unaprijediti sustav prevencije najčešćih ozljeda za hrvatske atletičarke i atletičare.Understanding the mechanism of sports injuries and knowledge about the influence and interaction of internal and external risk factors are the grounds for preventive activities to reduce the number and severity of sports injuries. Therefore, the main goal of this paper was to establish the type and frequency of injuries in athletics and to identify the causes and the time of their occurrence with regard to the athletics discipline. The study was conducted on a sample of 84 active athletes (45 male and 39 female) from 14 Croatian clubs (average age of 23.44 years with an average of 10.58 years of active practice in athletics) filling out an anonymous questionnaire containing 16 general and 9 specific particles. The research results indicate that the muscle rupture (17%) is the most common injury, followed by overuse syndrome (14%) and muscle strain (13%), while the hamstring (20%) and foot (19%) are the most frequently affected anatomical parts. Hamstring rupture and strain are predominant in the sprint events, while in the jumping disciplines, the most common are ankle sprain, overuse syndrome and muscle rupture and strain. Dominant injuries in the throwing events are overuse syndrome, nerve injury and muscle rupture and strain. The most common causes of injuries are the low level of technique performance, poor training conditions, own carelessness of the athletes and high level of tiredness. Most of injuries occurred during the summer competition period and preparatory period for summer competition period. Result of this study should improve the prevention system for Croatian track and field athletes

Usvajanje tehnike skoka u dalj korištenjem povratnih informacija različitih vrsta i frekvencija

The aim of this study was to examine the acquisition of the long jump skill in elementary school children using augmented feedback of varying type and frequency. Eighty-eight boys and girls aged (mean ± SD) 11 ± 0.5 years, without any prior experience in the long jump skill acquisition, were assigned to one of the four study groups: (1) the group receiving only verbal feedback on key errors, (2) the group receiving both verbal and video feedback on key errors, (3) the group receiving both verbal and video feedback on all errors, and (4) the group receiving no feedback. Before and after an 8-week training intervention, long jump distance and relevant kinematic variables were recorded. The results indicated that the group receiving both verbal and video feedback on all errors improved the most in terms of the long jump distance. Varying feedback influenced kinematic parameters differently, as there was no consistent change in the monitored kinematic variables across groups. It was concluded that when learning a complex motor skill in a typical Physical Education setting, elementary school children are likely to benefit the most when receiving frequent feedback (both verbal and using video analysis, focusing on all errors), in comparison with the situation in which they receive feedback reduced in the type (only verbal) and the frequency (focusing only on key errors).Cilj ovoga rada bio je ispitati utjecaj različitih količina i vrsta povratnih informacija (PI) u procesu usvajanja tehnike skoka u dalj kod učenika osnovne škole. Osamdeset i osam učenika i učenica, starosti 11 (±0,5) godina, bez prethodnoga iskustva u treningu skoka u dalj, raspodijeljeno je u jednu od četiriju skupina ispitanika koje su dobivale PI: (1) verbalno samo na ključne greške, (2) verbalno i vizualno samo na ključne greške, (3) verbalno i vizualno na sve greške ili (4) nisu primale PI. Duljina skoka i relevantni kinematički parametri skoka u dalj izmjereni su prije i nakon osmotjednog eksperimentalnoga tretmana. Rezultati istraživanja pokazali su kako je grupa koja je primala PI, na svaku grešku verbalnim i vizualnim putem najviše napredovala u smislu duljine skoka u dalj. Različite količine i vrste PI različito djelovale su na promatrane kinematičke parametre te nisu uočene konzistentne promjene između grupa. Zaključeno je kako djeca osnovnoškolske dobi prilikom usvajanja kompleksne motoričke vještine imaju više koristi od većih frekvencija PI (verbalnih i vizualnih na sve greške) u usporedbi s reduciranim PI prema vrsti (samo verbalne) ili frekvenciji (samo na ključne greške)

BIOMECHANICAL EVALUATION OF THE DROP JUMP EXERCISES IMPLEMENTED IN PREPARATION OF LONG JUMPERS

Cilj ovog istraživanja je opis i standardiziranje postupka korištenja osnovnih biomehaničkih tehnika za istovremeno dobivanje kinematičkih, kinetičkih i EMG podataka kod vježbi dubinskih skokova. Mjerenje dubinskih skokova izvršeno je korištenjem piezoelektrične platforme za mjerenje sile reakcije podloge, uređaja za mjerenje EMG aktivnosti muskulature i akvizicijom video signala na temelju kojih je kasnije učinjena kinematička analiza.Dubinske skokove izvodilo je pet ispitanika, skakača u dalj, koji su vrhunski natjecatelji, a analizirane vježbe često su primjenjivane u tehnologiji atletskog treninga.Analizirane biomehaničke varijable iskazuju visoku zahtjevnost izvođenih zadataka na lokomotorni sustav ispitanika. Rezultati ukazuju na veliku vertikalnu silu reakcije podloge na svim razinama opterećenja (visinama saskoka), što je pokazatelj da se korištenim vježbama dubinskih skokova uspješno može ostvariti opterećenje kao i kod skokova u dalj (vrijednosti vertikalne sile rakcije podloge kreću se od 3500 do 6300N). Rezultati horizontalne sile reakcije podloge očekivano su niži zbog znatno manje horizontalne brzine kretanja skakača i ne prelaze 1500N. Prema rezultatima EMG aktivnosti muskulature odrazne noge moguće je zaključiti kako je priprema u smislu predaktivacije muskulature neposredno prije doskoka izuzetno važna kako bi se izveo dobar skok. Maksimalne vrijednosti EMG aktivnosti muskulature postizane su, najčešće u trenutku kontakta s podlogom. Analiziranim vježbama dubinskih skokova uspješno se može simulirati kretna struktura odraza koja se pojavljuje kod skoka u dalj iz zaleta, i jednako tako izazvati zadovoljavajuće opterećenje neuromuskularnog sustava.The goal of the research was to give a description and to standardize implementation procedures of the basic biomechanical techniques for simultaneous acquisition of kinematic, kinetic and EMG data on the drop jump exercises. Data collection was done by simultaneous employment of piezoelectric platform, used for measuring ground reaction force, an EMG device for measuring muscular activity and video signal acquisition, on the basis of which the kinematic analysis was later performed. Then the signals were used to interpreting and describing the drop jump exercises. Five top-quality long jumpers performed the drop jump exercises, which were frequently used in the technology of the athletics training. The EMG results of the take-off leg muscle activity indicated that the voluntary preparation in terms of muscle preactivation just prior to landing is crucial for a good jump performance. The maximum values of EMG activity were most frequently achieved in the very moment of establishing contact with the ground. The analysed biomechanical variables set high demands on the locomotor system of the examinees. The results indicated the high vertical ground reaction force at all levels, suggesting that the applied exercises generated loads equal to the long jump specific loads in actual performance (values of the vertical ground reaction force ranged from 3500 to 6300N). The obtained horizontal ground reaction force was expectedly lower (not exceeding 1500N) due to the lower horizontal speed of movement

Proceedings of the 12th International Conference on Kinanthropology

Proceedings of the 12th Conference of Sport and Quality of Life 2019 gatheres submissions of participants of the conference. Every submission is the result of positive evaluation by reviewers from the corresponding field. Conference is divided into sections – Analysis of human movement; Sport training, nutrition and regeneration; Sport and social sciences; Active ageing and sarcopenia; Strength and conditioning training; section for PhD students

Test-Retest Reliability of Unilateral Horizontal Drop Jump in Children

Jumps are an indispensable activity for the development of coordination, muscle strength and power, especially in children. Positive effects of horizontal drop jump (HDJ) proved to be very important in improving individuals performance. HDJ presents a specific movement pattern that has similarities with running gait and take-off in different horizontal jumps. Influence and effect of implementating HDJ in children is yet to be determined. The aim of this research was to determine the test–retest reliability of the unilateral horizontal drop jump (UHDJ) in children of early school age (6–7 years). Participants (n = 31; 19 girls and 12 boys) were school-age children that regularly attended Physical Education classes (Girls: mean age 7.5 ± 0.3 years, mean height 127.1 ± 6.8 cm and mean weight 25.8 ± 5.2 kg; Boys: mean age 7.5 ± 0.2 years, mean height 127.5 ± 6.9 cm and mean weight 27.6 ± 7.1 kg). UHDJ was performed from an elevation of 30 cm relative to the platform with starting position 120 cm from the middle of the platform. A jump on the platform and a unilateral take-off in the distance were performed, followed by a bilateral landing on the mat. Intraclass correlation coefficient was used to determine the reliability between the two days of measurements. Test–retest reliability was calculated for all observed variables, and a good correlation was found between the performed measurements (ICC = 0.76–0.89). The α coefficient indicates good to excellent (0.86–0.94) internal consistency. These findings suggest the usefulness of applying a UHDJ in school-age children. Moreover, it can be used to identify children talented for sports, monitor the effects of training and discover and direct individuals towards suitable sports disciplines

4th International Scientific Conference on Kinesiology: Science and profession - challenge for the future : proceedings book

In the year 2005, when the University of Zagreb is celebrating the 336th anniversary of its establishment and the Faculty of Kinesiology University of Zagreb its 46th anniversary, the International Scientifi c Conference on Kinesiology is being organized for the fourth time. Thus, the proclaimed intention of the organizer, the Faculty of Kinesiology, to make the Conference a traditional forum for kinesiologists to exchange fi ndings, ideas, experiences and theories has become a reality. You will probably agree with us that, despite all the conveniences the modern communication technology has provided, a vivid dialogue, established in personal contacts of people who share similar vocational interests, is always a unique event and experience. We hope that the debates on how to foster excellence and joy in sport and exercise and on how to promote PE as an underpinning activity for sport, competitive and recreational alike, and life-long active life-styles, as well as discussions on numerous issues regarding human movement, health, exercise and business will bring fruitful results in form of new ideas and research projects. The ever-growing body of kinesiology or sport science knowledge is continuously transformed into higher education curricula which allow graduates and masters of science to become well-educated professionals who have insights into the recent advances in kinesiology. In Croatia a highly specialized education and training of sport and PE professionals has a hundred-and-ten-year-old tradition. Based on that long tradition, the Faculty of Kinesiology has prepared two new university study curricula, adjusted to the Bologna Declaration and the European Credit Transfer System (ECTS) and has obtained the accreditation to organize them commencing in academic year 2005/06. The new university graduate and postgraduate doctoral study programmes will enable a higher level of knowledge of students and will promote a higher two-way mobility of both students and scholars. The curricula have assimilated the orientation of the members of the Faculty of Kinesiology that the mission of higher education institutions is viable only in the symbiosis of educational (professional training) and elite fundamental, developmental and applied research work in the fi elds of general and applied kinesiology and in the cognate and adjacent, mainly anthropological, scientifi c branches. The motto of this year’s Conference is “Science and Profession – Challenge for the Future”. It suggests that the focus of attention is directed towards the inevitable connectedness between everyday practical issues and professions related to physical exercise and sport, on the one hand, and kinesiological research activities, theories, insights, fi ndings and inferences on the other. The assembly of kinesiologists from 25 countries has gathered to discuss diverse biological, medical, biomechanical, psychological, sociological, cultural and economic aspects of a variety of kinesiological issues presented in 226 papers written by 300 authors. Besides the contributing authors, much credit for the Conference scientifi c programme goes to the esteemed invited lecturers, both the plenary and the session introductory speakers, and chairpersons of particular thematic sessions, and the members of the Scientifi c Programme Committee. Thematically and methodologically related contributions have been divided into eleven thematic sections (APA and Sport for the Disabled; Biology and Medicine of Sport and Exercise; Biomechanics; Management of Sport; Physical Conditioning; Physical Education; Research Methodology; Sociology, History and Philosophy of Sport; Sport for All, Fitness and Health-related Activities; Sport Psychology; and Top-level Sport), which, in turn, represent recognizable groups of issues currently prevailing in the scientifi c research dealing with human movement, sport and exercise activities. Our special thanks go to the reviewers (62) who altruistically engaged their knowledge, effort, experience and time in making the conference papers consistent and good enough to enable creative clarifi cation and communication of ideas. Although time restrictions made it impossible to afford indepth reviews, the authors were requested to undertake revisions whenever it was possible in order to minimize the rejections. The selection and classifi cation process was performed according to the quality criteria that primarily regarded novelty and the amount of information, and quality of structure and presentation. Due to the formal quality and lack of consistency of quite a number of papers, the original idea of reproducing them Science and Profession - Challenge for the Future VII as submitted proved hardly tenable. Therefore, a certain amount of copy-editing has been performed, though restricted to a minimum and simply in order to achieve a reasonable degree of formal consistency. This has been a demanding and complex process, performed under serious time pressure. We do apologise for any mistakes or inconveniences this might have caused. The Proceedings Book is a reminder of the research fi ndings accomplished in the fi eld of kinesiology, or sport sciences, or kinetics, or kinanthropology throughout the past three years. The presented papers are a basis and a probable starting point for new ones since they cover a wide range of anthropological (understood in the widest sense), methodological and didactic investigations in the areas of physical education, competitive sport, physical recreation, and physical rehabilitation. The organizer, the Faculty of Kinesiology tried to make the 4th Conference on Kinesiology comparable to the quality level of many conferences worldwide. The Dean of the Faculty and the presidents of the Organizing and Scientifi c Committee wish to express their deep gratitude to all the invited speakers, contributors (authors), members of the Scientifi c Committee, reviewers, members of the Organizing Committee, members of the Proceedings Book Editorial Board, and, particularly, to all the Conference Offi ce executives who made the 4th Conference and the Proceedings Book possible. Our acknowledgments go to the Croatian Academy of Sciences and Arts and to its president a Fellow of the Croatian Academy Milan Moguš, PhD, for their traditional patronage of the Conference. Their support is of great value to the Faculty because it is a signifi cant recognition of the work done in the domain of kinesiology. Recognition of the Conference has been also granted by the co-organizer, the Ministry of Science, Education and Sport of the Republic of Croatia. We are convinced that the 4th Conference on Kinesiology will affi rm all the effort exerted so far in the kinesiology and will open new challenges for the future and better cooperation between scientists and the professionals. To all the Conference participants we wish a productive and benefi cial time and contacts. It is our hope that new research ideas and projects will emerge from it. We will welcome the forthcoming results at our next conferences. To those who were not able to actively participate in the Conference work this year, we offer these Proceedings as an invitation for cooperation of competent partners and for joining us at the 5th Conference on Kinesiology in three years time