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INTRODUCTION:Snowboarding is an increasingly popular sport, but it has been little studied so far, especially regarding the biomechanical characteristics (1). Most previous research concerned injury occurrence, the physiological profile of the snowboarding athletes (1) and dynamic variables characterizing the turn (2,3). Therefore, the aim of this study was to compare the turn technique of the snowboard giant slalom between elite and experienced recreational athletes, to improve the knowledge of performance factors and to provide suggestions to athletes and coaches. METHODS: Eight male snowboarders, four belonging to the Italian Snowboard National Team (EA, age 27±3.2y, height 1.80±0.10 m, mass 83.4±4.3 kg) and four experienced recreational athletes (RA, age 41.5±5.5 y, height 1.76±0.03 m, mass 89.0±12.2 kg) were analyzed during two performance on a snowboard slope (14 gates spaced at 21 m, 200m total descent). Eight wearable inertial and magnetic measurement units (APDM Opals, 128 Hz) were used for data collection. The sensors were fixed on sternum, sacrum, thigh, leg, toe of ski boot (right and left). Snowboarders were filmed when passing through the first 4 gates using a video camera (JVC full HD, 250hz) to compare the video recordings and the inertial sensor signal, and to define an algorithm to identifies automatically the transition of the gate and the change of the ski edge of all turns. These events were used to divide the turn in 4 phases: from change of ski edge to gate (T1) and from gate to change of ski edge (T2). Each event was identified for the backside-B and frontside-F turn, defining this way T1B, T2B, T1F, T2F respectively. RESULTS: Concerning time variables, EA showed shorter and more consistent times than RA in all turn phases (T1B 0.89±0.18s vs 0.99±0.11s, T2B 0.97±0.21s vs 1.53±0.50s, T1F 0.65±0.19s vs 1.23±0.3s, T2F 0.97±0.19s vs 1.31±0.22s), with significant differences (p

L’articolo mette a confronto i migliori atleti italiani di sesso maschile di getto del peso delle categorie Allievi e Assoluti praticanti la tecnica lineare. Lo scopo è cercare di spiegare l’evoluzione della tecnica dal settore giovanile a quello assoluto per identificare i parametri essenziali della prestazione. I lanci degli atleti, ripresi durante i Campionati Italiani di Categoria, sono stati analizzati tramite SIMI Motion. Sono state valutate le variabili temporali e cinematiche dei migliori atleti. Da quanto è emerso non ci sono particolari differenze tecniche tra Allievi e Senior, ma molti parametri di tutti gli atleti non sono in linea con quelli identificati in letteratura come fondamentali per la performance. Pertanto si ritiene necessaria nel passaggio tra le due categorie un maggior miglioramento tecnico per potere allineare le prestazioni degli atleti italiani a quelli World Class.

Il successo o meno di uno sprinter durante la stagione sportiva è legato non solo ad una corretta pianificazione dei mezzi e dei contenuti dell’allenamento, ma anche alla propria integrità fisica. Diventa prioritario pertanto da parte dell’allenatore cercare di prevenire gli infortuni del proprio atleta. A questo proposito, tra gli infortuni più frequenti nello sprint risultano quelli ai muscoli ischiocrurali. Secondo la letteratura più recente, le cause più probabili di tali infortuni sono legate ad uno squilibrio di forza tra quadricipite e ischiocrurali, ad un errato automatismo tecnico o ad un comportamento asimmetrico degli arti inferiori durante la corsa. Proprio su quest’ultima causa si stanno concentrando le ricerche di molti studiosi e si inserisce anche questo studio pilota che analizza, tramite l’optojump ed una ricostruzione tridimensionale del movimento (SIMI Motion System), i parametri cinematici lineari ed angolari nonché i dati temporali di 4 velocisti di livello nazionale durante una prova di corsa alla massima velocità. Le maggiori asimmetrie (indice di asimmetria SA superiore al 15%) si sono riscontrate soprattutto nei ROM articolari di ginocchio e caviglia e nella massima estensione dell’anca. I risultati sembrano dimostrare come l’asimmetria possa configurarsi sia come causa, ma anche come effetto degli infortuni agli ischiocrurali. A rinforzo di questa ipotesi, uno dei soggetti analizzati, che successivamente all’elaborazione dei dati, ha mostrato diversi parametri asimmetrici, proprio durante la sessione di acquisizione ha accusato un infortunio al comparto posteriore della coscia. Ai fini pratici, pertanto, potrebbe essere importante fotografare la situazione tecnica e fisica dello sprinter all’inizio della nuova stagione agonistica, in modo da provare a ripristinare, qualora ce ne fosse bisogno, una corretta simmetria di corsa prima di incominciare a sottoporre l’atleta a nuovi carichi di allenamento. Per far sì però che la ricerca possa effettivamente fornire agli allenatori ed agli atleti dei dati generalizzabili sull’asimmetria e sul collegamento tra questa e gli infortuni agli ischiocrurali, sono necessari ancora molti studi che coinvolgano un numero maggiore di atleti, differenziandone i livelli prestativi, seguendone la carriera longitudinalmente ed analizzando anche le possibili differenze di genere.

The goal of this study is of comparing athletes belonging to youth and senior categories, during the execution of the rotatory technique of shot put, and comparing them with the values recorded in literature for top level athletes, with the aim of observing how the most important kinematic parameters evolve and trying to understand the reason why since many years senior Italian athletes are no more at the top in the most important international events. The videos of the first two athletes, executing the rotatory technique, were acquired at the Italian Youth and Senior Championships. Through the three-dimensional system SIMI Motion (Simi Reality Motion Systems GmbH, Unterschleissheim, Germania) the time and kinematic variables of the throw were identified. The results show that young athletes have a technical incorrect behaviour in comparison with expert athletes, especially as to the body position, in the phases preceding the tool release. This study can offer to coaches some suggestions to try to correct some of the outlined individual mistakes.

Introduction Decathlon is one of the most challenging disciplines in track and field. Previous studies have assessed the relationships between the performance in the 10 decathlon events by means of correlations or cluster analyses (Woolf et al, 2007, Cox et al, 2002, Van Damme et al, 2000). The aim of this study was to assess the correlations between the 10 decathlon events and the final competitive outcome, with particular focus on possible strategies used to achieve the final score by athletes of the most represented nations in the top 100 all-time world ranking. Methods The 100 world top (all-time) decathlon performances (taken from IAAF scores) were analysed. Scores achieved before the change of the javelin throw rule in 1986, have been compared to the results obtained after 1986, after standardization of the different throwing results according to Borgström (2000). The ranking has been analyzed to investigate how the different events are clustered and affect the final score. Furthermore, the data of the 3 states with the highest number of athletes in the all-time list (Russia, Germany and USA) were compared to study how their training strategies may affect the final performance. Results In agreement with previous studies (Cox et al, 2002, Woolf et al, 2007), the analysis showed two main clusters observed in the dendrograms. The 100m, 110m hurdles and long jump belonged to the same cluster and their scores were well correlated with the final results (r between 0.536 and 0.564). The shot put and discus throw were linked to another cluster, and were not correlated with the final score. The javelin throw, the pole vault and the high jump showed a weaker relationship with the final score, probably due to the high level of technical skill required. There were no significant differences between the three examined nations , with the exception of the average 100m and 1500m results between Russia and USA (851 pts vs. 892pts, and 745 pts vs. 702 pts, respectively). Discussion The results show that the sprint events influence the decathlon performance more than other events. This outcome may be taken into account to select talents and develop a more effective training programs. Among the 3 examined nations, USA showed higher score than the Russia especially in the sprint events and consequently in the final score. Russia showed better scores in the throwing events and 1500m race. Finally, athletes from Germany were generally ranked between those of the other 2 nations in all the decathlon events. References Borgström A (2000). New Studies in Athletics, 15, 3/4, 25-28. Cox TF, Dunn RT (2002). The Statistician, 51, part 2, 179-187. Van Damme R, Wilson RS, Vahhooydonck B, Aerts P (2002). Nature, 415, 755-756. Woolf A, Ansley L, Bidgood P (2007). J. of Quantitative Analysis in Sports. 3,4,5.

Il decathlon è la specialità più varia dell’atletica e risulta pertanto una disciplina adatta alla costruzione del giovane atleta, ma difficile da definire dal punto di vista tecnico. Gli studi maggiormente diffusi tendono ad indagare le correlazioni tra le varie discipline e a osservarne il peso specifico sul punteggio finale, senza porsi il problema di definire un profilo tecnico ideale dell’atleta. Lo scopo di questo studio pertanto è quello di identificare, tra le 10 discipline del decathlon, quelle che maggiormente influenzano la prestazione, analizzando i primi 100 atleti della lista all-time divisi in quartili e valutare se esistono diverse strategie in base alle singole scuole metodologiche di allenamento per arrivare alla performance finale del decathlon. I risultati mostrano che la performance nel decathlon passa soprattutto nell’eccellenza nelle specialità dei 100m, 110hs, salto in lungo e 400m. Alla luce di questo dovrebbe essere orientato sia il reclutamento del talento che lo sviluppo del relativo programma di allenamento. Anche nel confronto tra le 3 nazioni più competitive nella specialità (USA, Germania e Russia), sono le stesse specialità che giustificano quasi integralmente la differenza di performance.

Training periodization, defined as a planned distribution of workload over time, has been used for several decades in strength and power sport training. The early model proposed by Matveev at the beginning of the 1960s has been deeply changed in subsequent development by other eastern european scientists. The aim of the study was to describe the origin and the fundamental characteristics of the most important periodization models to avoid misunderstandings found in western literature. At the end of the 1970s some alternative models to the traditional one, were proposed in order to optimize the training process and adapt the workload to the different needs of athletes. One of these new interpretations of training theory was the block periodization model which is based upon a concentration of a specific workload and a large use of special strength exercises. At the end of the 1980s in the United States researchers developed a highly varied periodization which was diametrically opposed to the block concepts of concentration of stimuli. This new approach was called Daily Undulating Periodization and was based upon the variation of the strength training goal in each training session. Understanding and classifying the different periodization models on a historical and methodological basis can help us to understand and correctly apply the different workload distributions in order to obtain best results.

Tre gruppi sperimentali di età diversa (7-9, 10-11, 12-13 anni) hanno svolto per 10 settimane un programma bisettimanale con obiettivo lo sviluppo delle capacità motorie in generale oltre che le abilità specifiche del basket. Il programma era differente per gruppi di età: le 2 fasce dei giovani svolgevano 30' di attività generale. mentre i più grandi 60' e prevedeva dei test condizionali in entrata ed uscita.Tutti i gruppi hanno migliorato nei test di forza e rapidità, anche se i dati significativi sono risultati solo quelli riguardanti il salto in lungo da fermo e la corsa. Nei test di flessibilità del tronco sono stati riscontrati invece dei peggioramenti. In conclusione viene rimarcata l'importanza della preparazione fisica generale per queste fasce d'età, con particolare attenzione per la flessibilità come presupposto importante per le attività più specifiche delle fasce d'età superiori.

Aim: In shot put competitions are commonly used the rotational (ROT) or glide (GL) techniques. Previous studies have compared the two styles with a cross-sectional approach, analyzing only one type of technique for each athlete, with the drawback that the characteristics of athletes may be confounding factors. Therefore, this study aimed to compare the biomechanical parameters of ROT and GL in national level shot putters able to correctly execute both the techniques. Methods: The Smart-DX (BTS Engineering, Milano) was used to collect and analyse the 3d data. The experimental set-up included a set of nine 250-Hz cameras and two force plates (Kistler 9286AA, Switzerland). Four high-level Italian shot putters were involved (2 males, 2 females). For each athlete 6 throws (3 ROT and 3 GL) were measured, acquired and for the analysis divided in 4 phases: T1 (first movement), T2 (flight phase), T3 (double support) and T4 (push-throw). Results: Some angles (right knee, hip/throwing direction) and execution times showed significant differences between the techniques mostly in T1, T2 and T3; the trunk incline, the distance between heels (higher in the GL) and the shot velocity showed differences in all phases. Indeed, the shot velocity had a gradual increase in GL, while in ROT it had an abrupt increase in T4. The mean distance thrown was higher when using GL in male, while it was similar for the two styles in female. The distance thrown was related, in both the techniques and genders, to many biomechanical indices, including the hip rotation, the distance between heels, the shot height and, especially in females (r = 0.88), to the velocity at release. Male putters showed a higher shot velocity than female in all phases of GL, but only in T4 of ROT. In males, the peak vertical GRF at the planting point was positively related to the distance thrown in GL and in ROT (r = 0.55 and r = 0.58, respectively), while in females only in GL (r = 0.67). Conclusion: The examined techniques showed different biomechanical characteristics in T1, T2 and T3, while T4 was rather similar. The main difference between genders was represented by the higher peak vertical GRF shown by male athletes at the planting phase, demonstrating that these athletes rely on the force expressed by the pointing leg. On the contrary, females count more on accelerating the shot as much as possible. The present findings, although at a preliminary stage, provide a framework for coaches to analyse the performance of their athletes and to examine which technique may be the best according to the individual characteristics. References Gutie´rrez-Davila M, Rojas J, Campos J, Ga´mez J, Encarnacio´n A (2009) Biomechanical analysis of the shot put at the 12th IAAF world indoor championships. New Stud Athlet 24(3):45–61 Stepanek J (1987) Comparison of the glide and the rotation technique in the shot put. Biomechanics in sports: proceedings of the 5th ISBS symposium, pp 135–146

The purpose of this study was to compare the double and triple Lutz figure skating jumps and determine their key biomechanical differences in order to provide coaches with helpful information for teaching the triple Lutz. Data were collected from five male world-class roller skaters using a stereophotogrammetric system. The most relevant difference concerned a higher pelvis rotational velocity of the triple with respect to the double Lutz, not only in the flight phase (4.1 vs. 3.3 rev/s, respectively) but also from the toe-pick. Furthermore, a higher vertical velocity at take-off was observed in the triple jump, that can be explained from the greater flexion-extension of the right hip and knee from toe-pick to the take-off. On the contrary, the average horizontal approach speed was lower for the triple compared to the double Lutz.

Introduction Knowing the biomechanical key factors of each jump is fundamental for figure skating coaches in order to more effectively teach triple jumps to their athletes. Notwithstanding the number of studies on ice skating (King et al., 2004), no biomechanical jump analysis, to the knowledge of the present authors, performed on roller skating. The purpose of the present study was to compare some kinematic characteristics of double and triple Lutz jumps in roller skating. Methods 5 elite male skaters performing a series of double and triple Lutz were acquired using 10 infrared cameras (Smart-D, BTS, Milan, Italy, 250 Hz). For the trunk, the upper limbs and the foot segments, markers were attached directly on specific anatomical landmarks. For the thigh and the shank segments, the calibrated anatomical system technique was exploited (Cappozzo et al., 1995). The resultant velocity angle was also considered. Five key events were identified for each jump: toe-pick (instant in which the toe-pick impacted the ground), end of gliding (last contact of the left foot), take-off (last contact of the right foot), maximum height (top of the flight phase), and landing (instant of contact with the ground). Results The hip and the knee were flexed at the toe-pick, whereas the flexion was clearly lower at the take-off. On the contrary, the ankle at toe-pick was in the neutral position, and plantarflexed at the take-off, but differently depending on the skater. The skaters’ horizontal velocities at take-off for the triple Lutz (mean: 2.69 m/s) were lower than those for the double one (mean: 3.17 m/s). Vertical velocities at take-off showed slightly higher values for the triple (mean: 2.90 m/s) compared to the double (mean: 2.72 m/s) Lutz. The average resultant velocity angle in the 5 athletes was 40° in the double and 47° in the triple Lutz, at the take-off. The greatest difference between the double and triple jumps was the rotational velocity during the flight estimated from the rotation of the pelvis segment. The pelvis rotation velocity was higher in the triple Lutz already during the toe pick (means: 0.84 rev/s for double and 1.75 rev/s for triple one). Jumping height and flight time were higher for the triple jump for three skaters. Discussion For the first time a biomechanical comparison between the double and the triple Lutz in roller skating was performed. Some of these findings were already roughly known to coaches and skaters, but only in the present study some specific descriptors of the jump were characterized and quantified. References King D, Smith S, Higginson B, Muncasy B, Scheirman G. (2004). Sports Biomechanics, 3, 109-123. Cappozzo A, Catani F, Della Croce U, Leardini A. (1995). Clinical Biomechanics, 10, 171-178.

A biomechanical analysis of the Triple Lutz was performed using a stereophotogrammetric system in five world-class roller skaters. On average, the pelvis centre showed a horizontal velocity at the toe-assist lower than in the previous phases. The horizontal velocity decreased after the toe-assist, then remained constant up to the take-off. The vertical velocity was already elevated at the left skate end-gliding, and reached higher values at the take-off. In the toe-assisting leg, the hip and the knee showed a limited eccentric work phase, whereas the ankle showed a marked loading. Regarding the gliding leg, at the toe-assist the hip was in the neutral position on the frontal plane, whereas it was markedly flexed, as the knee and the ankle. Taken together, the results showed rather different executive strategies in various phases of the movement, highlighting individual interpretative patterns.

Synthetic turf fields have become very popular, but little is known on how playing on artificial grass affects the soccer-specific physical performance. This study aimed to compare a natural vs. a synthetic grass surface concerning the physiological responses to an intermittent running protocol simulating the work rate of competitive soccer, and the effects of performing that protocol on sprinting ability, jumping ability, and muscle soreness. Nine soccer players [21.0  1.3 yrs; 1.82  0.05 m; 76.5  9.1 kg] carried out two 15-min blocks of the Loughborough Intermittent Shuttle Test (Nicholas et al., 2000), respectively on third generation synthetic turf (SYNT) and on natural grass (NAT). Heart rate (HR) was monitored throughout the test, and a ratings of perceived exertion (RPE) was collected after each block. At the end of the test, the subjects performed a countermovement jump (CMJ) and a 2x20-m maximal sprint. Muscle soreness was evaluated in the two days following the test using a 7-points Likert scale. The Average HR was significantly higher on SYNT than on NAT (1st block: 164  9 bpm vs. 157  8 bpm; 2nd block: 167  9 bpm vs. 161  8 bpm). The RPE showed a similar trend, tending to be higher on SYNT (1st block: 4.0  1.8 vs. 3.6  1.3, p=0.21; 2nd block: 5.1  1.9 vs. 4.7  1.6). The CMJ height was significantly higher after the test on SYNT (45.1  4.6 cm vs. 43.4  3.7), whereas the sprinting performance was similar in the two conditions (SYNT: 7.10  0.12 s; NAT: 7.03  0.14 s). Finally, muscle soreness was significantly higher after the test on NAT (1st day: 1.8  0.9 vs. 1.1  0.3; 2nd day: 1.4  0.9 vs. 0.6  0.7). These results can be interpreted in view of the higher compliance of the synthetic surface, involving a higher energy expenditure during running but a lower impairment of the elastic energy reuse action and a lower stress on the musculoskeletal system. REFERENCES • Nicholas CW et al. (2000), Journal of Sports Sciences, 18:97-104

La pratica dello stretching nella seduta di allenamento è argomento spinoso e ormai dibattuto in modo diffuso sia da chi pratica sul campo che dalla stessa ricerca scientifica. Stabilire se e quanto lo stretching influisca positivamente o meno sulla prestazione di forza, soprattutto di quella veloce, rimane un obiettivo a cui la letteratura deve cercare di dare una risposta, anche perché i tentativi fatti finora non hanno portato a risultati omogenei né a proposte operative standardizzate . In questo studio si è indagato per cercare di capire se un programma combinato di stretching e forza influenza positivamente la prestazione del vertical jump, rispettando i criteri operativi più diffusi in letteratura, allo scopo di offrire un contributo a chi lavora sul campo ed uno spunto per ulteriori approfondimenti per chi si occupa invece di ricerca scientifica.

In questa seconda parte del confronto tra generi nella partenza dai blocchi in atletica leggera (cfr 1^ parte AS 2010/4), viene analizzato il livello top mondiale. In questa ricerca sono analizzati 4 atleti maschi e 4 femmine top class internazionali, acquisiti durante il Golden Gala 2010. Per l’analisi tridimensionale si è utilizzato SIMI Motion System e si sono studiate le variabili cinematiche, angolari e temporali della posizione sul “pronti” e dei primi 2 appoggi. Anche in questo caso, così come nell’analisi sviluppata nella prima parte dell’articolo, i risultati mostrano una sostanziale standardizzazione del gesto nei 2 generi con una predilezione nelle donne a mantenere una posizione sui blocchi più chiusa e compatta rispetto agli uomini. Le poche differenze riscontrate sembrano collegarsi a fattori antropometrici o condizionali più che ad aspetti legati alla tecnica: questo ci porta ad affermare che nella pratica da campo risulta importante soprattutto riporre l’attenzione su alcuni parametri basilari come l’apertura degli angoli articolari dell’arto posizionato sul blocco posteriore durante il pronti e al via e l’inclinazione del busto durante i primi appoggi. Nell’uomo questa inclinazione viene mantenuta cercando di tagliare i primissimi passi in uscita dai blocchi, mentre nella donna è possibile sfruttare maggiormente i range articolari di anca e ginocchio degli arti in appoggio. E’ interessante notare come l’inclinazione del busto all’uscita dai blocchi sia molto simile in tutti gli atleti e che i 2 atleti (1 per genere) che commettono un errore tecnico su questo parametro, siano quelli che presenteranno il risultato finale peggiore, mostrando così come il sistema utilizzato possa tornare utile anche nell’evidenziare errori tecnici individuali.

La partenza dai blocchi risulta uno dei gesti dell’atletica maggiormente indagato dalla letteratura. E’ altresì vero però che sono pochi gli studi che mettono a confronto le stesse variabili nei due generi, soprattutto in condizioni di gara. In questa ricerca si sono raccolti i dati delle partenze dai blocchi di 12 velocisti (6 maschi e 6 femmine), durante i Campionati Italiani Giovanili Indoor di Ancona 2010 (i 6 Campioni Italiani delle categorie Allievi, Junior e Promesse maschili e femminili e 1 atleta piazzato sul podio di ogni categoria). Per l’analisi tridimensionale si è utilizzato SIMI Motion System e si sono studiate le variabili cinematiche, angolari e temporali della posizione sul “pronti” e dei primi 2 appoggi. I risultati mostrano che il gesto nei 2 generi e nelle diverse categorie di età risulta fortemente standardizzato, tanto che non esiste una differenza significativa tra i uomini e donne, a dimostrare che, probabilmente, gli aspetti tecnici e coordinativi nei primi 2 appoggi prevalgono su quelli condizionali, che invece, potrebbero influenzare maggiormente la successiva fase di accelerazione. Le variabili ottenute si sono anche messe in relazione con la prestazione finale, che è risultata correlata nei 2 generi solo con l’angolo dell’anca sul blocco posteriore al pronti e con il 1° volo all’uscita da questi. Il metodo utilizzato ha permesso anche di identificare alcune caratteristiche individuali ed eventuali errori esecutivi.

Humans prefer to use a limb rather than the other, and not always the same for different tasks. Furthermore, people show a variable functional asymmetry: somebody is markedly right- or left-sided when performing different tasks, while others show various degrees of mixed laterality (Greenwood, 2007). Aim of this study is to investigate the lateral choices among young athletes practicing different sports. 390 young athletes (M: 234; F156) practicing sport in Emilia-Romagna and Abruzzo, Italy, aged 11-14 were divided in eight sport groups: Soccer, Athletics, Volleyball, Basketball, Other Team Sports (OTS: Rugby, Handball, Water Polo), Individual Sports (IS: Triathlon, Gymnastics, Swimming, Roller Skating, Rowing), Combat Sports (CS: Judo, Karate, Wrestling), Sport requiring a lateral choice (SLC: Fencing, Tennis). Different tasks were used (performance test) to assess lateral choices: 11 tasks for the hand, 4 for the foot, 5 for twist rotation. Lateral choices were assessed following two criteria: first, noting the side used by the subjects in writing, throwing or kicking a ball; second, computing an index, taking into account the number of right and left performances for all the tasks. In this case subjects choosing the right or left side in all the tasks (or all except one) were considered right or left sided; the other subjects were considered and named “inconsistent”. Writing, throwing and kicking sidedness data were then reported for each sport or sport groups such as frequency and percentage of subjects right, left or inconsistent in hand, foot and twist choices among these sport categories. Lefthanders in writing and throwing are highly represented in SLC (15% of the sample and 11% respectively) and volleyball (11%); in kicking, OTS is the highest represented category with left choices (29%), followed by basketball and soccer (23%). Hand, foot and twist sidedness are then described for each considered sport or sport group. Lefthanders are highly represented in volleyball and SLC (8%), inconsistent in OTS (22%). Left footed are mostly represented in SLC (30%), CS and soccer (21%); inconsistent in soccer (26%), IS and volleyball (23%). Left twisters are numerous in SLC (33%) and athletics (18%); inconsistent in OTS (76%) and IS (75%). Left-handed and left-footed are highly represented in SLC, CS and soccer. This could be due to selection factors and training tactical and strategic choices, according with Groius et al.(2000). Inconsistents are prevalent in OTS for the hand, in soccer for the foot and in all the sports involving twist direction.

Nel capitolo dei metodi vengono descritti dettagliatamente i protocolli dei test utilizzati (Salto in lungo da fermo, Lancio della palla da seduti, Corsa a spola, Hand-grip, Sit & reach, Equilibrio dinamico, Comma test, Mimo e Punteggiatura) per la valutazione delle capacità motorie dei 186 soggetti analizzati nella ricerca.

Lo studio della corretta tecnica esecutiva di un qualsiasi gesto sportivo acquista maggior significato se la raccolta dei dati avviene durante l’evento agonistico. E’ solo in gara, infatti, che l’atleta si esprime al meglio e definisce quelli che sono i parametri che influiscono sulla prestazione. L’articolo analizza la cinematica del passaggio dell’ostacolo di 2 atleti top class mondiali ( 2° e 4° classificato ai Campionati Mondiali di Atletica del 2005) durante il Golden Gala di Roma del 2005, utilizzando il sistema SIMI. Vengono acquisiti i dati sul passaggio del 9° e 10° , sui passi e sull’Unità Ritmica relativa. I risultati mostrano come i comportamenti dei 2 atleti nel volume di acquisizione considerato sia profondamente diverso e come per il 2° atleta classificato si verifichino degli errori tecnici dettati dalla situazione contingente di gara, che pertanto influisce sul gesto per quanto questo sia perfettamente automatizzato e standardizzato. L’articolo valuta anche i buoni risultati ottenuti dal punto di vista metodologico: il sistema usato non condiziona minimamente l’atleta ripreso e mostra una relativa facilità di applicazione

INTRODUCTION Anthropometric characteristics of rugby players are very important for their performance. Aim of this study is to investigate the relationships between anthropometric parameters and selected motor tests indicative of rugby performance. METHODS 70 young rugby players (15,3  0,52 yr; 183,9  4,3 cm 91,02  15,84 kg) participating to meetings of the Italian Rugby Federation were recruited. They were assessed with a battery of 6 motor tests (squat- and countermovement jump, 30m running speed, 35 m shuttle running test, sit and reach, shuttle endurance test) and 26 anthropometric measurements (height, weight, 7 linear trunk and limbs lengths, 8 girths, 2 bone diameters and 7 skinfolds). Pearsons’ r correlation coefficient, cluster and factor analysis were used to study the relationships between variables. RESULTS 6 clusters were obtained from the correlation matrix including motor tests and anthropometric variables. The first one includes weight, waist, some skinfolds and girths. Other trunk and limbs girths are covered by the second cluster. In the third one motor strength and speed motor tests are included. The fourth cluster covers the endurance test linked to thigh, triceps and sural skinfolds. The fifth includes height and upper limb linear measurements. Humerus and wrist diameters are connected with flexibility test in the sixth cluster. 12 variables among the most representative of each cluster were selected. From the factor solution with varimax rotation 3 factors were extracted. The first factor, accounting for 42% of total variability, includes mass measures (body weight, chest and arm girths, and 3 skinfolds) and femur diameter. Motor tests are weakly and negatively saturated with this factor. The second factor, accounting for 23% of total variability, covers especially strength and speed tests. Endurance test is weakly but positively saturated with this factor, while 3 skinfolds are negatively saturated with motor performance. The third factor accounts for 12% of total variability and includes above all height, femur diameter and, negatively correlated, endurance test and shuttle running test. CONCLUSIONS It is important in rugby players to monitor body mass parameters and skinfolds because they may have a negative influence on performance. Highest players have to train agility because they tend to have the worst performances in agility tests.

The most recent cross-sectional studies on the evolution of physical abilities in youth took into account the secular trend on various aspects of motricity. In 1981 a survey was carried out by CONI on a national sample of young athletes (Carbonaro 1984). The purpose of the present study was to compare the results of some of the assessments performed in 1981 with the corresponding ones executed in 2009 on subjects with the same sport curriculum. The sample included 11-14 years old subjects attending the “Centri CONI di Avviamento allo Sport” for at least two years. The 1981 sample included all the Italian regions (M:1495; F:700), while the 2009 sample included all the provinces of Emilia-Romagna and Abruzzo (M:190; F:117). Anthropometric measurements (Body mass and Height), conditional tests (Standing Long Jump, Sitting Ball Throw, Shuttle Run, Hand-Grip and Seat & Reach) and coordination tests (Balance and Hand Movement Frequency) were carried out. A three-way ANOVA (gender x age x survey year) was used to analyze the considered DVs in the different conditions. Body mass was significantly higher in 2009 vs. 1981, while no differences between the survey years were shown for the height. In 1981, the SLJ, B and S&R performance was better than in 2009 in all age classes. Oppositely, the subjects tested in 2009 performed better than their 1981 counterparts in SBT, SR and HMF. In the HG 2009 test, male showed better results (without significant differences). So did females but only in the younger groups. In conclusion, some performances are improving while others are worsening and this may be due to differences in body weight, training quality and lifestyle even in non-sporting activities.

The purpose of this study is to verify if a specific strength training program can reduce the transition time from descent to ascent phase in squat exercise. The kinematic and temporal data of 3 depth squats with different load (35%, 40%, 45% of 1RM) during 2 test sessions, before and after a specific strength training program, have been collected. The Track and Field 400m Italian Champion have been analysed during the depth squat through an optoelectronic stereophotogrammetric system for tridimensional motion analysis. The collected data were: knee and hip angles, time of eccentric and concentric phase (descent and ascent times), the transition time (from descent to ascent phase). The results show that a specific strength training can develop the speed of movement and, particularly, decrease the transition phase time at heavy load. This method can be useful to search an optimal depth squat load and to develop the Stretch Shortening Cycle (SSC) speed.

Nel capitolo dei metodi vengono descritti dettagliatamente i protocolli dei test utilizzati (Salto in lungo da fermo, Lancio della palla da seduti, Corsa a spola, Hand-grip, Sit & reach, Equilibrio dinamico, Comma test, Mimo e Punteggiatura) ed i soggetti analizzati (207 in totale di cui 126 maschi e 81 femmine).

Introduction and objectives of the study The Youth Game are an italian sport event that involved the student of the middle school in several sports and are a good chance to analyze and compare the performance of great sample. In this study the data of 3 official track and field competition are collected, in order to value the differences about age, gender, school and provenience country. Methods The analyzed competition were: 30m of sprint, long jump and vortex throw. Trials have been performed on official track and measurements have been collected from Track and field federation referees. Subjects participating to this study, attended the 1st and 2nd class of the middle school of Bologna and his province (age 12-13 years). Students have been compared about the class, gender, town (big=BT, middle=MT and little town school=LT) and Country (Italy=IT or Other=OT).In tab. 1 is described the sample size. Tab. 1 NUMBER Class Male Female TOTAL 1 216 220 436 2 91 75 166 TOTAL 307 295 602 Results In tab. 2 are reported the means of the groups in the 3 trials. SPRINT m/sec JUMP mt THROW mt Class Male Female Male Female Male Female 1 5,30 5,22 2,86 2,58 23,62 14,44 2 5,55 5,37 3,11 2,82 27,76 16,04 The Statistical Analysis highlighted in all trials significant differences between genders and classes. In the comparison among schools, the only significant difference occur in the 2nd class student throw, where the ST schoolgirls achieve the best results. Between provenience country, the 1st class schoolgirls shows the only significant difference in sprint, where the IT girls run more quickly then the OT. Conclusions While the differences about gender and class were expectable, at the beginning of this study, a larger difference among the towns were expected; whereas the significant differences occur only in the 2nd class schoolgirls throw. In this case we can suppose that the LT girls can practice sport in a larger area and have more possibilities to play in the open air: in fact the trend shows best results in LT and MT also in long jump and sprint run. About the provenience country, it’s possible that the better social standing of IT parents lead daughters to be engaged in many activities and to spend more time to practice sport; so it’s possible to explain the best performance in sprint of the OT schoolgirls. An other step to master the research can be to identify the subject’s sport experience and TO study the influence on the mentioned data. References -Carbonaro A., Madella A., Manno F., Merni F., Mussino A. La valutazione nello sport dei giovani Società Stampa Sportiva, Roma (1998) -Ward D., Saunders R., Pate R. Physical Activity Interventions in Children and Adolescents Human Kinetics (2007) -Lea Lund J., Fortman Kirk M. Performance-Based Assessment for Middle and High School Physical Education Human Kinetics (2002)

The purpose of this study is to find analogies and differences among 3 different skills: speed run and two special exercises (bounding run and skipping). Three correlation patterns have been created, each for one of the 3 skills, every pattern takes origin by multivariate analysis (cluster analysis), using the same 12 variables. All these variables (spatial, temporal and kinematic) are relative to the Center of Mass (COM). Eight athletes were analyzed and the system used to get the data was the Vicon Motion System (3D optoelectronics system). The analysis has shown that only few variables of the 3 patterns are correlated in the same way, these few variables must to be taken into consideration to develop the running performance through these special exercises.