. l . I . a . ,- . ‘I a . . . . . ; v, I“ x . . -. . v " ,- ‘- \‘v .\ ‘ . V. 6 q .. .. l“ . . ..‘ . .0 AC! . , , r . . _ o . . . - a o ' . . r—r‘-“i.‘~ , y -n- ..-.‘... .. - ‘7. r0. 0 - ~ - yaOvvC-«ov I‘D - ». - . . coo-yo. 9.0~.‘.-‘m.~ EMATGGRAPHECAL AND MECHANICAL ANALYSIS OF THE HECHT VAULT Thesis for the Degree 0f M. A. ' MECHEGAN STATE NERSITY ANDRE VALUERE 197.0 . . . I .- . . . ; . . . ' .. ‘ . - - .. . n , ,o. '- . -. . 4 .., 4. . . . ' .. .0 , , . . A n , ‘ 0' ' .. ' ‘ . . . .0 v' ‘ . ' ' I .4 ' .. . _ .. l‘ . A ' .51’ .. ' . , I . ,, . o ‘ ' _ , .- v , . - .. ..,. ‘ .... . __ .. . -.. ., - ,.- n , ,0 ‘ - ' ' I. - ’ . , . . y,. . 4 . _. ,l _.u a t .. . ' v I . ‘ ' I . . o “ I I 1" ... . . ..- ' _ .- - - . . .‘_, . ‘ v . _,. ' ' ‘ I ...r- n‘ _'. -v , . . _.u.. _ I ”"4 p A .. l I ‘ "' ‘ V,. o u ' V ‘ 'r . .- - . .. .... ‘. ..0 .. - . - .1 .. . a . I ~- ' ..:.--. a ' a ' I ' I c- I ' "‘ O . I ' ‘ l . " . o ‘ _ . I. I' . I - .- “NJ“! Mvmm Tfiu‘wl ‘4 LI B P «4, R Y MiGE’ligu 8 3:34.26 Univc L 4} if}! A CINEMATOGRAPHICAL AND MECHANICAL ANALYSIS OF THE HECHT VAULT By Andre Valliere A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF ARTS Department of Health, Physical Education and Recreation Approved Professor of Physical Education Thesis Advisor Head of Department of Physical Education 1970 TABLE OF CONTENTS LIST OF TABLES LIST OF FIGURES Chapter I. II. III. INTRODUCTION The Problem. . Limitation of the Study Definition of Terms REVIEW OF RELATED LITERATURE Literature Related to the Descriptive Form . Literature Related to the Evaluation Criteria . . . . . . METHODS Subjects Direct Measurement of the Approach Velocity . . Cinematographical Procedures Filming Equipment Filming Technique . Calibration of the Camera . . Calculation of the Multiplier Analysis Equipment . Judging Procedures . . . . . Variables and Methods of Calculation Center of Gravity . . . Velocities Distances Angles Times Selection of Vaults ii Page iv Jr-IIUU l2 l2 13 14 ll! 15 17 18 18 19 19 20 21 21 22 23 23 Chapter Page IV. ANALYSIS OF DATA . . . . . . . . . 25 Statistical Techniques . . . . . . . 25 Results and Discussion . . . . . . . 25 Quantitative Aspects . . . . . . . 26 Approach . . . . . . . . . . 26 Take- off . . . . . . . . . . 28 Pre- -flight . . . . . . 30 Take- off from the Long Horse . . . . 30 Free Flight and Landing . . . . 34 Relationships to F. I. G. Criteria . . . 36 Graphic Presentation of Selected Hecht Vaults . . . . . . . . . 38 V. SUMMARY AND CONCLUSIONS . . . . . . “2 Summary . . . . . . . . . . . . 42 Conclusions . . . . A3 Recommendations for Further Study . . . A4 LIST OF REFERENCES . . . . . . . . . . US APPENDICES . . . . . . . . . . . . . U8 A. RAW DATA FOR HECHT VAULT . . . . . U9 B. INTERCORRELATIONS BETWEEN VARIABLES . 52 iii Table LIST OF TABLES The Physical Characteristics of the Subjects . . . . . . Approach Results Take—off Results Pre-flight Results Results of Take-off from the Long Horse . . . . . . . Results of Free Flight and Landing iv Page 12 27 29 31 32 35 LIST OF FIGURES Figure 1. Perfect Hecht Vault Execution 2. Initial Contact Evaluation 3. Time Recording Apparatus A. Placement of the Camera in Relation to the Long Horse and the Grid (Posterolateral View) . 5. Hecht Vault of Subject C 2 - Score 8070 o o o o o o o o o 6. Hecht Vault of Subject D 5 - Score 3.00 . . . . . . . . . Page 13 16 39 39 CHAPTER I INTRODUCTION At the 1962 World Gymnastics Championships, the Japanese competitor Yamashita performed an original vault on the long horse. It is now called the Yamashita vault and is a free body rotation in a piked position. This was, for gymnasts all over the world, the signal which opened the way for the search for more and more complex vaults. Some variations of the Yamashita vault have already been executed. In 1963 the Bulgarian Adamov performed Yamashita's vault with a full twist. Since then, no new modifications have been witnessed in the long horse event, not even at the 1968 Olympic Games. In contrast, the pommel horse, high bar, and floor exercises have all seen innovations. This might be explained by the following: 1. The points awarded to the vaults according to the International Gymnastics Federation do not motivate the athletes to study and perform more complex vaults. 2. There is a lack of emphasis on horse vaulting during the training periods. 3. There is a lack of research in this particular event. In the areas of science, education, and technology, research provides new knowledge, improved teaching methods and innovations in technique. This can also be true for athletics. Through trial and error methods, gymnasts have been looking for something new. Trial and error can bring about modifications and can also improve teaching methods; but as one knows, it is a rather slow process. It appears that new knowledge is necessary. Biomechanical research of gymnastics may help. This research will take two forms. First, the descriptive form will elaborate the components of movements in terms of time, velocity, force, angles etc. A better understanding of this knowledge will develop a sound basis upon which corrections, improve- ments, or modifications of the form as well as teaching methods will take place. These descriptions will also produce hypotheses for the second form of research. This will be the experimental method which will improve teaching methods and will possibly bring suggestions for completely new movements. In fact Mikov (8) in a previous biomech- anical research on long horse vaulting concluded that all possibilities for original performances have not been exhausted. In previous studies on the long horse done by Fetz and Opavsky (3), Gombos (A), Guerrera (5), Kotelnikova(7), Vanis (10) and Wiemann (12), it has been found that the horizontal velocity, the take-off angle from the board, the angle of the body with the horse at initial contact, the height of the free flight and the horizontal landing distance are the most important factors which differenciate good vaulters from bad ones. Most of these studies have been done with subjects of a high level. With subjects having less experience, are these same factors the most important? From a practical point of View, a vault is consid- ered good or bad when it has been evaluated according to the F. I. G. judging criteria. It is stated that the vault should be evaluated mainly according to the angle of the body with the horse at initial contact (minima 25—30 degrees), the height of the free flight and the horizontal landing distance (minima 1600 mm). It would then be interesting to compare the different movement components with those criteria stated by the F. I. G. It is the writer's interest to investigate the long horse vault in light of the rapid development and increased popularity of gymnastics in Canada as well as abroad. The Problem Based on the lack of quantitative description and the criticisms of the evaluation of the "hecht" vault the purposes of this study were: 1. To describe quantitatively, with the aid of cinematography, the biomechanical movement com— ponents of a hecht vault. 2. To find the relationship between those movement components and the criteria for judging this vault as stated in the F. I. G. rule book. Limitation of the Study The problem was delimited mainly by the number of subjects. Four amateur gymnasts were subjects for this study. Definition of Terms Approach: The approach refers to the phase of the vault before the take—off from the springboard. Take-off: The take-off refers to the phase of the vault when the gymnast is in contact with the springboard. Pre-flight: The pre—flight refers to the phase of the vault from take-off until the vaulter contacts the long horse with his hands. Initial contact: Initial contact refers to the moment the vaulter touches the springboard or the long horse. Last contact: Last contact is defined as the final moment the vaulter is touching the long horse. Free-flight: ~Free flight is the phase of the vault from last contact to the moment the vaulter's feet touch the ground at the landing. CHAPTER II REVIEW OF RELATED LITERATURE The literature relevant to the present study can be divided into two categories: (a) that dealing with the descriptive form of research; and (b) that dealing with current opinions on evaluation criteria.. Literature Related to the Descriptive Form Several studies have been conducted to describe quantitatively the different biomechanical components of a "hecht" vault. Tarakanov (9) studied the importance of the run in the learning process in long horse vaulting. He stated that a well adjusted run is of prime importance and that it facilitates the learning process and the fundamental technique of vaults and therefore makes it easier to perform them. In other respects, Wiemann (11) worked on the basic mechanics of forward rotation in gymnastics. He concluded, after having analysed movements performed by Dr. Oto, Yamashita, Endo, Nagosawa, Heckkinen, Minicelli and Hillebrandt, that contrary to popular opinion, the thrust at take off does not increase the rotational impulse but rather decreases it. He stated that as soon as the feet touch the board, a great angular 5 velocity is created which afterwards is reduced by the thrust just prior to final contact. Comparing the take off phase of a Yamashita vault, as executed by its creator and by Endo, with a "hecht" vault, performed by Minicelli, he found that in a jump such as the "hecht" which does not need as much rotation as the Yamashita vault, the unilateral stoppage creates a proportional angular velocity which is completely absorbed by the thrust on the board. In an another study Wiemann (12) stated that the time of contact on the horse is the factor that differentiates good vaulters from bad ones. Fetz and Opavsky (3) give some biomechanical component values of the hecht vault obtained in their study. They found a horizontal velocity of 6.3 m. per second at last contact with the ground prior to the preparatory jump and an elevation of the center of gravity in the free flight of 32 cm. They also found that the angle of body at contact with the horse is less than in all the other vaults. Gombos (A) found similar data in his study of the hecht vault. Guerrera (5) sought to quantify the mechanics of both the handspring and the hecht vault and to relate them to the scores awarded by the judges. He found that the higher scoring hecht vaults demonstrated a greater range of angular movement of the center of gravity on the springboard, a larger take-off velocity, a higher angle of the legs at initial contact and a greater rise of the center of gravity after last contact With the long horse. Kotelnikova (7) compared the performances of the hecht vault of three famous world gymnasts: Krbecs, Chaklin, Yamashita. It was found that the highest score was attained by the gymnast who had the greatest speed, the greatest horizontal distance from the hand contact with the horse to the landing spot, the greatest horizontal distance from the take-off to the nearest end of horse, and the smallest angle with horizontal at take—off. Literature Related to the Evaluation Criteria The Federation of International Gymnastics established the standards for the competitive evaluation of performances. Figure I depicts perfect performance of a hecht vault. Thus, in order to be awarded a perfect score of 10.0, the vaulter's performance must parallel the performance illustrated in Figure 1. The F. I. G. (1) also has established standards for specific phases of the vault. Figure 2, shows the different positions of the vaulter at initial contact. Points deductions with respect to these positions are as follows: 1. The maximum of 10.0 points will be given if the angle formed by the support of the hands through the stretched body (that is to say, the line from hands through the feet) with the top of the horse is at least 30 degrees. Figure 2. Initial Contact Evaluation 2. The maximum will not be more than 9.50 points for a horizontal support 3. The maximum will not be more than 9.0 points if the feet are not higher than the top of the horse, and the score will decrease (proportionately) if the feet are still lower. A. Of course, intermediary scores such a: 9.10, 9.20, 9.60 and 9.70 points, etc., are applicable. The F. I. G. stated that the vaults must show development during the second phase, demonstrating a high and long free flight. The following point deduction system applies to long horse vaults. 1. Flight and support of the hands below 30 degrees (see Figure 2, page 8) . . . . 2. Flight too low and not long enough following the support 3. When, after the vault and at the landing, the gymnast is not at a distance which cor- responds to the drawing (see Figure 1, page 8) A. Too strong a flexion of the body forward before landing 5. Bad direction of the vault 1/10 to 10/10 points 1/10 to 5/10 points 1/10 to 5/10 points 1/10 to 5/10 points 1/10 to 5/10 points 10. ll. 12. 10 Placing the hand (3) in the (A00 mm.) zone on the neck or croup side, or partly touching these zones (This rule recently changed). . . . 10/10 Placing the hand(s) in the zone (A00 mm.) in the center of the horse, or partly touching this zone . . . . . . . . 5/10 Bad position of the feet, legs, body, head, unnecessary strad- dling of the legs, each time . 1/10 to 3/10 If the faults just mentioned are committed during the entire vault . . . . . . . A/lO to 10/10 Touching the body of the horse with the feet, the legs, the knees, or other part of the body . . . . . . . . 2/10 to 5/10 For even more serious cases . . 6/10 to 10/10 Arms bent during the execution of the handspring . . . . . 1/10 to 10/10 Knees bent during the execution of the hecht (swan) vault . . 1/10 to 10/10 points points points points points points points points ll 13. Standing at the end of the vault. The landing after the vault is judged in the same manner as for the apparatus and floor exercise, that is: a. Small step or hop . . . 1/10 to 2/10 points b. Several steps or hops, touching the floor with hands without real support . . . . . . . 2/10 to 3/10 points c. Sitting, kneeling, falling on the back, or very bad posture . . . . 3/10 to 5/10 points d. If undesirable behavior before and after the vault 1/10 to 3/10 points Fetz (2) deals at length with the problem of two long horse evaluation criteria: The grip zones and the preflight angle. He rejects both criteria believing the vault should be evaluated principally for height and distance. Faults of preflight and grip should only be considered according to their bearing on height and distance. The author's fundamental question is: Does the preflight angle constitute a value intrinsically pertaining to the vault? From his viewpoint, good hechts often have a lesser angle than 30 degrees. CHAPTER III METHODS The purpose of this chapter is to describe the procedures used in this study. Subjects The subjects were four male volunteers. Their physical characteristics are presented in Table 1. TABLE l.-—The physical characteristics of the subjects. Subject Age Weight Height Vertical Standing Broad (Kg) (m) Jump (m)* Jump (m) A 23 76.A 1.676 0.660 2.667 B 21 63.6 1.676 0.72A 2.731 C 19 65.9 1-727 0.552 2.375 D 21 62.3 1.689 0.6A8 2.693 *The best of three trials. All had earned a degree in physical education. They possessed different degrees of jumping abilities and therefore, provided a range of scores. All of them were familiar with the sport as gymnasts but only two were competing in the senior category. 12 13 In preparation for the testing, the subjects were directed to wear only shorts and gymnastic shoes. This made it possible to determine the position and movements of the subjects' body segments by cinematographical techniques. Points of articulation at the shoulder, hip, knee and ankle points were determined by palpation and then marked to form black spots on the skin approximately 2.5 cm in diameter. The distance between each of the spots, as well as the heights of the performers while standing erect were also determined. Performances such as standing broad jump, vertical jump (Table 1) were also recorded to determine possible relationships between these data and the movement components. Direct Measurement of the Approach Velocity An apparatus (Figure 3) was built with a "breaking circuit switch" and a wooden pedal in order to determine the average running velocity between the starting point and the initial contact with the board. “a“? 6—7 Canon. 0 a. . O tLtCI'RK VIRGO!” Mm." 1.0! A] Figure 3. Time Recording Apparatus sumac“) . _ n I “£33021 1A This switch was connected to an Athletic Performance Analyzer which recorded the length of time (in hundreth of a second) during which the switch was open. A platform was placed underneath the springboard and served to break the circuit. The subject was asked to stand on the pedal (P) with the foot that he was going to move first; the contact at 81 was closed and the chronometer was set at zero time. As the foot left the pedal, the chronometer started and worked until the athlete contacted the springboard. This contact with the platform stopped the chronometer. The average running velocity was calculated from the_measured time and distance. Cinematographical Procedures Filming Equipment The photographs were taken with a Bolex 16 mm motion- picture camera which was mounted on a stationary tripod. A telephoto lens was used in order to get a better picture and minimize any perspective errors. Kodak tri—X reversal film no. 7278 was employed. The subjects were photographed against the espaliers which served as a background grid. The horizontal and some of the vertical wooden bars were covered with white masking tape. The espaliers were 1.5 m from and parrallel to the field of motion. The distance between the vertical bars was 90 cm while the distance 15 which separated the marked horizontal ones was 30 cm. An official springboard and long horse were used in this study. The height at the top of the horse was set at 1.35 m. The photographic data were colle3ted in the Maisonneuve Recreation Center, Montreal, Canada. The regular artificial lighting of the gymnasium was of sufficient intensity to meet the needs of good photography. Filming Technique The camera speed was set at 6A frames per second with a lens opening of f 2.8. The shutter speed provided a clear picture for later analysis. To minimize the effects of reduced spring tension on the camera spring, the camera was kept wound as fully as possible and was always started a few seconds prior to the testing in order to permit the camera to reach its regular speed before the picture taking began. The camera was installed 30 m from the field of motion as diagramed in Figure A. In order to avoid "to from" distortion introduced by "panning" Hubbard (6) states that the camera must be 30 to A0 feet from the subjects. The camera was placed so that its lens was parallel to and directly opposite the approximate mid point of the field of motion. This was about 10 m. and included: the last stride length, the length of the preparatory jump, the distance from the springboard to l6 \ \‘*%\\ \ Figure A. Placement of the Camera in Relation to the Long Horse and the Grid (Posterolateral View) 17 the horse, the length of the horse and the distance from the horse to landing. The 30 m distance between the field of motion and the camera, together with the use of a telephoto lens, reduced as much as possible any perspective error. At this distance, it was not necessary to move the camera from left to right in order to photograph the movement of a vaulter throughout his execution. The height of the camera above the floor was set at 1.5 m. Calibration of the Camera A medicine ball weighing 1.73 Kg was used to verify and determine the reproductibility of camera speed. The ball was filmed as it dropped from a heigqt of 2.A3 m. The elapsed time was calculated between tie moment the ball was released and the moment it contazted the floor. The following formula was used: S=l/2 gt3. .The value of g used was 9.80m/sec2. The calculated time (t) was equal to 0.67A6 of a second. Later, by careful observation of the film, the number of frames from the moment the ball was released until it reached the floor was determined by means of a film counter on the projector. Knowing that the ball fell 2.A3 m in 0.67A6 second, it was possible to check the true speed of the camera. The ball was filmed two times while dropping, and the camera speed was found to be one frame for each 0.01933 seconds of time. 18 Calculation of the Multiplier This factor was computed on the basis of the photo— graphed distance marks. A 3.658—m bench was photographed in the field of motion. When the film was projected on the wall, this bench appeared to be 76.3 mm long. After calculation, the multiplier was found to be .0A79A to give all the measurements in meters. The multiplier was used to convert distances measured after the projection of the film to lifesize distances. Analysis Equipment The developed film was placed in a 16 mm Spectro Analyser Projector, and each of the frames to be studied was projected on 1 mm graph paper fixed to a board mounted at right angles to the optical axis of the projector. In order to eliminate multiplier fluctuations, the projector was fixed and was operated at distance by mean of a cable control. Some marks like the long horse and the vertical and horizontal lines from the grid were drawn from the first frame of each sequence in order to see if the projected pictures showed the chosen marks in exactly the same relative positions. If through panning or otherwise there were discrepancies, corrections were made to coordinate plots on the squared paper. The next step was to pin a sheet of transparent typing copy-paper over the squared master—sheet and to project onto it each frame to obtain the different angles of the body segments. The trajectory 19 of the estimated center of gravity of the body was traced onto the master sheet (squared paper). lnformation such as distances, point of contact with the springboard, point of contact with the horse, point of contact at landing, etc. were also recorded. Judging Procedures Each gymnast was asked to perform five jumps. The first one was said to be for warming up, but it was recorded as well as the four others. The four remaining vaults were performed as if the gymnasts were competing, i. e. two consecutive vaults executed twice by each of the gymnasts. All the vaults were evaluated according to the F. I. G. criteria. One chief judge and four other judges composed the jury. From the four judges scores, the lowest and the highest scores were rejected and the score employed was the mean of the two other judges scores . Variables and Methods of Calculation This study involved five general categories of variables: (a) center of gravity, (b) velocities, (c) distances, (d) angles, and (e) times. These measures were selected to provide a comprehensive description of all phases of the vault. The statistical calculations (i. e. the mean, the standard deviation and the simple 2O Pearson coefficient of correlation) were calculated on an Olivetti Underwood Programma 101. Center of Gravity According to Dempster (13), the position of the center of gravity (c. of g.) with the body in the anatomical position is located at hip height (the crest of the ilium). If the arms are raised above the head simulating the body position of the vaulter through nearly all phases of the vault, the position of the center of gravity is shifted slightly toward the head. For purposes of analysis, the investigator believed that an estimate of the position of the center of gravity vas justified. The path of a vaulter's center of gravity covered a horizontal distance of approximately 6 m. Therefore, any slight error of estimation along the path in relation to the large distance traveled would be insignificant. Furthermore, since the body segments maintained a relatively constant relationship to one another throughout all phases of the vault, the position of the c. of g. would not significantly shift within the body. This also minimized the effects of the estimation process. The c. of g. positions were estimated for each vault at every two frames from the last contact with the ground prior to the preparatory jump to the contact with the ground at the landing. Positions were estimated at initial and final 21 contact with the springboard and the long horse and at the highest position of free flight. Velocities The velocity variables were the average horizontal velocity from the start to the initial contact with the board and the horizontal velocity of the preparatory jump. Velocities were calculated according to the formula V=d/t where V is the horizontal velocity, d is the distance and t the time. The latter was an estimate of the horizontal velocity using the distance between the point when the c. of g. is over the last contact prior to the preparatory jump and the c. of g. at initial contact with the springboard. This velocity approaches more closely the horizontal velocity at initial contact with the springboard. A greater error would have perhaps appeared, if the velocity had been calculated using the small distance between the last two positions of the c. of g. prior to the initial contact. Distances The horizontal and vertical distances were quantified from the projected film and converted to life size using the multiplier. The following distances were determined. 1. The horizontal distance from the starting point to the near end of the long horse. Note: This distance was measured directly. w , .sgrrx." .. y 22 2. The horizontal distance from the last contact with the ground prior to the preparatory jump to the vaulter's toe at take-off. 3. The greatest vertical height of the center of gravity above the floor during the preparatory jump. A. The horizontal distance from the far end of the “A springboard to the vaulter's toe at take-off. { 5. The horizontal distance from the far end of the spring- board to the near end of the long horse. 6. The vertical height of the center of gravity above ' g the long horse at initial contact. 7. The vertical height of the center of gravity above the horse at last contact. 8. The greatest vertical height above the long horse of the vaulter's center of gravity during the free flight. 9. The horizontal distance from the far end of the long horse to the vaulter's toe at landing. Angles The angles formed by the horizontal and the legs, the legs and the thighs and the trunk and the thighs were measured at initial contact with the springboard. With respect to the horizontal, the angles formed by the toe contact and the center of gravity at initial and final contact were determined to know the range of motion of the 23 vaulter on the springboard. The take—off angle was evaluated using the horizontal and the tangent to the pre-flight trajectory. At the initial and final contact with the long horse, angles with the horizontal and the forearm, the arms and the trunk, and the trunk and the legs were measured. The . ‘1. 'z’ measurements used to indicate the range of motion of these segments were determined as the differences between the initial and last contact angles. 1 11112: Since the time between frames was determined to be 0.01933 second, the amount of elapsed time in certain phases of the vault was calculated by multiplying that time by the number of frames used for each phase in question. The percentage time of each phase of the vault was determined as the ratio of the phase time to total vault execution time. The following phases and percentages were studied (a) contact with the springboard, (b) pre- flight, (c) contact with the long horse, (d) free flight, and (e) the time taken to perform the total vault from initial contact with the springboard to the landing. Selection of Vaults All the 20 hecht vaults filmed were used for the analysis. But, after having taken all the information from these sequences, it appeared that for one sequence the 2A camera had not worked with the same running speed as for the other vaults. This sequence was eliminated from the data. CHAPTER IV ANALYSIS OF DATA This chapter has been divided into the following major sections: (a) statistical techniques, (b) results and discussion, and (0) graphic presentation of the biomechanical movement components. Statistical Techniques Ranges, means, standard deviations, and correlations served the purposes of this analysis. The means provided measures of central tendency for each of the variables, while the standard deviations showed the variability. The simple Pearson coefficient of correlation was found for each of the variables and the judges‘ scores. However, a limitation existed in the latter technique because a single component was correlated with vault scores which are a measure of total performance. It was possible for certain vaults to be awarded identical scores even though specific components of the vaults were quite different. Results and Discussion To serve the purposes of this study, this section is divided as follow: (a) results and discussion of the 25 26 quantitative aspect, and (b) relationshipn between movement components and the F. I. G. criteria for judging this vault. Quantitative Aspects This section is divided into the following phases: (a) the approach, (b) the take-off, (c) the pre-flight, (d) the take-off from the horse, and (e) the free-flight and the landing. References are made to the literature whenever applicable. Raw data for the different movement Acomponents and the inter correlations between all variables can be found in Appendices A and B respectively. Approach Table 2 shows the results of the approach. It can be seen that no significant correlations were found between those movements components and the scores. According to some studies on long horse vaulting (3, A, 5, 7, 10), one might have expected a greater correlation with variable three. Mechanically, it can be said that for a better performance (i. e. a greater height of the c. of g. above the horse in the pre—flight, and a greater distance from springboard to landing) a greater velocity is needed. But, the score is given according to the overall form of the vault, and a greater velocity does not mean necessarily a greater score. If one compares the 8.7 scores of BA and C3 to the 3.0 score of D5 (see Appendix A), it is noticed that the best scores were 27 .uCMQHmficme on 0» mummmmooc mm: on:. mo L cm I mocmofimficmww no Hm>oa mo. um accofimficwfim COApmHoppoo mo ucoH0fimmooo u * Eoooopm mo mompmon NH u z moo. Mao. me.I mwm.l mmm. ema.l :>.m m. m.mH o. om.: 0. 22m. wwm. mmfi. mmwu mmo. wwa. wmaI o.Hm o.mmH Ammmpmmov Upwon Imcfipam spa: pom Iucoo Hwflpficfi um memes» new east» esp somepoo oawc< mma- o.mmH m.H:H Ammmtmmov vsmonwcfiuam npfls pompCoo Hmfipficfi pm mzmflcp pew mwma on» somepoo mawc< omI o.m> mm.mm . Amoosmouv opmon Iwcfipdm cue: pomucoo Hmfluficfi pm Hmpcou Ifipon one new mwoa one comzpon mamc< m I umm.m mmm.m A.omm\sv zpflooflo> Hmpcomfipom mwo.m mmm.m Ampmumev QESw >L0pwpw Idmso one go camcoq m I woo. mma. Ampmpoev dean ALOpmpm Ioopd one no unwamm mLOOm £pH3 cofiumfioppoo cofipmfi>ma ehmocmpm owcwm cam: mfibmflgm> mo mEmz oz mpdsmmm somehaaeuu.m memes 28 executed with almost the lowest velocities (5.66 and 5.79 m per second respectively) whereas the lowest score was achieved with a much higher velocity of 6.29 m per second. Take—off Three significant correlations (Table 3) were found in the take-off phase. The results showed a .50 correlation between score and variable 9. (range of c. of g. movement on springboard), which suggests that the vaults performed while the range of movement of the center of gravity of the gymnast contacting the springboard was greater received the higher scores. Guerrera (5) found similar data in his study. Fetz (3) found in his study an elevation of the center of gravity of 0.61 m from the last contact on the springboard to the initial contact with the horse which might mean that the vaulter took-off at a low angle and that his center of gravity while contacting the horse traveled through a great range of movement. 0n the other hand, a correlation coefficient of .53 with variable 10 suggests that the higher scores were obtained when the vaulters spent more time contacting the springboard. This contradicts Guerrera's data (5). He found a negative coefficient of correlation for this same variable. Mechanically speaking, for a greater performance the time spent on the board should be short. But, as in 29 .pcmOHchme on on mammmmom: was mmn. no h :< I conceamficwam ho Hm>mH mo. pm pQMOAMHcmfim coapmampmoo mo meHOHmmooo Eooomng mo mmoawmc NH ll 2 .mme. *mmm. *Hom. mma. NmH.I mo.H za.ma :Ho. mma. om.: mm.m m:.ma 0.0m o.HHH o.mm I mHH. I o.mm I 0.5m mm.w 0.0m mm.oa Unmon co 68“» mo emancoommm Ha 03H. Amscoommv ommon co oEHB OH mm.a: Amoohmmpv Upmonmcfimam so psoEm>oE .w mo .0 mo mmcmm m mm.moa Ammmhwtev Upwoomcfipam on» spa: pompcoo Hmcfim pm .w mo .0 on» cam Hancoufihoc map coozpmp mawc< w :o.mm Ammopmoov vmmonmcfimom map spas peepcoo Hmfipficfi at .m co .0 on» cam Hmpcoaano: on» cmmzpmn oawc¢ w oaoom spas coapmammnoo soapMfi>oQ ehmecwpm mwcmm new: manmflnm> mo memz oz mpHSmmh mmOImxmell.m mqm¢9 30 the approach (running velocity) it is dependent upon the athlete's abilities. A negative coefficient of correlation of —.5A was found between variable 11 and variable 18 which suggests that when the vaulter spent more time contacting the springboard he hit the horse (angle between forearm p: and the horizontal at initial contact) with a lower angle. 3 3 The correlations (appendix A) between the variables 7, a 9 and 10 (Table 3) of the take-off phase from the spring- 2 board and the variables 18, 20, 21 and 23 (Table 5) _ éI of the take-off phase from the horse, show that there is a great deal of relationship between the body position of the gymnast on the springboard and the body position at initial contact with the horse. Pre-flight No significant coefficient of correlation was found between the variables 12 through 17 (Table A) and the scores. A high coefficient of correlation between variable 15 (take-off velocity) and the scares might have been expected. Guerrera (5) found a significant coefficient of correlation of .63 with the same variables. Take-off from the Long Horse Table 5 shows the take-off results from the long horse. It can be seen that a significant negative co- efficient of correlation of -.635 was found between 31 .pcmOHMchHm on 0» mgmmmoooc mm: mm:. mo 9 Q< I moQMOHthme mo Ho>oH mo. pm pcmonHcmHm COHpmHmhmoo go pcmHOHmmooo Eovmmpm mo mmouwmo NH u z mNo. om.m No.mmI mw.mH mm.mH panHoIth hoe mEHp mo emancoommm NH omo. cmo. can. I see. rmm. masseutmv msfip panHcImhm mH mmH.I Hm. mm.m I :H.: mmo.m Aomm\ev mpHQOHm> who mxme mH Ham. N:.m o.m:I o.mm m.mm Ammmhmtev mecm coo meme :H mmH. Neo. mom. I Nmm. 0mm. Ahmpmsv mmhos MO 6C0 hwmc Op ommoowchom no Ucm ham “:0ch mocmpmfim MH moH.I Nmo. wmm. I mNm. owe. Ahmpmev esmonmzfiham no one can 0» won 809% mocmpmHQ mH mpoom ssz COHpMH>oQ COHpMHopmoo Unaccepm omcmm :mmz oHanpm> mo oemz oz mpHSmma psmHHMIomeI.z mqm<9 32 TABLE 5.—-Results of take-off from the long horse. No Name of Variable Mean Range Standard Deviation Correlation with Score l8 19 2O 21 22. 23 2A 25 26 27 28 29 3O 31 Angle between forearm and the horizontal at initial contact (degrees) A7. Angle between forearm and the horizontal at last contact (degrees) 108. Range of movement of forearm (degrees) 60. Angle between trunk and upper arm at initial contact (degree:) 128. Angle between trunk and upper arm at last con- tact (degrees) 76. Range of movement of trunk in relation to upper arm (degrees) 52. Angle between trunk and legs at initial contact (degrees) 17h, Angle between the trunk and legs at last contact (degrees) 156 Range of movement of the legs in relation to the trunk —--— Vertical distance of the highest c. of g. above the long horse at initial contact (meter) Vertical distance of the highest 0. of g. above the horse at last contact (meter) c. of g. height difference between initial and final contact (meter) Time contacting the long horse (seconds) 0 Percentage of time of the take-off from the long horse 15 .392 .5A0 .1A9 .2A9 .71 36.5 87.0 31.0 109.0 58.0 28.5 150.0 .AAl .0A8 .l7A 13.2A 56.0 5.1 11A.0 5.29 73.5 8.53 99.0 11.98 71.5 1A.57 188.0 7.93 .575 .075 .6A2 0.052 .2AA 0.051 17.91 1.31 -.635* .A53 .659 .665” —.21u * .563 .073 .327 .117 - 368 .11A -.015 N u 17 degrees of freedom coefficient of correlation significant at .05 level of significance - An r of .A56 was necessary to be significant. o .umn Juz'-.. ‘u-n-r I! ,..- . , '_.-_—.-.--n-.-I .l L ' AA. I .-.y ’. ‘I‘ggr ”an 1... _ -2- *_ 33 variable 18 (angle between forearm and the horizontal at initial contact) and the scores. This suggests that the smaller the angle at contact, the higher the score. The results show four other significant correlations of scores with variables 20, 21, 23 and 25. A .665 correlation was found for variable 21, which suggests that the greater the angle between trunk and the upper arm at initial contact with the horse the greater the score. This phase is, of course, very important since it is from the hand contact with the horse that the specific vault is performed. Everything done before this phase prepares the gymnast to perform the vault. This vault is initiated just like any other vault, i. e. with a clockwise rotation to be completed after the hand contact with a counterclockwise rotation. The gymnast must then hit the long horse at an angle such that the push with the upper segments creates a counterclockwise rotation. What should this angle be? The angle could differ slightly from one gymnast to another, but it could not be as great as the one used to perform the yamashita vault. Weimann (11) states that the take-off action of the upper arms on the long horse cancels the clockwise rotation. Therefore, for a given take-off force, there should be an optimum angle which will allow the vault to be well executed in the form prescribed by the F. I. G. Because of the 3A excentric thrust, a part of the force exerted on the horse will be used for height while the other part will be used for counterclockwise rotation. To maximize height, the gymnast will bring his center of gravity as close as possible over his hands by a piking action. In this study, a .515 correlation of score with variable 25 (i. e. angle between trunk and legs at last contact) was found. This suggest that the greater the angle between the trunk and the legs, the greater the score. A mean angle of 156 degrees was found between those segments. When one compares the scores of 3.0 of D5 and 8.7 of 02, it is noticed that D5 had angles of 56.0, 109.0 and 130 degrees respectively for variables 18, 21 and 25 while 02 had angles of A3.0, 133.5 and 156.0 degrees. Free Flight and Landing Table 6 shows the results of the free flight and the landing. The height and the horizontal distance from the horse to the landing are the principal criteria used to judge any vault. The .539 and .678 correlations between score and variables 32 and 33 suggest that the highest 0. of g. above the long horse and the c. of g. height difference between last contact anc the highest 0. of g. above the horse are well related to the score. These results are in agreement with the findings of Guerrera (5), Kotelnikova (7) and Fetz (3). A negative coefficient of correlation of -.596 was found between variable 3A and a..." QT XI:- .I-‘vggup' _‘._‘ 35 .154". x- [I fly... .. 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A? 31293 02504 9952