Correlation between sensor-motor coordination and biomechanical characteristics of Yurchenko vault Journal: Journal of Applied Biomechanics… [631676]

For Peer Review
Correlation between sensor-motor coordination and
biomechanical characteristics of Yurchenko vault
Journal: Journal of Applied Biomechanics
Manuscript ID Draft
Manuscript Type: Original Research
Keywords:Video motion analysis, movement postural orientation, statistics, tests,
performance

Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer Review1 Abstract
2 Optimal vaulting technique depends on many variables. This study aims to highlight the
3 influence of the sensor-motor coordination on the kinematics and dynamic characteristics of
4 Yurchenko vault in female gymnasts aged 14 to 17 years. The fulfilment of the research tasks
5 involved the organization of 3 tests for the evaluation of sensor-motor coordination (S-MC):
6 static balance, static-kinematic stability and static-dynamic stability. In order to reveal the
7 influence of the S-MC indicators on the biomechanical characteristics of Yurchenko vault by
8 means of the method of movement postural orientation, a video biomechanical analysis was
9 made using Physics ToolKit and Kinovea programs. By selecting the most efficient
10 biomechanical indicators required for the correct execution of the vault, a linear parametric
11 correlative analysis (Pearson’s) was conducted between the indicators of the S-MC, the
12 biomechanical characteristics of Yurchenko vault and the performances achieved in the
13 handspring vaults event. The results of the study highlighted the strong connections at
14 p<0.01, p<0.05 and moderate connections with values of r= 0.500 – 0.650 approximately
15 level between these indicators and their influence on the technical execution.
16
17 Keywords: video motion analysis, movement postural orientation, statistics, tests,
18 performance.
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20 Word Count: 2 579
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25Page 1 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer Review26 Introduction
27 Artistic gymnastics has made significant progress in its development, consistent with the
28 changes in the Code of Points 2017-2020 regarding the content,1 construction and
29 composition of the exercises, the current trends of high performance sport and the correct
30 assessment of gymnasts’ efforts based on the knowledge of the biomechanical
31 particularities,2-4 the physical training level and the physiological stress of the body.5
32 Vaulting is a very dynamic activity; during a competition, the vault, including run-up, will be
33 completed in just a few seconds.6 Although the execution of a vault seems to be, at first
34 glance, simpler than any other routine on the other apparatus, however it requires particular
35 skills of the athletes, like:7 spring, speed, strength, coordination and orientation in space,
36 concentration and courage. Vaulting is the event with only one basic technical structure, the
37 back handspring and its variants; the difficulty and value of these ones are evaluated
38 according to their length and height of the second flight and also depending on the saltos and
39 twists in different axes.8
40 Therefore the physical training in gymnastics is mainly focused on the improvement of the
41 technique of movement execution. The purpose is to avoid the following issues:9 a poor
42 physical training leads to a faulty technique and to failure in competition; a good technical
43 and physical training which is not supported by proper mental training result in modest
44 performances. Physical training takes two forms:10,11 general physical training and specific
45 physical training. Thanks to its aesthetical and spectacular features, artistic gymnastics – a
46 sport with complex technique – involves special aptitudes of the athletes who aim at high
47 performance. Depending on the share of these skills, we can speak of:9 coordinative capacity
48 (skill), speed, strength, joint mobility and endurance.
49 Athletes’ coordinative capacities differ from one sports branch to another; they are
50 characterized by a complex of predominantly psycho-motor skills and an optimum operation Page 2 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer Review51 of the sensitive vestibular system which has a great importance for achieving great sports
52 results in various branches of sport and contributes to the more efficient and rapid learning of
53 new movements.12-14
54 According to Blume (1981), quoted by R. Manno, (1996) the constitutive elements of the
55 coordinative capacity(including the segmental coordination) are:15 capacity for combining
56 and joining the movements, capacity for spatial-temporal orientation, capacity for kinesthetic
57 differentiation, capacity for balance, capacity for motor reaction, capacity for movements
58 transformation, sense of rhythm. The coordination capacity depends of a series of complex
59 factors that could restrict the performance in certain cases. These ones are:16 the optimal
60 tonus of the cerebral cortex and the mobility of the fundamental cortical processes (excitation
61 and inhibition), intra and inter-muscular coordination, functional status of the receptors
62 (kinesthetic, tactile, static-dynamic, visual and acoustic analyzers).
63 Purpose of the study. This study aims at highlighting the influence of sensor-motor
64 coordination on the kinematic and dynamic characteristics of Yurchenko vault in female
65 gymnasts aged 14 to 17 years.
66 Hypothesis of the paper. The correlative analysis made between the components of sensor-
67 motor coordination capacity, the indicators of the biomechanical features of sports technique
68 in Yurchenko vault and the performances achieved in competition by the female gymnasts
69 aged 14 to 17 years will point out the connection level between these indicators and their
70 influence on the technical execution.
71 Methods
72 Participants
73 A number of 7 female gymnasts, whose age was 14 to 17. These gymnasts were members of
74 the female national team: 2 gymnasts of 14 years old, one gymnast of 15 years old – Junior I
75 category; 2 athletes aged 16 and 2 athletes aged 17 – senior. The subjects of the study were Page 3 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer Review76 selected from the team who participated in the Romanian National Championships of
77 Bucharest – 2014 in the handspring vaults event.
78 Sensor-Motor Coordination (S-MC) tests
79 Test 1, Briuk” test, static balance (SB), test for maintaining body balance on tiptoe with eyes
80 closed and arms along the body (keeping at least 15-20 sec.); Test 2, static-kinematic stability
81 (S-KS) – 5 forward rolls in 5 sec. with 10 in-place jumps with eyes closed, in the centre of
82 the graduated circle (maximum deviation 35 cm) and Test 3, static-dynamic stability (S-DS)
83 – stuck landing, in-depth salto from the higher bar (uneven bars), assessed by penalties for
84 the execution mistakes 0.1 -1.0 points, 3 attempts were granted.
85 Video computerized analysis
86 We used the video computerized analysis by means of ”Kinovea” and ”Physics ToolKit”
87 programs of biomechanical analysis, based on the method of movement postural orientation14
88 and assessment of sports technique key elements with complex coordination of movement
89 structure;11 a number of 10 Yurchenko vaults (3 – Yurchenko stretched saltos YSS, 4 – YSS
90 with 360° twist and 3 – YSS with 720° twist) were analyzed bio-mechanically, in
91 competition conditions, during the Romanian National Championships, Bucharest 2014.
92 The physic structure of the test routines during the research focused on the biomechanical
93 analysis of the key elements of Yurchenko round-off vault with backward salto stretched,
94 taking into account the functional structure and the causes as a whole, characteristic of the
95 translational and rotational motion of body segments around GCG axis (fig. 1).
96 Figure 1 here
97 Statistical analysis
98 The correlative analysis was performed in the research final testing between the components
99 of S-MC capacity, the indicators of the biomechanical features of sports technique in
100 Yurchenko vault and the performances achieved in competition by the female gymnasts aged Page 4 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer Review101 14 to 17 years. ”KyPlot” program for statistical calculation and the parametric test linear
102 correlation – Pearson were used.17
103 The issues listed below were analyzed:
104 a) Horizontal variables: 1-3 indicators, S-MC: SB (test 1, sec), S-KS (test 2, cm), and S-DS
105 (test 3, points); 4-6 indicators, Performances obtained in competition (points) – handspring
106 vaults event during the Romanian National Championships of Women’s Artistic Gymnastics,
107 Bucharest, 2014, regarding the difficulty, execution and final score on this apparatus.
108 b) Vertical variables (Biomechanical indicators): 1-4 indicators, biomechanical indicators
109 required by the analysis: IR (kg∙m2) – inertia of rotation, RM (m) – radius of movement of
110 body segments: toes, shoulder and arms; 5-9 indicators, angular characteristics of the key
111 elements of sports technique: in preparatory phase – LP1 – launching body posture 1 (angle
112 between joints of ankle – shoulders), MP1 – multiplication of body posture 1 (angle between
113 toes – shoulders), LP2 – launching body posture 2 (angle between hand joint – foot ); in basic
114 phase: MP2 – multiplication body posture 2 (angle between hip – torso); in final phase: CP –
115 concluding body posture, (angle between hip – torso) – landing; 10-19 indicators, spatial
116 characteristics of the body segments trajectory (m): LP1 – shoulders, MP1 – maximum height
117 of GCG flight, LP2 – toes, MP2 – maximum height of GCG and CP flight– shoulders; 20-29
118 indicators, kinematic characteristics of angular velocity (rad/s): LP1 – shoulders, MP1 – arms
119 and toes, LP2 – toes, MP2 – arms, shoulders and toes and CP – arms, shoulders and toes; 30-
120 34 indicators, dynamic characteristics of force resultant of GCG movement (N) in all the key
121 elements of vaults phases.
122 Results
123 During the correlative analysis we selected 34 biomechanical indicators considered more
124 efficient for highlighting the influence of the correct technical execution of Yurchenko vault.
125 The results of the correlative analysis of the S-MC indicators, the performances recorded in Page 5 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer Review126 competition and the biomechanical indicators of Yurchenko vault point out the following
127 elements (table 1):
128 Table 1 here
129 Figure 2 here
130 Test 1, SB (fig. 2) presents strong connections at p<0.01 with radius of movement (RM, m)
131 arms r=-.799 and at p<0.05 with radius of movement (RM, m) shoulders, r=-.690; trajectory
132 of shoulders in concluding posture (CP, m) r=.687; with angular velocity of arms in the 1st
133 flight, regarding the multiplication of body posture (MP1, rad/s) r=.665 and the resultant of
134 force in the 2nd flight, regarding the multiplication of body posture (MP2, N) r=-.736.
135 Moderate connections with the radius of toes (RM, m) r=-.536; with the angular velocity of
136 shoulders in launching posture 1 (LP1, rad∙s-1) r=.532 and toes in the 2nd flight, in terms of
137 multiplication of body posture 2 (MP2, rad∙s-1) r=-.561; with the resultant of force of GCG
138 movement in the launching posture 1 (LP1, N) r=.572 and LP2, (N) r=.563 while the other
139 indicators show insignificant, weak or even non-existing connections at p>0.05.
140 Figure 3 here
141 Test 2, S-KS (fig. 3) shows moderate connections with the trajectory of shoulders (X, m)
142 r=.619 and (Y, m) r=-.523; with the resultant of force in launching posture 2 (LP2, N) r=-.536
143 while the other indicators show insignificant, weak or even non-existing connections at
144 p>0.05.
145 Figure 4 here
146 Test 3, S-DS (fig. 4) presents strong connections at p<0.05 with radius of movement toes
147 (RM, m), r=.690 and RM shoulders r=.724; trajectory of shoulders in concluding posture
148 (CP, X, m) r=.711; with the resultant of force of GCG in the 1st flight, in terms of body
149 posture multiplication (MP1, N) r=.702 and MP2 in the 2nd flight r=.652. Moderate
150 connections with IR (kg•m2) r=.544; with RM, (m) arms r=.513; with the angle between hip Page 6 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer Review151 and torso in the 2nd flight of MP2, (degrees) r=-.515; with LP1 of shoulders (X, m) r=-.628
152 and Y, (m) r=.595; with the trajectory of GCG inMP1 in the 1st flight X, (m) r=-.618 and Y,
153 (m) r=.609; with the trajectory of GCG in MP2 in the 2nd flight Y, (m) r=.579; with the
154 trajectory of shoulders in CP Y, (m) r=.500 with angular velocity of shoulders in launching
155 posture 1 (LP1, rad∙s-1) r=-.535 while the other indicators show insignificant, weak or even
156 non-existing connections at p>0.05.
157 Figure 5 here
158 The performances achieved in competition concerning the difficulty of the vaults (fig. 5)
159 have strong connections at p<0.01 with the hip-torso angle in the 1st flight of MP1 (degrees)
160 r=-.821 and the hip-torso angle (degrees) in the concluding posture (CP) r=-.855; at p<0.05
161 with the trajectory of shoulders in CP Y, (m) r=-.687; with the angular velocity of arms in the
162 1st flight of MP1 (rad∙s-1) r=.698; with the resultant of force of GCG movement in LP2, (N)
163 r=.691 and in the 2nd flight of MP2, (N) r=-.716.
164 Figure 6 here
165 In terms of the score for execution (fig. 6), there are strong connections at p<0.05 with the
166 trajectory of GCG in the 2nd flight of MP2 X, (m) r=.727 and of CP X, (m) r=.715; with the
167 angular velocity of toes in the 1st flight of MP1 (rad∙s-1) r=.753; the final score (fig. 7) has
168 strong connections at p<0.01 with the angle hip-torso in CP (degrees) r=-.814; with the
169 resultant of force of GCG movement in LP2 (N) r=.786; at p<0.05 with the angular velocity
170 of arms in the 1st flight of MP1 (rad∙s-1) r=.664 and toes in LP2 (rad∙s-1) r=672.
171 Figure 7 here
172 Moderate connections regarding the vaults difficulty with the hip-torso angle in the 2nd flight
173 of MP2 (degrees) r=.508; with the angular velocity of toes in LP2 (rad∙s-1) r=-.562; with the
174 resultant of force of GCG movement (N) r=.591; score for execution with the toes-arms angle
175 (degrees) r=-.557; final score with the hip-torso angle in the 1st flight of MP1 (degrees) r=-Page 7 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer Review176 .603; with GCG trajectory in the 1st flight of MP2 – Y (m) r=.509 and shoulders Y (m) r=-
177 .586; with the resultant of force in the 2nd flight of MP2 (N) r=-.530 and of CP (N) r=.576
178 while the other indicators show insignificant, poor or even non-existing connections at
179 p>0.05.
180 Discussions
181 According to the Code of Points in Women’s Artistic Gymnastics, the handspring vaults are
182 divided into 5 groups and the handspring vaults Yurchenko belongs to group IV (Round-off
183 (Yurchenko) with/without 3/4 turn (270°) in 1st flight phase – salto bwd with/without turn in
184 2nd flight phase). The changes of the CoP 2017-2020 highlight the decrease of the difficulty
185 value of Yurchenko vault by 0.4 points (4.00 p. with stretched salto bwd off, 4.60 p. – with
186 1/1 turn (360°) off and 5.40 p. – with 2/1 turn (720°) off).1
187 Handspring vaults are based on one technical structure and variants thereof, the handspring
188 rollover. Thus, while dealing with the biomechanical issues of handspring vaults, many
189 authors tried to identify the mechanical variables that govern successful performance of the
190 handspring with full turn vault,18 to find the best technique for women’s Yurchenko layout
191 vault through an application of optimal control theory on a five-segment model consisting of
192 the hand, entire arm, upper trunk, lower trunk and entire leg,19 to predict an individual’s
193 optimal Yurchenko layout vault by modifying the selected critical mechanical variables.20
194 The dynamic optimization technique is feasible for complex movements, using the
195 Yurchenko layout vault,21,22 the parameters of contact with the floor,23 the computer
196 simulation of gymnastics vault landings,24 the kinematics analysis of the centre of mass in the
197 springboard phase,25 the development of the velocity for vault runs in artistic gymnastics.26
198 The researchers investigated how the kinematic factors during the horse (table) contact phase
199 influence the post-flight performance in handspring vaulting,27 they tried to point out the
200 biomechanical explanation of judges’ detection of scores relative to the on-board and pre-Page 8 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer Review201 flight phases of the Yurchenko vault with one twist on table.28 A biomechanical comparison
202 of this type of vault and two associated teaching drills was made,29 characterizing the normal
203 (Fz) and anterior-posterior (Fx) hand contact forces of female gymnasts performing a
204 handspring vault on the modern vault table,30 the effect of biomechanical variables on the
205 assessment of vaulting in top-level artistic female gymnasts in World Cup competitions.31 It
206 is important to know the biomechanical characteristics of the technique for elite female
207 gymnasts performing the vault group Round-off, flic-flac on vault table,32 to determine which
208 kinematic characteristics may be used as performance indicator(s) for vault,33 to analyze the
209 kinematics of springboard phase, the kinematic variables of table vault in artistic
210 gymnastics,34 the run-up velocity measurements shown in previous studies and to interpret
211 the data and the possible influences based on the methodologies of the studies.35 It is also
212 necessary to identify the kinematic variables that govern successful performance and judges'
213 scores and to establish correlative relationships of the variables of layout with full twist
214 Yurchenko-type vault in women’s vaulting.36
215 The improvement of sports technique based on biomechanical indicators of Yurchenko vault
216 in women’s artistic gymnastics, the e-learning by computer video analysis, the use of e-
217 training in mathematics modelling of the biomechanical characteristics and the application of
218 transfer technology in the improvement of learning the elements in women's artistic
219 gymnastics were also studied by the specialists.37-39
220 The correlative analysis between the studied indicators regarding the S-MC development, the
221 performances achieved in handspring vaults events and the biomechanical characteristics of
222 Yurchenko vault reveals strong connections at p<0.01, p<0.05 and moderate connections
223 with values of r= 0.500–0.650 approximately.
224 The results of the study provide additional scientific data necessary for the development of
225 the linear and branching algorithmic diagrams used in the learning of Yurchenko vault, basic Page 9 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer Review226 element of the macro-methods, while the weak connections of the insignificant differences
227 between indicators contributed to the more efficient selection of the preparatory and aiding
228 exercises meant to improve the technique of execution.
229 These findings, along with the bases of the learning macro-methods, were introduced in the
230 training sessions of the female gymnasts of the national team, in the national training centers
231 of Deva, Onesti and Bucharest city and in the artistic gymnastics departments and clubs.
232 They were presented under the form of theoretical and methodical recommendations in the
233 courses given at the Faculties of Physical Education and Sport of Bucharest (deepening
234 courses in different sports branches at the Ecological University of Bucharest and course of
235 applied biomechanics – master degree at the National University of Physical Education and
236 Sport of Bucharest) and in the Center for Coaches’ Training Improvement of the National
237 University of Physical Education and Sport of Ukraine.
238 In summary, the computerized video biomechanical analysis consistent with the method of
239 movement postural orientation highlights the improvement of the key elements of Yurchenko
240 vault sport technique in the case of the female gymnasts of 14 – 17 years old on the basis of
241 the angular, spatial, kinematic and dynamic characteristics indicators and the performances
242 obtained in competition. The correlative analysis between the components of the capacity for
243 sensor motor coordination, the indicators of the biomechanical characteristics of Yurchenko
244 vault sports technique and the performances obtained in competition by the female gymnasts
245 aged 14 to 17 years showed the connection between these indicators and their influence upon
246 the technical execution, fact that validates the hypothesis proposed by the research.
247 Acknowledgment
248 We express our gratitude to the Romanian Gymnastics Federation and especially to Mrs.
249 Anca Grigoras Mihailescu – federal coach and to the coaches of the Olympic Team who
250 helped us to conduct this research. This research was based on the results achieved during the Page 10 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer Review251 postdoctoral studies of the first author, from 2012 to 2014, dealing with the fundamentals of
252 the learning macro-methods of the young female gymnasts during the basic specialization
253 stage of training in women’s artistic gymnastics. The research respected the ethical standards
254 of the research, the participants / the next of kin of the participants gave their consent to take
255 part in the research.
256 References
257 1. Fédération Internationale de Gymnastique – FIG, Code of Points 2017-2020, Women’s
258 Artistic Gymnastics. Part III, Apparatus, Section 10 – Handspring vaults; Part IV Tables
259 of elements. Updated 12 to 18 December 2016: 40-43, VT – Group 4–2. http://www.fig-
260 gymnastics.com/publicdir/rules/files/en_WAG%20CoP%202017-2020.pdf. Accessed
261 September 24, 2018.
262 2. Arkaev LJ, Suchilin NG. Kak gotovit' chempionov. Teorija i tehnologija podgotovki
263 gimnastov vyshej kvalifikacii. Moscow: Fizkul'tura i sport; 2004.
264 3. Bruggmann GP. Biomechanics of gymnastics techniques, Sport Sci Review. 1994; 3:79–
265 120.
266 4. Prassas S, Kwon YH, Sands W. Biomechanics of artistic gymnastics. J Sport Biomech.
267 2006;5:261–292. doi: 10.1080/14763140608522878.
268 5. Manolachi V. Theory and Practice of Women’s Sport (Evaluation, Planning, Direction
269 and Nutrition). [Monograph]. Bucharest: Discobolul; 2018.
270 6. Readhead L. Gymnastics: Skills, Technique, Training. The Crowood Press; 2011.
271 7. Vieru N. Handbook of sports gymnastics. Bucharest: Driada Publishing House; 1997.
272 8. Filipenco E, Tomșa N, Buftea V. Gymnastics, Theoretical and Practical-Methodical
273 Course of Handspring Vaults. Chisinau: USEFS Publishing Hous; 2014.
274 9. Grigore V. Artistic gymnastics – theoretical bases of sports training. Bucharest: Semne;
275 2001.Page 11 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer Review276 10. Smolevskij VM, Gaverdovskij JK. Sportivnaja gimnastika. Kiev: Olimpijskaja literature;
277 1999.
278 11. Gaverdovskij JK. Teorija i metodika sportivnoj gimnastiki . Moscow: Sov. Sport; 2014.
279 12. Dragnea A, Bota A. Teoria activitatilor motrice [Theory of motor activity]. Bucharest:
280 Didactic and Pedagogic Publishing House; 1999.
281 13. Gidu DV, Straton A, Hrițac F. Eye-hand coordination in third form pupils, An Ovid Univ,
282 Sci mov health. 2010;10(suppl. 2):688 –691.
283 14. Boloban VN. Sensomotor coordination as the basis of technical preparation. Sci in the
284 Olympic sport. 2015;2:73-80. http://sportnauka.org.ua/wp-
285 content/uploads/nvos/articles/2015.2_11.pdf.
286 15. Mano R. Les bases de l’entraînement sportif. Bucharest: MTS-CCPPS, SDP. 1996;371-
287 374.
288 16. Bota C, Prodescu B. Physiology of physical education and sport – ergo-physiology ,
289 Râmnicu Vâlcea: Antim Ivireanu Publishing House; 1997.
290 17. Thomas, J.R., Nelson, J.K. Research Methods in Physical Activity (2nd ed.). Human
291 Kinetics; 1996.
292 18. Takey Y. Three-Dimensional Analysis of Handspring with Full Turn Vault:
293 Deterministic Model, Coaches' Beliefs, and Judges' Scores. J Appl Biomech.
294 1998;14(2):190–210. https://doi.org/10.1123/jab.14.2.190.
295 19. Koh M, Jennings L, Elliott B, Lloyd D. Prediction of an optimum technique for the
296 women’s yurchenko layout vault. Paper presented at: 19 International Symposium on
297 Biomechanics in Sports. 2001. J R. Blackwell, RH. Sanders (Editors). University of San
298 Francisco. https://ojs.ub.uni-konstanz.de/cpa/article/view/3919. Accessed September 18,
299 2018.
300 20. Koh M, Jennings L, Elliot B, Lioyd D. A Predicted Optimal Performance of the Page 12 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer Review301 Yurchenko Layout Vault in Women’s Artistic Gymnastics. J Appl Biomech.
302 2003;19:187–204. doi: 10.1123/jab.19.3.187.
303 21. Koh M, Jennings, L. Dynamic optimization: inverse analysis for the Yurchenko layout
304 vault in women's artistic gymnastics. J Biomech. 2003;36(8);1177–1183.
305 https://doi.org/10.1016/S0021-9290(03)00085-X.
306 22. Koh M, Jennings L. Strategies in preflight for an optimal Yurchenko layout vault. J
307 Biomech. 2007;40(6): 1256-1261. https://doi.org/10.1016/j.jbiomech.2006.05.027.
308 23. Seeley MK, Bressel E. A Comparison of Upper-Extremity Reaction Forces between the
309 Yurchenko Vault and Floor Exercise. J Sports Sci Med . 2005;4(2):85–94.
310 https://www.ncbi.nlm.nih.gov/pubmed/24431965.
311 24. Mills C. Computer simulation of gymnastics vault landings. A Doctoral Thesis.
312 Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy
313 at Loughborough University; 2005. https://dspace.lboro.ac.uk/2134/33645. Accessed
314 September 16, 2018.
315 25. Penitente G, Merni F, Fantozzi S, Perretta N. Kinematics of the Springboard Phase in
316 Yurchenko-Style Vaults. Paper presented at: 25 International Symposium on
317 Biomechanics in Sports; August 23 – 27, 2007, Ouro Preto – Brazil. https://ojs.ub.uni-
318 konstanz.de/cpa/article/view/389. Accessed September 10, 2018.
319 26. Naundorf F, Brehmer S, Knoll K, Andreas Bronst A, Wagner R. (2008). Development of
320 the velocity for vault runs in artistic gymnastics for the last decade. Motor Performance
321 and Control. Paper presented at: 26 International Conference on Biomechanics in Sports.
322 July 14 – 18, 2008, Seoul, Korea. https://ojs.ub.uni-konstanz.de/cpa/article/view/1905.
323 Accessed September 16, 2018.
324 27. Chen HC, Yu, CY, Cheng KB. Computer simulation of the optimal vaulting motion
325 during the horse (table) contact phase. Paper presented at: 27 International Conference Page 13 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer Review326 on Biomechanics in Sports; August 17 – 21, 2009; Limerick, Ireland. https://ojs.ub.uni-
327 konstanz.de/cpa/article/view/3077. Accessed octomber 14, 2018.
328 28. Penitente G, Merni F, Fantozzi S. On-board and pre-flight mechanical model of
329 yurchenko one twist on vault: implications for performance. Paper presented at: 27
330 International Conference on Biomechanics in Sports; August 17 – 21, 2009; Limerick,
331 Ireland. https://ojs.ub.uni-konstanz.de/cpa/article/view/3295. Accessed September 16,
332 2018.
333 29. Elliott B, Mitchell J. (2010). A Biomechanical Comparison of the Yurchenko Vault and
334 Two Associated Teaching Drills. Int J Sport Biomech. 2010;7(1):91–107. doi:
335 10.1123/ijsb.7.1.91.
336 30. Penitente G, Sands WC, McNeal J, Smith SL, Kimmel W. Investigation of Hand Contact
337 Forces of Female Gymnasts Performing a Handspring Vault. Int J Sports Sci Eng.
338 2010;04(1):15–24.
339 http://www.worldacademicunion.com/journal/SSCI/sscivol04no01paper02.pdf. Accessed
340 September 20, 2018.
341 31. Farana R, Vaverka F. The effect of biomechanical variables on the assessment of
342 vaulting in top-level artistic female gymnasts in world cup competitions. Acta Univ
343 Palacki Olomuc. Gymn. 2012;42(2):49–57, doi: 10.5507/ag.2012.012.
344 32. Kashuba V, Khmelnitska I, Krupenya S. Biomechanical Analysis of Skilled Female
345 Gymnasts’ Technique in «Round-off, Flick-Flack» Type on the Vault Table. J Phys
346 Educ Sport. 2012;12(4):431–435. doi:10.7752/jpes.2012.04064.
347 33. Jeroen Van der Eb, Marije Filius, Guus Rougoor, Cas Van Niel, Joël de Water, Bert
348 Coolen, Hans de Koning, Optimal velocity profiles for vault. Paper presented at: 30th
349 International Conference of Biomechanics in Sports. July 02-06, 2012; Melbourne,
350 Australia. https://ojs.ub.uni-konstanz.de/cpa/article/view/5162.Page 14 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer Review351 34. Fernandes SMB, Carrara P, Serrгo JC, Amadio AC, Mochizuki L. Kinematic variables
352 of table vault on artistic gymnastics. Rev Bra Educ Fís Esporte. 2016;30(1):97–107.
353 http://dx.doi.org/10.1590/1807-55092016000100097.
354 35. Fujihara T. Revisiting run-up velocity in gymnastics vaulting. Paper presented at: 34 th
355 Intrenational Conference on Biomechanics in Sports. July 18-22, 2016; Tsukuba, Japan.
356 https://ojs.ub.uni-konstanz.de/cpa/article/view/6881. Accessed September 20, 2018.
357 36. Park CH, Kim, YK. Three-dimensional Kinematic Analysis of the Yurchenko Layout
358 with 360-degree Twist in Female Vaults: Deterministic Model and Judges' Scores. Kor J
359 Sport Biomech. 2017;27(1): 9-18. http://dx.doi.org/10.5103/KJSB.2017.27.1.9.
360 37. Boloban V, Potop V. Osnovy makrometodiki obuchenija sportivnym uprazhnenijam (na
361 materiale zhenskih vidov gimnasticheskogo mnogobor'ja). Bases of macromethods of
362 sports exercise training (as exemplified in woman's all-around gymnastics). Sci in
363 Olympic sport. 2015;07(4):55–66. http://sportnauka.org.ua/wp-
364 content/uploads/nvos/articles/2015.4_7.pdf.
365 38.Potop V, Urichianu ST. Analysis of Physical Training Influence on the Technical
366 Execution of Yurchenko Handspring Vault . In V. Manolachi, C.M. Rus, S. Rusnac
367 (eds.), Paper presented at: New Approaches in Social and Humanistic Sciences; June 8-
368 10, 2017; Iasi, Romania: LUMEN Proceedings.
369 https://doi.org/10.18662/lumproc.nashs2017.34. Accessed September 10, 2018.
370 39.Kim Y K, Cheol-Hee Park CH. Three-dimensional analysis of yurchenko layout with
371 360° twist in female vaults: modified deterministic model and judges’ scores. Paper
372 presented at: 35th Conference of the International Society of Biomechanics in Sports,
373 June 14 – 18, 2017. German Sport University Cologne, Cologne, Germany. https://dshs-
374 koeln.sciebo.de/index.php/s/CamALh9yXz0k6Vt. Accessed September 20, 2018.
375Page 15 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer Review376 Table 1 Correlation of sensor-motor coordination development indicators with Yurchenko
377 vault biomechanical characteristics and the performances achieved in competition (n =10).
r, Pearson Control tests Results comp.(points)
№Biomechanical
indicatorsTest 1
(sec) Test 2
(cm) Test 3
(points) D. E. Final
score
1IR (kg·m2) -.127 -.461 .544 .352 .221 .379
2 toes -.536 -.368 *.690 -.382 .177 -.218
3 should *-.690 -.189 *.724 -.483 .257 -.259
4RM,
(m)
arms **-.799 .144 .513 -.372 .068 -.260
5 LP1 -.238 -.143 -.118 .394 -.557 .049
6 MP1 -.333 .189 .118 **-.821 .088 -.603
7 LP2 .123 -.117 -.452 .309 -.213 .143
8 MP2 .458 -.002 -.515 .508 -.139 .334
9KE,
(deg)
CP -.409 .201 .073 **-.855 -.306 **-.814
10LP1 x .133 .619 -.628 .003 .051 .026
11should,
m y -.112 -.523 .595 .294 .181 .315
12MP1 x -.155 .285 -.618 .311 -.244 .129
13GCG,
m y -.056 -.103 .609 -.219 .288 -.037
14LP2 x .051 .469 -.270 -.171 .399 .053
15toes,
m y -.044 -.414 .494 .398 .063 .341
16MP2 x .091 -.025 .434 -.221 *.727 .166
17GCG,
m y .078 -.396 .579 .436 .358 .509
18CP x .156 -.301 *.711 .138 *.715 .442
19should,
m y *.687 .078 .500 *-.687 -.101 -.586
20LP1 should rad∙s-1.532 .284 -.535 .465 -.176 .283
21MP1 arms rad∙s-1*.665 -.319 -.393 *.698 .250 *.664
22 toes rad∙s-1.351 -.060 .256 -.126 *.753 .253
23LP2 toes rad∙s-1-.275 .185 -.404 -.562 -.495 *.672
24MP2 arms rad∙s-1.079 -.187 -.371 .028 -.446 -.186
25 should rad∙s-1-.429 .283 .148 -.374 -.156 -.366
26 toes rad∙s-1-.561 .417 .310 -.369 .221 -.187
27CP arms rad∙s-1.228 -.089 -.253 -.178 -.344 -.301
28 should rad∙s-1.458 -.024 -.169 .387 .038 .322
29 toes rad∙s-1.466 .084 -.427 .377 -.066 .265
30LP1 N .572 -.323 -.031 .478 .449 .585
31MP1 N -.464 -.284 *.702 -.486 .091 -.339
32LP2 GCG N .563 -.536 .042 *.691 .523 **.786
33MP2 N *-.736 .081 *.652 *-.716 .067 -.530
34CP N .276 -.091 .019 .591 .239 .576
378 Note. IR (kg∙m2) – inertia of rotation, RM (m) – radius of movement of body segments, KE –
379 key elements; x – horizontal; y – vertical; LP1 – launching body posture 1, MP1 –
380 multiplication of body posture 1, LP2 – launching body posture 2, MP2 – multiplication body
381 posture 2, CP – concluding body posture, landing; test 1 – static balance (sec); test 2 – static-
382 kinematic stability (cm); test 3 – dynamic-kinematic stability (points); D. – difficulty; E. –
383 execution; comp. – competition; 1-4 indicators: biomechanical indicators required by the
384 analysis; 5-9 indicators: angular characteristics of the key elements of sports technique (deg.-
385 degrees); 10-19 indicators: spatial characteristics of the body segments trajectory (m); 20-29
386 indicators: kinematic characteristics of angular velocity (rad∙s-1); 30-34 indicators: dynamic
387 characteristics of force resultant of GCG movement (N). Parametric test linear correlation
388 Pearson’s; df = 8; **p<0.01, r=.764; *p<0.05, r=.631.Page 16 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer Review
in preparatory phase: 1) LP1 – launching posture of the body1, flip off of the springboard (preparatory
movement) and 2) MP1- multiplication of posture of the body 1 – the 1st flight, half back rollover and 3) LP2
– handspring on apparatus, flip off of the table; in basic phase: 4) MP2 – multiplication of posture of the
body 2, the 2nd flight that highlights the shape of salt and the momentum of maximum height of GCG (1 ½
stretched salt backwards, 1 ½ stretched salt backwards with 360° and 720° turn); and in final phase: 5) CP
– concluding posture of the body, moment of landing damping and freezing (standstill landing).
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Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer Review
Biomechanical indicator (n=34) – table 1, 1-4 indicators: biomechanical indicators required by the analysis;
5-9 indicators: angular characteristics of the key elements of sports technique (degrees); 10-19 indicators:
spatial characteristics of the body segments trajectory (m); 20-29 indicators: kinematic characteristics of
angular velocity (rad/s); 30-34 indicators: dynamic characteristics of force resultant of GCG movement (N).
Parametric test linear correlation Pearson’s; df=8; **p<0.01, r=.764; *p<0.05, r=.631
228x142mm (96 x 96 DPI) Page 18 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer Review
Biomechanical indicators – table 1 and fig. 2. Parametric test linear correlation Pearson’s; df=8; **p<0.01,
r=.764; *p<0.05, r=.631
228x142mm (96 x 96 DPI) Page 19 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer Review
Biomechanical indicators – table 1 and fig. 2. Parametric test linear correlation Pearson’s; df=8; **p<0.01,
r=.764; *p<0.05, r=.631
228x142mm (96 x 96 DPI) Page 20 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer Review
Biomechanical indicators – table 1 and fig. 2. Parametric test linear correlation Pearson’s; df=8; **p<0.01,
r=.764; *p<0.05, r=.631
228x142mm (96 x 96 DPI) Page 21 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer Review
Biomechanical indicators – table 1 and fig. 2. Parametric test linear correlation Pearson’s; df=8; **p<0.01,
r=.764; *p<0.05, r=.631
228x142mm (96 x 96 DPI) Page 22 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer Review
Biomechanical indicators – table 1 and fig. 2. Parametric test linear correlation Pearson’s; df=8; **p<0.01,
r=.764; *p<0.05, r=.631
228x142mm (96 x 96 DPI) Page 23 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer Reviewa) Horizontal variables:
Table 1 Results of sensor motor coordination development of junior gymnasts aged 14 to 17, (n=10)
Nr.
Crt.Gymnasts Age,
years Test 1,
(sec)Test 2,
(cm)Test 3,
(points)
1 S.A. 14 20,06 22 9,5
2 I.A. 15 18,02 21 9,5
3 T.P. 16 14,31 22 9,5
4 C.A. 14 22,12 21 9,4
5 Z.S. 16 19,28 23 9,4
6 O.A-M. 17 20,38 20 9,5
7 S.S. 17 18,84 22 9,5
8 Z.S. 16 19,28 23 9,4
9 O.A-M. 17 20,38 20 9,5
10 S.S. 17 18,84 22 9,5
Note: Test 1 – “Biriuk” test, static balance; Test 2 –static-kinematic stability; Test 3 – static-dynamic stability –
standstill landing;
Table 2 Performances obtained in competition– handspring vaults event during the Romanian
National Championships of Women’s Artistic Gymnastics, Bucharest, 2014, (n =10)
Nr.
Crt.Gymnasts Hansdspring
vaults Difficulty
(points)Execution
(points)Final score
(points)
1 S.A. YSS 4.4 8.250 13.250
2 I.A. YSS 4.4 9.050 13.450
3 T.P. YSS 4.4 8.100 12.500
4 C.A. YSS 360° 5.0 8.150 12.550
5 Z.S. YSS 360° 5.0 8.275 14.075
6 O.A-M. YSS 360° 5.0 8.925 14.725
7 S.S. YSS 360° 5.0 8.575 14.375
8 Z.S. YSS720° 5.8 8.275 14.075
9 O.A-M. YSS 720° 5.8 8.925 14.725
10 S.S. YSS 720° 5.8 8.575 14.375
Note: Yurchenko stretched saltos YSS, YSS with 360° twist and YSS with 720° twistPage 24 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer Reviewb) Vertical variables:
Table 3 Biomechanical indicators required by Yurchenko vault analysis (n =10)
RM, (m)Nr.
Crt.Gymnasts Handspring
vaultsIR
(kg·m2
)toes should arms
1 S.A. YSS 14,24 0,705 0,415 0,501
2 I.A. YSS 13,04 0,679 0,398 0,451
3 T.P. YSS 19,65 0,813 0,448 0,6
4 C.A. YSS 360° 15,42 0,686 0,352 0,436
5 Z.S. YSS 360° 14,45 0,635 0,357 0,464
6 O.A-M. YSS 360° 21,22 0,704 0,393 0,464
7 S.S. YSS 360° 20,14 0,709 0,37 0,483
8 Z.S. YSS720° 14,45 0,599 0,362 0,435
9 O.A-M. YSS 720° 21,22 0,723 0,394 0,47
10 S.S. YSS 720° 20,14 0,709 0,389 0,504
Note:IR – inertia of rotation; RM – radius of movement;Yurchenko stretched saltos YSS, YSS with 360°
twist and YSS with 720° twistPage 25 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer ReviewTable 4 Angular characteristics of the key elements Yurchenko vault (n =10)
Key elements of sports technique (degrees) Nr.
Crt.Gymnast Handspring
vaults LP1 MP1 LP2 MP2 CP
1 S.A. YSS 92 129 63 142 140
2 I.A. YSS 99 108 64 143 136
3 T.P. YSS 103 126 73 146 142
4 C.A. YSS 360° 101 113 75 170 130
5 Z.S. YSS 360° 98 109 73 164 138
6 O.A-M. YSS 360° 103 105 70 157 136
7 S.S. YSS 360° 101 109 72 175 137
8 Z.S. YSS720° 103 102 73 170 130
9 O.A-M. YSS 720° 100 100 77 170 125
10 S.S. YSS 720° 101 97 63 145 120
Note: LP1 – launching posture of the body; MP1 – multiplication of posture of the body – the 1st flight; LP2 –
launching posture of the body, handspring on apparatus; MP2 – multiplication of posture of the body, the 2nd flight; CP
– concluding posture, landing;Page 26 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer ReviewTable 5 Spatialcharacteristics of the body segments trajectory Yurchenko vault (n =10)
Key elements of sports technique
LP1 MP1 LP2 MP2 CP
shoulders maximum
height of GCG
flighttoes maximum
height of GCGshouldersNr.
Crt. Gymnasts Handspring
vaults
Xm Ym Xm Ym Xm Ym Xm Ym Xm Ym
1 S.A. YSS 1,1 1,409 0,577 1,758 0,711 2,522 -0,174 2,267 -1,489 1,167
2 I.A. YSS 0,729 1,416 0,646 1,512 0,302 2,598 -0,591 2,227 -1,952 1,278
3 T.P. YSS 0,821 1,534 0,78 1,601 0,283 2,785 -0,565 2,274 -1,978 1,265
4 C.A. YSS 360° 0,848 1,413 0,726 1,453 0,283 2,57 -0,578 2,193 -2,018 0,915
5 Z.S. YSS 360° 1,119 1,458 0,765 1,572 0,453 2,704 -0,807 2,308 -2,251 0,864
6 O.A-M. YSS 360° 0,724 1,627 0,568 1,816 -0,056 3,142 -0,591 2,479 -1,649 0,981
7 S.S. YSS 360° 0,821 1,55 0,57 1,744 0,239 2,998 -0,49 2,462 -1,596 1,049
8 Z.S. YSS720° 1,213 1,387 0,867 1,467 0,467 2,627 -0,533 2,187 -1,947 1,027
9 O.A-M. YSS 720° 0,829 1,603 0,784 1,513 0,392 2,958 -0,56 2,499 -1,726 0,897
10 S.S. YSS 720° 0,611 1,573 0,588 1,697 0,124 2,998 -0,532 2,523 -1,527 0,984
Note: X – horizontal of the body segments trajectory, Y – vertical of the body segments trajectory; LP1 – launching
posture of the body; MP1 – multiplication of posture of the body – the 1st flight; LP2 – launching posture of the body,
handspring on apparatus; MP2 – multiplication of posture of the body, the 2nd flight; CP – concluding posture, landingPage 27 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer ReviewTable 6 Kinematic characteristics of angular velocityof the body segments Yurchenko vault, 20-29
indicators,(n =10)
Key elements of sports technique (rad/s)
LP1 MP1 LP2 MP2 CPNr.
Crt
.Gymnast
s Handspring
vaults
should arms toes toes armsshouldtoes armsshouldtoes
1 S.A. YSS 32,1 24,839 36,709 33,347 10,374 32,308 39,241 9,502 8,831 4,105
2 I.A. YSS 33,607 26,947 20,334 36,03 10,072 32,72 35,815 19,998 2,597 3,053
3 T.P. YSS 27,408 22,156 19,381 43,535 32,24 37,093 34,935 11,604 4,687 3,053
4 C.A. YSS 360° 35,075 35,481 19,926 42,355 36,812 32,063 19,736 31,378 22,821 15,37
5 Z.S. YSS 360° 40,575 29,818 25,297 36,245 21,596 23,728 30,495 18,659 10,426 9,548
6 O.A-M. YSS 360° 34,103 26,586 27,188 29,816 37,498 24,164 24,886 12,826 15,289 4,751
7 S.S. YSS 360° 34,643 27,248 22,201 34,792 21,385 40,42 28,456 8,317 13,265 6,125
8 Z.S. YSS720° 35,156 31,049 21,77 35,376 26,588 33,294 33,726 2,888 8,054 4,468
9 O.A-M. YSS 720° 33,426 38,888 26,189 30,501 18,099 26,142 29,058 4,815 5,841 5,191
10 S.S. YSS 720° 37,121 29,842 23,37 23,098 13,84 26,944 29,058 23,615 26,689 14,264
Note: LP1 – launching posture of the body; MP1 – multiplication of posture of the body – the 1st flight; LP2 –
launching posture of the body, handspring on apparatus; MP2 – multiplication of posture of the body, the 2nd flight; CP
– concluding posture, landingPage 28 of 34
Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics

For Peer ReviewTable 7 Dynamic characteristics of force resultant of GCG movement (N) in all the key elements of
vaults phases (30-34 indicators), (n =10)
Key elements of sports technique (N) Nr.
Crt
.Gymnast
s Handspring
vaultsLP1
MP1 LP2 MP2CP
1 S.A. YSS 6,10E+03 3,84E+03 2,71E+03 4,99E+03 7,98E+03
2 I.A. YSS 3,97E+03 3,10E+03 2,35E+03 4,95E+03 2,60E+03
3 T.P. YSS 3,64E+03 4,71E+03 1,79E+03 5,64E+03 8,43E+03
4 C.A. YSS 360° 5,85E+03 3,09E+03 2,85E+03 2,85E+03 9,27E+03
5 Z.S. YSS 360° 5,33E+03 2,65E+03 2,43E+03 3,34E+03 7,89E+03
6 O.A-M. YSS 360° 6,92E+03 4,27E+03 3,75E+03 3,20E+03 1,27E+04
7 S.S. YSS 360° 7,75E+03 4,11E+03 1,79E+03 4,12E+03 1,17E+04
8 Z.S. YSS720° 6,94E+03 2,52E+03 3,17E+03 2,67E+03 1,04E+04
9 O.A-M. YSS 720° 8,92E+03 3,18E+03 4,35E+03 3,32E+03 1,03E+04
10 S.S. YSS 720° 4,21E+03 3,39E+03 3,49E+03 3,97E+03 1,14E+04
Note: LP1 – launching posture of the body; MP1 – multiplication of posture of the body – the 1st flight; LP2 –
launching posture of the body, handspring on apparatus; MP2 – multiplication of posture of the body, the 2nd flight; CP
– concluding posture, landing;Page 29 of 34
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Human Kinetics, 1607 N Market St, Champaign, IL 61825Journal of Applied Biomechanics