Aerobics Training for Athletes Limb Joints and Research on the Effects of the Characteristics of the Strength

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1 Send Orders for Reprnts to The Open Cybernetcs & Systemcs Journal, 05, 9, Open Access Aerobcs Tranng for Athletes Lmb Jonts and Research on the Effects of the Characterstcs of the Strength Pengyu Zhao * P.E. Department, JLn usness and Technology College, Changchun 30507, Jln, Chna Abstract: Aerobc exercse s a "young" and loved by people of sports, therefore, n recent years research on aerobcs s numerous, ths artcle s on the bass of predecessors' research on aerobcs athlete tranng body posture s analyzed and studed, for the study of the acton process of knee jont force analyss provde the mage of the space analytc foundaton; The two -dof rgd body dynamcs model was establshed, for the acton process of knee jont torque analyss provdes a theoretcal bass; Later n ths paper, by applyng a table n the form of more clearly show the dfferences between the two aerobcs athletes, through the comparson we can draw on the dfferences between two aerobcs athlete was more obvous, therefore, for calsthencs athletes need to shoulder jont control n 65 - degree s more approprate, and sums up wth the ncrease of the dffculty n the tme-consumng, dfferences between two calsthencs athletes wll be more and more obvous, at the same tme reflects the calsthencs athletes ablty s promnent, through the comparson we found that the elbow of calsthencs athletes under than aerobcs athlete ablty, therefore proves that the no. aerobcs athlete's comprehensve strength s strongest. Then by studyng the aerobcs athlete's habts are drawn n the Angle of mnmum rght knee jont poston wth a mnmum rght knee jont Angle poston under the two postons when the jont Angle of the hour, the greater the moment wll heavy torque, the greater the muscle torque wll ncrease, the study wll be the study of aerobcs bomechancs analyss theory plays a certan role n promotng. Keywords: Aerobcs athlete, bomechancs, lmb jonts and muscle strength, physologcal functons.. INTRODUCTION Aerobcs event belongs to non-olympc Games events, aerobcs development n Chna hasn t been accepted by people after gong through a consderable long process, wth people s lvng standards mprovement, Chnese aerobcs event are also enterng nto every cvl mnd, n the early perod of the century, Chnese aerobcs athletes partcpated n world aerobcs champonshps, and acheved good result of rankng the seventh, and subsequent one year, n Chnese ndvdual men competton, t got good result of rankng the top fve, and n the process, Chnese aerobcs have also gradually caught up wth nternatonal pace, t let aerobcs to gradually move towards maturty []. Regardng aerobcs event research, many scholars and experts have carred out research, and meanwhle got abundant results, such as: Tan Yn-Yue n compettve aerobcs event technques analyss, took natonal aerobcs men sngles top eght athletes n 005 as research objects to make research, the result showed that regardng jumpng techncal moton knee jont buffer range should be smaller than ts supportng leg ankle jont buffer range, Chnese aerobcs were to be mproved n dffculty elements ar posture controllng, movement pattern control aspect, from whch men were obvously weaker than women, so men aerobcs athletes should more ntensfy n the aspect []. ut women aerobcs athlete durng takng-off of dffculty element, they weren t n place as men aerobcs athletes [3], Lu Hao had ever targeted at year 994to 004, three years frames aerobcs evaluaton rules, he made researches, fnally got that aerobcs technques changes from beautfcaton to compettveness were manly evolved by rules, and put forward hgher level requrements on perfecton of routne [4]. The paper just on the bass of above researches, targeted at aerobcs athletes lmb jonts and muscle strength, t makes systematc researches, by applyng bomechancs and to other methods, t makes analyss to provde theoretcal gudance for aerobcs athletes better performng ther technology.. IOMECHANICAL ANALYSES OF AEROICS ATHLETES LIM JOINTS AND MUSCLE STRE- NGTH FEATURES Research based on aerobcs can dvde t as abcd four knds, from whch the paper a knd totally ncludes Capoera knd, Helcopter knd, Flar knd, cut knd, A-Frame knd, Plo push up knd, Wenson support knd, and push up knd. A-frame knd s seres of motons totally contans seven knds that are respectvely explosve A-frame, explosve A-frame to Wenson, explosve A-frame twst to /, explosve A- frame twst to / and then to Wenson, explosve A-frame twst to / and then rase legs to Wenson, I arm explosve A-frame, I arm explosve A-frame and then to Wenson, n the whole process, knee part movement s relatve frequent, n the followng t makes research on knee force problems X/5 05 entham Open

2 06 The Open Cybernetcs & Systemcs Journal, 05, Volume 9 Pengyu Zhao ase on aerobcs athletes bomechancs research, t can dvde lower lmbs force nto low mpact pace, hgh mpact pace and non-mpact pace three man knds, from whch low mpact pace ncludes: marchng type, touchng step type, steppng forward type, one leg rasng type; hgh mpact pace: steppng forward and jumpng type, two legs takng-off type, one leg takng-off type, back kckng and runnng type; non-mpact pace. Accordng to human body composton and attrbutes knematcs features, t can regard human body as rgd system model that s composed of 4 lnks, n the system, calculaton the human body deducts rght knee beneath jonts weghts can be regarded as total weght deducts rght knee beneath two jonts weghts, and rght knee beneath two jonts weghts total weght G can be got by formula () calculatng: ( ) G = mg P + P j () In formula (), m represents human body total mass, g represents local gravty accelerated speed, P, Pj are respectvely rght knee beneath two jonts relatve weghts. On the condton of human body balance, t can accord to mechancal condtons and force translaton theorem, for aerobcs tranng process knee force status, t makes analyss, as formula () shows relatonshps among muscle strength moment N U, frcton moment N f, supportng moment N n and gravty moment Nm that deducts rght knee jont beneath jonts. N N + N = N U + () f n m The paper manly researches human body knee jont force status n aerobcs athletes tranng process, the parts that are correlated to knee jont s hp jont, thgh and shank, t can smplfy human body lower lmbs nto plane two rgd bodes two freedom degree model, from whch t gets nvolved n Hp, Thgh, Knee, Shank and ankle, apply Lagrange equaton to establsh constrant partcle system dynamcal equaton, defne Lagrange functon L as dfference between system dynamc energy K and potental energy P, as followng: L = K P (3) In above formula K, P can use any convenent coordnate system to express, system dynamc equaton s as followng formula shows : d L L F = =,,, n dt q q (4) In above formula, q s dynamc energy and potental energy coordnate, q s correspondng speed, F s the coordnate acted force, thgh and shank jont varables are respectvely usng ntersecton angles, to express, hp jont and knee jont correspondng moments respectvely use N N h, k to express, thgh and shank masses are respectvely usng m,m to express, thgh and shank lengths are respectvely l,l, thgh and shank mass center poston and jont p, p center s dstances are respectvely, therefore t s clear that thgh mass center coordnate( X,Y ) s solvng accordng to followng formula, smlarly shank mass center coordnate ( X,Y ) can also be solved by applyng same methods: X = psn Y = pcos X = lsn+ psn( + ) Y = lcos pcos( + ) (5) System dynamc energy E k and system potental energy E expressons are as followng formula shows: p Ek = Ek + Ek, E Ek = ml E p = E p + E E p = mgp k = m p + m p ( + ) + ml p( + ) p, E p = mgp( cos ) [ cos( + )] + m gl ( cos ) (6) cos y above formula, t s clear that above formula showed Lagrange functon expresson, by formula (3) showed system dynamc equaton, t can get hp jont and knee jont torques M and M as followng formula shows: h M M + h k k = + + Among them, n above formula, followng formula shows: + (7) jk expresson s as = 0 = 0 = 0 = m p = m p + m p + ml + ml p cos (8) = ( + ) + ( + ) m p ml g sn m pg sn = + = + m p ml p cos m p ml p cos ( ) = ml p sn = ml p sn = ml p sn = + = m pg sn + When aerobcs athletes take tranng, hp jont s a key jont that decdes A-frame knd and others seres of movements completon, hp jont movement s whole body gravty center that decdes heght and balance functons, besdes to clearly express, we use a to represent Wenson posture, then use b to represent explosve A-frame twst to / posture, use c to represent explosve A-frame to Wenson and then rotate to /, use d to represent explosve A-frame posture, besdes we also use an, bn, cn, dn to respectvely express above four groups left and rght hp jonts central

3 Aerobcs Tranng for Athletes Lmb Jonts and Research The Open Cybernetcs & Systemcs Journal, 05, Volume 9 07 Table. Two aerobcs athletes hp jont parameters comparson (unt: mm). an bn cn dn Table. Two aerobcs athletes hp jont parameters movement comparson. No. Aerobcs Athlete No. Aerobcs Athlete x± SD x± SD a Left 06.4 ± ± 6.45 a Rght ± ± b Left ± ± 7.45 b Rght ± ± 8.9 c Left ± ± c Rght ± ± 6.45 d Left ± ± d Rght ± ± 0.84 an ± ± bn ± ± 7.09 cn 0.3 ± ± 6.5 dn ± ± 5.34 pont postons. When two aerobcs athletes take tranng, hp jonts Z axs postons relatve parameters are as followng Table show: y above Table, we can get: n above two aerobcs athletes tranng, n explosve A-frame twst / to Wenson posture and explosve A-frame twst to / these two movements, No. aerobcs athlete s best both n explosve A- frame to Wenson and explosve A-frame two movements 3D coordnates and Z axs, and n two aerobcs athletes tranng, regardng peak poston hp jonts comparatve status s as Table show: y above Table, we know that when No. and No. aerobcs athletes complete ab two groups of movements, there are no bg dfferences between No. and No. aerobcs athletes, whch proves the two complete the two knd of movements have no dfference; and cd two groups of movements exst obvous dfferences, n hp jont sprng heght aspect, No. athlete s far hgher than No. athlete. When two aerobcs athletes take tranng, peak hp jonts comparson s as followng Table 3 show: y above Table 3, we can see that n comparson between No. and No. athletes, there are obvously dfferences from prevous table, two people have very bg dfferences n coordnate poston, and n hp jont peak, No. athlete s hgher than No. athlete but t s not especally obvous. Regardng athlete should jont angles research, t manly starts and ends wth push up, t s about man exerton phase n push up phase, t can play balance roles, but t cannot last to movement completon, so the phase manly analyzes jont angles features and makes comparson, startng parameters are as followng Table 4 show: Endng phase shoulder jont correlaton parameters analyss Table 5: y above Table 5, we can get n startng moment, No. 0 and No. two athletes shoulder angle are less than 70, and n endng moment No. shoulder angles are slghtly bg and No. left and rght shoulder s not balance. Elbow jont n general, t doesn t partcpate movement completon process as shoulder jont, but t partcpates n balance mantanng process, so carres out two athletes comparson and analyss by followng table, as followng Table 6 show: In order to more vvdly hghlght two aerobcs athletes dfferences problems, the paper makes use of bar chart form more clearly presentng mutual dfferences and connectons, after that make analyss of angles parameters n endng moment, ts result s as followng Table 7 show: y above Table 7, we can get that n endng moment, No. aerobcs athlete left elbow angle s qute small n bd two groups, and No. aerobcs athlete two drectons elbow jonts angles are larger than that of No. aerobcs athlete, so

4 08 The Open Cybernetcs & Systemcs Journal, 05, Volume 9 Pengyu Zhao Table 3. Two aerobcs athletes hp jont comparson. Parameter No. Aerobcs Athlete No. Aerobcs Athlete x± SD x± SD a Left ± ±.85 a Rght ± ± b Left 06.4 ± ± 0.64 b Rght ± ± 4.04 c Left ± ± 4.3 c Rght ± ±.33 d Left ± ±.45 d Rght ± ± an 0.3 ± ±.56 bn ± ±.575 cn ± ± dn ± ± Table 4. Aerobcs athletes startng moment should jont angles coeffcents Table 5. Aerobcs athletes endng moment should jont angles coeffcents Table 6. Aerobcs athletes startng moment elbow jont angles coeffcents Table 7. Aerobcs athletes endng moment elbow jont angles coeffcents

5 Aerobcs Tranng for Athletes Lmb Jonts and Research The Open Cybernetcs & Systemcs Journal, 05, Volume 9 09 Table 8. Aerobcs athletes habtual poston posture quadrceps femors weght loadng status. Aerobcs Athletes Code No. Quadrceps Femors Muscle Strength n Aerobcs Athletes Habtual Poston Posture Aerobcs Athletes Themselves Weght Weght earng Ratos Average value ± standard devaton ± ± ± 0.48 No. should contract more elbow jont angle regardng A- frame knd n startng moment. Durng aerobcs athletes tranng process, muscle s the man body that generates strength. When n standng poston posture, human knee jont surroundng muscle mantans jont stablty; t can guarantee human standng posture. It s well known that every ndvdual standng posture has a certan dfference so that make every ndvdual muscle torque has also the dfference. When aerobcs athletes take tranng, they le n the habtual posture, ts rght knee jont stablty manly reles on quadrceps femors and lgament to mantan, and whle knee jont makes flexon n habtual poston, t wll let quadrceps femors excessve extenson that prone to be fatgued, causng patellar lgament also prone to get njured. In order to make research on knee jont muscle tolerable loadng status when aerobcs athletes take tranng, t get quadrceps femora s load bearng muscle strength values and ther ratos wth themselves own weght n habtual poston posture as Table 8 shows. y above Table 8 data, t s clear that knee jont n flexon, ts quadrceps femors muscle strength weght bearng ratos are n the range of [.5, 4.09] tmes, arms force deceases by comparng wth standng poston posture, whle muscle torque ncreasng leadng quadrceps femors muscle strength ncreases, meanwhle muscle strength ncreasng can cause quadrceps femors weght bearng ncreases that let t prone to get tred. Patellar lgament s the extenson of quadrceps femors tendon, quadrceps femors extenson would also accompany by patellar lgament extenson, whle quadrceps femors extenson wll also accompany wth patellar lgament extenson, quadrceps muscle strength s bascally also loaded by patellar lgament, so strengthen quadrceps femors muscle strength and patellar lgament tractve tenson s effectve way to prevent njury. CONCLUSION The paper frstly ntroduces body postures status when aerobcs athletes take tranng to provde space analyss mage base for researchng ts moton process knee jont force analyss; establshes two rgd bodes two freedom degrees dynamcal model to provde theoretcal bass for moton process knee jont moment analyss; after that, the paper through applyng table form, t more clear presents two aerobcs athletes exstng dfferences, by comparng, we can get that two aerobcs athletes dfferences are relatve obvous, so for No. aerobcs athlete, he should control shoulder jont n that s sutable, and n consumed tme, t summarzes wth dffcultes ncreasng, two aerobcs athletes dfferences wll be more obvous, and meanwhle t reflects No. aerobcs athlete ablty s relatve promnent, by elbow jont aspect comparng, we fnd that No. aerobcs athlete ablty s stronger than No. aerobcs athlete, so t proves No. aerobcs athlete comprehensve strength s stronger. Fnally by researchng aerobcs athletes body rght knee mnmum jont angle, t gets habtual posture and rght knee mnmum jont angle nstant posture such two postures, when jont angle gets smaller, muscle strength moment wll be bgger, and gravty moment wll be bgger, and muscle strength moment wll accordngly ncrease. CONFLICT OF INTEREST The authors confrm that ths artcle content has no conflct of nterest. ACKNOWLEDGEMENTS Declared none.

6 0 The Open Cybernetcs & Systemcs Journal, 05, Volume 9 Pengyu Zhao REFERENCES [] W. Kun, and Z. Mn, Analyss of compettve aerobcs group horzontal supportng type dffculty element technques and muscle actvty features, Journal of Xan Physcal Educaton Unversty, vol. 7, no. 06, pp , 00. [] Z. Mng-Jun, and W. Qng-Sheng, Flatfoot sports shoes desgnng sports bomechancal features analyss, Journal of Huzhou College, vol. 3, no. 06, pp. 0-05, 0. [3] Y. Hong, Compettve aerobcs straddle jump to push up threedmensonal knematcs analyss, Journal of Mltary Sports College of Further Educaton, vol. 30, no. 0, pp , 0. [4] L. Xng-Guan, Applcaton of sports bomechancs n aerobcs, Journal of Nanjng Sport Insttute (Natural Scences), vol. 07, no. 04, pp , 008. Receved: June 0, 05 Revsed: July 9, 05 Accepted: August 5, 05 Pengyu Zhao; Lcensee entham Open. Ths s an open access artcle lcensed under the terms of the ( whch permts unrestrcted, noncommercal use, dstrbuton and reproducton n any medum, provded the work s properly cted.