Journal of Chemical and Pharmaceutical Research, 2014, 6(6): Research Article

Transcription

1 Available online Journal of Chemical an Pharmaceutical Research 04 66: Research Article ISSN : CODENUSA : JCPRC5 Research on the ynamics an biomechanical moels of Sana sie kick Jian hang an Fengmei u College of Physical Eucation Chuzhou University Anhui China ABSRAC As one of China s traitional martial arts sort Sana has been arresting the attention of various countries an regions. hrough research this aer obtains the mechanics relationshi ynamics relationshi an rotary inertia of athletes oing rear sie kick an learns about the otential energy generate by athletes oing sie kick. In the sie kick moel of Sana athletes establishe in this aer athletes can increase the momentum of knee joint through the effective braking effect of hi joint in accorance with the rincile that momentum is transferre from roximal to istal. hen the momentum is transferre to the ankle joint via the braking of knee resulting in the en acceleration. his aer also raws the conclusion that the angular velocity of the left thigh of athletes oing sie kick eens on the angular velocity of the hi joint an the velocity of waist but that of the calf is etermine by the angular velocity of the knee joint an left thigh. In aition the angular velocity of the calf shoul be greater than that of the thigh which is more conucive to the acceleration of the knee joint. When oing sie kick athletes shoul fully fol thigh an calf an reuce the limb s rotary inertia to imrove the angular velocity of the knee raily. In the meanwhile muscle grous in sie kick can be fully contracte to enable athletes leg muscle force to achieve the best conition an enhance its contraction see. China s athletes can conuct targete training base on the research result of this aer. Key wors: Mechanics an ynamics analysis; rotary inertia; moment equation of rotation tensor INRODUCION As the crystallization of Chinese martial arts Sanshou has evolve to moern Sana through five thousan years of eveloment. It originate from the self-efense methos use to resist beasts an foreign enemies in rimitive society. Nowaays Sana consists of a variety of martial arts by incluing Chinese traitional martial arts an referring to foreign martial arts. It absorbs the essence from these martial arts an eliminates its own shortcomings. With the assage of time the basic exercise form of moern Sana is abstracte. Moern Sana is mainly comrise of two forms of attack: linear tye an arc tye. Comare with aekwono the attack form of Sana is more various an flexible in that it ays attention to the combination of fists an feet flexibility an the integration of attack an efense. After many years of war followe by the founation of new China an the coming of reform an oening u China s Sana rose again from the bottom. It was arove as an official event in 989 an inclue in the National ames in 99. echnical characteristics of Sana: Moern Sana has two forms: linear tye an arc tye. In Sana fist osition mainly consists of whie boxing forwar unch whi fist an lift fist while foot osition reominantly inclues kicking heel kick foot swee leg whi leg swing an hook kick. Characterize with no leaning an fast wrestling close wrestling is mainly about the estruction of center of gravity an swing circle. he style of lay inclues claming wrestling an reacting wrestling an the efense ways of Sana are comrise of no touching efense an touching efense. In terms of cometition rules of Sana the traitional contest in martial arts is emloye. If one arty fails in the contest whose cometition system is for the best of three games it loses. Although Chinese Sana bears strong antagonism it iffers from aekwono an Western Boxing not to mention hai Boxing 854

2 Jian hang an Fengmei u J. Chem. Pharm. Res : ominate by such ferocious attacks as elbow-strike an knee-strike an Juo. Most Sana athletes have high morality. Accoring to Sana rules Sana athletes are forbien to use elbow knee an anti-joint techniques or attack the neck crotch an hinbrain of the oonent. Sana is ominate by hitting near kicking far an close wrestling. During the Sana cometition rocess athletes nee to roar louly to eter the oonent in the manner. An relevant research shows that by way of utterance 0% of the human boy muscle can accelerate 9% of its contraction velocity in the absence of the buren of work. With the buren of work the acceleration effect is more significant being about 4%. herefore in contests Sana athletes woul yell at each other. Sana s foot osition reominantly inclues kicking sie kicking foot swee leg whi an so on. his aer will focus on the sie kick which has goo strike effects an recise attacks.. ESABLISHMEN AND SOLUION OF HE MODEL. Basic stes of sie kick Sie kick is a linear attack form of Sana. Its stanar action is as follows. Athletes shoul firstly ut on the guar osition shift the center of gravity towar the right leg by taking a ski ste of the right foot buckle the knee of the left leg tilt the uer boy an kick out towars the attack irection swiftly. In the rocess of sie kick athletes shoul attack the abomen chest an hea of the target by straightening the knee joint of the attack leg raily rotecting the jaw with the right han an sweeing with the left han. Figure is the emonstration of Sana sie kick. Fig. : Demonstration of hea attack of sie kick by athletes Fig. : Demonstration of abomen attack of sie kick by athletes he thigh an calf of Sana athletes are now consiere as two rigi boies with ifferent volumes while an 855

3 Jian hang an Fengmei u J. Chem. Pharm. Res : are built into a moel with three egrees of freeom as shown in figure. o z L y L x z x y an Fig. : Freeom egree emonstration of leg attack of sie kick by athletes stan for the hi joint knee joint an ankle joint of Sana athletes resectively the L L anatomical angle of the thigh an the calf an λ λ is then we have λ λ the length of the leg. Set that the three-imensional vectors of an are i.e. the actual angular velocity of the thigh an calf of athletes an that the see of. When Sana athletes o sie kick the ankle s instantaneous velocity of the attacking leg is relate to its initial see. In other wors the angular velocity of is subject to the angular velocity of the thigh an calf of the attacking leg an the angular velocity of. herefore the see of an its relative velocity is relate to the see of. he exression is V D D V L D V V L D an D reresent the actual velocity vector of the see of relative to the osition vector from to an the osition vector from an resectively. Accoring to the vector L theorem the imacts of the local motion of an L on are figure out. + + D+ D + D D D D Simlifie into + D In this formula is the osition vector of in the reference system by an D the see of generate by. the see of generate 856

4 Jian hang an Fengmei u J. Chem. Pharm. Res : he relationshi between the angles of an an the osition of in figure is ecomose an written as cos cos sin sin cos sin x D D y D D z D D hen the angles of an are ifferentiate an the relationshi between the angles an the osition vector of can be obtaine through the erivation of the above formula ransforme into the following matrix form: In the light of the roerty of the matrix an vector rouct metho the above formula can be written as W. W is shown as follows. W W is the ifferential relationshi between angular islacement of noes in current structure an infinitesimal islacement of. Substitute the matrix equation into the above formula the following formula can be obtaine: W t t or [ ] W Substitute it into the calculation formula of the relative velocity of the following formula can be obtaine:

5 Jian hang an Fengmei u J. Chem. Pharm. Res : [ ] + D. Rotary inertia analysis of shooting basket by basket by basketball athletes When Sana athletes o sie kick their leg movements are shown in figure 4. θ Fig. 4: Demonstration of leg attack of sie kick by Sana athletes As the attacking leg is rotary when athletes o sie kick rotary inertia of the whole boy of Sana athletes can be obtaine base on the rotary inertia theorem. hat is P Σ m r i i mi stans for the quality of each articile of human boy an r reresents the length from each In this formula articile to the axis of athletes. he continuous function of the human boy is P r m r ρv v v hus when Sana athletes o sie kick the rotation tensor Rc of the attacking leg is Rc v ρ r E r r V Vector exression of any oint O r r in the boy of Sana athletes is E + r E + r E rouct of two vectors. hen the unit tensor is. r r reresents the E he unit orthogonal curvilinear frame is V E E E ;. When Sana athletes o sie kick the resultant moment vector of the attacking leg yc Rc Rc Σ χ+ ω χ Σ yc is reresente as 858

6 Jian hang an Fengmei u J. Chem. Pharm. Res : he moment equation on each coorinate axis of athletes attacking legs rojects the original moment equation onto the three coorinate systems. herefore when athletes o sie kick the resultant moment attacking leg rotation is φ I generate by φ I reresents the angular acceleration of attacking leg in sie kick an An there is the rotary inertia of the attacking leg. m i I φ he angular acceleration of the thigh is w χ φ t t hen the angular acceleration of the calf φ is w w χ χ φ + + t t t t hrough the Lagrange equation the constraine article kinetic equation is establishe i.e. D H P D is the ifference between system kinetic energy H an otential energy P. he system kinetic equation is D D Fi i L n t i i In this formula energy an otential energy an i stans for the corresoning velocity of article i the coorinate of the article kinetic F i the force exerte on the i coorinate. reresent the angle between L L the thigh an the coorinate axis an the angle between the calf an the coorinate axis resectively corresoning length an center of an q q the istance between the center gravity osition of the thigh an calf an the resectively. It can thus be seen that areal coorinate of the thigh is q sin q cos q sin + q sin + q cos q cos +. the Likewise the areal coorinate of the calf can be figure out. he exressions of system kinetic E energy k an system otential energy E are 859

7 Jian hang an Fengmei u J. Chem. Pharm. Res : Ek Ek + Ek Ek mq Ek ml + mq + + mlq 0 + cos E E + E E mgq cos E mgq cos + + mgl cos herefore M h an M k which reresent the moment of an that of resectively are as follows. Mh A A A A A A A M k A A + A A + + A A A In the above formula Bijk is A 0 A 0 A 0 A mq A mq + mq + ml + ml q cos A mq + ml g sin + mqg sin + A mq + mlq cos A mq + ml q cos A ml q sin A mlq sin A mlq sin A A + A A mq g sin + From the above analysis we know that when athletes o sie kick they shoul raise the see of the leg to the maximum as soon as ossible. hat is to say the rojection see of on the axis is elevate to the maximum at the final stage to maximize the see of the attacking leg on sagittal lane. herefore in the light of the rincile of matrix vector rouct only when meet the constraints of 45 < + < 90 0 < < o o an an increase coul the see of be the maximum on the sagittal lane. his requires that at the L rearatory stage of sie kick the iving flexion of L o an shoul not excee 45 an that the anatomical angle change see of the left thigh an calf must be fast an live u to the muscle relaxation characteristics in muscle mechanics. If the iving flexion of the left thigh an calf is excessive muscle relaxation will be cause because of the muscle contraction. Also meet the constraine conitions which makes increase. In can be seen that when athletes o sie kick it is require that anatomical angle change rate of the left thigh an calf shoul reach the maximum within unit time an that anatomical angle change rate of the left thigh shoul be greater than that of the left calf. o meet these conitions the mechanics analysis is conucte on the left legs of athletes oing sie kick. Since the calf is consiere as a rigi boy athletes are subject to three forces when oing leg whi i.e. reaction force of the groun to calf frictional force of the groun an stress of the joint. At the rearatory stage the see of each noe is 0 an the force of the leg is in a state of equilibrium. hen at the kicking stage muscle fibers are fully activate which increases the force on the groun instantaneously estroys the equilibrium state an changes the see of each noe thereby altering the angular velocity of the leg. By virtue of the transmission of a rigi boy o when the attacking leg goes above the groun the angle between the thigh an the calf reaches nearly80. he force is transmitte to the thigh along the action line of the thigh. But as the thigh is joine with the calf the force will fae. herefore that the angular velocity of the calf is greater than that of the thigh is more conucive to the acceleration of the knee joint. 860

8 Jian hang an Fengmei u J. Chem. Pharm. Res : CONCLUSION his aer firstly obtains the otential energy generate by athletes oing sie kick by stuying the kinematical equation of basketball shot. An it raws the conclusion that when athletes o sie kick the angular velocity of the left thigh eens on the angular velocity of the hi joint an the see of the waist while that of the calf is etermine by the angular velocity of the knee joint an the left thigh. When athletes reare for sie kick the o iving flexion of the left thigh an calf shoul try not to excee 45. hat the angular velocity of the calf is greater than that of the thigh is more conucive to the acceleration of the knee joint. hen rotary inertia analysis is conucte to obtain the momentum relationshi of each noe. hrough the Lagrange equation the constraine article kinetic equation is establishe. he resulting sie kick moel shows that athletes can increase the momentum of knee joint through the effective braking effect of hi joint in accorance with the rincile that momentum is transferre from roximal to istal. hen the momentum is transferre to the ankle joint via the braking of knee resulting in the en acceleration. Acknowlegment Aware the Anhui Provincial Deartment of Physical eucation research roject "he Enlightenment of aijiquan inheritance exerience on eveloment of Wushu". Project number: ASS0408 REFERENCES [] Sorts biomechanics writing grou. Sorts biomechanics [M].Beijing:Higher Eucation Press [] HE higang et al. hejiang Sort Scienceno [] LI ugang. Combating event grou an sorts biomechanics [M].Wuhan: Hubei Science an echnology Press 00. [4] LI ugang. he basis of sorts training biomechanics [M].Wuhan:Hubei Science an echnology Press no [5] Vlaimir trans. LU Aiyun. Sorts biomechanics [M]. Beijing:Peole's Sorts Press : [6]M EN Junqing et al. Journal of jipeno. :