Track & Field Technical Certification. An Overview of the Throwing Events

Transcription

1 Track & Field Technical Certificatin An Overview f the Thrwing Events

2 Intrductin Track and Field cmpetitins include fur thrwing events. They are the Sht Put, the Discus Thrw, the Javelin Thrw, and the Hammer Thrw. This curse will cncentrate n the glide style f the sht put, the discus thrw, and the javelin thrw. Instructin in the rtatinal style f sht put and the hammer thrw are available in the supplementary sectins f this curse. In the fllwing sectin, we will examine basic technical aspects that all thrwing events share. Mechanical Factrs Affecting Thrw Perfrmance. Five factrs dictate the perfrmance n any given thrw, and all technical teaching is geared tward affecting these parameters. These are: The Implement s Velcity at Release The Implement s Angle f Release The Implement s Height at Release Aerdynamic Factrs Release Psitin with respect t the Pint f Measurement The velcity at release is the mst imprtant f these. Phases f the Thrwing Events. Each f these events is cmpsed f the phases listed belw. The Preliminary Mvements The Apprach Arrival in the Delivery Psitin The Delivery The Finish We will nw examine each f these phases in detail. Keep in mind explanatins are applicable t right handed thrwers.

3 The Preliminary Mvements Each thrwing event cntains a grup f preliminary mvements which prepare the thrwer fr executin f the thrw. These typically include the fllwing. Gripping and Psitining the Implement Assuming the Starting Psitin Rhythmic r Setup Mvements The Apprach Purpses f the Apprach. Each thrwing event includes sme type f apprach. The apprach can take different frms (a glide in the sht put, rtatins in the discus, r sht put, r a runup in the javelin). In each case, the apprach serves three purpses. Develping Mmentum and Velcity. The apprach prvides the thrwer and the implement with mmentum and velcity, increasing the pprtunity fr gd perfrmances. Insuring an Accurate Delivery Lcatin. The apprach shuld place the thrwer in the crrect physical lcatin frm which t execute the delivery f the implement, s that prper technique can be used and distance preserved. Psitining the Bdy fr Delivery. The apprach shuld place the bdy in the crrect physical psitins and mtr envirnment t execute the mechanics f the delivery crrectly. Acceleratin. The apprach shuld cnsist f a gradual, smth acceleratin. It is a cmmn errr fr a thrwer t accelerate t quickly in the apprach, nly t decelerate later.

4 Psture. Thrwers shuld demnstrate prper psture in rder t achieve the prper bdy psitins fr the delivery. The psitins and alignment f the head, trs, and pelvis determine the quality f psture and shuld be cnstantly addressed. Amplitude f Mvement. The apprach shuld display large ranges f mtin and extended bdy psitins. These are mre cnducive t mmentum develpment. Arrival in the Delivery Psitin The Delivery Psitin. The delivery psitin is the psitin frm which the thrwer can best execute the delivery f the implement. One purpse f the apprach is t place the bdy in the mst effective delivery psitin. The delivery psitin f any thrw shws certain psitins and is subject t certain bimechanical principles, which are discussed belw. Bimechanics f the Delivery Psitin Linear and Rtary Mtin. In every thrwing event, during delivery the implement travels a path that cmbines linear and rtary characteristics. Sme events feature ne mre than the ther, but bth are present in each. Psture. Prper alignment f the cre f the bdy is prerequisite t prper delivery f the implement. A prper alignment f the head insures relaxatin, balance, and permits a gd strike. Drpping the head r turning the head away during the thrw are cmmn errrs. A neutral alignment f the pelvis with respect t the spine enables relaxatin, prper leg functin, and effective turning. Excessive bending at the waist upn arriving in the delivery psitin is a cmmn mistake, placing the pelvis in a frward psitin. Setting up a Lng Path f the Implement. The lnger we apply frce t the implement, the greater the mmentum and velcity we can create. T enable a thrwer t lengthen the amunt f frce applicatin time, the path f the implement during the delivery shuld be lengthened as much as pssible. This is dne in tw ways. Placing Bdyweight n the Rear Ft. During the delivery, bdyweight is transferred frm the right (back) ft t the left (frnt) ft, effectively increasing range f mvement and the length f the implement s linear path. T

5 set up this crucial weight transfer, the thrwer s weight shuld be cmpletely cncentrated n the rear (right) ft in the delivery psitin. Clsing the Upper Bdy. During delivery, the bdy shuld turn smthly in the directin f the thrw. Lengthening the path f this rtatin prvides mre pprtunity fr the thrwer t apply frce t the implement. Fr this reasn, in the delivery psitin, the bdy shuld be turned away frm the directin f the thrw t sme degree. Adjusting the Stance t Set Up a Blck. Mmentum that is created in the thrwer s bdy must eventually be stpped s that it can be effectively transferred t the implement. This is dne when the left leg plants firmly in the delivery psitin, stpping the hrizntal and rtatinal mvement f the thrwer s bdy. In these thrwing events, the feet in the delivery stance are lcated apprximately in line with the directin f the thrw and the thrwer s directin f travel. This alignment f the feet enables the left leg t perfrm this blcking functin. Separatin. During delivery, the bdy must turn smthly in the directin f the thrw. Hwever, the upper and lwer bdies d nt turn frm the same psitins at the same time. In the delivery psitin, the shulders are rtated farther frm the directin f the thrw than the hips. This relatinship f the hips and shulders is called separatin, referring t the separatin f their respective axes. In these thrwing events, the delivery psitins shw the hips aligned 90 degrees frm the directin f the thrw, and shulders clsed even mre. The Delivery This phase cnsists f mvements f the thrw itself, beginning upn arrival in the delivery psitin. The delivery is cmprised f mvements f the upper and lwer bdies. The mvements f the upper bdy are called the strike. Fllwing are bimechanical principles gverning the delivery. Cnsistent Acceleratin f the Implement. Acceleratin f the implement must be cnsistent and psitive. Accelerating the implement t quickly initially, nly t decelerate later is a cmmn errr. Summatins f Frces. Upper bdy activity in delivery and the strike shuld result frm a summatin f frces. Large muscles f the legs and trs initiate the mvement and vercme

6 inertia, s that the smaller muscles f the shulders and arm can cntribute effectively later. Each thrw differs slightly, but prximal t distal jint firing sequences must be preserved. Transfer. During delivery, the bdyweight shuld transfer smthly frm the rear (right) ft t the frnt (left) ft, lengthening the implement s linear path. Turning. During delivery, the bdy shuld turn smthly frm a clsed psitin until the thrwer is facing the directin f the thrw. Lifting. During delivery, the legs extend, lifting the implement and cntributing t vertical frce prductin. Trque. Thrwers initiate the turning f the lwer bdy prir t the turning f the upper bdy. This creates a twisting f the cre f the bdy called trque. This trque creates stretch reflexes in the trs musculature, enabling greater subsequent acceleratin f the implement. Blcking. In thrwing, mmentum that is created in the thrwer s bdy must eventually be stpped s that it can be effectively transferred and imparted t the implement. This is dne in tw ways. The Left Leg Blck. The left leg plants firmly in the delivery psitin, stpping the hrizntal and rtatinal mvement f the thrwers bdy. This accelerates the thrwing side and transfers mmentum t the upper bdy and implement. Prper alignment f the feet is essential t prper blcking. The Left Arm Blck. The left arm shuld mve in clse t the side f the thrwer as the delivery is initiated, assisting in stpping the left side f the upper bdy. This accelerates the thrwing side and transfers mmentum t the implement. This blck shuld nt include a backwards mvement f the bdy s left side, but slely a stpping f the upper bdy s rtatin as frward mvement cntinues The Finish The Finish cnsists f the parts f the thrw perfrmed after the implement has been released. Mechanics f the Finish. N frce can be applied t the implement after it is released, s at release the thrw s distance is predetermined. Hwever, the finish is imprtant because the

7 thrwer must redirect mmentum t prevent fuling. Als, thrwers wh d nt finish crrectly typically lse distance because the delivery is altered in anticipatin f the pr finish. Parts f the Finish The Fllw Thrugh. The fllw thrugh is cmprised f the cntinued mtin f the thrwing arm after the implement has been released. The Reverse. The reverse is a maneuver that enables the thrwer t fllw thrugh, and maintain r regain balance after the thrw is cmpleted t prevent fuling. While it varies frm event t event, it typically invlves adjusting the stance and trs.