Kicking in Soccer - Northern Michigan University

1 1 Kicking in SoccerThorsten SterzingInstitute for Sports Science, Chemnitz University of Technology, GermanyInternational Society of Biomechanics in Sports 2010 Congress, Marquette, MI, : Art and SportsSoccer SubjectUniversity of Duisburg-Essen, Germany2005 Sculpture Soccer Player Ren e Sintenis - Berlin, Germany19272 Outline Kicking Movement Measurement Technology Performance Criteria Influence of Footwear Research PerspectivesFootwearMeasurement TechnologyMovementPerformancePerspective Kicking : Complex Motor Movement6 Phases:5 Phases:Bauer 1990 Approach angle Plant foot forces Swing limb loading Hip flexion and knee extension Foot to ball contact Follow-throughBarfield 1998 Approach Support leg Kicking leg Foot to ball contact Ball flightLees et al. 2010 FootwearMeasurement TechnologyMovementPerformancePerspective 3 Kicking Leg Angular VelocityLees 1998 FootwearMeasurement TechnologyMovementPerformancePerspective Kicking Leg Segment SpeedLees 1998 FootwearMeasurement TechnologyMovementPerformancePerspective 4 Key Aspects for Fast and Accurate KickingVelocity:Accuracy:Kellis & Katis 2007 Kicking Type, Technique Skill level, Limb Dominance Age, Maturity, Gender Muscle Strength & Power Approach Speed and Angle Energy Transfer between Body Segments Approach Speed Kicking Velocity Reduction Foot to Ball Contact Point Ball SpinFootwearMeasurement TechnologyMovementPerformancePerspective Foot to ball impact characteristicsFoot to Ball Contact: Impact PhaseinitialfullfinalOpen - loop movementDuration.

2 6 - 16 msvarious authorsinitialfullfinalFootwearMeasureme nt TechnologyMovementPerformancePerspective Tsaousidis & Zatsiorsky 1996 Displacement of the ballMixture of impact-like and throwing-like aspects5 Impact PhaseShinkai et al. 2009 FootwearMeasurement TechnologyMovementPerformancePerspective Kicking Techniques Full Instep Side Foot Toe Kickp Inner Instep Outer InstepInstep Kicks:Other:SpinSpecificFootwearMeasurem ent TechnologyMovementPerformancePerspective Knuckle KickSpecificTechniques6 Predominant Kicking Techniques PurposesFull InstepInner InstepSide FootWomen5188330 Men4260407 Men4260407 Team incidents during a 90 minute Soccer game, Althoff et al. 2010 Passing, CrossingShots on GoalClearanceFootwearMeasurement TechnologyMovementPerformancePerspective Full Instep Kick Giovanni van Bronckhorst (Netherlands) World Cup 2010: Uruguay vs.

3 Netherlands (2-3)FootwearMeasurement TechnologyMovementPerformancePerspective 7 Inner Instep Kick Yasuhito Endo (Japan) World Cup 2010: Denmark vs. Japan (1-3)FootwearMeasurement TechnologyMovementPerformancePerspective Side Foot KickElano (Brazil) World Cup 2010: Brazil vs. North Korea (2-1)FootwearMeasurement TechnologyMovementPerformancePerspective 8 Velocity Levanon & Dapena 1998 Nunome et al. 2002 Neilson & Jones 2005 Kicking PerformanceBasic PerformanceCriteria ..Accuracy Kristensen et al. 2005 Scurr & Hall 2009 Sterzing et al. 2009 FootwearMeasurement TechnologyMovementPerformancePerspective High Speed Videoprovided by Shinkai et al. 2009 FootwearMeasurement TechnologyMovementPerformancePerspective 9 Motion Analysis SystemsFootwearMeasurement TechnologyMovementPerformancePerspective Radar Gun 20 milliwatt Ka band dual horn microwave speed range:1 to 480km/hFootwearMeasurement TechnologyMovementPerformancePerspective acquisition time: update rate:100per second10 Finnoff et al.

4 2002 Plywood wall laminated with carbon paper for impact imprintsMeasurement Technology for Kicking Accuracy Circular electronic target (concentric wire frame) Ball contact generates electrostatic charges Software based determination of ball impact locationScurr & Hall 2009 Digital camera recording (25 Hz)Hennig et al. 2009 FootwearMeasurement TechnologyMovementPerformancePerspective Kicking Accuracy Measurement Technology-High speed video capturing of ball impact location (200 Hz)CMOS Camera HCC-1000, VDS Vossk hler, GermanySterzing et al. 2009-Accuracy determination: distance ball center to bull s eyeMaxTRAQ , Innovisions Systems, MI, USAF ootwearMeasurement TechnologyMovementPerformancePerspective 11 Relation of velocity (VEL) and accuracy (ACC)Sterzing et al. 2009 Simultaneous quantification of VEL and ACC ofFootwearMeasurement TechnologyMovementPerformancePerspective full instep, inner instep and side foot kicks Speed - accuracy trade-off Variability of VEL and ACC6 Kicking Conditions2 Performance TasksIIIIIIIVFull InstepInner Instep3 KickingTechniquesMaximization ACC(Max ACC)Maximization VEL(Max VEL)VVISide FootTechniquesFootwearMeasurement TechnologyMovementPerformancePerspective 12- 19 Soccer players (4th -6thleague)- Kicking of stationary ball 6 m target distanceMethods- 6 repetitive trials per Kicking condition (total.)

5 36 kicks)- Mean and standard deviation (SD)- Coefficient of variability (CoV)Repeated measures ANOVA across subjects-Repeated measures ANOVA- Post-hoc test (Bonferroni)- Coefficient of variability (CoV6 repetitive kicks)within subjectsFootwearMeasurement TechnologyMovementPerformancePerspective Experimental Set-up- Radar gun for VEL measurementsStalker Pro, Applied Concepts, TX, USAHi hd idt if b ll it lti(200 H )-High speed video capturing of ball impact location (200 Hz)CMOS Camera HCC-1000, VDS Vossk hler, Germany- ACC determination: distance ball center to bull s eyeMaxTRAQ , Innovisions Systems, MI, USAF ootwearMeasurement TechnologyMovementPerformancePerspective 13 Performance TaskMax VEL[km/h] Kicking Velocity (p< 0,001)Max ACCT echniqueTaskMeanSDCoVFull InstepInner InstepSide FootReduction of VEL to 82-86%, independent of Kicking techniqueqFull InstepMax VEL103,166,510,063 Full InstepMax ACC87,7611,170,127 Inner InstepMax VEL100,756,900,068 Inner InstepMax ACC82,9914,450,174 Side FootMax VEL89,795,650,063 Side FootMax ACC77,3811,270,146 FootwearMeasurement TechnologyMovementPerformancePerspective Performance Task[cm] Kicking Accuracy (p<0,001)

6 Max VELMax ACCT echniqueTaskMeanSDCoVFull InstepInner InstepSide FootDecrease of ACC by 29-41%,dependent on Kicking techniqueqFull InstepMax VEL59,5114,040,236 Full InstepMax ACC45,939,900,216 Inner InstepMax VEL50,8512,290,242 Inner InstepMax ACC39,6511,020,278 Side FootMax VEL40,5314,380,355 Side FootMax ACC28,837,900,274 FootwearMeasurement TechnologyMovementPerformancePerspective 14 Within Subject Variability (CoV6 repetitive kicks)VELACCT echniqueTaskCoV6 kicks CoV6 kicks Full InstepMax KV0,0340,633 Full InstepMax KA0,0440,550 Inner InstepMax KV0,0320,477 Inner InstepMax KA0,0520,613 Side FootMax KV0,0290,573 Side FootMax KA0,0470,572,,Reduction of velocity did not lead to more constantaccuracy. FootwearMeasurement TechnologyMovementPerformancePerspective Findings VEL differences between techniques confirmed ACC differences between techniques fundamentally quantified VEL and ACC relation appeared stable for the two performance tasks Variability of VEL extremely low within subjectsMotor InputFootwearMeasurement TechnologyMovementPerformancePerspective Motor Input Variability of ACC considerably high especially within subjectsMotor Output15 Discussion of Speed Accuracy Trade-offTennisServeServeKickSliceStraig htty [km/h]acy [cm]p < = n.

7 TechnologyMovementPerformancePerspective Sterzing & Rodewald 2010 Ball VelocitBall AccuraDoes footwear influence Kicking velocity?commercial shoe models 2004 Copa MundialMercurial VaporAZT 90 IITiempo PremierPR [km/h]p < <Copa MundialPR Mania Tiempo Premier AZT 90 IIMercurial VaporFootwearMeasurement TechnologyMovementPerformancePerspective 16 Requirements of Soccer Footwear5less importantQuestionnairen = 24922,533,544,5 Sterzing et al. 2007 FlexibilityKicking VelocityKicking AccuracyComfortSpinBall SensingTractionStabilityWeightDurability Protection11,5more importantFootwearMeasurement TechnologyMovementPerformancePerspective Kicking Velocity& Soccer FootwearFootwearMeasurement TechnologyMovementPerformancePerspective 17 Systematic Evaluation of Isolated Shoe Features9 FootwearMeasurement TechnologyMovementPerformancePerspective General Testing ProceduresBiomechanics LaboratoryUniversity of Duisburg-EssenRadar GunStalker ProFootwearMeasurement TechnologyMovementPerformancePerspective 18 General Testing Procedures Plate KistlerPhoto Cell ArrangementSwing Phase Time.

8 Foot strike (GRFs) to initial ball movement (photo cell)FootwearMeasurement TechnologyMovementPerformancePerspective General Testing Procedures TechnologyMovementPerformancePerspective 19 Neutral Shoe Method at Contra Lateral FootSupport FootKicking FootFootwearMeasurement TechnologyMovementPerformancePerspective About 20 experienced Soccer players Familiarization with laboratory testing environmentGeneral Testing Procedures ctd. Familiarization with laboratory testing environmentWarm-upPractice trials 6 maximum full instep kicks per shoe condition stationary ball3-step approachStandardized resting intervalsRandomization of shoe conditions between subjects Ranking of ball velocityRating of study specific itemsFootwearMeasurement TechnologyMovementPerformancePerspective 20 Support Foot TractionDiego Forlan (Uruguay) World Cup 2010: Uruguay vs.

9 Netherlands (2-3)FootwearMeasurement TechnologyMovementPerformancePerspective FootwearMeasurement TechnologyMovementPerformancePerspective Support Foot TractionYasuhito Endo (Japan) World Cup 2010: Denmark vs. Japan (1-3)21 Plantar Pressures Support FootSterzing & Hennig 2005 FootwearMeasurement TechnologyMovementPerformancePerspective Peak PressureTime to Peak PressurePlant Foot ForcesBarfield 1995 FootwearMeasurement TechnologyMovementPerformancePerspective 22 ZFGHFGFFGFSGHFG600800100012001400[N]Resu ltant Shear Force < [ms]Swing Phase Timep < TechnologyMovementPerformancePerspective ZFGHFGFFGFSGHFGG859095100105[km/h]Ball Velocityp < ,533,544,5slowPerception Ball Velocityp < TechnologyMovementPerformancePerspective 8085 ZFGFFGHFGFSG11,5fastZFGFFGHFGFSGF unctional traction necessary for fast kicking23 Shod vs.

10 Barefoot KickingBeach SoccerRegular SoccerFootwearMeasurement TechnologyMovementPerformancePerspective Ball Conditionoutdoor regularindoor regular cm weight:4366g cm weight:4229 gReduction of Skin PainFootwearMeasurement TechnologyMovementPerformancePerspective 24 Kicking Velocityown shoeOSHBARSOCAAANNN92,59597,5100p = [km/h]FootwearMeasurement TechnologyMovementPerformancePerspective OSHNNNAAASOCBAR8082,58587,590 Mean (SEM)Perception Variablesown shoeOSHBARSOCAAANNN45 Perception Ball Velocityp < Painp < TechnologyMovementPerformancePerspective 123 OSHNNNAAASOCBAR betterlow123456 OSHNNNAAASOCBARMean (SEM)25 Impact Phase: High Speed Video (1 kHz)initialfullfinalReduction of passive, forced plantarflexion for barefoot kicks Passive, forced plantarflexion for shod kicksLees 1993, Shinkai et al.