Player Surface Interaction: Injury and Performance

Transcription

1 Player Surface Interaction: Injury and Performance Darren Stefanyshyn Human Performance Laboratory University of Calgary

2 Player Surface Interaction Injury traction Performance energy

3 Sport Surfaces and Injuries Overuse and acute injuries non uniformity high stiffness minimal surface deformation insufficient friction excessive friction Experimental evidence?

4 Soccer Injury Cutting and dribbling 2/3 of ACL injuries non-contact Andreasson et al., 1986 Ekstrand and Nigg, 1989

5 Tennis Injuries Surface Frequency Rel.. Frequency of pain of pain [%] [%/hours/week] Clay Synthetic Sand Synthetic Surface Asphalt Felt Carpet Synthetic Grill Nigg et al., 1980

6 Traction and Injuries Torg and Quedenfeld,, Quantified number and severity of knee and ankle injuries in American Football 4 seasons first season - 7 stud football shoe following seasons - 15 stud soccer shoe

7 American Football Injury Football shoe Injuries/team/game Soccer shoe Injuries/team/game Public league Knee Catholic league Knee ankle Torg and Quedenfeld,, 1971

8 American Football Injury Rotational traction Release coefficients on grass Football shoe Soccer shoe.55 ± ± 0.03 Torg and Quedenfeld,, 1974

9 American Football - Traction Release 0.60 Coefficients Not safe Probably not safe Probably safe Safe football shoes = 0.49 soccer shoes = 0.31 Torg and Quedenfeld,, 1974

10 Traction and Injury Lambson et al., 1996 Quantified ACL injuries in American Football 3 seasons Prospective 4 shoe conditions

11 Traction and Injury Shoe ACL Tears Injury Rate Art. Turf Torque [Nm] Nat. Turf Torque [Nm] Edge Flat Screw in Pivot disk Lambson et al., 1996

12 Factors Affecting Traction Not Coulomb friction (e.g. Van Gheluwe et al., 1983; Valiant et al., 1985; etc.) Relative velocity Normal force Surface contact area

13 Influence of Surface Translation friction coefficient infilled turf surfaces running shoe M max [Nm]

14 Influence of Surface Translation friction coefficient infilled turf surfaces soccer shoe M max [Nm]

15 Traction and Internal Loads Joint loading ultimately plays a functional role in the development of sport injuries. Traction Joint Loading Injury

16 Knee Joint Moments Sagittal Frontal Transverse Flexion-extension extension Ab-adduction Ab-adduction Rotation Rotation

17 PFPS Retrospective Study Two groups of runners Group 1 (n=20) positive PFPS diagnosis Group 2 (n=20) never diagnosed with PFPS

18 External Rotation Knee Moment Retrospective Moment [Nm] Asymp PFPS Time [% of stance] -50

19 Abduction Knee Moment Retrospective Moment [Nm] Asymp PFPS Time [% of stance] -100

20 Retrospective PFPS Maximal external rotation moments were 8 Nm (22%) higher for injured runners Maximal abduction moments were 24 Nm (20%) higher for injured runners

21 Prospective Running Study 145 runners Bilateral data collected at beginning of running season Shod and barefoot Injury data collected over 6 month running season

22 Prospective PFPS 6 subjects diagnosed with PFPS Physical examination criteria None had previous PFPS

23 Prospective PFPS 2 to 1 matched with uninjured subjects gender weekly running distance years of running experience mass 3-dimensional knee joint moments

24 External Rotation Knee Moment Prospective Moment [Nm] 75 Asymp PFPS Time [% of stance] -50

25 Abduction Knee Moment Prospective Moment [Nm] Asymp PFPS Time [% of stance] -100

26 Prospective PFPS Maximal external rotation moments were 9 Nm (90%) higher for injured runners Maximal abduction moments were 25 Nm (65%) higher for injured runners

27 Prospective Injury Frequency [%] Knee abd. moment 80 Knee ext. rot. moment Low 25% Mid 50% High 25% Stefanyshyn et al. (2001)

28 Knee Moments and Injury Hewett et al Prospective study Female ACL injury 205 subjects Knee adduction moment [Nm] ** Mizuno et al Uninjured ACL Adduction and rotational moments result in high ACL strain

29 Sport Surfaces - Joint Moments 5 indoor sport surfaces 21 subjects 11 male 10 female Three movements shuffle, vcut,, run shuffle Standard court shoe

30 Knee Moments Knee Extension Moment [Nm] 200 extension Side Shuffle 100 Knee Adduction Moment [Nm] Surface 1 Surface 2 Surface 3 Surface 4 Surface flexion 50 Knee Rotation Moment [Nm] 100 Normalized Time adduction external Normalized Time internal 50 Normalized Time 100

31 Forces Side Shuffle Force (vertical) [N] Normalized Time Surface 1 Surface 2 Surface 3 Surface 4 Surface Force (medio - lateral) [N] Force (a- p) [N] Normalized Time Normalized Time 100

32 Influence of Surface F vertical F resultant F vertical F resultant Surface 5 Surface 1 F m-l F m-l

33

34 Translational Friction Knee moments External Rotation Moment [Nm] Adduction Moment [Nm] R 2 = 0.02 R 2 = Static Friction Static Friction

35 Rotational Friction Knee moments External Rotation Moment [Nm] Adduction Moment [Nm] R 2 = R 2 = M max max [Nm] M max max [Nm]

36 Higher Friction Lower Friction μ = 1.79 μ = 1.36

37 Soccer Shoes adidas Nova running adidas Copa adidas World Cup adidas TRX

38 Methods 12 recreational soccer players Two movements running cut, 180 turn Infilled artificial turf Kinetics and kinematics

39 Methods - Traction 6-DOF Stewart platform

40 Linear Traction Coefficient Nova Copa World Trx

41 Rotational Traction Moment [Nm] Nova Copa World Trx

42 Cut Knee Joint Moments Knee Joint Moments [Nm] Adduction 75 Rotation Nova Copa World Trx Nova Copa World Trx

43 Linear Traction Knee Moments Knee Joint Moment [Nm] 60 Cut 40 Knee adduction Knee rotation Linear coefficient

44 Rotational Traction Knee Moments Knee Joint Moment [Nm] Cut Ankle eversion Ankle rotation Rotational Traction Moment [Nm]

45 180 Turn Knee Joint Moments Knee Joint Moments [Nm] Adduction 50 Rotation Nova Copa World Trx Nova Copa World Trx

46 Linear Traction Knee Moments Knee Joint Moment [Nm] turn 40 Knee abduction Knee rotation Linear coefficient

47 Rotational Traction Knee Moments Knee Joint Moment [Nm] 180 turn Knee abduction 20 Knee rotation Rotational Traction Moment [Nm]

48 Soccer Cleat Summary Cleats only had a significant effect during rotational movement Rotational and possibly translational traction seem to affect knee joint moments

49 Injury Summary Traction plays a large roll Rotational and possibly translational Influences joint moments Surfaces have large influence Rotational movements important Needs to be studied further

50 Energy The ability to do work. More work throw farther skate faster jump higher Energy Work Performance

51 Energy and Performance Maximize energy return Minimize energy lost Optimize muscular output Nigg and Segesser,, 1992; Nigg, 2000

52 Energy and Performance Maximize energy return Minimize energy lost Optimize muscular output Nigg and Segesser,, 1992; Nigg, 2000

53 Maximizing Energy Return Energy transfer in sports body foot shoe surface and eventually surface shoe foot body

54 Energy Return E returned = E input - E lost

55 Energy Input W = F athlete o dr = ΔEsurface E = ½ k surface x 2 deformation stiffness

56 Energy Input Surface Approx Stiffness [N/m] Deform Energy [m] [J] Tumbling floor Gymnastic floor Running track Gymnasium floor

57 Energy Lost Force [N] Force [N] Force [N] Energy input Energy returned Energy lost Deformation [mm] Deformation [mm] Deformation [mm]

58 Energy Lost - Surfaces Energy Loss [%] Infilled Turf Point Elastic

59 Criteria for Energy Return Large enough to influence performance Returned at the right location in the proper direction at the appropriate time with the right frequency Nigg and Segesser,, 1988

60 Right Location and Direction Anterior posterior force Normalized time

61 Right Frequency Deformation Sprinting E input E return Time [s]

62 Tuned Indoor Track McMahon and Greene 1978, 1979 Optimal stiffness dependent on runner s lower leg stiffness Increased performance 2-3% Outdoor tracks?

63 Current Outdoor Track Surfaces Given subsurface Solid - thin Homogeneous Isotropic

64 Sport Surfaces S 1 S 2 S 3 running direction S 4 S 5 (Baroud,, Nigg and Stefanyshyn, 1999)

65 Input Forces Ground Reaction Force [N] 1600 vertical anterior-posterior medio-lateral Time [msec]

66 Conventional Surface S 1 running direction

67 Conventional Surface Energy production [J] S E input Ereturn E lost Time [msec]

68 Structured Surface S 5 running direction

69 Structured Surface Energy production [J] S E input conventional surface Ereturn E lost Time [msec]

70 Energy Return [J] 10 2% in Running 5 Mechanical S 3 energy S 500 J per stride 4 S 2 Nigg and Segesser, 1992 S 5 1% S 1 (Baroud,, Nigg and Stefanyshyn, 1999)

71 Right Direction end of stance middle of stance beginning of stance

72 Maximizing Energy Return Energy transfer in sports body foot shoe surface and eventually surface shoe foot body

73 Surfaces and Shoes S 1 S 2 S 3 S 4 S 5 running direction S 11 S 52

74 Energy Return [J] 15 S 52 3% in Running 10 Add shoe! 2% 5 S 2 S 3 S 4 S 5 1% S 1 S 11

75 FE Model Limitations Linear material model Only one material Only one set of input forces Arbitrarily selected structural shapes Not validated

76 Energy Return Large enough to influence performance Returned at the right location in the proper direction at the appropriate time with the right frequency Nigg and Segesser,, 1988

77 Energy/Performance in Surfaces Relevant in: Tumbling floors Gymnastics Indoor tracks Outdoor tracks

78 Acknowledgements Thank you