The association between ground hardness and injury over the course of a season in professional football

Transcription

1 The association between ground hardness and injury over the course of a season in professional football David Rennie Head Physiotherapist Leicester City Football Club

2 Health & safety at work act 197 An employer must make every reasonable practical effort to ensure the health and safety of employees at work. The pitch is their place of work. Daily mail on line 1..1

3 Fear of escalating injury costs Daily mail on line 9..1

4 Pitch construction and maintenance

5 Current standards player surface IOG 1 High: 5-1 (G). Standard: 55-1 (G). Basic 35- (G). Why?

6 Current standards: evaluate & manage expectations

7 Current standards player surface IOG 1: High: 5-1 (G). Standard: 55-1 (G). Basic 35- (G). What values do injuries occur? What types of injuries are they likely to be? Links need to be made.

8 Aetiology of injury within football Risk of injury >1 high risk industrial occupations. Intrinsic: Age, previous injury, core stability, biomechanics, ethnicity. Extensive literature addressing intervention protocols.

9 Aetiology of injury within football Participation exposes individual to external or extrinsic risk. Extrinsic Factors Pitch/Stadia surroundings. Opponents. Footwear. Climatic conditions. Surface Traction. Ground hardness.

10 Available evidence: Ground hardness & injury Ekstrand & Nigg (1989) % injury attributable. Orchard (1 & ) study AFL Takemura et al (7) NZ rugby. Twomey et al (9) Community AFL no relationship. Norton et al (1) Relationships ground hardness and game speed. No objective research in professional football

11 Research questions in professional football Is injury associated with ground hardness? Is there a difference between training and match data? Does pitch construction affect injury?

12 Methodology LCFC Professional Players. N=. Mean age. yrs (17-39). Injury incidence: training and matches prospectively recorded. Injury defined: any any pain or disability suffered by a player during a match or training session and subsequently assessed by the head physiotherapist physiotherapist.

13 Methodology Ground hardness:.5kg Clegg- Hammer. 15 sites: 5 readings (1m) each site. Prior to every training session or match.

14 Results: Seasonal variability Graph 1. Ground hardness variability for training and match data over the 8-9 season 1 Ground hardness (G) 1 8 August September October November December Calendar Month January February March April May

15 Table 1. Training and Match Ground hardness and injury in relation to pitch construction Pitch type Exposure Mean Standard Hardness deviation Sand soil mix Sand soil mix Fibre sand Desso Range Average Injuries per game

16 Results Average monthly ground hardness and incidence of injuries in Training Aug. Sept Oct Nov Dec Jan Calender Month Feb Mar Apr May Total injuries Ground hardness (G) 8.

17 Results Average monthly ground hardness and incidence of injuries in Matches Aug Sept Oct Nov Dec Calender Month Jan Feb Mar Apr Total injuries Ground hardness (G 7

18 Results: correlation and binary logistic regression analysis The association between ground hardness and all injuries incurred during training in the 8-9 season, r=.3 (P<.1) all injuries Ha r dne s s

19 Results: correlation and binary logistic regression analysis The association between ground hardness and all match-day injuries incurred in the 8-9 season (P>.5) 1 1 all injuries Ha rdne s s

20 Results Elementary differential calculus. Minimum risk of injury occurs when ground hardness =.59/(*.3)=98 (G)

21 Discussion Pitches soften over the course of the season. Different findings to that of AFL and Rugby. Training. Matches. Limitations.

22 The Future Continue longitudinal study. Objective tests moisture, traction, hardness, GPS. Performance Indicators as a factor of ground hardness. Prozone information: Heat Maps reflect a more accurate exposure to the surface.

23 Thank you & Questions?

24 Appendix 1. Raw training data.. Raw Match Data. 3. Bibliography.

25 Appendix 1: Raw Training Data Results: Table 1. Training exposure, injuries and ground hardness data over the course of the 8-9 season. Month Number training sessions Total Hours Average Standard trained ground deviation (Hours:Mins) hardness of hardness 9: August 17 September 13 : 8.91 October 1 3:9 November 11 December Total injuries Muscle Soft Ligament Joint Tendon Nerve Injury tissue : : January 18 1: February 1 : March 1 5: April 1 15: Total 19 8:

26 Appendix : Raw Match Data Table. Match exposure, injuries and ground hardness data over the course of the 89 season. Month Number Total Match Average Standard matches Hours ground deviation of (Hours:Mins) hardness hardness Total injuries Muscle Soft Ligament Joint Tendon Nerve Injury tissue August 9: September 9: October 5 7: November 8 1: December 5 7: January 7 1: February 9: March 9: April 5 7:

27 Bibliography Adams, W.A. & Gibbs, R.J. (199) Natural turf for sport and amenity: science and practice. Wallingford, Oxon, UK: CAB International. Adams, W.A., Gibbs, R.J., Baker, S., & Lance, D. (199) Making the most of natural turf pitches. A national survey of winter games pitches with high quality drainage designs. Natural Turf Pitch Prototypes Advisory Panel Report No. 1, Sports Council. Bahr, R., & Engbretsen (9) Handbook of sports medicine and science: Sports Injury Prevention. Wiley-Blackwell, Chichester, Uk. Baker, S. (1985) Playing standards for natural turf sports surfaces. In: Shildrick, J.P., Ed. Proceedings of the 3rd National Turfgrass Conference, Nottingham, Bingley, England: National Turfgrass Council, Baker, S. (1999) The playing quality of turfgrass sports surfaces. In: Aldous, D.E., Ed. International turf management handbook. Melbourne, Australia: Inkata Press, 31-. Baker, S., Gibbs, R.J., & Adams, W.A. (199) Making the most of natural turf pitches. Final results of a case studies approach: I. Ground cover and botanical analysis. Natural Turf Pitch Prototypes Advisory Panel Report No., Sports Council. Baker, S.W. & Bell, M.J. (198) The playing characteristics of natural turf and synthetic turf surfaces for association football. Journal of the Sports Turf Research Institute,, Baker, S.W. & Isaac, S.P. (1987a) The effect of rootzone composition on the performance of winter games pitches. I. Sward characteristics. Journal of the Sports Turf Research Institute, 3, 57-. Baker, S.W. & Isaac, S.P. (1987b) The effect of rootzone composition on the performance of winter games pitches. II. Playing quality. Journal of the Sports Turf Research Institute, 3, Bell, M.J., Baker, S.W., & Canaway, P.M. (1985) Playing quality of sports surfaces: a review. Journal of the Sports Turf Research Institute, 1, -. Canaway, P.M., Bell, M.J., Holmes, G., & Baker, S.W. (199) Standards for the playing quality of natural turf for association football. In: Schmidt, R.C., Hoerner, E.F., Milner, E.N., & Morehouse, C.A., Eds. Natural and Artificial playing fields: characteristics and safety features, Phoenix, Arizona, Philadelphia: ASTM, 9-7. Clegg, B. (197) An impact testing device for in situ base course evaluation. Proceedings of the Australian Road Research Bureau, 8, 1-.

28 Bibliography Ekstrand, J. & Nigg, B.M. (1989) Surface related injuries in soccer. Sports Medicine, 8, 5-. Football Association () Performance quality standard. Available at: Accessed 8th October 5. Fuller, C.W. & Hawkins, R.D. (1997) Assessment of football grounds for player safety. Safety Science, 7 (), Hawkins, R.D. & Fuller, C.W. (1999) A prospective epidemiological study of injuries in four English professional football clubs. British Journal of Sports Medicine, 33, IOG (1) Guidelines for performance quality standards part one; sports surfaces natural and non turf. Milton Keynes, UK: The Institute of Groundsmanship. IOG () An Introduction to performance quality standards. nd ed. Milton Keynes, UK: The Institute of Groundsmanship. McClements, I. & Baker, S.W. (199) The playing quality of rugby pitches. Journal of the Sports Turf Research Institute, 7, 9-3. McNitt, A.S., Landschoot, P.J., & Petrukak, D.M. () Evaluation of the playing surface hardness of an infilled synthetic turf system. In: Nektarios, P.A., Ed. Proceedings of the first international conference on turfgrass management and science for sports fields, Athens, Greece, Leuven, Belgium: ISHS, Milburn, P.D. & Barry, E.B. (1998) Shoe-surface interaction and the reduction of injury in rugby union. Sports Medicine, 5 (5), Orchard, J. (1) The AFL penetrometer study: Work in progress. Journal of Science and Medicine in Sport, (): -3. Orchard, J. () Is there a relationship between ground and climatic conditions and injuries in football? Sports Medicine, 3 (7): 19-3 Orchard, J. & Powell, J.W. (3) Risk of knee and ankle sprains under various weather conditions in American football. Medicine & Science in Sports and exercise, 35: (7), Rogers III, J.N. & Waddington, D.V. (199) Portable apparatus for assessing impact characteristics of athletic field surfaces. In: Schmidt, R.C., Hoerner, E.F., Milner, E.N., & Morehouse, C.A., Eds. Natural and artificial playing fields: characteristics and safety features, Phoenix, Arizona, Philadelphia: ASTM, 9-11.

29 Bibliography Shildrick, J.P. & Dye, A.L. (1983) A review of playing surfaces research. London: National Turfgrass Council. Takemura, M., Schneiders, A.G., Bell., & Milburn, P.D. Association of ground hardness with injuries in rugby union. British journal of sports medicine, (7): 1: Thornton, D.J. (1973) A field trial of sportsfield construction materials extremely high in sand. Journal of the Sports Turf Research Institute, 9, 9-. van Wijk, A.L.M. (198) Playing conditions of grass sports fields. Wageningen: Centre for Agricultural Publishing and Documentation.