Anders Hauge Engebretsen Former researcher at the Oslo Sports Trauma Research Center. Resident at the Oslo University Hospital, Rikshospitalet/ Ullevål, Department of pediatric surgery. - The Oslo Sports Trauma Research Center and hamstring injuries (6th MuscleTech Network Workshop) 13th and 14th October, Barcelona 2014

1. Hamstring injuries
Prevention and risk factors
Anders Hauge Engebretsen MD PhD Oslo Sports Trauma Research Center

2. Oslo Sports Trauma Research Center Background Hamstring injuries Prevention Risk factors Discussion Take Home message
Hamstring injuries

3. Oslo Sports Trauma Research Center
Background
Hamstring injuries
Prevention
Risk factors
Discussion
Take Home message
Hamstring injuries

4. ”Intellectuals solve problems; geniuses prevent them”
Albert Einstein
(1879 – 1955)

5. www.ostrc.no – www.klokeavskade.no
… to prevent injuries and other health problems in sports through research on risk factors, injury mechanisms and injury prevention methods in sports, particularly football, team handball and alpine skiing.

6. Combining clinical work and research
Oslo Sports Trauma Research Center
Oslo University Hospital (Ullevål)
Olympic Training Center

7. The partners
Olympic
Training Center
Ullevål University
Hospital
Oslo Sports Trauma
Research Center
Norwegian Research Center for Active Rehabilitation (NAR)

9. Growing…

10. And growing…

11. Oslo Sports Trauma Research Center
Background
Hamstring injuries
Prevention
Risk factors
Discussion
Take Home message
Hamstring injuries

12. Hamstrings muscles

13. Swanson & Caldwell Med Sci Sports Exerc 32: 1146-1155, 2000
When does the injury occur?
Maximal EMG- activity during sprinting:
Towards end of swing phase – eccentric phase
Push-off during knee extension

14. Junge&Dvorak -00; Andersen -04; Ekstrand -10; Ekstrand -13
Injured body parts
- head: 2-10%
- trunk: 5-9%
- arms: 2-6%
- lower extremities: 70-90%
- groin: 10-20%
- thigh: 12-25%
- knee: 15-23%
- ankle: 17-36%
- foot: 5-8%

15. Junge&Dvorak -00; Andersen -04; Ekstrand -10; Ekstrand -13
Injured body parts
- head: 2-10%
- trunk: 5-9%
- arms: 2-6%
- lower extremities: 70-90%
- groin: 10-20%
- thigh: 12-25%
- knee: 15-23%
- ankle: 17-36%
- foot: 5-8%

16. Junge&Dvorak -00; Andersen -04; Ekstrand -10; Ekstrand -13
Injured body parts
- head: 2-10%
- trunk: 5-9%
- arms: 2-6%
- lower extremities: 70-90%
- groin: 10-20%
- thigh: 12-25%
- knee: 15-23%
- ankle: 17-36%
- foot: 5-8%

17. Drawer and Fuller -01; Andersen et. al -04; Ekstrand et al.-10; Ekstrand et al-13
Type of injury
- muscle injuries
20-45%
- joint and ligament
18-48%
- contusion
14-20%
- fracture
2-7%

18. Risk of hamstring injury
6-29% of all injuries in football, Australian rules football, rugby, basketball, track sprint
High recurrence rate
Woods -04; Orchard -02; Meeuwisse -03; Croisier -04; Brooks -05; Brooks -05; Garrett -06; Engebretsen -13; Alonso -11; Petersen -10; De Vos -14

19. Risk of hamstring injury
Continued high prevalence of injury rates from 2001 to 2008
Eccentric training seems promising for prevention
Prevention of hamstring strains more effective than knee injuries
Drawer and Fuller -01; Andersen et. al -04; Ekstrand et al.-11; Ekstrand et al-13; Petersen et al -10

20. Risk factors
Previous injury
Age
Males vs Females
Low hamstring strength
Low H:Q strength ratio
Low ROM?
Inadequate warm-up before maximal activity?
Muscular fatigue towards end of match or training?
Peak performance?
Junge & Dvorak 2000; Dupont 2010; Ekstrand 13;

21. Mechanisms of injury
40-60% player to player contact
20% «foul play»
Muscle injuries
Running
Giza et al. -03, Andersen -04 et al., Fuller -04 et al., Ekstrand et al. -13

22. Oslo Sports Trauma Research Center
Background
Hamstring injuries
Prevention
Risk factors
Discussion
Take Home message
Hamstring injuries

23. Football and injuries Screening, risk factors and prevention
Anders Hauge Engebretsen
Oslo Sports Trauma Research Center, Norwegian School of Sport Sciences
&
Orthopaedic Center, Division of Neuroscience and Musculoskeletal Medicine
Ullevaal University Hospital

24. Age
Physical fitness (speed, spenst)
Previous injury
Weight/height
Impared function
Anatomy
Multifactorial model of etiology
Exposure to extrinsic
risk factors
Inciting event
Predisposed
athlete
Athlete
at risk
INJURY
Intrinsic risk factors
Risk factors for injury
Injury mechanisms
Meeuwisse WH: Clin J Sports Med 4; 166-170, 1994

25. All players (n=508)
Testing for potential risk factors
Questionnaire
Clinical examination
Specific tests

26. All players (n=508)
Players with increased risk of injury (n=388)
Players with low
risk of injury (n=120)
Simple self assessment (questionnaire)
Previous injury last year
Impaired function

27. All players (n=508)
Players with increased risk of injury (n=388)
Players with low risk of injury (n=120)
Simple self assessment (questionnaire)
High risk
intervention group
(n=193)

28. All players (n=508)
Players with increased risk of injury (n=388)
Players with low
risk of injury (n=120)
Simple self assessment (questionnaire)
High risk
control group
(n=195)
High risk intervention group (n=193)

29. All players (n=508)
Players with increased risk of injury (n=388)
Players with low
risk of injury (n=120)
Simple self assessment (questionnaire)
High risk control group (n=195)
High risk intervention group (n=193)
Low risk
control group (LRc)
(n=120)

30. Number of players with different programs
115 players - one program
72 players - two programs
21 players - three programs
2 players - four programs
105 ankle programs
81 hamstrings programs
65 knee programs
64 groin programs
Total 315 programs

31. Nordic Hamstring exercise
Week
1
2
3
4
Sessions/week
1
2
3
3
Sets and Repetitions
2 x 5
2 x 6
3 x 6-8
3 x 8-10
5-10
3
3 x 12+10+8
10+
1
3 x 12+10+8

32. With gratitude to ”Muscle Animations” (Tron.Krosshaug@nih.no

33. Injury definition
Acute injury
”Time-loss” injury
Overuse injury
Medical attention (independent of time-loss or not)
Ankle, Knee
Acute injury
Hamstring, Groin injury
Acute and overuse injuries

34. Statistical methods
Screening and prevention
Z-test
Chi-square tests
Risk factors
Generalized estimating equations (STATA, Texas, USA)
Univariate analyses (p<0,10)
Multivariate analysis

35. Oslo Sports Trauma Research Center
Background
Hamstring injuries
Prevention
Risk factors
Discussion
Take Home message
Hamstring injuries

36. Incidence of injuries (per 1000h)
0
1
2
Intention to treat analysis – Hamstring
RR=1.55 95%CI 0.83-2.90
HRi Hamstring (n=76) HRc Hamstring (n=85)

37. Oslo Sports Trauma Research Center
Background
Hamstring injuries
Prevention
Risk factors
Discussion
Take Home message
Hamstring injuries

38. Hamstring - questionnaire
0
1
HaOS
Player information and injury history Hamstring Outcome Score
P-value

39. Hamstring - questionnaire
0
1
HaOS
Player information and injury history Hamstring Outcome Score
P-value

40. Hamstring - Clinical examination and tests
0
1
P-value
Clinical examination Specific tests

41. Risk factors for hamstring injury
Previous injury
Adjusted OR, 2.19; 95% CI, 1.19-4.03; P=0.01
Don’t panic - it’s just a pulled hamstring

42. Oslo Sports Trauma Research Center
Background
Hamstring injuries
Prevention
Risk factors
Discussion
Take Home message
Hamstring injuries

43. Conclusions - Injury prevention
The targeted intervention did not affect injury risk
Low compliance

44. Compliance
0
10
20
30
40
50
60
70
80
90
Ankle Knee Hamstring Groin
Non-compliant
Compliant
%

45. Per protocoll analysis - Hamstring
HRi Compliant HRc
Incidence of injuries (per 1000h)
0
1
2
RR=0.94 95%CI 0.28-3.22

46. Prevention of hamstring injuries
Conclusion: Eccentric training, with good compliance, appears to be successful in prevention of hamstring injury.

47. Bahr R, BJSM 2009 Adapted from Leadbetter WB. Cell-matrix response in tendon injury. Clin Sports Med 1992;11:533-78

48. Time-loss
Symptoms

49. Oslo Sports Trauma Research Center
Background
Hamstring injuries
Prevention
Risk factors
Discussion
Take Home message
Hamstring injuries

50. Hamstring injuries
Prevention
Eccentric training
Risk factors
Previous injury

53. Mjølsnes et al. Scand J Med Sci Sports, 14: 311-317, 2004
cons ext ecc flex isom flex 90 isom flex 60 isom flex 30
Knee torque (Nm)
-10
-5
0
5
10
15
20
25
30
Nordic hamstring
Hamstring curl
Eccentric strength training

54. Pyramide of evidence
Level VI
Level V
Level IV
Level III
Level II
Level I
Sackett et al, 2000

55. Prevention of hamstring injuries
Askling
Arnason fleks
Arnason NH
Petersen
Relativ risiko
0
1
2
3
♂ ♂ ♂
n= 30 n= n/a n= 942

56. Overuse injuries
”Time-loss” vs pain
All injuries included?
Impared function not necessarily included

57. Overuse injuries under-reported
Limited knowledge
Significant complaints
Still players choose to play