2. Hamstring strength, Training ‘sweet
spot’ and shared decision making
Nicol van Dyk
Rehabilitation Department
#researchinreallife
3. Disclosure statement
Has no relevant financial
relationships to disclose
Will not be discussing
the off-label or
investigational use of
products
Have no affiliation with
Leicester City
4.
5.
6. 1.Train smarter AND harder
2. Hamstring strength
3. Shared decision making
4. Beetroot shots performance boosters
5. Ice Chambers -135°C
Learning objectives from Leicester City
11. 1. Train smarter AND harder
2.Hamstring strength
3. Shared decision making
4. Beetroot shots performance boosters
5. Ice Chambers -135°C
Learning objectives from Leicester City
12. Are you sure you
want to do that?
We need to talk
about Hamstring
Strength
Argh….
13. • Hamstring Strain Injuries (HSI) remain the
most common muscle injury in football
(Hagglund et al 2013, Ekstrand et al 2011, Eirale et al 2013)
Introduction
14. • Incidence 12-15% (Opar et al 2012)
• 37% of all muscle injuries (Ekstrand et al 2011)
16. Cost of an injury in a line up player in a UEFA Champions League
team
– 20,000 €/day
Average absence days (28 players)
1100 days (50 injuries – 22 days each)
1100 x 20,000 € = 22 million €
(Sergei Palkin, CEO Shakhtar Donesk)
20. 3. Introduce a
preventative
measure
Assess it’s
effectiveness by
repeating step 1
1
2. Establish etiology
and mechanisms of
sports injuries
1. Establish the
extent of the
injury problem:
• Incidence
• Severity
van Mechelen et al 1992
22. • Previous Injury
• Increase Age
• Ethnicity
• Flexibility
• H:Q Ratio
• Weight/BMI
• Height
• Functional Measures
• Quadriceps isokinetic
strength
• Hamstring eccentric
strength
• Peak Torque
• Type of activity
Risk factors for Hamstring Injury
23. • Previous Injury
• Increase Age
• Ethnicity
• Flexibility
• H:Q Ratio
• Weight/BMI
• Height
• Functional Measures
• Quadriceps isokinetic
strength
• Hamstring eccentric
strength
• Peak Torque
• Type of activity
24. • Previous Injury
• Increase Age
• Ethnicity
• Flexibility
• H:Q Ratio
• Weight/BMI
• Height
• Functional Measures
• Quadriceps isokinetic
strength
• Hamstring eccentric
strength
• Peak Torque
• Type of activity
• MRI
Can Strength be identified as
a risk factor for Hamstring
Injury?
25. – Rod Whiteley
– Philipp Jacobsen
– Cristiano Eirale
– Roald Bahr
– Erik Witvrouw
– Anne van der Made
– Arnlaug Wangensteen
– Bruce Hamilton
– Hans Tol
– Bhavesh Kumar
– Patrice Muxart
Acknowledgement
26.
27.
28. All Teams in
Qatar Stars
League
(n=14 teams)
2010-2014
No isokinetic tests
performed
(n=52 subjects)
Isokinetic Tests during
Periodic Health Evaluation
(n=614 subjects)
mean follow up of 2.24 years
Q Con 60°/s
(n= 556)
H Con 60°/s
(n= 555)
Q Con 300°/s
(n= 556)
H Con 300°/s
(n=556)
H Ecc 60°/s
(n=562)
Materials & Methods
4 seasons
614
subjects
1931
Isokinetic
Tests
performed
Total Injuries 190
1st time injuries
131
190
injuries
29. Odds Ratio p-value 95% CI
Q Con 60 0.99 0.06 0.99 - 1.00
H Con 60 0.99 0.17 0.99 - 1.00
Q Con 300 0.99 0.97 0.99 - 1.00
H Con 300 0.99 0.20 0.99 - 1.00
H Ecc 60 0.99 0.12 0.99 - 1.00
Q Con 60 BW 0.71 0.03* 0.52 - 0.97
H Con 60 BW 0.75 0.29 0.43 -1.29
Q Con 300BW 1.10 0.87 0.56 - 1.89
H Con 300 BW 0.75 0.29 0.43 - 1.29
H Ecc 60 BW 0.73 0.04* 0.54 - 0.99
Q Con 60/ H Con 60 0.76 0.32 0.44 - 1.32
H Con 60/ H Ecc 60 1.08 0.90 0.34 - 3.40
Q Con 300/ H Con 300 1.46 0.26 0.76 - 2.79
Q Con 300/ H Ecc 60 1.46 0.35 0.66 - 3.25
Q Con 60 BW 0.71 0.03* 0.52 - 0.97
H Ecc 60 BW 0.73 0.04* 0.54 - 0.99
Results
Q Con 60 Body Weight Effect Size 0.17 6.9 Nm
H Ecc 60 Body Weight Effect Size 0.18 7.1 Nm
33. Health by Exercise, Geo Taylor
1880
Prevention AJSM, Petersen et al
2011
130
years!
Nordic Hamstring Exercise
34.
35.
36.
37. Petersen et al 2011 &
van der Horst et al 2015
The Nordic Hamstring RCT’s
Dr. Anthony Shield (@das_shield)
Combined Results
Nordic groups: 753 players → 25 injuries
Control groups: 768 players → 77 injuries
67.5% reduction in hamstring injuries
38. Nordic Hamstring Exercise
• Low speed
• Hip extension
• Knee flexion
• Muscle targeted
– BF(short head)
– ST
Mechanism of Injury
• High Speed
• Hip flexion
• Knee extension
• Muscle at risk
– BF(long head)
Heiderscheidt et al 2010 JOSPT
It works in practice but not in
theory?
43. 0
5
10
15
20
25
30
35
BF ST SM
control
injury
* P=0.001
* P=0.003
T2 shift in control group and previously injured group
%
35%
18%
9%
Results
ST is most metabolic active in both groups
(Schache et al 2013, Oliver et al 2009, McAllister et al 2014)
44. ±80% of Metabolic Activity
More symmetrical pattern
After hamstring injury
rad.washington.edu
45. • Max eccentric activation
• BF activated & elongated
• Main muscle: ST
• BF is not made for this work
↓ fascicular length
↓ stretch tolerant
= more likely to fail!
±80% of Metabolic ActivityWhy are BF & ST coupled?
More symmetrical pattern
After hamstring injury
(Onishi et al 2002; Higashihara et al 2010; Schache et al 2013) rad.washington.edu
46. Choice: Do we only treat the victim,
or also the cause?!
57. References
1. Aagaard P, Simonsen EB, Magnusson SP, Larsson B, Dyhre-Poulsen P. A new concept for isokinetic hamstring: quadriceps muscle strength ratio. Am. J. Sports Med.
1998;26(2):231–237.
2. Arnason A, Andersen TE, Holme I, Engebretsen L, Bahr R. Prevention of hamstring strains in elite soccer: an intervention study: Prevention of hamstring strains in soccer.
Scand. J. Med. Sci. Sports 2007;18(1):40-48. doi:10.1111/j.1600-0838.2006.00634.x.
3. Bahr R. Risk factors for sports injuries -- a methodological approach. Br. J. Sports Med. 2003;37(5):384-392. doi:10.1136/bjsm.37.5.384.doi:10.1136/bjsm.2005.018408.10.
4.Eirale C, Farooq A, Smiley FA, Tol JL, Chalabi H. Epidemiology of football injuries in Asia: A prospective study in Qatar. J. Sci. Med. Sport 2013;16(2):113-117.
doi:10.1016/j.jsams.2012.07.001.
5. Ekstrand J, Hagglund M, Walden M. Epidemiology of Muscle Injuries in Professional Football (Soccer). Am. J. Sports Med. 2011;39(6):1226-1232.
doi:10.1177/0363546510395879.
6. Ekstrand J, Hagglund M, Walden M. Injury incidence and injury patterns in professional football: the UEFA injury study. Br. J. Sports Med. 2011;45(7):553-558.
doi:10.1136/bjsm.2009.060582.
7. Freckleton G, Pizzari T. Risk factors for hamstring muscle strain injury in sport: a systematic review and meta-analysis. Br. J. Sports Med. 2013;47(6):351-358.
doi:10.1136/bjsports-2011-090664.
8. Hagglund M, Walden M, Ekstrand J. Risk Factors for Lower Extremity Muscle Injury in Professional Soccer: The UEFA Injury Study. Am. J. Sports Med. 2013;41(2):327-335.
doi:10.1177/0363546512470634.
9. Van der Horst N, Smits D-W, Petersen J, Goedhart EA, Backx FJG. The Preventive Effect of the Nordic Hamstring Exercise on Hamstring Injuries in Amateur Soccer Players: A
Randomized Controlled Trial. Am. J. Sports Med. 2015;43(6):1316-1323. doi:10.1177/0363546515574057.
10. Opar DA, Williams MD, Timmins RG, Hickey J, Duhig SJ, Shield AJ. Eccentric Hamstring Strength and Hamstring Injury Risk in Australian Footballers: Med. Sci. Sports Exerc.
15;47(4):857-865. doi:10.1249/MSS.0000000000000465.
11. Opar MDA, Williams MD, Shield AJ. Hamstring strain injuries. Sports Med. 2012;42(3):209–226.
12. Orchard J, Marsden J, Lord S, Garlick D. Preseason hamstring muscle weakness associated with hamstring muscle injury in Australian footballers. Am. J. Sports Med.
1997;25(1):81–85.
13. Petersen J, Thorborg K, Nielsen MB, Budtz-Jorgensen E, Holmich P. Preventive Effect of Eccentric Training on Acute Hamstring Injuries in Men’s Soccer: A Cluster-
Randomized Controlled Trial. Am. J. Sports Med. 2011;39(11):2296-2303. doi:10.1177/0363546511419277.
14 .Tol JL, Hamilton B, Eirale C, Muxart P, Jacobsen P, Whiteley R. At return to play following hamstring injury the majority of professional football players have residual
isokinetic deficits. Br. J. Sports Med. 2014;48(18):1364-1369. doi:10.1136/bjsports-2013-093016.
15. Gabbett Br J Sports Med doi:10.1136/bjsports-2016-095973
16. H Paul Dijkstra et al. Br J Sports Med 2014;48:523-531
Erik Witvrouw presentation http://www.slideshare.net/MuscleTechNetwork/10-barcelona-2014-erik-witvrouw-40239277
18. Schuermans et al BJSM 2015 Biceps femoris and Semitendinosus – teammates or competitors Br J Sports Med 2014;48:1599-1606 doi:10.1136/bjsports-2014-094017
19. Van Dyk et al AJSM 2016 Hamstring and Quadriceps Isokinetic Strength Deficits Are Weak Risk Factors for Hamstring Strain Injuries: A 4-Year Cohort study
20. http://m.bbc.com/sport/football/36189778
References
Editor's Notes
What does it mean to be scientific? How do we define science? I would like to start by watching this short clip.
We were all I think stunned when this happened a few weeks ago. Now there are many reasons why a team like this wins one of the biggest competitions in the world. But just after, Alister McGowan wrote an article for BBC sport… Now many of you know this, I know George Nassis posted it on LinkedIn, Dermot Simpson and Jonny King posted it on twitter, as did many others.
We were all I think stunned when this happened a few weeks ago. Now there are many reasons why a team like this wins one of the biggest competitions in the world. But just after, Alister McGowan wrote an article for BBC sport… Now many of you know this, I know George Nassis posted it on LinkedIn, Dermot Simpson and Jonny King posted it on twitter, as did many others.
Change this slide or leave it altogether
Add bubble to show how different departments have contributed to the project maybe? Too much? Already acknowlegded them?
So each of the variables were included in the regression model, which took into account the confounding variables that was identified in the analysis.
Mention Limitations – could not control for exposure
What does this technique imply?
We took an MRI scan of both upper legs in rest. Afterwards, the subjects performed a a strenuous bilateral eccentric hamstring exercise on the rhythm of a metronome until exhaustion. Immediately thereafter we took a new scan. We calculated the T2 relaxation times of each scan for the hamstrings components. The difference between the T2 value at rest and the T2 value after exercise is called the T2 shift. This provides an indication of the amount of activity performed by each hamstring component during the exercise. not to engage in intensive training or football competition 48h prior to testing.
Besides mfMRI, patients completed the Kujala questionnaire and 7 VAS pain scores.
The patients completed a seven weeks rehabilitation period, including neuromuscular co-ordination, stabilization and strengthening exercises and stretching and mobilization if needed.
After treatment, the mfMRI and subjective assessment were repeated.
What does this technique imply?
We took an MRI scan of both upper legs in rest. Afterwards, the subjects performed a a strenuous bilateral eccentric hamstring exercise on the rhythm of a metronome until exhaustion. Immediately thereafter we took a new scan. We calculated the T2 relaxation times of each scan for the hamstrings components. The difference between the T2 value at rest and the T2 value after exercise is called the T2 shift. This provides an indication of the amount of activity performed by each hamstring component during the exercise. not to engage in intensive training or football competition 48h prior to testing.
Besides mfMRI, patients completed the Kujala questionnaire and 7 VAS pain scores.
The patients completed a seven weeks rehabilitation period, including neuromuscular co-ordination, stabilization and strengthening exercises and stretching and mobilization if needed.
After treatment, the mfMRI and subjective assessment were repeated.
More metabolic activity in injured group, while less time to exertion p=0.045
Injured group have significantly less ST activity, and significantly more BF activity More symmetric pattern
Metabolic activity (MA) of ST is always sign higher than BF & SM
Significant decrease of ST MA and
significant increase of BF MA in injured players
Why are ST and BF coupled??
Common tendon?
Metabolic activity (MA) of ST is always sign higher than BF & SM
Significant decrease of ST MA and
significant increase of BF MA in injured players
Why are ST and BF coupled??
Common tendon?
Metabolic activity (MA) of ST is always sign higher than BF & SM
Significant decrease of ST MA and
significant increase of BF MA in injured players
Why are ST and BF coupled??
Common tendon?
Metabolic activity (MA) of ST is always sign higher than BF & SM
Significant decrease of ST MA and
significant increase of BF MA in injured players
Why are ST and BF coupled??
Common tendon?
Jimmy Vardy is having a party.
Mo Farah with his coach, physiotherapist and physiologist at the warm-up track, London 2012 Olympic Games.
The Integrated Performance Health Management and Coaching Model. All the specialties operate in the performance health and coaching ‘box’. Health (injury, illness and prevention) is managed by specialist sports medicine physicians (led by the CMO/Medical Director); coaching is managed by the Head Coach. Both departments are managed by the Performance Director or (CEO) depending on the structure and size/culture of the organisation/club. The health and coaching departments operate in synergy and also ‘independently’ with appropriate autonomy at times. All professional service providers are independently registered and professionally governed by the relevant Professional Bodies like the General Medical Council and the Faculty of Sport and Exercise Medicine for physicians in the UK. CEO, Chief Executive Officer; CMO, Chief Medical Officer; GP, general practitioner.