Per Hölmich Head of Aspetar Sports Groin Pain Center, Aspetar, Orthopaedic and Sports Medicine Hospital, Doha, Qatar & Associate Professor, Sports Orthopedic Research, Center - Copenhagen (SORC-C), Arthoscopic Center Amager, Copenhagen University Hospital, Denmark. - Nordic Hamstring for prevention in football - what did we learn? (6th MuscleTech Network Workshop) 13th and 14th OCtober, 2014

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Nordic Hamstring for prevention in football
- what did we learn?
Per Hölmich
Sports Groin Pain Center
Aspetar Orthopaedic and Sports Medicine Hospital
Doha, Qatar
&
Sports Orthopedic Research Center - Copenhagen
Arthroscopic Center Amager
University of Copenhagen, Denmark
Arthroscopic Center Amager / SORC-C
Copenhagen

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Arthroscopic Center Amager / SORC-C Copenhagen
Amager University Hospital, Copenhagen

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Sports Orthopedic Research Center – Copenhagen SORC-C
Research focus:
Clinical evaluation (PRO, Strength, etc.)
Diagnosis
Treatment
Prevention
- of injuries to the
Shoulder
Hip, groin, and hamstrings
Knee
Tendons and muscles
… and often using football as a model
Arthroscopic Center Amager / SORC-C

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Arthroscopic Center Amager / SORC-C
Football & Hamstring injuries
•Worldwide more than 265 million people play soccer FIFA: The big count
•Hamstring injury is the most common injury in soccer Arnason et al. SJMSS 1996 & Woods et al. BJSM 2004
•In the UEFA injury study hamstring injuries (12%) & adductor injuries (9%) were the two most common injuries Werner et al & Ekstrand et al 2009/2011 BJSM

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Arthroscopic Center Amager / SORC-C Copenhagen

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Hamstring injury prevention
•Eccentric hamstring strength training has been proposed as a method to prevent hamstring injuries
Crosier et al. Sports Med; 2004
Askling et al. Scand J Med Sci Sports; 2003
Arnason et al. Scand J Med Sci Sports; 2008
Arthroscopic Center Amager / SORC-C Copenhagen

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Eccentric strengthening?
Effects of eccentric strengthening:
Arthroscopic Center Amager / SORC-C
Mjølsnes et al.; SJMSS 2004
VS
I-Quad.-I--------Hamstring--------------I

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Arthroscopic Center Amager / SORC-C
Arnason et al.; SJMSS, 2008

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Results – strength training
Total Match Training
Hamstring injury incidence (per 1000 h)
0,0
0,5
1,0
1,5
2,0
2,5
3,0
Training group
No training
RR: 0.35
p<0.001
Arthroscopic Center Amager / SORC-C Courtesy of R. Bahr
Arnason et al.; SJMSS, 2008

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Arthroscopic Center Amager / SORC-C
AJSM, 2011

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MATERIAL AND METHODS
•Design: Open cluster-randomised controlled trial
•Teams from Premier League to 4th division
•Stratified according to playing level and geographical location
•Allocated to: Training group; n=461 players Control group; n=481 players
Arthroscopic Center Amager / SORC-C

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MATERIAL AND METHODS
•Players in the training group completed a 10- week eccentric strength training program (Nordic hamstring exercise)
Arthroscopic Center Amager / SORC-C

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Arthroscopic Center Amager / SORC-C

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Arthroscopic Center Amager / SORC-C
MATERIAL AND METHODS
•All acute hamstring injuries in accordance with UEFA / FIFA definitions were recorded for one full season Fuller et al. Scand J Med Sci Sports 2006

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MATERIAL AND METHODS
Compliance:
The teams in the intervention group performed a mean of 91% of the 27 intended training sessions
(mean 24.6, SD 2.3; range 18 to 27 sessions)
Injuries:
A total of 67 acute hamstring injuries in 67 players
(44 new and 23 recurrent injuries)
Arthroscopic Center Amager / SORC-C

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RESULTS
Overall injury risk
Control Intervention
Strains per 100 player seasons (%)
0
2
4
6
8
10
12
14
Rate ratio: 3.32; CI: 1.56-7.08; p<0.002
Number needed
to treat:
13
Arthroscopic Center Amager / SORC-C
Petersen et al, AJSM 2011

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Control Intervention
Strains per 100 player seasons (%)
0
10
20
30
40
50
RESULTS
New injuries Recurrent
injuries
Control Intervention
Strains per 100 player seasons (%)
0
2
4
6
8
10
12
14
Rate ratio: 2.54; CI: 1.02-6.34; p=0.046
Number needed
to treat:
25
Rate ratio: 7.29; CI: 1.96-27.03; p<0.003
Number needed
to treat:
3
Arthroscopic Center Amager / SORC-C
Petersen et al, AJSM 2011

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Conclusion
•It is possible to prevent hamstring injuries in football by completing a specific eccentric hamstring strength training programme (RR = 3.32 , p<0.002)
•Eccentric training is particular effective in preventing recurrent injuries (RR = 7.29, p<0.003)
Arthroscopic Center Amager / SORC-C

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Arthroscopic Center Amager / SORC-C
Inj prev; 2014 & IOC prevention congress 2014

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EMG study of Nordic Hamstring Exercise (NHE)
•18 non-symptomatic male students
•EMG and kinematic analysis of the NHE
•Comparing NHE with traditional maximal eccentric exercise performed on an isokinetic machine
•Higher level of Biceps Femoris activity with the NHE
Ditroilo et al. JEK; 2013
Arthroscopic Center Amager / SORC-C

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Measuring Eccentric hamstring strength during Nordic hamstring reliably
Arthroscopic Center Amager / SORC-C Copenhagen
Opar D et al. JOSPT; 2013

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Eccentric strength as a risk factor -elite Australian footballers (n=210 & 28 injuries)
•Low levels of eccentric hamstring strength during the Nordic hamstring exercise
- at the start (256N)
- at the end (279N)
…of preseason displayed significantly greater risk
(RR 2.7 / 4.3) of future Hamstring strain injury
Arthroscopic Center Amager / SORC-C Copenhagen
•The additional risk from advancing age or previous injury was mitigated by higher levels of eccentric hamstring strength Opar D et al. MSSE; 2014

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Nordic break point angle - a field based tool for assessment of eccentric strength?
•A meaningful relationship between eccentric knee flexor peak torque (average of right and left limbs)
&
•The Nordic break point angle (the point whereby the subject can no longer resist the increasing gravitational moment during a Nordic hamstring lower)
(r = -0.808, r2 = 65%, p<0.00001)
Sconce E et al. J Sports Rehabil; 2014
Arthroscopic Center Amager / SORC-C Copenhagen

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What did we learn?
•It is possible to prevent hamstring injuries in football by completing the Nordic Hamstring programme
•Eccentric training is particular effective in preventing recurrent injuries
•It is equally effective in amateur football
•Higher EMG activity in BF during NHE than during traditional isokinetic exercise
•Low pre-season levels of eccentric strength during NHE, increase the risk of future Hamstring injury 4- fold
•The risk factors of higher age and previous injury can be mitigated by doing NHE
•The Nordic break point angle seems to be correlated to eccentric hamstring strength
Arthroscopic Center Amager / SORC-C Copenhagen

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Practical Conclusion – Nordic Hamstring Exercise
•NHE is targeting BF better and can be used to increase eccentric hamstring strength
•Strength measured from NHE can be used as a tool to assess players for risk before season and perhaps before RTP (Nordic break point angle?)
•Increased strength from NHE can mitigate the risk of previous injury and higher age
•Very effective for prevention of hamstring injuries in football
Arthroscopic Center Amager / SORC-C Copenhagen
Future perspective: a place in the
treatment of hamstring injuries??

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Arthroscopic Center Amager / SORC-C Copenhagen
www.sportskongres.dk

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Arthroscopic Center Amager / SORC-C Copenhagen
http://www.aspetar.com/WCGP2014/index.aspx
01. – 03. November 2014

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Arthroscopic Center Amager / SORC-C
Copenhagen
01. – 03. November 2014

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Arthroscopic Center Amager / SORC-C
Copenhagen
Thank you

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Arthroscopic Center Amager / SORC-C Copenhagen

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Arthroscopic Center Amager / SORC-C Copenhagen