Risk factors for rectus femoris muscle injuries - Eduard Alentorn Geli - 8th MuscleTech Network Workshop Monday 3rd October, 2016 #MTN8th

1. RISK FACTORS FOR
RECTUS FEMORIS MUSCLE INJURIES
Eduard Alentorn Geli MD, MSc, PhD,
FEBOT, FACGME
Consultant, Orthopedic Surgery
Fundación García Cugat
Artroscopia GC, Hospital Quirón
Mutualidad de Futbolistas
Barcelona, Spain

2. INTRODUCTION
Very common muscle injury
(Ekstrand 2011)
Unique aspects: anatomy and pre-season
incidence predominance
(Hasselman 1995; Orchard 2002; Woods 2002)
More missed games than other muscle
injury locations
(Ekstrand 2011)
High re-injury rate 21%
(Hagglund 2013)

3. INTRODUCTION

4. INTRODUCTION
RISK FACTORS
INTRINSIC EXTRINSIC
PREVENTION
MODIFIABLE
RELEVANCE

5. INTRODUCTION

6. INTRODUCTION
PURPOSE:
To review the muscle-specific risk factors
identified

7. RISK FACTORS
Intrinsic factors
• AGE:
– Incidence of muscle injuries
in general increases with
age (Ekstrand 2011)
– Calf and hamstrings only
muscle groups with
significant increase in
incidence of injury with age
(Ekstrand 2011; Orchard 2001).
– Age = not a risk factor for
quadriceps injury (Ekstrand 2011;
Orchard 2001: Hagglund 2013)

8. RISK FACTORS
Intrinsic factors
• PREVIOUS INJURY:
– Previous quadriceps and hamstring muscle injury 
increase risk RF injury in AF (Orchard 2001)
– HT injury reduced stride length as a protective
mechanism, but might be harmful for RF

9. RISK FACTORS
Intrinsic factors
• PREVIOUS INJURY:
– Previous injury not a risk factor in soccer: only 7
injuries (Fousekis 2011)
– Quadriceps injury the season before increased risk of
injury in soccer: HR 3.10; 95% CI 2.21-4.36 (Hagglund 2013)
– Risk also increased for adductors and calf muscle
injuries in the preceeding season in soccer(Hagglund 2013)

10. RISK FACTORS
Intrinsic factors
• ANTROPOMETRIC CHARACTERISTICS:
– Heavier and shorter individuals had a trend towards
higher risk of quadriceps muscle injuries (Fousekis 2011).
– Only 7 quadriceps injuries (only trend).

11. RISK FACTORS
Intrinsic factors
• ANTROPOMETRIC CHARACTERISTICS:
– Height below 1.82cm  increased risk of quadriceps
injury compared to taller players in AF (Orchard 2001)
– Body size is not associated with increased risk of
quadriceps muscle injuries in soccer (Bradley 2007)
– Stature and body mass not associated with risk of
quadriceps muscle injury in soccer (Hagglund 2013)

12. RISK FACTORS
Intrinsic factors
• DOMINANCE:
– Significantly more quadriceps muscle injuries in the
dominant vs non-dominant leg in soccer players
• 60% vs 33% (Ekstrand 2011)
• 63% vs 37% (Hagglund 2013)
– Quadriceps injuries more common in dominant
kicking leg in AF (RR 2.13 1.59-28.6 95% CI) (Orchard 2001)
– No significant differences for hamstring, adductors,
and calf muscles (Ekstrand 2011; Orchard 2001)

13. RISK FACTORS
Intrinsic factors
• DOMINANCE:
– No differences in rate of dominant vs non-dominant
side injury between patients with or without
quadriceps muscle injury in soccer players:
• N=6 injuries (Bradley 2007)
• N=13 injuries (Witvrouw 2003)

14. RISK FACTORS
Intrinsic factors
• FLEXIBILITY:
– Injured soccer players had lower pre-season
quadriceps muscle flexibility compared to non-
injured players (Witvrouw 2003)

15. RISK FACTORS
Intrinsic factors
• FLEXIBILITY:
– Trend towards quadriceps flexibility asymmetries in
injured soccer players (Fousekis 2011)

16. RISK FACTORS
Intrinsic factors
• FLEXIBILITY:
– Quadriceps flexibility was not different between
quadriceps injured and non-injured soccer players
(Bradley 2007)
– Only 6 quadriceps muscle injuries.

17. RISK FACTORS
Intrinsic factors
• STRENGTH:
– Preseason concentric isokinetic knee extensors strength 
not risk factor for quad injuries in soccer players (Fousekis 2011)
– Preseason eccentric isokinetic knee extensors strength
differences in injured compared to uninjured: OR 5.01, 0.92-
27.14 95% CI) (Fousekis 2011)

18. RISK FACTORS
Extrinsic factors
• SPORT:
– Sprinting and kicking: not proven but most commonly
occur in these actions (Mendiguchia 2012)
– Champions League less risk than home leagues (Hagglund 2013)
• PLAYING POSITION:
– Not a risk factor for knee extensors injury (Bradley 2007)
– Decreased risk in goalkeepers (Hagglund 2013)

19. RISK FACTORS
Extrinsic factors
• TIME OF THE SEASON:
– More quadriceps injuries during pre-season: Rectus
femoris was the most common (29%) (Woods 2002)
– Significant differences between pre- and in-season
incidence of rectus femoris and biceps femoris
injuries (Woods 2002)
– No differences between in-season and pre-season in
soccer (Hagglund 2013)

20. RISK FACTORS
Extrinsic factors
• FIELD:
– Higher quadriceps injuries after low rainfall week
with dryer and harder field in AF (Orchard 2001)
– No differences between northern (marine west
coast)/southern (Mediterranean) climates in
European soccer (Hagglund 2013)

21. RISK FACTORS
Extrinsic factors
• FIELD:
– More quadriceps injuries during pre-season: Rectus
femoris was the most common (29%) (Woods 2002)
– Ground condition was dry in 70% of cases in pre-
season (Woods 2002)
– Not a risk factor analysis.

22. SUMMARY OF STUDIES
PARAMETER YES NO VEREDICT
Age 0 3 

23. SUMMARY OF STUDIES
PARAMETER YES NO VEREDICT
Age 0 3 
Previous injury 2 1 (1) 

24. SUMMARY OF STUDIES
PARAMETER YES NO VEREDICT
Age 0 3 
Previous injury 2 1 (1) 
Shorter 1 2 (1) 

25. SUMMARY OF STUDIES
PARAMETER YES NO VEREDICT
Age 0 3 
Previous injury 2 1 (1) 
Shorter 1 2 (1) 
Heavier 0 3 

26. SUMMARY OF STUDIES
PARAMETER YES NO VEREDICT
Age 0 3 
Previous injury 2 1 (1) 
Shorter 1 2 (1) 
Heavier 0 3 
Dominant 3 2 (2) 

27. SUMMARY OF STUDIES
PARAMETER YES NO VEREDICT
Age 0 3 
Previous injury 2 1 (1) 
Shorter 1 2 (1) 
Heavier 0 3 
Dominant 3 2 (2) 
Flexibility 1 2 (2) 

28. SUMMARY OF STUDIES
PARAMETER YES NO VEREDICT
Age 0 3 
Previous injury 2 1 (1) 
Shorter 1 2 (1) 
Heavier 0 3 
Dominant 3 2 (2) 
Flexibility 1 2 (2) 
Strength (eccentric) - 1 (1) 

29. SUMMARY OF STUDIES
PARAMETER YES NO VEREDICT
Age 0 3 
Previous injury 2 1 (1) 
Shorter 1 2 (1) 
Heavier 0 3 
Dominant 3 2 (2) 
Flexibility 1 2 (2) 
Strength (eccentric) - 1 (1) 
Position 1 1 (1) 

30. SUMMARY OF STUDIES
PARAMETER YES NO VEREDICT
Age 0 3 
Previous injury 2 1 (1) 
Shorter 1 2 (1) 
Heavier 0 3 
Dominant 3 2 (2) 
Flexibility 1 2 (2) 
Strength (eccentric) - 1 (1) 
Position 1 1 (1) 
Pre-season 1 1 

31. SUMMARY OF STUDIES
PARAMETER YES NO VEREDICT
Age 0 3 
Previous injury 2 1 (1) 
Shorter 1 2 (1) 
Heavier 0 3 
Dominant 3 2 (2) 
Flexibility 1 2 (2) 
Strength (eccentric) - 1 (1) 
Position 1 1 (1) 
Pre-season 1 1 
Dry field 1 1 (1) 

32. The RF risk factors model
Bahr and Krosshaug, BJSM 2005

33. The RF-RF model
Adapted from Bahr and Krosshaug, BJSM 2005
Fatigue
Warm-up
Contractile
properties
Muscle
imbalance
Intermuscular
coordination
Core stability
. . .
Previous
injury
Anthropometrics Dominance
Flexibility Strength
PREDISPOSED ATHLETE
?
SUSCEPTIBLE
ATHLETE
DRY FIELD
INJURY
SPRINTING
KICKING
Position
PREVENTION

34. CONCLUSIONS
EVIDENCE FOR QUADRICEPS
LIKELY
•Previous injury
•Shorter individuals
•Dominant leg
•Decreased flexibility
•Side-to-side differences in
eccentrinc isokinetic knee
extensors strength
•Dry field
•Player position
DOUBTFUL
•Heavier individuals
•Side-to-side differences in
concentric isokinetic knee
extensors strength
•Pre-season

35. CONCLUSIONS
FURTHER
RESEARCH
CONFIRM RISK FACTORS DISCOVER NEW ONES
REDUCE RECTUS FEMORIS INJURIES
PREVENTION PROGRAMS

37. THANK YOU!!!!!
ealentorngeli@gmail.com