Quadriceps Muscle Injuries - William Garret (Eduard Alentor-Geli) 8th MuscleTech Network Workshop MTN8th Monday 3rd October, 2016

1. Quadriceps Muscle Injuries:Quadriceps Muscle Injuries:
An OverviewAn Overview
William E Garrett, MD, PhDWilliam E Garrett, MD, PhD
Duke University Medical CenterDuke University Medical Center

2. IntroductionIntroduction
Muscle injuries are a major cause ofMuscle injuries are a major cause of
time lost to sporttime lost to sport
Yet they have received the leastYet they have received the least
attention from research and clinicalattention from research and clinical
investigationinvestigation

3. Muscle Injury EpidemiologyMuscle Injury Epidemiology
Professional Football (Soccer)Professional Football (Soccer)
•UEFA study of 51 teams /2299players/ 9yearsUEFA study of 51 teams /2299players/ 9years
•Players averaged 0.6 injury/ yearPlayers averaged 0.6 injury/ year
•31% of all injuries31% of all injuries
•27% of missed time27% of missed time
Ekstrand et al., AJSM, 2011

4. Muscle Injury EpidemiologyMuscle Injury Epidemiology
92% of injuries affected 4 muscle groups92% of injuries affected 4 muscle groups
Hamstrings 37%
Adductors 23%
Quadriceps 19%
Calf 13%
Ekstrand et al., AJSM, 2011

5. Muscle Strain InjuriesMuscle Strain Injuries
Quadriceps muscle injuries in professionalQuadriceps muscle injuries in professional
soccer cause more time lost than any othersoccer cause more time lost than any other
muscle injury (Ekstrand 2011)muscle injury (Ekstrand 2011)

6. Mechanism of InjuryMechanism of Injury
• Indirect traumaIndirect trauma
• Stretch is required with or without activation.Stretch is required with or without activation.
• These injuries usually involve high speedThese injuries usually involve high speed
athletic activities with eccentric contraction:athletic activities with eccentric contraction:
–SprintingSprinting
–KickingKicking

7. Mechanism of InjuryMechanism of Injury
• Experimental animal studies (Garrett et al.):Experimental animal studies (Garrett et al.):
– Muscle maximally tetanically stimulatedMuscle maximally tetanically stimulated  lose forcelose force
but no structural damage observed (force loss due tobut no structural damage observed (force loss due to
nerve injury?)nerve injury?)
– Role of stretching: 2 groupsRole of stretching: 2 groups  stretch + activation vsstretch + activation vs
stretch alone:stretch alone:
• Both injured with same amount of stretchBoth injured with same amount of stretch
• Activated muscles that failed had only 15% more force atActivated muscles that failed had only 15% more force at
time of complete disruption.time of complete disruption.
• Activated muscles absorbed more energyActivated muscles absorbed more energy

8. (strength)
(flexibility)
Mechanism of injuryMechanism of injury

9. Mechanism of injury:Mechanism of injury:
Effect of Muscle Activation During StretchEffect of Muscle Activation During Stretch
Length-Tension Deformation
Force
Length

11. Greater Force of ContractionGreater Force of Contraction
More Energy AbsorbedMore Energy Absorbed
Prior to FailurePrior to Failure
Implications for strengthImplications for strength
and fatigue effectsand fatigue effects
Mechanism of injuryMechanism of injury

12. Mechanism of InjuryMechanism of Injury
• Stronger muscle (eccentriccally stretched)Stronger muscle (eccentriccally stretched) 
absorb more energy before length for injury.absorb more energy before length for injury.
• Flexible musclesFlexible muscles  stretch further beforestretch further before
injury point.injury point.
• Flexible musclesFlexible muscles  allow active muscleallow active muscle
forces to decelerate the joint beforeforces to decelerate the joint before
excessive stretchingexcessive stretching

13. Mechanism of InjuryMechanism of Injury
Injured muscles are:Injured muscles are:
– Those that are slowing down or stopping motionThose that are slowing down or stopping motion
– Activated or contractingActivated or contracting
– Being lengthenedBeing lengthened
Implications:
–Flexibility: ability of muscle to be stretched without
injury  risk factor/preventive role
–Strenght: ability to absorb load while stretching 
risk factor/preventive role

14. Histological studiesHistological studies
The tendon is not injured.The tendon is not injured.
The muscle tearsThe muscle tears
• Within the muscle fibersWithin the muscle fibers
• Near the muscle-tendonNear the muscle-tendon
junctionjunction
• Often small amount ofOften small amount of
muscle fiber still attached tomuscle fiber still attached to
the tendonthe tendon

15. Pathological ChangesPathological Changes
Regardless of muscleRegardless of muscle
fiber architecturefiber architecture

16. Histological studiesHistological studies
• Entire muscle fiber does not dieEntire muscle fiber does not die
• Its membrane is sealed over near the pointIts membrane is sealed over near the point
of rupture.of rupture.
• Muscle stretched to beyond ultimate failureMuscle stretched to beyond ultimate failure
 very short fibers left at the tendon portionvery short fibers left at the tendon portion
• Muscle mildly stretchedMuscle mildly stretched  only a few fibersonly a few fibers
torn at the muscle/tendon junctiontorn at the muscle/tendon junction

17. Histological studiesHistological studies
• Injury usually occur at the proximal or distalInjury usually occur at the proximal or distal
end of the muscle/tendon junctionend of the muscle/tendon junction
• Muscle fibers do not seem to tear away fromMuscle fibers do not seem to tear away from
the proximal or distal endsthe proximal or distal ends

18. Histological studiesHistological studies
• Damage near muscle/tendon junctionDamage near muscle/tendon junction
actually predicts failure at a lower amount ofactually predicts failure at a lower amount of
strain.strain.
• Small injuriesSmall injuries  muscle at more risk formuscle at more risk for
major injurymajor injury
• Small injuriesSmall injuries  predict larger injuriespredict larger injuries
(previous injury as risk factor)(previous injury as risk factor)

19. Histological studiesHistological studies
• Incomplete or non-Incomplete or non-
disruptive injuries (smalldisruptive injuries (small
strains):strains):
– TThe muscle is tornhe muscle is torn
enough to beenough to be
histologically abnormalhistologically abnormal
and be able to generateand be able to generate
less forceless force
acute
Initial bleeding +
inflammatory cells

20. Histological studiesHistological studies
48 hr
7d
Macrophages and other inflammatory
cells to debride the damaged tissue
Connective tissue reconnects the
muscle fibers to the tendon

21. Recovery Following Non-Disruptive InjuryRecovery Following Non-Disruptive Injury
Recovery ofRecovery of
contractilecontractile
function infunction in
approximatelyapproximately
one weekone week
(rabbit model)(rabbit model) 0
10
20
30
40
50
60
70
80
90
100
0 hrs. 24 hrs. 48 hrs 7 days
Time After InjuryTime After Injury
Force Generation % of ControlForce Generation % of Control
70.570.5
51.151.1
74.574.5
92.592.5
Histological studiesHistological studies

22. Rectus Femoris InjuriesRectus Femoris Injuries
• Rectus femoris injury is probably moreRectus femoris injury is probably more
common than is generally reportedcommon than is generally reported
• The most common of quadriceps musclesThe most common of quadriceps muscles
• BiarticularBiarticular
• Stretched with hip extension and kneeStretched with hip extension and knee
flexion (kicking sports at start offlexion (kicking sports at start of
accelerated hip flexion and kneeaccelerated hip flexion and knee
extension).extension).

23. AnatomyAnatomy
• Direct head:Direct head:
– AIISAIIS
– Spreads out over the anterior surface of the muscleSpreads out over the anterior surface of the muscle
• Indirect head:Indirect head:
– Edge of acetabulum and superior hip capsule.Edge of acetabulum and superior hip capsule.
– Forms a tendon within the larger rectus femoris.Forms a tendon within the larger rectus femoris.
– Muscle/tendon junctions arising from indirect headMuscle/tendon junctions arising from indirect head
often covered by muscle fibers arising from directoften covered by muscle fibers arising from direct
head.head.
– Looks like a muscle strain in the middle of muscleLooks like a muscle strain in the middle of muscle
– BullBull’’s eye sign = muscle tear around central tendons eye sign = muscle tear around central tendon

24. AnatomyAnatomy
• Direct head:Direct head:
– AIISAIIS
– Spreads out over the anterior surface of the muscleSpreads out over the anterior surface of the muscle
• Indirect head:Indirect head:
– Edge of acetabulum and superior hip capsule.Edge of acetabulum and superior hip capsule.
– Forms a tendon within the larger rectus femoris.Forms a tendon within the larger rectus femoris.
– Muscle/tendon junctions arising from indirect headMuscle/tendon junctions arising from indirect head
often covered by muscle fibers arising from directoften covered by muscle fibers arising from direct
head.head.
– Looks like a muscle strain in the middle of muscleLooks like a muscle strain in the middle of muscle
– BullBull’’s eye sign = muscle tear around central tendons eye sign = muscle tear around central tendon

25. ANATOMY
DIRECTDIRECT
INDIRECTINDIRECT **
**
**
**
**

26. ANT APONANT APON
INTRA MUSINTRA MUS
TENDONTENDON
II DD
DEEPDEEP
AJSM23,4AJSM23,4’’9595
A MUSCLE WITHIN A MUSCLEA MUSCLE WITHIN A MUSCLE

27. Clinical presentationClinical presentation
–pain in anterior thigh after highpain in anterior thigh after high
speed, high force muscle actionspeed, high force muscle action
–initial painful swellinginitial painful swelling
–subsequent bulge with musclesubsequent bulge with muscle
activationactivation
–appearance of ruptured muscle-appearance of ruptured muscle-
tendon unittendon unit

30. Clinical courseClinical course
–prolonged improvementprolonged improvement
–often near-complete recoveryoften near-complete recovery
–some have persisting pain andsome have persisting pain and
asymmetryasymmetry
–some have question of a neoplasmsome have question of a neoplasm
–Initially considered to be distal MTJInitially considered to be distal MTJ
injuries often avulsions due to massinjuries often avulsions due to mass
effecteffect ““PopeyePopeye””

31. MRIMRI
–high T2 signal in rectus femorishigh T2 signal in rectus femoris
–only a portion of muscle involvedonly a portion of muscle involved
–central portion of muscle is mostcentral portion of muscle is most
involvedinvolved

34. TreatmentTreatment
–out of many injuries, very fewout of many injuries, very few
surgeriessurgeries
–symptoms are usually tolerablesymptoms are usually tolerable
without surgerywithout surgery
–a significant incisiona significant incision

35. TreatmentTreatment
Make every effort to treat theseMake every effort to treat these
conservativelyconservatively
Surgery is not easy or intuitiveSurgery is not easy or intuitive

36. SummarySummary
–occur in high intensity and velocityoccur in high intensity and velocity
situations: stretching +/- activationsituations: stretching +/- activation
(sprinting or kicking)(sprinting or kicking)
–almost always activated eccentricallyalmost always activated eccentrically
–occur at muscle-tendon junctionoccur at muscle-tendon junction
–conservative treatmentconservative treatment
–flexibility/strength should helpflexibility/strength should help
preventionprevention