Transcript Hamstring Strains - Fetterman Events

Hamstring Strains
Season Ending Injury
Epidemiology
 A. Second Most common injury in NFL, Knee sprains
number 1
 b. Running backs 22%, Defensive Backs 14%, Wide
Receivers 12%
 C. 12% of all injuries in pro soccer.
 D. Memphis State University study: HS Injuries were third
most common sports injuries behind Knee and Ankle.
Most affected in Sports
 Sprinting Sports
 Soccer
 Rugby
 Australian Rules Football.
 Gymnastics and dancing
Significant Recovery Time
 Increased recovery time and increased chance of recurrance.
 A. Study of 858 Australian rules footballers: 12.6 %
recurrence in the first week. 8.1% in second week. 30.6 %
recurrence in the course of a 22 week season.
 15 out of 30 sprinters recurrence.
 Second injury is more severe and results in more time lost
than initial injury.
Anatomy
Anatomy ( cont.)
Innervation
Sciatic Nerve Entrapment
Mechanism of Injury
 Maximum HS Lengths Occurred during the late swing phase
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of sprinting.
A. 7.4 % SM, 8.1% ST, 9.5% BF
Peak Length did not increase as speed increased
Peak HS Force did increase as speed increased
Negative MT activity increased with speed.
Running Gait
Late Swing Phase
Causes ( continued)
 Data demonstrates that injury occurs as peak length and peak
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force meet ( eccentric forces).
Most Common Injury is to the BF.
Weakest component is the MT Junction.( MTJ ).
Most injuries occurrat the proximal MTJ.
Avulsion Injuries occur mostly in gymnastics or dancing.
A. Hip flexion combined with knee extension.
Causes ( continued)
 Trunk, Hip , Pelvic movement
 Verrdall et al. Using video analysis Showed:
 A. High speed running with pelvic twisting to catch a ball
 B. Contralateral Hip Flexor contractile forces had the largest
influence on increased stretch.
 C. Conclusion : sudden perturbations to the trunk and pelvis
caused by the sudden action during high speed running
creates peak stretch and negative work simultaneously
Causes from a Chiropractic View point
 Running Mechanics as it relates to:
 SI Joint Nutation
 Pelvic Rotation
 Symetric Movement and transition of motion at the T/L
Junction.
 Lumbar Segmental Function as it relates to Iliopsoas
Function.
 Pronation: Internal Tibial Rotation.
Pronation in Running
Factors Affecting Recovery Time
 A. American Football: 8.3 days.
 B. Australian Football: 23-27 days
 C. High Speed Sports: 22-37 days.
 D. Competitive Sprinters: 6-50 weeks.
 Kicking Injuries: median time 50 weeks
 Stretch related injuries averaged 31 weeks.
 Askling Et Al: Involvement of the proximal tendon of the
semimembranosis, adductor magnus, quad femoris
Risk of Recurrence
 Rates of Recurrence:
 Depending on population groups:
 Low of 7%, high of 70% average 30%.
 Sherry and Best: 6-8 reinjuries occur in the first two weeks.
 Greatest predictor is a prior injury: 74% in australian
Footballers.
Re injury Healing Time
 25 days for second injuries vs. 14 days for first time injuries.
 Australian FB: 26 days vs 35 days: 10 of 31 had second HS
injuries.
 MRI: First injury showed 95 mm damage longitudinally for
first injury vs. 115 mm for second injury.
Risk factors
 Age: Higher Risk
 Hip Flexor limitations on Contralateral side.( iliopsoas)
 Increased Anterior Pelvic Tilt.
 Decreased Rectus Femoris Flexibility( Thomas Test)
 Decreased HS flexibility has not been related to higher
incidence on HS strains
 Sprinters have less HS flexibility as a result of previous HS
injury.
Efficacy of HS Stretching in injury
prevention
 Overall, the body of evidence to support HS stretching as a
means of preventing HS injuries is weak and needs further
evidence before it is accepted into practice
Strength Training
 A. Muscle Imbalances may be an important component in
identifying athletes at risk.
 B. Quad to HS ratio .45 unilaterally or .85 bilaterally = 95%
confidence interval for injury.
 C. Biodex evals may not be practical at the High school
Level.
Efficacy of strength Training for
Prevention
 The HS eccentrically de cellerate knee extension and hip
flexion at the end of the swing phase of the running gait. This
has been identified as when HS strain occurs.
 Studies show that the HS’s tensile strength can be increased
doing eccentric strength training.
 Askling et al: Eccentric overloading of female soccer players.
 A.30 elite players divided into two groups. 10 months of
training. Group 1. did basic HS training including stretching.
Group 2 did 4 sets of 8 reps 1-2 times per week with focus
on eccentric contractions. Results 3/15 vs 10/15
Strength Training ( continued)
 Brooks et al: Eccentric training had lowest injury rate vs
traditional strength training.
 A. .39 vs 1.1 per 1000 hrs.
 Gabbe et all: 4% of eccentric group has HS injury vs. 13% of
control group.
 Best results optained using eccentric bilateral biarticular
exercises.
Biarticular eccentric exercises
 Eccentric box drop
 Eccentric backward step
 Eccentric loaded lunge drop
 Eccentric forward pull
 Single leg dead lift.
Loaded Lunge Drop
Eccentric Box Drop
Eccentric Back drop
Forward Pull
Eccentric Resistance
Eccentric Resistance
Neuromuscular Control Training
 NFL Study showed most injuries occurred in the first two
weeks of training camp.
 A. Conditioning
 B. Less movement control: study of 28 NFL players
investigated for low limb movement discrimination. 6
subsequenly experienced HS strains. All 6 showed had
movement discrimination deficits below the mean.
 Core Training: Pelvic stabilization Training.
 Form running and running mechanics drills
Summary
 Preseason evaluation of muscle imbalances
 Focus of eccentric resistance training
 Focus on neuromuscular control
Injury Character
HS Strain
Avulsion
Refered pain
Onset
sudden
sudden
Usually gradual
mechanism
Sprinting, kicking,
self directed
stretching
Passive knee
extension with hip
flexion. Secondary
trauma
Unknown
Pain
Minimal to severe
sever even with rest
Tightness, cramping.
Min to smoderate
Function
Difficult walking
Often unable to walk Reduce symptoms
with activity, worse
after.
Brusing
Mild baseball size
Severe, usually entire none
thigh
palpation
Substancial local
tenderness
severe
Minimal to none
Decrease in length
substancial
substancial
minimal
Lumbar and Si exam
Occassionally
abnormal
Possible acute nerve
injury in addition
abnormal
MRI
Abnormal signal T2
Abnormal signal T2
normal
Diagnosis
 History of an event
 Difficulty walking
 Palpation at the site of injury
 Normal vs abnormal HS strength
 Provocative tests for Low back, SI, Pyriformis will be
positive for refered pain.
 Provcoative tests for HS Strength at various angles, HS length
and knee extension positive for HS injury
 Ecchymosis
 Avulsion and Hematoma
Avulsion
 Common in immature athletes
 Palp defect may be felt
 Athletes 9-16 Should be imaged a/p Pelvis
 Positive if greater than 2 cm dispacement
MRI
 Used to determine extent and location, Chronic vs Acute
 In Acute there will be edema and increased signal intensity
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on T2 imaging
In Chronic usually scar tissue will be evident
Study of 83 HS injuries only had positive MRI on 68
A. Small tears donot image well
B. Symptoms may be refered
C. Positive MRI 5/10 pain score v 2/10 on negative.
D. Time lost 24 days positive 16 days negative
MRI ( continued)
 Conclusion: Clinical examination was a better predictor of
time lost for minor injuries. MRI for moderate to severe
injuries
 Transverse tears greater than 50% of the injured area or
60mm had a predictive value of time lost and recurrence.
Treatment
 Initial goal is to reduce pain and inflamation
 Proper treatment will reduce the formation of scar tissue
thus reducing the risk of reinjury
 Rehabilitation: Restore motion, strength, agility, and trunk
stabilization.
Modalities
 HVG
 Interferential
 Versacooler
 NASIDS
 Compression
 Ice
 Light Therapy ( Laser/LED)
Kinesiotaping
Rehabilitation
 Begin as symptoms allow
 Two Theories:
 A. Worrell Et Al : Four phase program of strengthening and
stretching. To remodel and align scar tissue.
 B. A model focusing on the pelvis as the attachment site of
the HS muscle thus neuromuscular control of the
lumbopelvic region including A/P pelvic tilt to create
optimal function in sprinting and high speed skill movement.
 C, Studies show the PATS to be significantly better.
Progressive stretching/strengthening 6/13 had recurrence
 PATS 0/13 had recurrence
Progressive Agility and Trunk
Stabilization
PATS
 Studies show that the ability to control the lumbopelvic
region during high speed skilled movement prevents HS
injuries.
 A. Pelvic muscles influence the peak stretch of the HS and
lack of control may contribute to HS strains
 Conclusion: Neuromuscular control of the hip and pelvis is
crucial in promoting function of the HS.
Treatment
 RICE
 Modalities Including Cyriax Cross Fiber
 Motor Point Therapy
 Spinal Adjustments
 Eccentric Resistance Exercises
 Neuromuscular Pelvic Stabilization
 PATS ( progressive agility and trunk stabilization)
 Return to Play: Manual Resistance in four positions at four
angles.