ACL Prevention

1
ACL Prevention

• Amanda KW Kelly, MD
• Case Western Reserve University
• Rainbow Babies and Childrens Hospital

2
Outline

• Background
• Injury risk factors
• ACL prevention programs

3
Background

• 250,000 ACL injuries/yr in USA
• 1.5 billion annual cost
• 80 - 90 return to previous level of play
• Typical recovery 6-9 mo
• 70 ACL injuries are NON-contact

Boden 2000 Physspportsmed
4
Importance of ACL Injury

• Season ending injury
• 6-9 mo recovery time
• Children often must wait several yrs for repair
• Costly

5
ACL Anatomy
PCL
ACL
LCL
MCL
6
ACL Function

• Keep tibia from sliding forward on the femur

7
Injury Mechanisms

• Pivot
• Landing from jump
• Contact

http//sportzfun.com/v-web/gallery/slideshow.php?s
et_albumNamesoccer
8
Injury Mechanism Pivot

• Deceleration change of direction, foot planted
• Causes twisting injury of knee
• Traction at shoe/playing surface interface
• Often close to another player

ACL
9
Mechanism Pivot

• Importance of ground-shoe surface interface in
  pivot mechanism

Shoe surface interface
10
Mechanism landing

• Knee slightly flexed on landing
• Quad pulls tibia forward

11
Mechanism Contact

• Hit on outside of leg
• Foot planted
• Twisting of knee

12
Mechanism

• Pivoting with knee slightly bent, twisting knee
• Landing from jump knees slightly bent, quads
  pull tibia forward
• Too much shoe traction
• Poor balance
• Uneven ground throwing off balance

13
Risk Factors

• Poor landing pivot style
• Stronger quads than hamstrings
• Shoe / playing surface interface
• Playing surface quality
• Female gender

14
Risk Factors

• Landing / Pivoting with knee slightly bent
• Places ACL in vulnerable position
• Additional torsion/twisting can ? injury

Boden 2000 Physsportsmed
15
Risk Factors

• Hamstring/Quadriceps imbalance
• Poor hamstring strength
• Hamstrings protect ACL
• Quads stretch/stress ACL
• Slow activation of hamstring muscles with pivot /
  landing

Hewett AJSM 1999, Crosier AJSM 2002, Huston 1996
AJSM, Orchard AJSM 1997, Baratta AJSM 1988
http//www.preventaclinjury.com/knee_biomechanics.
htm
16
Risk Factors

• Footwear
• Longer cleats at edge of sole with fewer, smaller
  cleats in the middle of the sole
• ?s torsional resistance

Lambson 1996 AJSM
17
Risk Factor

• Uneven playing surface
• Unexpected foot position may change muscle
  activation patterns
• Balance thrown off

Boden, Orthopedics
18
Risk Factors

• Female Gender
• 2-8x more common in girls
• Poor hamquad strength
• Activate hams more slowly
• Land with knees sl bent
• Boys land with knees more bent

19
Female Gender

• Hormonal Influences
• ACL has estrogen receptors
• Estrogen can ? ligament looseness
• Estrogen levels ? in girls compared to boys
• Estrogen ?d at specific times in menstrual cycle
• Studies VERY inconsistent
• Every phase of cycle has been implicated in at
  least 1 study

20
Female Gender

• Knee anatomy
• Smaller intercondylar notch
• ACL may get stretched across bone and torn
• Athletes with bilateral ACL injuries have smaller
  ICN

www.hughston.com
Harner 1994 AJSM, Anderson 1999 AOSSM
21
Female Gender

• Lower extremity alignment
• Women more knock-kneed
• May allow quad to exert more stress on ACL
• Data not great

Nisell 1985 ActaOrthopScandSuppl
www.hughston.com
22
Prevention Strategies

• Shoe wear / field surface
• Bracing
• Exercise Programs
• Change muscle strength activation
• Change landing / Pivoting patterns
• Sportmetrics
• PEP

23
Prevention shoe wear

• Shoes with lower ACL injury risk
• Cleats flat, all the same size on forefoot
• Screw in cleats with 0.5in ht/diameter cleats
• Pivot disk 10-cm circular edge on sole of
  forefoot
• Flat shoes on turf
• Want balance of too much / too little traction

Lambson 1996 AJSM
24
Prevention

• Improve playing field????

25
Bracing

• Several studies
• Inconclusive results
• No change in muscle activation patterns
• No ? ACL shown in any study
• Loads placed on brace during play exceeds brace
• BUT, many kids who have had ACL surgery FEEL more
  stable in brace

26
Training Programs

• Balance board training
• Improves balance joint position sense
• Caraffa, 1996, Knee Surg Sports Traum Arthrosc
• 20 min training sessions
• 87 ? ACL injuries
• 7x ? injury

27
Training Programs

• Frappier Acceleration Training Program
• Frappier Acceleraton, Fargo, North Dakota
• Heidt, 2000, Amer Orthop Soc Sports Med
• 7 wk preseason training 3d/wk
• 2d/wk treadmill sessions
• 1d/wk plyometric (jump training)
• ?d total serious knee injuries
• ACL ?d but not significantly

28
Training Programs

• Sportmetrics
• Hewett, 1999, Amer J Sports Med
• Cinicinnati Sportsmedicine Research and Education
  Foundation
• PEP (Prevent injury Enhance Performance)
• Mandelbaum, 2005, Amer J Sports Med
• Santa Monica Orthopedic and Sports Medicine
  Research Foundation

29
Program Goals

• Emphasize proper jump/land techniques
• Land on balls of feet
• Soft landing
• Toe-to-heel rocking of the foot
• ? ground reactive forces
• Knees flexed
• Knees forward
• Discourage inward buckling of knees (knock-kneed
  landing)
• Chest over knees

Hewett 1999 AJSM, Mandelbaum 2005 AJSM, Boden
2000 Physportsmed
www.physsportsmed.com
30
Training Programs

• Sportmetrics
• 6 week Preseason-training program
• 60 90 minute work-out
• PEP
• 15 minute work-out
• Use in place of usual pre-practice warm-up 3 d/wk

31
PEP Program

• Designed to replace usual warm-up

• Warm-up
• Jog 50yd
• Shuttle run 50yd
• Backward run 50yd
• Stretch
• Calf, quad, ham, inner thigh, hip flexor
• 2 x 30s each

correct
incorrect
Mandelbaum 2005 AJSM
32
PEP Program

• Strength
• Walking lunges 20yd x 2
• Russian hamstr 30s
• Single toe raise 30x

Mandelbaum 2005 AJSM
33
PEP Program

• Plyometrics
• Lateral hops 30s
• Forward hops 30s
• Single leg hops 30s
• Vertical jumps 30s
• Scissor jumps 30s

Mandelbaum 2005 AJSM
34
PEP Program

• Agilities
• Shuttle run 40yd
• Diagonal run 40yd
• Bounding run 50yd
• Knees bent
• Avoid upright position

incorrect
correct
Mandelbaum 2005 AJSM
35
Sportsmetrics

• Warm-up
• Stretching 3 sets, 30s each
• Calf, quad, hamstring, hip flexor, IT Band, low
  back, posterior deltoids, latissimus,
  pects/biceps
• Skipping 2 laps
• Side shuffle 2 laps

36
Sportsmetrics
(Side-side/front-back)
Hewett 1999 AJSM
37
Sportsmetrics
Hewett 1999 AJSM
38
Sportsmetrics
Hewett 1999 AJSM
39
Jump Definitions

• 180? jumps 2-footed, rotate 180 ? in the air
• Bound for distance start bounding in place,
  increase distance with each step, knees high
• Broad jumps-hold landing 2-footed jump, as far
  as possible hold landing 5s
• Cone jumps double leg, side-side, front-back
• Hop, hop, stick single leg hop, stick landing 5s
• Jump into bounding 2-footed jump, land on 1 leg,
  progress into bounding for distance
• Jump, jump, jump, vertical 3 broad jumps with
  vertical jump after last broad jump
• Mattress jumps 2-footed jump on mattress/tramp,
  side-side front-back

Hewett 1999 AJSM
40
Jump Definitions

• Scissors jump start in stride position, one foot
  in front of other, jump up alternating foot
  position in air
• Single-leg jumps, distance single-leg hop for
  distance, hold landing 5s
• Squat jumps standing jump, raise arms overhead,
  land in squat position hands on floor
• Step, jump up, down, vertical 2-footed jump onto
  step, jump off with 2 feet, then vertical jump
• Tuck jump standing, bring both knees up to
  chest, repeat
• Wall jumps ankle bounces, arms overhead bounce
  up/down off of toes

Hewett 1999 AJSM
41
Sportsmetrics

• Weight-training 12 reps upper body, 15 lower
• Abdominal curl
• Back hyperextension
• Leg press
• Calf raises
• Pullover
• Bench press
• Lat pull downs
• Forearm curl
• Warm-down, stretch

Hewett 1999 AJSM http//www.sportsmetrics.net/
42
Training Programs

• Both PEP and Sportmetrics well studied
• Aim
• Change landing / pivoting patterns
• Flex knees more
• Stop over several steps instead of sudden stop
• Improve hamstring strength activation
• BOTH prevent ACL other serious knee injury by
  achieving these aims

43
Goals

• Emphasize proper landing technique

WRONG
RIGHT
44
Proper landing

• Before Training

• After training

Barber-Westin, 2006, AJSM Noyes 2005 AJSM
45
Decreased Injury

• ?d non-contact injuries in trained groups

0.47
UT Untrained T Trained MC Male Control
0.35
0.09
0.05
0
PEP Mandelbaum 2005 AJSM
Sportsmetrics Hewett 1999 AJSM
46
Performance Enhancement

• ? vertical jump
• 10 ? jump height
• ? strength
• 44 ? hamstring strength
• ? sprint speed
• Improved power endurance
• Improved running economy

Diallo JSMPF 2001, Turner JSCR 2003, Siegler JSCR
2003, Spurs EJAP 2003, Newton MSSE 1999. Witzke
MSSE 2000, Hewett 1999 AJSM
47
Improved Bone Density

• Female athletes participating in jump training
  build more bone
• ? risk for stress fracture
• Prevent time lost from injury
• ? risk for osteoporosis later in life

48
References

• Barber-Westin SD et al. Jump-Land Characteristics
  and muscle strength development in young
  athletes. Amer J Sports Med. 2006 34(3)1-10
• Boden BP et al. Etiology and prevention of
  noncontact ACL injury. PhysSportsMed. 2000 29(4)
• Caraffa A et al. Prevention of anterior cruciate
  ligament injuries in soccer a prospective
  controlled study of proprioceptive training.
  KneeSurgSportsTraumatolArthrosc. 1996419-36
• Heidt RS et al. Avoidance of soccer injuries with
  preseason conditioning. AmJSportsMed. 2000
  28(5)659-62
• Hewett TE et al. The effect of neuromuscular
  training on the incidence of knee injury in
  female athletes a prospective study. Amer J
  Sports Med 1999. 27(6) 699-706
• Lambson RB et al. Football cleat design and its
  effect on anterior cruciate ligament injuries a
  3-yr prospective study. AmJSportsMed.199624(2)155
  -9

49
References

• Mandelbaum BR, Silvers HJ, Watanabe DS.
  Effectiveness of a neuromusclular and
  proprioceptive training program in preventing
  anterior cruciate ligament injuries in female
  athletes a 2-year follow-up. Amer J Sports Med.
  2005 33(7) 1003-9
• Noyes et al. The Drop-Jump Screening Test. Amer J
  Sports Med. 2005 33(2)197-207