Title: ACL Prevention
1ACL Prevention
- Amanda KW Kelly, MD
- Case Western Reserve University
- Rainbow Babies and Childrens Hospital
2Outline
- Background
- Injury risk factors
- ACL prevention programs
3Background
- 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
- gt 70 ACL injuries are NON-contact
Boden 2000 Physspportsmed
4Importance of ACL Injury
- Season ending injury
- 6-9 mo recovery time
- Children often must wait several yrs for repair
- Costly
5ACL Anatomy
PCL
ACL
LCL
MCL
6ACL Function
- Keep tibia from sliding forward on the femur
7Injury Mechanisms
- Pivot
- Landing from jump
- Contact
http//sportzfun.com/v-web/gallery/slideshow.php?s
et_albumNamesoccer
8Injury 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
9Mechanism Pivot
- Importance of ground-shoe surface interface in
pivot mechanism
Shoe surface interface
10Mechanism landing
- Knee slightly flexed on landing
- Quad pulls tibia forward
11Mechanism Contact
- Hit on outside of leg
- Foot planted
- Twisting of knee
12Mechanism
- 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
13Risk Factors
- Poor landing pivot style
- Stronger quads than hamstrings
- Shoe / playing surface interface
- Playing surface quality
- Female gender
14Risk Factors
- Landing / Pivoting with knee slightly bent
- Places ACL in vulnerable position
- Additional torsion/twisting can ? injury
Boden 2000 Physsportsmed
15Risk 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
16Risk Factors
- Footwear
- Longer cleats at edge of sole with fewer, smaller
cleats in the middle of the sole - ?s torsional resistance
Lambson 1996 AJSM
17Risk Factor
- Uneven playing surface
- Unexpected foot position may change muscle
activation patterns - Balance thrown off
Boden, Orthopedics
18Risk 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
19Female 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
20Female 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
21Female 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
22Prevention Strategies
- Shoe wear / field surface
- Bracing
- Exercise Programs
- Change muscle strength activation
- Change landing / Pivoting patterns
- Sportmetrics
- PEP
23Prevention 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
24Prevention
- Improve playing field????
25Bracing
- 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
26Training 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
27Training 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
28Training 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
29Program 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
30Training 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
31PEP 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
32PEP Program
- Strength
- Walking lunges 20yd x 2
- Russian hamstr 30s
- Single toe raise 30x
Mandelbaum 2005 AJSM
33PEP Program
- Plyometrics
- Lateral hops 30s
- Forward hops 30s
- Single leg hops 30s
- Vertical jumps 30s
- Scissor jumps 30s
Mandelbaum 2005 AJSM
34PEP Program
- Agilities
- Shuttle run 40yd
- Diagonal run 40yd
- Bounding run 50yd
- Knees bent
- Avoid upright position
incorrect
correct
Mandelbaum 2005 AJSM
35Sportsmetrics
- 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
36Sportsmetrics
(Side-side/front-back)
Hewett 1999 AJSM
37Sportsmetrics
Hewett 1999 AJSM
38Sportsmetrics
Hewett 1999 AJSM
39Jump 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
40Jump 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
41Sportsmetrics
- 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/
42Training 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
43Goals
- Emphasize proper landing technique
WRONG
RIGHT
44Proper landing
Barber-Westin, 2006, AJSM Noyes 2005 AJSM
45Decreased 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
46Performance 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
47Improved 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
48References
- 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
49References
- 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