ACL Injury Prevention

Training Female Athletes to Training Female Athletes to Beat the OddsBeat the Odds

What is the ACL?

● Ligament that spans from the anteromedial tibia to the posterolateral femur.

● Provides primary stability to anterior tibial translation , internal tibial rotation, and hyperextension.

How is it injured?

● ACL injuries occur most frequently in planting, cutting, and pivoting sports.

● Female athletes are 4 to 10 times more likely to injure their ACL compared to male athletes participating in the same sport (Hughston Health Alert, Hughston Sports Medicine Foundation. 2002).

mechanism of injury...

● Twisting / pivoting

● Hyperextension● Landing on a

straight knee

Most Injuries Most Injuries are “non-are “non-contact”contact”

Why do women suffer from an increased

incidence of ACL injury?● Theories:

• Anatomical Differences• Hormonal Differences• Ligament Laxity• Learned Factors (conditioning)

Anatomical differences

● Intercondylar notch• women tend to have

a narrower intercondylar notch

• less room for ACL to move (esp. during twisting and bending)

Alignment of the knee...

● Women have a wider pelvis = greater Q-Angle

● Twisting and valgus forces on knee tends to increase

Hormonal Influences

● Estrogen?● Relaxin?

Estrogen

● Preliminary research indicates “estrogen receptors” on ACL

● Current research is focusing on the incidence of ACL injury compared to phase of menstrual cycle.

Relaxin

● Relaxin: Hormone released by pregnant women• Causes increase in ligament laxity

(allows for relaxation of pelvic girdle to accommodate fetal passage).

● Has been shown to have systemic effect and risks of ligamentous injury in pregnant women.

Ligamentous Laxity

WIDER PELVIS FEMORAL ANTEVERSION GENU VALGUM EXTERNAL TIBIAL TORSION LIGAMENTOUS LAXITYOF OTHER SUPPORT

STRUCTURES

INCREASED "IMPULSE" ONLIGAMENTOUS STRUCTURES

Learned Factors

● Muscular Strength/Power

● Jumping / Landing

● Cutting / Deceleration

Strength/Power

● Men tend to have higher strength-to- weight ratios compared to women

● Men tend to have lower quadriceps-hamstring strength ratios compared to women

...Strength/Power

● Quadricep / Quadricep / Hamstring Hamstring Strength RatioStrength Ratio• Males: 70%

• hamstring power & strength serve as agonists to the ACL

• Females: 50%

• depend on ligaments to protect knees on landing

Jumping / Landing

● Experience?● Research indicates

that women land w/ straighter knees and hips compared to men.

● Women tend to land w/ genu-valgum (pivot -shifts the knee)

Cutting / Deceleration

● Women tend to turn & pivot in a more erect position compared to men

● Lack of hip & knee flexion requires ligaments to absorb the force rather than the hip musculature.

Training to Prevent Injury

● Focus on Strength / Power / Endurance

● Focus on Correct Landing Mechanics

Correct Mechanics

● Knee should align with great-toe

● Force should be absorbed by powerful hip musculature.

…common mistakes

● Due to increased Q-Angle, women often land from jumps in a “knock-knee” position

● COG moves downward, causing twisting of tibia on femur

COGCOG

…common mistakes

● Again, knee position should be aligned with great toe upon landing

● Normal tibio-femoral relationship will exist

How To Develop an Injury Prevention

Program For Your Team● Points to Emphasize:Points to Emphasize:

• Overall conditioning: most injuries occur late in practice/game

• Program periodization: adjust intensities and volume to account for in-season playing

• Multi-Phase Jump Training: you must allow for large learning curve and strength development.

Overall Conditioning

● Cardiovascular and muscular endurance should be established early

● Flexibility training must be continually emphasized

Overall Conditioning...

● Metabolic training: Training should be specific for metabolic demands of sport (i.e. do volleyball players ever run a mile continuously during a game?).

Program Periodization

● Adjust training volume, intensity, and technique to allow for adequate recovery and adaptation

Multi-Phase Jump Training

● Training should allow for several distinct phases• Strength Development• Deceleration Technique Training• Performance-Oriented Training

Strength-Development Phase

● Include exercises for all body parts.● Volume should be relatively high

(reps: 8-12, sets: 3-6 transition to reps: 4-8, sets: 2-4)

● Abdominal “Core” training should be included during all phases.

● Include exercises which emphasize force absorption...

Parallel SquatParallel Squat

Romanian Dead-Lift Romanian Dead-Lift (RDL)(RDL)

Dumbbell LungesDumbbell Lunges

Glute-Ham RaiseGlute-Ham Raise

Step-upsStep-ups

Static & Dynamic Balance Training

Stork-StandsStork-Stands

Stability-Ball ProgressionStability-Ball Progression

Deceleration Technique

● Continue with previous exercises

● New exercises should emphasize decelerating through the HIPS & Torso and Change-of-Direction

Lateral LungeLateral Lunge

Step-DownStep-Down (emphasize (emphasize torso flexion through hips)torso flexion through hips)

Lateral Step-DownLateral Step-Down

Squat-JumpSquat-Jump

Jump To BoxJump To Box

Box-Drop & Box-Drop & HoldHold (freeze (freeze

@ 90°)@ 90°)

Performance-Oriented Training

● Add exercises that emphasize explosiveness through hips & knees

● Focus on “Rebounding” from landing position

● Gradually shift to high-level plyometrics and unilateral movements

Depth-Jump w/ reboundDepth-Jump w/ rebound

Lateral Box-HopsLateral Box-Hops

Zig-Zag Barrier-HopZig-Zag Barrier-Hop

Depth-Drop w/ Change of DirectionDepth-Drop w/ Change of Direction

Single-Leg Depth JumpSingle-Leg Depth Jump

helpful hints...

● Never use Never use concrete landing concrete landing surfacessurfaces

● Proper footwearProper footwear-no running shoes, boots, or sandals!

● Allow for Allow for recovery!!!recovery!!!

Remember...

● Always emphasize proper landing technique

● Allow for “learning-curve”

● “Teach” everyday!!!

Questions ?Questions ?

Thank You!