Chan Hon Yan 99060146D Chan Man Leung Sunny 99946540D Choi Chor Kei Leo Fung Mo Ching Ivy 99199765D 99023277D

Topic 2

Mary, a 21 years old University student, belongs to Hong Kong Basketball Team.

She twisted her (L) knee while landing from a rebound during competition 3 months ago.

Her doctor informed her that she had suffered from a grade II ACL injury, and recommended Mary to have intensive rehabilitation with special emphasis on functional training.

Outline of Presentation Gender Sports Skill Pathology Psychology Rehabilitation Program Return to Sports

Introduction

In a 5 year study, knee injuries accounted for 15% of total basketball injuries in National Collegiate Athletic Association (NCAA).

Almost 20% of the knee structure injuries are ACL injury.

The ACL injury rate in women was 4.1 times greater in basketball. (Arendt & Dick, 1995)

Injury mechanism

Non-contact

 planting & cutting  straight-knee landing  one-step landing with the knee hyperextended  pivoting & sudden deceleration

Effects on Structures after ACL injury

Static stabilizer  Medial menisci --- increase cross sectional area and volume, thickening at its attachment  Posterior capsule --- thickening (Jackson et al., 1999)  Decrease Bone Mineral Density (BMD) in the periarticular cancellous bone of femur and tibia (Boyd et al., 2000).

Effects on Structures after ACL injury

Dynamic stabilizer  Hamstrings  Quad  Gastrocnemius Increase demand

Non-copers vs Copers

Non-copers  had instability with activities of daily living .  They stiffened their knees by landing in less flexion and accepting weight with less flexion in both walking and jogging.   May lead to excessive joint contact forces which have potential to damage articular structure. (Rudloph et al., 1998) cannot return to previous performance

Non-copers vs Copers

Copers  return to all pre-injury activity without limitation.

 Copers demonstrated increased hamstrings EMG, may be a compensation mechanism.

(Tibone & Antich, 1993 and Boerboom et al., 2001)  It has been suggested that Quadriceps and Gastrocnemius are also important for compensatory dynamic knee stabilization . (Nyland et al., 1997 and Kivist & Gillquist, 2001)

Why are women more susceptible?

Intrinsic factors (Huston LJ. et al, 2000)  Q-angle  femoral notch irreversible  joint laxity  hormonal influence - need more research to prove

Why are women more susceptible?

Extrinsic factors  Proprioception  muscle strength  neuromuscular control  knee stiffness

Risk Factors

Proprioception (Rozzi SL. et al, 1999)  Female took longer than male to detect joint motion moving in the direction of knee joint extension  May be less sensitive to potentially damaging force Increase risk for ligament injury

Risk Factors

Muscle strength (Huston LJ. & Wojtys EM. 1996)  Female athletes has weaker knee extension & flexion strength than male

Risk Factors

Neuromuscular control    Muscle recruitment pattern response to anterior tibial translation (Huston LJ. & Wojtys EM. 1996) Female athlete – quad-dominant Male athlete, men and female control subjects – hamstrings-dominant quad-dominate pattern: more strain on the ACL than cocontraction or contract the hamstrings first

Risk Factors

Knee stiffness  Important component to knee stability and injury prevention  Mm increase the joint contact force & decrease tibiofemoral displacement, dissipating potentially dangerous loads, lowering the force carried by the ACL and other passive structure

Risk Factors

Knee stiffness  Valgus & Varus stiffness (Brant JT. & Cooke TD.,1988)  knees in female rotate 66% more than males & 35% less stiff  Ability to voluntarily stiffen the knee (Wojtys EM et al, 1999)  Men: 4 times  Women: 2 times

Basic Skill in basketball

Running Cutting Pivoting Rebounding Shooting (adapted from R J Emerson 1993)

Running

Change of speed and direction  To get away from opponents  To guard the route of offending opponent require slide-steps, backward steps Sudden deceleration & stopping prior to change of direction  knee almost fully extended + twisted

Cutting

Use of technique such as fake, stops and pivot to get away from opponent Cutting method  Side-step Cut  Cross-over Cut Require sudden change of  Speed  Direction

Pivoting

Use of technique getting away from opponent by moving body and step one or more steps on one foot while keeping the other stationary  Produce tibia torsion to knee

Points to consider in return to sport

Position Habits in performing skills

Position

Center  Perform much pivoting under net for scoring  Require more strength in jumping  Many collision and body contact under net Need more proprioceptive training for balance during landing May consider any uses of brace to prevent re-injury

Position

Wing & Guard  Perform many high speed cutting and shooting with 2-steps stop  Perform much dribbling  Abilities required:  High power in initiating movement  High agility with sudden change of cutting direction or pace need to  stabilization of knee & agility

Habit in Skills

Kirkendall DT et al (2000) Cutting maneuver with less knee & hip flexion with knee valgus  Higher injury rate of ACL training to perform cutting with knee  flexion  ACL injury reduced by 89%

Psychological Support

Explain to player  nature and severity of the injury  prognosis for recovery  recommended courses of therapy  estimate time frame of rehabilitation Reassurance and support Peer support

Visual-Motor Behaviour Rehearsal (VMBR)

Rehearse an entire performance  e.g. Landing with proper foot placement Review and correct a specific performance  e.g. Remind herself the wrong habit in sport Practice approaching the crowd or competition with confidence

Goals of rehabilitation

Gender aspect:  To minimize possible risk factors for recurrence of ACL injury in female basketball player Sports aspect:  To restore physical capacity in competing in basketball games Psychological aspect:  To overcome fear associated with the injury movement

Functional Training

Perturbation training Plyometric training Agility training Sport-specific training

Perturbation Training

Techniques involving perturbation of support surfaces  roller board  tilt board  roller board & stationary platform Induce compensatory muscle activity

Advantages of Perturbation Training

Fitzgerald et al., 2000 : Enhance the probability of successful return to high-level physical activity  perturbation group with greater long-term success Improve knee stability  reduce the risk of continued episodes of giving way of knee during athletic participation

Plyometric Training

Neuromuscular training Develop power, strength & coordination involve a prestretching of muscle  induce the stretch-shortening cycles

Plyometric Training

Goal:  Decrease reaction time between eccentric lengthening of mm and concentric mm contraction  Increase power

Advantages of Plyometric training

Hewett et al, 1996 &1999: Decrease landing forces Increase vertical jump height Improve knee stabilization  Improve hamstring-to-quadriceps strength ratio  Decrease incidence of knee injury in female athletes

Examples of Plyometric Training

Hewett et al, 1996 &1999: Cone jump Jump, jump, jump, vertical

Agility Training

Allow pt to adapt to:  quick changes in direction  quick starting and stopping  cutting & pivoting  improve proprioception Agility training significantly improves mm reaction time in response to anterior tibial translation (Wojtys et al, 1996)

Figure-of-eight Drills

gradual change of direction allow adaptation to cutting activity  Longer distances  shorter distances (smaller surface area  tighter “ 8 ” )  backward “ 8 ”

Cutting Maneuver Drills

Sidestep cut Crossover cut   half-speed  45 o  60 o  full-speed 90 o cutting  Carioca

Shuttle Run

Involve straight plane running, acceleration, deceleration, cutting & pivoting

Others

• SEMO drill • incorporate forward, backward, diagonal acceleration and lateral movt Start

Sport Specific Training

Start when full speed agility training was achieved sport specific tasks are added during the agility training For basketball player:  Dribbling skills  Ball catching  Ball passing

Sport Specific Training

Started w/o being opposed Progressed to one-on-one opposition Progressed to real competition

Question & Answer Session

References

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16(2):113-22, 1988. Boden BP. Dean GS. Feagin JA Jr. Garrett WE Jr. Mechanisms of anterior cruciate ligament injury.

Orthopedics

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Physical Therapy

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