A Comprehensive

Rehabilitation Protocol for

Physical Therapists on

Return to Skiing after

Surgical ACL repair

Dana Hindman

Boston University Sargent College

Mentor: Jonathan Raymond, PT

Lecture Objectives• Review ACL anatomy and biomechanics• Educate about common ski injuries, epidemiology

and risk factors for ACL disruption• Understand skiing mechanics and musculoskeletal

requirements for proper ski form• Discuss surgical intervention techniques for skiers

with ACL disruption• Propose a safe and effective rehabilitation program

for skiers returning to sport after an ACL surgical repair

• Review appropriate outcome measures for use during the functional stage of rehabilitation

• Compare bracing techniques and their effectiveness during return to skiing

ACL anatomyO: Posteromedial aspect of lateral femoral condyle of femurI: anterolateral aspect of medial tibial spine• Consists of 2 fiber groups that

originate from separate “bundles”– Not as well-defined as

previously hypothesized1

• Primarily consists of type I collagen fibers to resist tensile forces1

• Multiple non-parallel fibers– allow for dissipation of forces

and adjustment of length in response to multi-directional loads2

A biomechanical review of the ACL• Works synergistically with other

structures to maintain equal balance of forces at the tibiofemoral joint2

• Primary restraint against anterior tibial translation3

– Provides >80% of between 30-90°of knee flexion

– Intact ACL allows for ATT 3-5mm

• Major constraint against tibiofemoral rotational movements and external valgus forces2

• ACL loading during activity3

– 169 N during walking– 445 N during stair descent – Skiing?!

Epidemiology of ski injuries • Prior to 1980’s, tibia and ankle fractures were the most

common ski injuries4

– Advancements of bindings/boot systems improved these by ~90%

• Knee injuries account for 33.4% of all injuries sustained during alpine skiing3

• 45-60% of all ski-related knee injuries involve the ACL– Combined MCL and ACL more common than ACL alone2

• 10% of all ski accidents involve the ACL4

– 2x higher incidence since 1970

In highly competitive skiers:4

• Primary ACL injury rate equal between men and women– higher recurrent ACL injury rate among women (41.5%)

• Prevalence of bilateral ACL rupture as high as 34%

Risk Factors: Non-modifiable• Previous knee injury

– 3.1x higher risk for ACL-reconstructed knees than ACL-intact knees5

• Female during the pre-ovulatory phase of menstrual cycle– 2.4-fold increase in ACL ruptures

during the follicular and ovulatory phases of menstruation6

• 3-fold elevation in relaxin

• Poor skiing conditions7,8

– End of the day– Extreme weather (wind, snow, ice,

limited visibility)– Hazardous terrain

• Moguls• Glades • Powder

Risk factors: Modifiable7

• Core deficits

– Absolute and relative flex: ext strength ratio > or < 1

– Decreased neuromuscular control of the trunk

– Poor hip abductor and extensor strength

• Hamstring: Quadriceps strength ratio deficits

• Side to side differences in strength, neuromuscular control, and proprioception

• Poor balance ability

Mechanisms of ACL injury• Phantom foot

– 70% of all ACL injuries during skiing3

– Occurs when skier catches

an edge during a turn or jump landing

– Components:8

• Trunk COM shifted posteriorly

• Hips below knees

• Uphill ski un-weighted

• Upper body facing downhill ski

– Results in extreme knee flexion

and tibial IR of downhill ski

Phantom foot

Mechanisms of ACL injury

• Boot-induced anterior drawer (BIAD)3

– Mainly occurs during a jump landing

– Quick quadriceps contraction with an extended knee when tails catch the snow

– Forces the back of the ski boot against the calf

Mechanisms of ACL Injury • Slip-catch9

Mechanisms of ACL injury• The dynamic snowplow9

Downhill skiing biomechanics• “Skier’s tuck” position

– Aerodynamic – Components:

• Shoulders lower than mid-back • Rounded spine • Full hip flexion• Knee flexion 86-114°9

• Elbows bent to 90°• Hands in front of face (above

knees)

• Posteriorly directed COM during jump landings was shown to have the highest correlation to ACL disruption12

– T-F joint compression and ATT due to extreme quadriceps contraction

Downhill skiing biomechanicsSlalom turning

Outside leg: accepts majority of the weight bearing forcesInside leg: achieves greater hip and knee angles; greater torque forces at the knee joint

Surgical considerations for the ACL-injured skier

• Surgeon-dependent decision – Allograft vs. autograft– Reconstruction site for autograft

• Most common autograft sites: bone-patellar tendon-bone and hamstring soft tissue graft

• No differences between bone-patellar-bone and hamstring graft10

– Laxity– Clinical outcome– Time to return to sport – Function (single hop test)

• New technique being investigated using quadriceps tendon11

– Easy to harvest– reduces donor site morbidity– Decreased A-P laxity in knee joint compared to BPTB @ 24 months– Success rate of graft similar to HS and BPTB techniques

Proposed Post-ACLrRehabilitation Protocol for Skiers

Goals for all stages: • protect the graft • prevent further ACL injury

Phase 1: Acute early rehabilitation Weeks 1-3

Phase 1: GOALS

1. Decrease pain/knee joint effusion

2. Increase knee joint mobility

3. Prevent incisional/scar tissue adhesions

4. Normalize gait pattern

5. Prevent deconditioning

Phase 1: PROGRAM

• Cardiovascular conditioning

• Soft tissue mobilization/scar tissue massage

• Joint mobilizations PRN

• Isometric quadriceps recruitment

– Via NMES

– EMG-based biofeedback

• Core strengthening exercises7

• Non-injured leg strengthening work

Minimum criteria for advancement from phase 1phase 212

1. Minimal joint effusion

2. Normal symmetrical gait pattern

3. Symmetrical functional quadriceps AND HAMSTRINGS recruitment

4. No episodes of giving way/apprehension with closed-kinetic-chain activities or ADLs

5. Knee PROM: symmetrical and functional extension; 90% of flexion of contralateral knee

Phase 2: Advanced phaseWeek 4-10

Phase 2: GOALS

1. Normalize lower extremity biomechanics

2. Restore muscular strength

3. Improve CV endurance

4. Optimize neuromuscular control, balance, proprioception

Phase 2: PROGRAM • General LE stretching program PRN • Cardiovascular exercises

– Treadmill w/ incline– Eccentric LE ergometry13,14

• no increased knee pain, effusion or stability differences between traditional and ECC groups

• Greater improvements in quad strength and hopping distance in ECC group

– Elliptical trainer

• LE weight shifting• Closed-kinetic-chain knee flexion

exercises12

– No >than 60° of TF flexion initially d/t ATT @ higher angles

– TRAIN FOR ENDURANCE

• Targeted hip and abdominal strengthening exercises (clams, bridging, bird-dog, etc…)

Skier tuck position on 2 half foam rollers

BOSU w/ lateral sport cord resistance

Hip and knee neuromuscular exercises in ski-specific positions

Minimum Criteria for Advancement from Phase 2Phase 312

1. Symmetrical double-limb squat held at 60°for 30s

2. Symmetrical single-limb squat to 30° without varus/valgus compensations

3. Full strength (5/5) of hip abductors, extensors and internal rotators in standard MMT positions

Phase 3: Sport-specific trainingMonths 2-4

Phase 3: GOALS12

1. Achieve quadriceps and hamstring strength values ≥85% of uninvolved leg

2. Improve neuromuscular stabilization at the knee joint

3. Improve CV fitness to pre-injury levels

4. Successfully complete a functional return-to-skiing test

Standardized outcome measures for ACL rehabilitation

• Combination of 4 hop tests more valid and reliable than a single test alone15

– Highly correlated to changes on GROC and LEFS

Vail Sport Test16

• Specific functional outcome measure for return-to-skiing

• Assesses a series of dynamic, multi-planar functional activities against sport cord resistance

• Measures a patient’s power, neuromuscular control, movement quality and muscular endurance

• Scoring based on judgment of clinician on form, time and pain levels

• Total composite score of 54 points– Higher=better

– Passing score is 46/54 (85%)

• Excellent psychometric properties– Intra-rater reliability 0.95-1

– Inter-rater reliability 0.97 (average of all components)

Vail Sport Test: Backward Jog

Phase 3: PROGRAM

• CV training with high resistance

• Targeted hamstring and quadriceps strengthening exercises for strength and power

– Eccentric hamstring curls with ankle weights/pulley system

– Sports cord WB exercises

• Double-limbsingle-limb plyometric ski-specific lower extremity exercises

– Slow eccentric phase w/ normal speed concentric phase

– Shuttle leg pressfull WB plyometrics progression

• Lateral agility training

Advanced sport-cord exercises

Single leg squat against sports cord resistance

Lateral bounding movement with sports cord perturbations in multiple directions

Forward and backward running movements against sports cord tension

Opposing the phantom foot

Lateral agility training options for skiers• Lateral box jumps (double limbsingle limb)

• Lateral box jumpovers

• Pro-fitter 3D machineTM

• PRO ski simulatorTM

Pro-Fitter

Ski simulator

Minimum Criteria for Advancement from Phase 3Phase 412

1) Examination and clearance by referring physician

2) Successful completion of the Vail Sport Test or other series of functional tests determined by trainer/PT

3) Communication with trainer/ski instructor and physician on recommendations for on-slope rehabilitation

Phase 4: Return-to-sport trainingMonths 4-6

Stage 4: Return to ski program12

To brace or not to brace: That is the controversy!

The jury is not out…

• Prospective cohort study (2006)17

demonstrated that using a CTi2 brace during skiing after ACLr demonstrated:

– Decreased laxity of the surgical graft

– Statistically significant lower injury rate (4%) compared to the the non-braced group (9%)

– All knee injuries requiring surgery @ 6 months were in the non-braced group

CTi2 brace

To brace or not to brace: That is the controversy!

BUT…• A 2014 study trialed 4

different braces on ACL-injured patients18

B1-soft knee sleeve w/ patellar reinforcement + 2 lateral stabilization metal barsB2-neoprene sleeve w/ metal lateral stabilizersB3-elastic brace w/ double-joint metallic bars, patellar reinforcement + fixation strapsB4-rigid knee brace w/ all B3 components

B1

B2

B3

B4

To brace or not to brace: That is the controversy!

• Results showed:18

– B2 improved stability index in A-P direction compared to other brace options

– B3 worsened stability index in A-P direction than without any knee support

– No significant difference for braced group in medio-lateral stability or sensorimotor function compared to non-braced group

SO WHAT DO WE DO??• Educate the patient about the bracing research despite its

conflicting evidence • Recommend that the patient discuss with their

surgeon/orthopedist whether or not bracing is right for them

Equipment considerations for the ACL injured skier

• Current bindings have pivot point at the center of the heel radius

• Best setup based on biomechanical analysis20

– 2 binding release mechanisms anteriorly and posteriorly

– fast release characteristic

• KneeBinding unitTM

– Pure lateral heel release mechanism

– Flat binding with width of the boot

– Provides some flex for shock absorption during jump landings and extreme carving

Other components of patient education21

• Common mechanisms of injury

• Appropriate fall technique– “if you feel like you are going to fall, fall”

– When in doubt, shift your mass forward

• How to reduce individual risk based on modifiable and non-modifiable factors– Avoid skiing in poor weather and slope conditions as possible

– Do not ski beyond fatigue

– Get ski tune-up and binding setting checks often (at least 1x/yr)

– Do routine testing of binding release every single time you hit the slope

– Ski under control—if you’re skiing too fast for YOUR level, SLOW DOWN!

• Resources for equipment and further on-slope training

Limitations of research

• Majority of the body of literature on skiing and injuries is from before 2000

• Only 6 studies that address rehabilitation specific to returning to skiing

• Insurance limitations on length of rehabilitation course for these patients

• Equipment needed for return-to-skiing rehabilitation expensive and not readily available for use in most outpatient, non-specialized clinics

Questions?

Feel free to email me at dhindman@bu.edu with any follow

up questions/concerns regarding this topic. Happy to find you the answer if

I don’t have it immediately!

Thank You!(and thanks Jon, you’re the best

mentor EVER!)

Eat all the brownies…PLEASE!

References1. Siegel L, Vandenakker-albanese C, Siegel D. Anterior cruciate ligament injuries: anatomy,

physiology, biomechanics, and management. Clin J Sport Med. 2012;22(4):349-55.2. Pressman A, Johnson DH. A review of ski injuries resulting in combined injury to the anterior

cruciate ligament and medial collateral ligaments. Arthroscopy. 2003;19(2):194-202.3. Dargel J, Gotter M, Mader K, Pennig D, Koebke J, Schmidt-wiethoff R. Biomechanics of the

anterior cruciate ligament and implications for surgical reconstruction. Strategies Trauma Limb Reconstr. 2007;2(1):1-12.

4. Pujol N, Blanchi MP, Chambat P. The incidence of anterior cruciate ligament injuries among competitive Alpine skiers: a 25-year investigation. Am J Sports Med. 2007;35(7):1070-4.

5. Oates KM, Van Eenenaam DP, Briggs K, Homa K, Sterett WI. Comparative injury rates of uninjured, anterior cruciate ligament-deficient, and reconstructed knees in a skiing population. Am J Sports Med. 1999; 27(5): 606-10.

6. Lefevre N, Bohu Y, Klouche S, Lecocq J, Herman S. Anterior cruciate ligament tear during the menstrual cycle in female recreational skiers. Orthop Traumatol Surg Res. 2013;99(5):571-5.

7. Raschner C, Platzer HP, Patterson C, Werner I, Huber R, Hildebrandt C. The relationship between ACL injuries and physical fitness in young competitive ski racers: a 10-year longitudinal study. Br J Sports Med. 2012;46(15):1065-71.

8. 14. Langram M. Specific risk groups. Stay Safe on Snow. Available at: http://www.ski-injury.com/specific-risk-groups.

9. Bere T, Flørenes TW, Krosshaug T, et al. Mechanisms of anterior cruciate ligament injury in World Cup alpine skiing: a systematic video analysis of 20 cases. Am J Sports Med. 2011;39(7):1421-9.

10. Samuelsson K, Andersson D, Karlsson J. Treatment of anterior cruciate ligament injuries with special reference to graft type and surgical technique: an assessment of randomized controlled trials. Arthroscopy. 2009;25(10):1139-74.

References Continued11. Geib TM, Shelton WR, Phelps RA, Clark L. Anterior cruciate ligament reconstruction using quadriceps tendon autograft: intermediate-term outcome. Arthroscopy. 2009;25(12):1408-14.12. Kokmeyer D, Wahoff M, Mymern M. Suggestions from the field for return-to-sport rehabilitation following anterior cruciate ligament reconstruction: alpine skiing. J Orthop Sports Phys Ther. 2012;42(4):313-25.13. Gross M, Lüthy F, Kroell J, Müller E, Hoppeler H, Vogt M. Effects of eccentric cycle ergometry in alpine skiers. Int J Sports Med. 2010;31(8):572-6.14. Gerber JP, Marcus RL, Dibble LE, Greis PE, Burks RT, Lastayo PC. Safety, feasibility, and efficacy of negative work exercise via eccentric muscle activity following anterior cruciate ligament reconstruction. J Orthop Sports Phys Ther. 2007;37(1):10-8.15. Reid A, Birmingham TB, Stratford PW, Alcock GK, Giffin JR. Hop testing provides a reliable and valid outcome measure during rehabilitation after anterior cruciate ligament reconstruction. Phys Ther. 2007;87(3):337-49.16. Garrison JC, Shanley E, Thigpen C, Geary R, Osler M, Delgiorno J. The reliability of the vail sport test™ as a measure of physical performance following anterior cruciate ligament reconstruction. Int J Sports PhysTher. 2012;7(1):20-30.17. Briggs KK, Farley T, Steadman JR. Effect of functional bracing on knee injury in skiers with anterior cruciate ligament reconstruction: a prospective cohort study. Am J Sports Med. 2006;34(10):1581-5. 18. Bottoni G, Kofler P, Hasler M, Giger A, Nachbauer W. Effect of knee braces on balance ability wearing ski boots (a pilot study). The Engineering of Sport. 2014; 72: 327-331.19. Heinrich D, Van den bogert AJ, Nachbauer W. Relationship between jump landing kinematics and peak ACL force during a jump in downhill skiing: a simulation study. Scand J Med Sci Sports. 2014;24(3):e180-7.20. St-onge N, Chevalier Y, Hagemeister N, Van de putte M, De guise J. Effect of ski binding parameters on

knee biomechanics: a three-dimensional computational study. Med Sci Sports Exerc. 2004;36(7):1218-25.

21. Hunter RE. Skiing injuries. Am J Sports Med. 1999;27(3):381-9.