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Peak Performance Physical Therapy & Sports Training EVIDENCE-BASED PRACTICE UPDATE (December, 2022) What Constitutes “Passing” When ACLR Return to Play Tests Disagree? by William Slapar, PT, DPT, OCS, CMTPT, CAFS Clinical Scenario...What would you do? A 21 yr old female competitive college soccer player underwent ACLR 7.5 mo ago and has progressed through jog-walk - - - > running- - - >sprinting work and agility progressions. She is presently at an estimated 90% intensity with her functional training. The patient was performing rehab at a facility near her home over the summer and has returned late August to college locally to continue rehab and resume soccer. Updated ReEvaluation testing locally showed the following: Isometric Quads at 600 angle 90% and at 300 was 65% Anterior Stepdown (toes off + posterior lean) @ 6” with front racked 20# DB’s was 65% with mild asymmetric dynamic valgus tendency SLB 6” cones rotational no touches test 70% with asymmetric overpronation tendency > dynamic valgus and delayed resupination action 900 rotational timed hop testing was 75% with mild asymmetric overpronation and dynamic valgus tendency but no frank instability sx reported 3x Ant crossover hop 85% with visible asymm opp leg swing and poorer 3rd hop landing (~ 300 stiff legged vs healthy limb ~ 500 knee flexion dampening) Her PT from home indicated she’d be starting practices at 50% effort and volume and expect to transition to full 100% intensity within 2-3 weeks. At your FU visit the Lachmans’ and Pivot Shift are (-), she has very mild inferior pole tenderness and only a trace effusion. She is eager to resume and confirms a subjective 90% function rating. After reviewing the above local PT ReEval findings you recommend: The knee is doing great and she should proceed with her home PT’s recommendations for a progressive 50% - - - >100% intensity college soccer practices return. Ortho FU 4 wks. The knee is steadily advancing - - keep doing intensive rehab focusing on Quad and Hamstring strength and retest in 3 wks just prior to next ortho FU to reassess RTP potential The knee is improving nicely - - - more strength/power and dynamic control needed before safe to resume soccer play beyond (I) ball drills. Continue functional rehab progression including dynamic valgus control PRE and reactive stability training, retest and FU ortho visit in 3-4 wks. The knee is doing great and she should continue PT work and then proceed with her home PT’s recommendations in 2 wks for a progressive 50% - - - >100% intensity college soccer practices return. Ortho FU in 6 wks. CURRENT EVIDENCE Thompson X.D, Bruce A.S, et al. Disagreement in Pass Rates Between Strength and Performance Tests in Patients Recovering From Anterior Cruciate Ligament Reconstruction, The Journal of Sports Medicine, 2022;50(8):2111-2118 SUMMARY: Many physicians, surgeons, physical therapists, athletic trainers and even personal trainers deal with patients with an ACL injury. A critical discussion between all has been passing rates on tests related to return to play (RTP) criteria for athletes after ACLR. In this article, Thompson et al did a cross sectional study on ACLR subjects that are 5-12 months post-surgical. They utilized a commonly suggested/referenced limb symmetric index (LSI) of 90% for the battery of return to play test and isokinetic testing as return to play criteria. They compared outcomes with quadriceps isokinetic testing vs single leg (SL) maximum distance single hop and triple hop. The authors hypothesized pass rates would be non-uniformly distributed comparing gender, activity levels, and that more would pass hop than strength testing. The authors found 36.5% disagreement between non-weightbearing isokinetic 900/sec quad strength (peak torque) and SL hop test LSI pass rates. For those passing hopping but failing isokinetic testing, a greater portion included patients with higher pre-injury activity ratings, approximately 7 months post-op having more difficulty passing strength tests than hop tests, which they had hypothesized correctly. The key issue then becomes determining why we have so many not passing the strength pass rates and how dynamic hop testing is being passed when the quadriceps, a key power production muscle for the concentric and eccentric demands of hopping, remains significantly weak as defined by isokinetic measures. A potential source of error when using limb symmetry postoperatively as the key indicator of recovery is the integrity of the non-operative limb, which we now know from studies, does underperform most often compared to pre-surgical status. That risks falsely elevating limb symmetry scores for the post-operative side, in this case, the ACLR knee, and giving passing grades prematurely, thereby exposing patients to potentially greater re-injury risk. Making pre-op measurements either (i.e. pre-season test battery) prior to injury or prior to surgery (which would likely exclude a significant portion of patients whose injured knee may not allow safe hop test performance of the uninjured limb) would improve accuracy of subsequent RTP tests use LSI of 90% as the criteria for passing. While isokinetic strength testing is very good at isolating concentric knee extensor muscle force production and is considered very reliable as a measurement property, it does lack great authenticity of the WB demands the knee and quads must deal with performing at-risk activities of hopping, cutting, jumping, agility etc. While a SL hop has the advantages of measuring a much more global and authentic movement demand associated with sport, its weakness is that no single muscle group deficit can be identified with such testing. Multi-joint tests like these must have some constraints in order to minimize obvious or excessive compensatory actions. For example, in this study, while isokinetic testing operationally controlled for excessive UE involvement by crossing arms the hop test description did not contain any clear language indicating control over arm swing or opposite limb swing, leaving substantial potential for the expected poorer ACLR knee/limb to perform acceptably due not to excellent capacity of the quads/knee necessarily but due to asymmetric arm and/or opposite leg swing during testing. It is critical that physical therapists/athletic trainers be hypervigilant during all types of testing, but especially during final rehab stage RTP testing as false (+) passing on LSI scoring can lead to patients resuming higher risk activities. Physicians likewise have a key role in discerning the types and accuracy of RTP testing being utilized as they discern progressive activity allowances. While quad strength and sagittal plane/vertical force based hop testing is a key and valuable measure we believe it is critical that frontal and transverse plane capacities must also be scrutinized as these are known contributors to the mechanism of injury, yet too often are ignored with clinical RTP testing. A crossover triple hop can begin to identify some of this frontal/transverse plane control required however we advocate intentional plane dominant side-side and also rotary timed hop testing as well. (We’d love to hear your professional insights on this topic. Let me know your thoughts after reading this summary at PT@PeakPTRochester.com or if you have a patient case you'd like to discuss) Background: ACL re-injury rates at 29.5% (30.4% ipsilateral and 69.6% contralateral knee) after returning to physical activity. Clinicians, whether surgeons or PT’s/ATC’s, have difficulty in determining the correct test criteria to follow on functional performance and strength tests especially when there is disagreement in scoring. Purpose: The purpose of this study is to show a comparison of the pass rates between strength (isokinetic peak torque) and SL hop and triple hop tests comparing results among men and women as well as to compare lower versus higher preinjury activity levels (Tegner). Authors hypothesized that the pass rates would be non-uniformly distributed among gender, and activity levels, and that more subjects would pass hop tests over strength tests. Methods: Testing completed by a total of 299 participants (146 Men; 153 women) at a mean of 6.8 +/-1.4 months on unilateral/uncomplicated ALCR. Isokinetic testing at 900/s and 1800/s was used for quadriceps strength, while single leg (SL) hop and triple hop test was measured in cm for jump distance. The measurements were evaluated and compared via the Limb symmetry index (LSI), passing defined as 90% . Findings: Pass rates were found to be non-uniformly distributed between the SL HOP test and 900/sec isokinetic test (p<.001). Of the 299 subjects, 36.5% (102/299) failed the strength test while passing the SL HOP test, and also reported that there was no difference between men and women with pass rates. A higher portion of those passing hop testing but failing strength testing reported higher preinjury Tegner activity levels. Author's Conclusion: Patients with ACLR who had higher activity levels prior to surgery were more likely to pass hop testing despite failing strength testing, likely through movement compensations to achieve jump symmetry despite the presence of weak quadriceps. THE PEAK PERFORMANCE PERSPECTIVE ACL reconstruction remains a “hot topic” across multiple medical field journals, whether it is through biomechanics, surgery/orthopedics, or sports medicine. Surgeons and rehab professionals are tasked with deciding when a patient recovering from ACLR is ready to begin jogging progressions and agility/jumping work and eventually when return to play (RTP) to actual athletics/recreational activities can safely begin. Since re-injury rates are considered unacceptably high it is imperative that high quality testing be used as a basis for these key decisions. Paterno M. et al 2014, showed re-injury rates near 30% overall, with 30% being to the ipsilateral knee and nearly 70% to the contralateral knee on a 24 month follow-up study of ACLR. It’s initially surprising to many that a 70% contralateral knee injury rate could exist on the knee that did not have disuse atrophy or painful inhibition of the quadriceps muscle. Might this implicate underlying contralateral limb biomechanical risk factors, poor technique tendencies, or post-operative deconditioning effects on the “normal” leg…or might it suggest an abnormal reliance on the “healthy/normal” leg due to incomplete rehab and/or premature return to sports placing excess demands on the post-operative side? Statistics like these are the cause for both surgeons and PT’s/ATC’s to take notice and explore deeper understanding of contributing factors so we each can be more effective in our responsibilities working to optimize outcomes and reduce re-injury. Functional performance and strength tests are used as a guide to both measure progress of rehabilitation and for RTP criteria. Not only which tests to use but what criteria to base the ‘passing score’ on varies highly and is in disagreement between clinicians. Common tests include isolated (typically quads, NWB isokinetic) muscle strength, SL hop or triple hop along with crossover triple hop, vertical jumping, and/or agility tasks. Side-side comparison, typically with a “passing score” as 90% is used for the limb symmetry index (LSI). As a surgeon or orthopedist, when do you know that your patient has met RTP criteria? Do you have specific criteria you adhere to? Are you strict in using those passing grades as requirements or how often do other factors play a role in approving RTP despite the patient not yet passing RTP testing? How confident are we, as both surgeons/orthopedists and rehab professionals, that the tests used are highly likely to be effective tools in reducing re-injury rate? Unfortunately, the current literature suggests we’re not tremendously effective on a consistent basis. For return to sport or work it would be ideal if we had and used specific details about expected demands, chose specific tests based on those functional requirements, and had agreed criteria passing grades rather than a singular “RTP battery” used as a standard for all. Because no one job or sport is the same, they are all unique and require different skills. Thompson et al show there is difficulty in patients reaching this “passing score” on isokinetic strength testing in the knee extensors. Quadriceps strength is necessary for all knee surgeries and for ACLR’s we all can agree is a must. Studies have shown it is one of the top factors relating to satisfaction after surgery and level of activity performed. Returning to running and sport a person must be able control impact on a single leg repetitively in succession and for cutting/agility movements certainly larger sudden, unexpected larger impact loads. These are without a doubt where we can start when looking at RTP. In this study Thompson et al showed that SL HOP and quad strength pass rates do not line up uniformly at an average 7 month mark of rehabilitation. SL HOP metric was passed more than isokinetic quad strength tests using the 90% LSI criteria. Even though that is what they should have done for the past 7 months is work on quad strength. But we have to look at how the quadriceps was tested in strength and how it was actually strengthened. In the study they used an isokinetic machine in which the patient was performing a kicking motion at 180 and 900/s. While this is a very reliable measure it does have some controversy or debate associated with it based on the “authenticity” criteria - real life demands of the quads in work, recreation, and sport most often involve gravity based body weight demands through squat motions and injury most often occurs during deceleration phases. It is critical to remember these often involve combined planes of motion into the frontal and/or transverse plane as well, and not simply just sagittal plane performance. Isokinetics would be most authentic for things like kicking a ball where distal limb loading occurs, however, even then those loads are minimal and rapid contractile forces produce acceleration prior to any external load where force is generated. Isokinetic devices show acceleration (and some also eccentric deceleration measures as well) limited to the sagittal plane only. Great care in how to facilitate the quadriceps must be performed early in rehab to diminish likelihood of compensations by the short toe and ankle flexors or the hip extensors for motions or squatting, lunging, and stair negotiation. This is performed by understanding the biomechanics, carefully watching form, use of surface EMG biofeedback, and knowing how to target the quadriceps through functional movements. Too often what are thought to be “closed chain” or “functional” training methods become facilitators of abnormal neurologic habituation/compensation patterns. Anterior step downs with the distal foot off the box, and other similar quad dominating techniques, are key in stimulating the weak quads during ACLR rehab and testing. This provides the opportunity to more authentically stimulate and measure quad performance in WB environments while minimizing compensatory muscle activation that clouds the validity of test results. We often see patients perform NWB isometric knee extension testing well only to grossly underperform on WB testing. Therefore we never rely mainly on nwb test findings. While this study did not look at frontal and transverse planes, which together contribute to the dynamic valgus mechanism of the injury, this must be a key focus of rehab. Careful considerations of dorsiflexion loss, hip weakness of the abductors and ERs, overpronation foot mechanics, and femoral anteversion make rehab very multifactorial. Specifically testing for and addressing these dynamic valgus factors, rather than oversimplifying strengthening of the quadriceps and hips in general is a key aspect to high level functional rehabilitation. One of the key issues with the Thompson et al study here is the lack of clear control over arm swing and opposite leg swing during hop testing. While arms contribution during isokinetic testing was controlled they do not address arm/leg swing as confounding factors during hop testing. This leaves room for the “apparent” success (i.e. passing) of SL hop and triple hop findings to not have been due to excellent quad/knee performance but potentially due to momentums generated from elsewhere. We believe strongly in hop testing and find it very useful in discerning when the patient is ready for the next step. Using the SL Hop shows the sagittal plane well but there must be more standardization of this test to really show that the LEs are what are providing the power and distance rather than other influencers, upper extremities or the contralateral extremities. We need to avoid allowing a false (+) passing test which could actually put someone on the field with an actual increased risk. Thompson et al. did state that here were compensatory movement patterns used to pass the hop tests but was not clear on what. The fact that higher Tegner activity patients pre-op were most often the ones who passed hop testing but failed isokinetics may speak to proprioceptive/neurologic aptitude and their ability to compensate with high performing remaining “triple extension” hip and ankle power sources. This likely needs more study but we find a “cleaner” testing method of hands remaining on hips simply removes arm swing as a variable, thereby isolating true LE power more clearly. Cueing and observation to ensure hop performance is due to actual hop efforts and not contralateral leg swing is key. Quality assessment of final landing is critical as well - focusing on willingness of the knee to tolerate dampening forces into knee flexion vs weaker patients using a “peg leg” style landing. Of course frontal and transverse plane control must also be visualized and considered. Finally, opposite limb training must be included in formal rehab and home programming in order to avoid false (+) pass rates due to underperformance of the healthy limb occurring over time based on deconditioning effects. This also may have played some role in the Thompson et al results but is not clear how it differently may have affected isokinetic vs hop outcomes. The battery of tests must consider the sport/activity that the individual wants to return to but more importantly any known MOI that occurred, and its biomechanical contributors. While the single hop and triple hop sagittal plane tests are useful some other examples are lateral SL hop, vertical hop, triple cross-over hop, rotational hops, SL squatting ability under load, Anterior step down test with toes off…etc. These tests are biomechanically and proprioceptively more consistent with the functional demands and MOI prevention considerations of most patients. THE PEAK PERFORMANCE EXPERIENCE Justin said: “I never knew how much went into an ACL rehab. I definitely have more confidence in my knee now than I did prior to surgery with squatting and lunging. I never liked lunges because my knee hurt.” History: Justin is a ski instructor and trainer for the youth US ski team. During a ski session he fell and his ski did not come off. He felt a “pop” in his knee during his fall. He came to Peak for pre-hab and then post-op for his ACLR with partial lateral meniscectomy. Objective: (*=pain) 6 mo ReEval 7 mo ReEval Isometric 600 Quad 74% 89% 6” cone 600 pron - 600 sup rotational no touches 20sec 48% 62% SL squats 15sec 78%, fatigue shows consistent DKV @ last 5 sec 89%, inconsistent DKV happening rarely 3x Crossover Ant Hops 9’11” w/ reduced knee flexion and more hip flexion, contr leg swing, min DKV 10’2” w/ improved knee flexion (but still reduced), less contraleg swing, min DKV 900 Rotational Hops 10sec (30 unit radius) 4x (67%) (50 unit radius) 8x (80%) WB Quads Anterior (toes off) Stepdown 6” 10# DB’s 12x (75%) 15# DB’s 15x (75%) Key Findings: ALCR in which there was a lateral meniscectomy. Pt is in the intermediate phase of treatment showing weakness still in the quadriceps functionally and isometrically. Pt has inconsistent anterior pelvic tilting during such as well. The hopping test shows hip flexion compensation during lands of hops with minimal dynamic knee valgus. During rotational hops there was less speed from time of impact to lift but very minimal to no dynamic knee valgus during both trials. Treatment: In this intermediate phase dynamic frontal and transverse planes were worked on to really minimize the dynamic valgus and enhance the stability of the lower extremity. Squatting on incline board was done to mimic transfer of forces at angles with dumbbell hang position for skiing efforts. Unstable surface SL squatting was performed to improve overall stability of force absorption with a noncompliant surface. Toes off anterior step downs were still used with a posterior lean for quadriceps strengthening through function with a cross reach to minimize DKV while overloading the muscles. Speed training to improve fast twitch fiber reaction on unstable and slated surfaces for proper ground reaction to sport. Justin required fast small impact drills to mimic the oscillatory action of skiing downhill. The Vibeplate also helped with Single legged balance training for the nervous system at high levels for return to fast oscillatory motions as well. Outcome: Pt is still working through physical therapy to start skiing soon with small slopes. Pt shows great determination to get back to it with consistent work on HEP and shows changes weekly. You can trust the Physical Therapists at PEAK PERFORMANCE to do a thorough evaluation, to search for related but underlying contributing factors to kinetic chain dysfunction, and to design exercise progressions that both respect tissue healing and creatively use biomechanics principles to prevent symptoms and optimize carryover to your patients' functional goals. Call us at 218-0240 to discuss your patient's specific needs. Peak Performance is just minutes away from your patients in Penfield, Fairport, Pittsford, Brighton, Rochester, and, of course, East Rochester. We promise Individualized, hands-on and biomechanically appropriate Physical Therapy for your patients. No "one-size-fits-all" approaches. We WILL go the extra mile and "dig deeper" to discover underlying causes for injury risk and delayed recovery using the most advanced Evidence Based methods available and, we’re able to make unique adjustments to exercise prescriptions to speed the return to function and to minimize or prevent symptoms from interfering. No surprises. No hassles. Confident your patient is in the right place. COME VISIT US AT 161 E Commercial St Just 1 mile off 490 exit (585) 218-0240 www.PeakPTRochester.com