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Peak Performance Physical Therapy & Sports Training EVIDENCE-BASED PRACTICE UPDATE April 2022 Key Mistakes in ACLR Return to Sports Decision Making: Can We Trust Hop Testing Data? by Mike Napierala, PT, SCS, CSCS, FAFS Clinical Scenario...What would you do? A 27 yr old male semi-pro developmental league football wide receiver sustained a non-contact deceleration injury during a cutting move and has an MRI confirmed isolated ACL tear. He underwent autologous patellar tendon ACL reconstruction and has been participating in BIW - - > weekly post-operative physical therapy. He has progressed very well and is presently at the 12+ month mark. Subjectively he is painfree. On clinical exam he has (-) Lachmans and Pivot Shift test findings. Your quick MMT of quads and hamstrings sitting on table are very good and painfree. He is eager and confident in his readiness to resume football practices. He reports performing progressive agility and plyometric drills at PT. His PT Re-Evaluation report did not yet make it through for review. He wants your approval to resume non-contact practices including route running and change of direction drills w defender, blocking drills…progressing to full contact scrimmaging and play over the next 4 weeks. My clinical thinking is: He needs to wait until at least the 9 month mark to reduce risks of contralateral knee ACL injury. He is doing well. He may return gradually now and progress his participation based on his comfort level and coaching feedback on movement quality. Perform in-office single leg squats, vertical and rotary hop testing observation and then decide. Call PT to discuss Re-Eval findings while Pt is in office or wait to obtain test findings before final decision. Counsel patient on risk management and call back with orders once testing reviewed. CURRENT EVIDENCE Kotsifaki A, et al. Symmetry in Triple Hop Distance Hides Asymmetries in Knee Function After ACL Reconstruction in Athletes at Return to Sports. Am J Sports Med, 50:2, 2022, 441-450. https://journals.sagepub.com/doi/pdf/10.1177/03635465211063192 SUMMARY: ACLR recovery risks becoming a “routine” for both surgeons, therapists, and patients alike. As a surgeon/physician how do you really know an athlete is ready and safe to return to sports (RTS)? Are you certain they’ve prepared properly and thoroughly in their rehab? Key decision making centers around the quality of rehabilitation especially in the intermediate phase leading up to return to function progressions and eventual testing used to determine return to play. Recent data on recovery from ACLR regarding return to prior sports participation is disappointing. Some evidence suggests that only 65% return to prior levels of sports participation and risks of a second ACL injury have been reported up to 29% (Australian football/rugby showing rates of even 40%). . Limb symmetry index (LSI) is often used for RTS testing of strength and hop performance among others. Consensus is, however, lacking regarding the “best practices” on specific tests and scoring to optimize successful return and reduce future injury risk to the ipsilateral or contralateral knee. Some data suggests that LSI values alone do not accurately reflect the function and biomechanical performance properties of the ACLR knee and limb. Kosifaki et al performed 3D motion analysis during a triple anterior hop test comparing 23 healthy male controls with 24 post-op ACLR male athletes who were cleared for RTS(ages 18-35, Tegner > 7). Among inclusion criteria were quads LSI > 90% and hop battery tests LSI > 90%. They used 42 reflective markers with a 14-camera system and force plate, requiring hands remain on hips and a 2 second hold upon final landing. The ACLR group had 97.1% LSI . The ACLR group showed the involved limb landed with greater hip flexion, trunk flexion, anterior tilt and peak knee flexion angle was less as well as less knee flexion moments. ACLR involved limbs also showed knee work absorption LSI of 80% with second rebound and final landing but only 51% and 66% for work generation LSI during first and second rebound take offs. Hip work was higher and ankle work lower for the involved ACLR group. In controls and uninvolved limbs alike the knee plays a greater role during the abslorption or typical “injury” phase than in the propulsion phase thought to create the distance of the hop test findings. It is imperative that surgeons and therapists be critical about not only the RTS phase of recovery but the intermediate phase preceding that. This phase oftentimes is considered “routine” and merely a “putting in the work” mindset by both clinicians and patients. But it is this foundational strength and power development phase that can set up the knee-quads and lower extremity for success or for compensation based “false success” noted in mere LSI based testing. Traditional PT rehab exercises involving triple extension, while being functional, also risk setting up the ACLR athlete for compensatory patterning with the hip extensors from early on. The ability to “isolate” the quads during integrated functional patterning is critical. Unfortunately it’s all too often a missed or lost art in rehab clinics across the world. That may be the reason that despite such extensive therapy so many ACLR studies show persistent quad weakness, and, that quad weakness remains one of the key limiting factors to successful RTS. This study also did not examine frontal and transverse plane issues with landing mechanics regarding “dynamic valgus” risk factors. These also must be appreciated and addressed during testing performance, beyond simple LSI numerics. Surgeons and physicians during the post-operative phase remain in a critical role because they must discern if the rehab being done is appropriate and thorough enough to confidently trust that desired outcomes will be achieved. Routine care and mere protocol adherence is likely to fail. The literature certainly demonstrates that as a total collective the health care system is not presently producing high outcomes for our ACLR patients. Below are further details regarding key approaches that distinguish biomechanically authentic methods of approaching Quad rehab and hop testing beyond traditional approaches for the sake of optimizing function and reducing re-injury risk. Background: ACLR return to sport (RTS) and second injury rates are both unacceptable. Limb symmetry index (LSI) with hop testing is commonly used as a means of assessing readiness for sport but some data suggests kinetics/kinematics may not be normal despite symmetry of distance measures. Purpose: To determine if restoration of lower limb biomechanics during triple hop for distance testing is ensured by passing discharge criteria post-ACLR. Methods: Controlled clinical lab study using 3D motion analysis of 24 male athletes after ACLR who were cleared to RTS (LSI > 90% for quad strength and hop battery testing) compared to 23 healthy male athletes (participants 18-35 yr ). A 14-camera + force plate, using 42 body markers, was used to collect data. Findings: Despite reaching 97% LSI for ACLR involved side distances, the absorption work LSI was 80% and work generation were only 51% and 66% for first and second rebounds respectively. The relative knee work was less for involved limbs and hip work larger (P < 0.001) for all phases vs uninvolved and control limbs. Hip, pelvis, trunk compensations were noted with ACLR involved side limb testing. Author's Conclusion: Triple hop limb symmetry masked important knee deficits in knee joint work which were more prominent during work generation (concentric push off) than absorption (eccentric landing). THE PEAK PERFORMANCE PERSPECTIVE Surgeons and physicians caring for post-op ACLR patients are most often comfortable with familiar rehabilitation protocols they have often used for years. These oftentimes have been introduced during fellowship training or possibly through interaction with “experts in the field” via publications or conferences. ACLR recovery risks becoming a “routine” task for both clinicians and patients alike, especially for surgeons who perform numerous ACLR’s monthly even upwards to 150+ per year. For patients, physical therapists, and athletic trainers the multiple visits weekly process also risks a “routine” feeling that can undermine the appreciation for subtle biomechanical factors that must be addressed if the RTS phase is to go well. The real question at hand is are we all being scrutinizing enough? Are we discerning the subtle details as best possible in order to optimize recovery and reduce reinjury risks? The literature would suggest we are not! As a surgeon/physician how do you know your patient is ready to RTS? Do you carefully scrutinize the test reports sent by PT’s and ATC’s? How often do you recommend delaying RTS or has it become routine to approve progression based more so on time than supportive data? While there is no consensus or clear answers as to the “right” thing to do the successful return to sport data and second injury data are both disappointing to say the least. While individual experiences may be different the collective data suggest that surgeons and therapists/trainers are too often failing to ensure optimal recovery, including for those allowed to RTS. Over 30% of those undergoing the long recovery process of ACLR never make it back to their prior and expected level of sports participation. One in five sustain a second ACL injury. Surgeons sit at the healm of decision making in terms of protocols used and in discernment over where rehabilitation is done. Therapists and trainers are daily making treatment decisions that impact the training effect achieved…whether that be potentially reinforcing compensation patterns or optimizing more authentic normal neuromuscular function. We all have a hand in these mediocre outcomes. We all want excellence though. Kotsifaki et al demonstrated that despite 97% limb symmetry with triple anterior hop testing that important biomechanical performances were significantly still abnormal/asymmetric compared to the uninvolved limb and control limbs. Knee work was less, especially for concentric push off following an absorption (ie, plyometric type “rebound” effect”) though still only 80% for the typical injury phase eccentric absorptions. Proximal segment compensation from hip/trunk extensors was evident on involved limbs as well. Symmetry on triple hop distances was clearly NOT achieved because the “knee” itself was normal and symmetric! Underlying this subpar performance at the knee, even in just these sagittal plane indicators, is quad strength deficits. Traditional post operative protocols and real-life rehabilitation programming often attempt to utlize what are thought to be “functional” approaches to exercise advancements, with the intention of stimulating the neuromuscular system and mimicking real-life demands for activities like stair climbing that will eventually evolve into decelerating a cut or landing a jump. That means “triple extension” based exercises that intend to stimulate the hip-knee-ankle activation used for successful squating maneuvers. Typically that involves squats, leg presses, split squats, lunges, step downs, step ups, sled pulls and pushes and eventually impact based drills for jumping and hopping…etc. Unfortunately post operative pain and effusion disproportionately effects quadriceps performance more so than other related muscle groups in squat function. That open door for compensation, especially from the hip extensor hamstrings and glutes, more often than the short plantarflexors means that PT’s and ATC’s doing ACLR rehab must be keenly aware of how to recruit quads preferentially. Otherwise the risk is that too early or too casual or careless an “advancement” to functional ADL prep training exercises like stepdowns or step ups etc will produce significant compensation patterns that become harder to undo later down the road. Avoiding these mistakes requires attention to detail and personalized/customized exercise programming and cueing. The use of surface EMG biofeedback can be helpful but the real key is understanding biomechanics and carefully observing exercise techniques during squatting drills. While in one hand we appreciate and desire the “protective” effect of hamstring co-activation regarding it’s potential to reduce anterior shear forces we also need care in habituating quad inhibition and inadequacy during strength training drills. We don’t believe the answer is merely a focus on seated NWB quad extensions to isolate the quad but generic “functional” exercises like lunges and stepdowns done incorrectly can facilitate quad avoidance that will lead to poor declaration mechanics down the road. While this study did not examine frontal and transverse plane mechanics risk factors (ie. Dynamic valgus/IR) which is well known and accepted, these are key areas of focus during ACLR rehab. Since this is a multifactorial issue there is not a singular protocol-based approach or exercise that can simply be done to address dynamic valgus control or deceleration. Focused testing for anteversion, abnormal foot mechanics leading to overpronation issues, hip weakness issues of the abductors and/or external rotators, and dorsiflexion loss are some of the key underlying causes that we find related to dynamic valgus/IR that can be addressed with proper physical therapy care. We do perform hop testing and find it valuable. Normative data tells us that significant asymmetry is not normal. Yet, we also know from Kotsifaki et al’s data and others that mere LSI symmetry is also not enough information to prove normal function. Without expensive research level testing equipment clinical testing relies on keen observation skills and qualitative assessment beyond simple number crunching. But the well studied sagittal plane dominated tests used over the past decades in ACLR research we believe are lacking in their authenticity to real-world mechanism of injury biomechanics where frontal and transverse plane forces also occur. We utilize side-side hopping tests along with rotational hopping tests to force the knee to prove it can handle/decelerate and stabilize dynamic valgus/rotational type loading. Many PT exercise programs post ACLR also maintain a prolonged focus on “knee over the foot” directional intention for landing drills. While this is necessary and safe early on during healing concern time frames it is deleterious to neuromuscular training of authentic biomechanics loading forces the athletes will incur when they do return to the court or field and must contend with multiplanar knee and lower extremity loading. A key consideration is whether rehab has taught that knee and LE to successfully decelerate and reverse dynamic valgus/rotational inertial loading. The reality is that these forces WILL happen to athletes knees during sport. Excellent rehab does not pretend that conscious control of intended ideal paths will always be the norm. It must progress to contending with the original MOI and prove that safe dynamic stabilization and progression of the intended sports movement can happen. Below is a case study of my son’s ACLR experience at Peak Performance. Unfortunately the demands of work and parenthood altered his ideal rehab consistency further into his recovery but his excellent progress in the early formative months post op set him up for his return to football practices and soon to be game play. THE PEAK PERFORMANCE EXPERIENCE Jordan said: “I feel faster than I was before I got hurt. I'm making cuts in practice, getting open and catching the ball. I’m not 100% yet but I’m feeling good!" HX: 29 yr old male sustained a change of direction R knee giving way injury doing a wide receiver route in practice on turf in March 2021. He underwent autologous patellar tendon ACLR 3.29.21 and initiated rehab 2 days later. Subjective: At 7 month ReEval patient reported 1/10 max sx, 70% subjective function. By his 9 month ReEval he reported less frequency of symptoms but not yet painfree, likely due to his progression of activity and reducing HEP and PT compliance (new baby). Subjective function 80% , able to do sprinting, light route running and catching, IKDC 90%. Objective: (*=pain) 7 mo ReEval 9 mo ReEval Isometric 600 Quad 56% 78% 6” cone 900 pron - 600 sup rotational no touches 20sec Prior testing 114%...NT NT Vertical Hop 70% 550/470 3x Crossover Ant Hops 18’3” w reduced knee ant excursion and min excess trunk/hip flexion 19’0’ (97%) w improved knee and trunk mechanics + no abn Dyn Valg 900 Rotational Hops 10sec (40 unit radius) 9x (100%) (60 unit radius) 10x (111%) WB Quads Anterior (toes off) Stepdown 6” 40# DB’s 20x (71%) 50# DB’s 24x (86%) Key Findings: During intermediate phase mild increased hip flexion (ant tilting pelvis) often occurred during intended quad dominant squat PRE type drills and excessive trunk incline (hip extensor compensation) along with limited anterior knee excursion would occur during lunges and split squats. Frontal and transverse plane control had become excellent by 3 months post op and was advanced accordingly but did not require the typical extra attention often noted. Compliance became an increasing issue with PT visits falling off and HEP reducing significantly with birth of first child during at the 8 month post op mark. Treatment: During intermediate phase rehab dynamic frontal and transverse plane proprioceptive/stability drills were advanced via single leg balance drills including use of VibePlate plus reduced visual feedback (eye/eyes closed) work and distraction/perturbation techniques with ball passing and manual perturbations, eventually leading into “on-impact” mini squats with perturbations producing dynamic valgus type loading forces for deceleration/stabilization. Early on reliance on hip extensors and plantarflexors to assist squat function triple extension drills were gradually transitioned into Quad dominant stimuli using “front rack” (upright trunk) DB’s positioning, toes off Ant stepdowns with posterior trunk lean and posterior pelvic tilt cueing and lunging drills with toes off ¾” plywood landings to optimize knee flexion moments for quad recruitment. Impact drills were progressed into single leg push offs for power, single leg landings in place - - - > with distance excursion …and then multiplanar landings. Eventually proximal kinetic chain demands with inertial loading into diagonal patterns producing dynamic valgus replications of sport-like demands were included and then finally with reactive catching medicine balls into “at-risk” positions of the trunk-BUE. Plyometrics and agility drills proceeded as well with intention transition into combined frontal-transverse plane demands. Outcome: Pt has continued HEP inconsistently and returned to weekly (9+ mo mark) - - - >biweekly football practices and now at one year post op has done full contact scrimmaging and preparing for first official team scrimmage out of town. 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