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Peak Performance Physical Therapy & Sports Training EVIDENCE-BASED PRACTICE UPDATE (July 2022) Clinical Decision Making on Reducing Dynamic Knee Valgus-rotation …It’s not always the hip! by William Slapar, PT, DPT, OCS, CMTPT, CAFS Clinical Scenario...What would you do? A 16 year old female comes in for follow-up four weeks after evaluation for persistent left medial patellar pain that developed during running and lacrosse without any specific trauma. She’d already been seeing a personal trainer and has continued working on hip Abd’s and ER’s strengthening drills related to asymmetric dynamic valgus noted on your initial exam. Rest from running/sports x 2 weeks and gradual return to activity was prescribed. She was able to continue strength training with her hip stabilizers but symptoms returned as she resumed interval runs and 50% effort and volume lacrosse practice. Single leg squat observation shows no change of dynamic knee valgus/rotation vs eval findings. Ober’s (-) . Merchant view plain films showed mild but symmetric lateral patellar tilt and glide and Insall-Salvati ratio was (-) for patella alta. Patient is a junior who is eager to get back to lacrosse participation especially for upcoming exposure tournaments and scouting camps to attend this summer. My clinical thinking is: Course of prescription NSAID’s, painfree cross training and no practice, and order MRI to further assess and R/O chondral pathology - FU in 2 wks. Order patellofemoral buttress stabilizer brace and do gradual return to lacrosse. FU 2-3 wks. Refer to sports-ortho Physical therapy including biomechanical eval including distal factors (since hip work thus far not effective controlling dynamic valgus/rotation) - BIW x 4 wks allowing gradual activity return per symptom status. FU 4 wks. Refer for instrument assisted soft tissue mobilization of especially ITB/ lateral structures along with dry needling. CURRENT EVIDENCE Ban R., Yang F. “ Preliminary study on acute effects of an intervention to increase dorsiflexion range of motion in reducing medial knee displacement.” Clinical Biomechanics, 95, 2022; 2-6. SUMMARY: Dynamic Knee Valgus (DKV) is a commonly seen biomechanical failure that can lead to various different knee injuries, from as minor as an MCL sprain or patellar subluxation event to as severe as an ACL tear. Physicians ordering Physical Therapy must consider if they trust a thorough biomechanical screening and care plan will be performed. Key concerns may need to be emphasized on prescription orders for initial care episodes, in post-op cases, and especially changes in therapy providers following failed early rehab attempts when surgery is not yet indicated. There are many different biomechanical factors that may contribute to DKV. Most often physicians/physical therapists/trainers focus on the proximal influence, the hip. This article by Ban and Yang shows that there is an oftentimes missed distal influence as well, limited dorsiflexion, that is amenable to treatment that mutually reduces DKV. This pilot study tested 8 healthy participants (18-32 yo, 6 female, 2 males) presenting with DKV, or medial knee displacement(MKD) (measured as an outcome for DKV), during an overhead squat, where the MKD was reduced by a heel lift. Dorsiflexion ROM was measured in 3 different static forms (passive straight knee, passive bent knee, and lunge). Their intervention (foam roll, static stretching, PF/inversion strength exercise and single leg squats) increased DF ROM and resulted in a reduction in MKD, thus decreasing DKV. Dorsiflexion loss, while a distal sagittal plane restriction, causes a proximal compensatory transverse and frontal plane effect at the knee resulting in DKV. Limited DF can result in a compensatory strategy of talus Internal rotation that unlocks the MTJ to produce needed “DF” but at the midfoot. Kinetic chain biomechanics dictate that talar motion will induce tibial Internal rotation and abduction, leading to femoral internal rotation and adduction - all resulting in DKV. The body often seeks the path of least resistance, here, with the midfoot’s available DF becoming the resource when the ankle proper (TCJ) DF is limited. While that mechanism may produce DKV, likewise, the frontal/transverse plane knee may become it’s own “path” for shock absorption and adaptation to ground changes through DKV when the foot-ankle are not compliant with adequate eversion. This study did not examine all factors contributing to DKV, therefore DF loss alone cannot be assumed the cause of DKV/MKD. Therapists must test all possible contributing factors to DKV to optimize patient outcomes. High quality care goes beyond the simple treatments used in this study to include manual therapy and more biomechanically authentic exercise options to optimize neuromuscular integration for ADL and athletic use. Nevertheless, there was a measurable benefit from a single care episode in reducing MKD/DKV. Depending on the severity of the restriction this may normally take weeks for a difference on DKV. Because traditional therapy often assumes a proximal cause when DKV is present physicians may need to specify “assess and treat knee valgus prox/distal factors” for initial PT scripts. For “failed” cases, it may be beneficial to review with patients specifically what exercises were done to determine if therapists/trainers had discovered and addressed distal factors or not. Background: Dynamic Valgus, medial knee displacement, which has been an important biomechanical failure we see in athletes, especially females, has been associated as a risk factor in lower extremity injury, especially ACL tears. Loss of dorsiflexion (DF) has recently been shown to contribute to medial knee displacement (MKD). Purpose: (1) to explore an intervention to increase ankle dorsiflexion range of motion during the three static measurements (2) to test if increasing dorsiflexion ROM could reduce MKD in individuals who demonstrated MKD corrected by a heel lift in squatting. Methods: Eight healthy participants (18-32 yo, 6 female, 2 males) who displayed dynamic valgus in an overhead squat that was alleviated by a 2 inch heel lift were included Treatment included foam rolling, knee flexed and extended slant board stretch, tubing inversion and WB PF raises in IR, plus single squats for integration - all done in single session. The dorsiflexion was assessed in 3 different ways statically: passive straight-knee, passive bent-knee, and weight-bearing lunge. Findings: A single session of interventions targeting dorsiflexion ROM increased dorsiflexion in all three static positions (all P < 0.01 with moderate effect sizes) and a significant reduction in medial knee displacement (P =0.02) during an overhead squat. Author's Conclusion: The intervention protocol used was beneficial in improving dorsiflexion limitations for those showing MKD on squat testing related to apparent DF restriction and that addressing DF ROM may be helpful in reducing MKD as a a risk factor for ACL injuries. THE PEAK PERFORMANCE PERSPECTIVE Physicians treating knee injuries commonly see Anterior Cruciate Ligament (ACL) tears but also other conditions and injuries that often may experience common overload positioning, whether as microtrauma or as a sudden event, that involve dynamic valgus/rotation. Patellar dislocations and instability, MCL injuries, and meniscal injuries are among these. Early decision making on treatment choices and ensuring risk factors have been properly identified and are being addressed is critical. Physicians making initial treatment orders or especially in cases of “failed care” are tasked with identifying key factors that may require specific emphasis on prescriptions they write to ensure Physical Therapists/Athletic Trainers address biomechanical issues properly in rehab. Anterior cruciate injuries are one of the most common injuries in sports. The fact that this injury is most often a non-contact injury and occurs with between 600-2300 N of force shows that there are numerous factors that we must consider before treating a patient to prevent/reduce the risk of this injury. One well studied and accepted concept related to risk is dynamic valgus/rotation, the biomechanical failure that leads to the increased stress/tensile load on the ACL along with other structures. Ban and Yang provide an important piece of work in connecting the loss of DF with abnormal MKD-DKV during squatting and the ability for even a single session of therapy exercises to significantly influence DKV. We define dynamic knee valgus as being a combination of excessive femoral adduction along with internal rotation in combination with tibial abduction and internal rotation. It is commonly measured via the resultant “medial knee displacement” for objective testing in research or clinical observation. Most often physicians and therapists/trainers alike risk assuming the source is commonly referenced proximal factors at the hip. This results in exercises to strengthen and neuromuscularly train the hip abductors and external rotators. While these are critical considerations and often effective methods careful evaluation is needed in the rehab setting to ensure the primary and ALL key influences potentially contributing to DKV have been identified. Too often a “protocol-like” approach is taken that automates a series of hip based exercises without specific objective evaluation to determine underlying factors. Ban and Yang do a great service to orthopedic and rehab professionals in identifying that a lack of dorsiflexion could be causing a distal or “bottom-up” mechanical compensation into knee dynamic valgus/rotation. However, while this can definitely be true we must then evaluate the other parts of the lower kinetic chain. Each of the reasons listed below requires its own unique treatment path toward the goal of reducing the severity and frequency of DKV, with the end goal of reducing abnormal loading on the at-risk tissues surrounding or in the knee. Strength and motion of the hips are certainly critical, but sometimes it is a bony anomaly, such as anteversion that is pre-loading the system. The foot, not only regarding DF, but also other foot mechanics as the first body part dealing with ground reaction forces that induce kinetic chain loads is critical. Sometimes orthotic intervention is necessary to reduce abnormal forces and to optimize the ability of the neuromuscular system to then improve dynamic stability control actively through exercises. High quality knee rehabilitation must include a substantial checklist to determine the most significant and likely issues for a patient presenting with DKV/MKD. Common deficits we see with patients who have DKV are: Lack of dorsiflexion: this often results in either early heel rise, which reduces the contact area and thus stability within the lower extremity or very often we see this sagittal plane TCJ restriction causing overpronation at the STJ which unlocks the MTJ to obtain the necessary sagittal dorsiflexion for force absorption eccentrically…resulting in the tibial IR distally that contributes to DKV or MKD along with reduced distal stability in general Foot alignment/structure: abnormal foot mechanics issues, including rearfoot and forefoot varus “deformities” can result in compensatory overpronation; this results in tibial IR forces that contribute to DKV tendencies Limited calcaneal eversion: the STJ needs to be able to evert for proper adaptation to the uneven ground and force absorption as a part of our body’s deceleration process; Limited calcaneal eversion can cause excessive compensatory MTJ collapse into general foot pronation and/or kinetic chain demands on the knee to adapt to the frontal/transverse plane absorption normally dealt with by the STJ Hip anteversion: this is a huge disadvantage to DKV, and other joints, due to the anatomy having an increased tendency to femoral internal rotation, displacing the knee medially Weak hip ABD and ER: strength deficits of these are commonly accepted contributors proximal causes of DK, allowing for excessive femoral frontal and transverse plane collapse medially due to ground reaction forces and superincumbent body weight loading Quadriceps weakness: since force dampening/absorption involves the pronation kinetic chain pattern including tibial and femoral IR especially, quad weakness may result in poorer control of knee flexion and a tendency for the knee to collapse medially (far more often than excessive lateral movement) The case below illustrates an example of an athlete who had DF limitations that contributed to abnormal knee dynamic valgus who was helped by specific functional manual therapy and customized therapeutic exercise progressions where proximal factor approaches alone would have missed key contributing factors she needed addressed. THE PEAK PERFORMANCE EXPERIENCE Allison said: “I was able to play my tournaments all weekend long (4 games) and did not have any knee pain on either knee” History: Allison is a Junior in high school who has been playing lacrosse all season and now getting scouted during the summer. She has to run/sprint, cut, play defense,using all three planes of movement at all times during her play. Her knee pain came about as a repetitive overuse nature. She had R sided knee pain that with rest ordered from an Orthopedist resolved but then her opposite L side started to bother her two weeks later. Objective: (*=pain) Eval 4 week Re-Eval STJN WB DF R=250 L=150 R=280 L=250 6” Anterior step down L= * 1st rep, w/ mod. DKV, R= 15x, min-mod DKV increases with reps L=15x (fatigue with 1/10 pain) min. DKV R=x20(fatigue), min. DKV SLB rotations L=stays in pronation, lacking resupination R=5th digit WB with resupination L= min. resupination, LOB R=mod resupination ability Single legged hop 10 sec L= 1x *, mod DKV, with immediate RLE touch down R= mod DKV, LOB L=min DKV, min frontal trunk sway to regain balance R=min DKV, SLB mini-squats L = Mod DKV and * R=mod DKV L=min DKV R=mod DKV Prone Hip PROM (IR/ER) R=55/300 L=53/300 NT Key Findings: LE Posture: squinting patella B with overpronation B; anteversion of B hips, anterior step down shows anterior pelvic tilting of the hips with shaking of the tested leg due to quad inability to descend body weight eccentrically with proper control in sagittal and frontal plane. Hamstring imbalance, ABD and ER strength was near symmetrical based on handheld dynamometer. Treatment: Manual FMR DF mobilization in wb/function followed by STJ neutral stretching of the soleus and calf, supination drills to improve overall foot mechanics in the rearfoot for supination efforts and forefoot for pronation control. Anterior step downs 4-6” with toes off box to isolate the quads better, Hamstring strengthening in functional weight bearing 3D movements. Lunges for all planes with different foot positions during landings to mimic natural lifting patterns. Deceleration exercises through multiple planes at foot positions to mimic on-field play for cutting/agility, multiplanar landings for single legged hips and multiple hops with turns, Blaze Pod reactivity lacrosse drills, and progression of multiplanar speed drills to achieve working in two or more planes at once. Outcome: Pt was able to achieve a personal goal of competing in summer tournaments and scouting camps while being in PT for just 3 sessions and starting speed days within 2 weeks of PT evaluation.Pt is a continuing PT to complete her 3D functional exercise progressions to further optimize the ability to control abnormal DKV in order to improve performance and reduce risk. Pt has difficulties in the frontal plane with more than just sagittal movements. Also increasing proximal kinetic chain work to further improve physical performance.