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EVIDENCE BASED PRACTICE UPDATE November 2020 New Evidence on Running Injuries... Thinking beyond simple “overuse” WHAT WOULD YOU DO? A 27 yr old recreational runner complaining of unilateral plantar fascia pain developing with running 2 wks ago after increasing mileage from 20- - >30 mi/wk over the prior 3 weeks is in for evaluation. They have run for 6 years with only short bouts of minor musculoskeletal issues related to running, never requiring formal care, never needing more than one week rest. This time one week rest did not allow a painfree return to running. Their shoes demonstrate substantial lateral aspect of heel wear patterns. You notice an asymmetric medial collapse on that side during a brief hallway jog assessment. PMH includes an ankle sprain one year ago that is no longer symptomatic and patient reports 100% function restored. · Do you recommend complete rest for 2-3 weeks from running? · Do you order Physical Therapy or NSAID’s first or both? · If NSAID’s - do you have any reservations regarding affects on stages of tissue healing? · What is your hypothesis for unilateral symptom development? · What immediate recommendation can you give to alter potential abnormal forces while potentially allowing some running still? · Do you have a generic “plantar fasciitis protocol” that addresses this patient’s contributing factors? · Do you expect the Physical Therapist to implement the generic protocol or to evaluate the patient for unique biomechanical influences and address accordingly? SUMMARY Physicians regularly see runners who are experiencing pain and looking for solutions. The current pandemic may compel even more fitness enthusiasts to take up running as gyms are closed or limited. Beyond making a diagnosis and recommending proper treatment/therapy physicians are in position to immediately impact symptoms for many runners with in-office education. Last month (Click HERE to read) we brought you a running article that showed a common flaw in running (abnormal hip adduction via pelvic drop) that was a significant cause of injury in many runners. This month’s review focuses on impact-related ground reaction forces (GRF) in running. Johnson et al showed that various markers related to GRF were greater in injured runners vs healthy controls and also uniquely for those subgroups with patellofemoral pain, plantar fasciitis, and achilles tendinopathy but not for tibial stress injury or ITBS. While the findings demonstrate an association and not necessarily causal relationships, in combination with other existing literature there is good basis for counseling and training runners in methods to reduce GRF. Physicians can simply do so with several different recommendations when they believe impact related forces are playing some role in a runner’s symptoms. CURRENT EVIDENCE Johnson, Adam, Tenforde, Davis. Impact-Related Ground Reaction Forces are More Strongly Associated With Some Running Injuries Than Others. AJSM, 48:12, 2020 pp. 3072-3080 Background: It has been reported that 33-50% of recreational runners sustain injuries, with the causes of which are multifactorial. This includes things like running mechanics, shoe choice, ground stiffness, muscle strength/endurance, flexibility, and daily or weekly mileage. Common injury diagnoses are primarily divided into the achilles tendonitis/tendinopathy, patellofemoral pain, plantar fasciitis, tibial bone stress related and iliotibial band syndrome. Purpose: This controlled lab study retrospectively compared vertical load rates and stiffness between healthy and injured runners and also within injury groups. Methods: Male and female runners age 25 to 52 y.o. with >2/10 pain on a VAS during running who used a rearfoot striking running pattern and utilized conventional running shoes (ie. not minimalist shoes) met the inclusion criteria. One hundered twenty-five injured runners (divided among the five diagnoses: Patellofemoral pain, Iliotibial band syndrome, Tibial bone stress injury, Achilles tendinopathy, and Plantar fasciitis) were compared to 65 matched healthy controls. All participants were analyzed at one treadmill session with 3D video analysis using a self-selected speed. Ground Reaction Force (GRF) variables were measured and compared between groups and also for individual diagnoses. GRF measures included Vertical Stiffness (change in the body’s center of mass [COM] relative to a change in the vertical GRF), VILR or Vertical Instantaneous Load Rate (peak rate of change in vertical GRF between two successive points), VALR or Vertical Avg Load Rate (avg rate of change in vertical GRF across 20% to 80% of the region of interest),and VSIL or Vertical Stiffness at Initial Loading (peak vertical force divided by the vertical change in COM over 20-80% region of interest). (See Figure) Results: Injured runners had a significantly higher VALR compared to healthy controls. VALR and VILR were higher in the patellofemoral pain and the plantar fasciitis groups compared with healthy controls. Significantly higher VSIL were found with patellofemoral and achilles tendinopathy groups in comparison to the healthy control groups. All injured groups showed significantly higher force impact (16-20%) in all 3 areas but only the above reached statistical significance. Authors’ Conclusion: Impact variables for the injured group were higher than healthy controls but are driven by specific injury diagnoses. This highlights the need to take an injury specific approach to biomechanical risk factors with running injury. PEAK PERFORMANCE PERSPECTIVE Karen Napierala, MS, AT, PT, CAFS With the gyms vacillating between closed and open in the past 6 months many people are opting to keep it simple…. to run. This potentially means more people who have not trained to run now will be running to train or stay fit. This will likely lead to more physician office visits due to a spike in injuries. It bears repeating – 33-50% of recreational runners will develop injury. Physicians can easily also go beyond the necessary diagnostic role with early treatment via patient education/counselling (see below). These results certainly suggest that we need to address impact loading for injured runners, especially at least those who are rearfoot strikers and have patellofemoral pain, plantar fasciitis, or achilles tendinopathy. Johnson et al’s findings also support Van Der Work et al’s findings of a positive association between vertical impact rates and general running-related injuries. These longer term studies have also shown the increased loading rate directly related to the progression of injury and further cartilage damage. From a treatment perspective it is encouraging to note that Chan et al did report that training runners to reduce vertical loading rates lowered running injuries by 62% over one year. Physicians are in a unique position even during their first encounter with runners who rearfoot strike to begin education/counselling. Runners should know that studies indicate >40 miles/wk increase injury risk within the next year. And, we must remember - runners WILL often keep running regardless of having pain. Rather than ordering a full stoppage initially it’s possible to help them find the threshold where they remain pain free. Here are two simple, practical methods to reduce the volume and then the severity of GRF based contributing factors: 1. Determine total weekly mileage. The first option, of course, is simply to have them cut their daily mileage (2/3, ½...etc) and reduce frequency by 1 day/wk to begin with. Many runners we see admit to non-compliance when an “all-or-nothing” complete refrain from all running is the first recommendation a physician or PT gives. 2. Increase cadence by 10%. Efficient runners often have a cadence (step count) of 85-95 steps/minute (ie. 170-190 stride rate). Advise your runner to count their steps (every time R foot lands) in one minute when they are fresh and then again when they are fatigued or at the end of a run (ie., a runner at 77 step count would have to add 8 steps to their cadence and now reset the metronome at 85). There are free metronome apps they can download to their phone, providing an excellent and consistent audible cue for them. Rearfoot strikers particularly have been known for their slight over striding at heel strike which increases GRF. This can happen for two reasons. First, is when the runner reaches forward with their heel to contact the ground. (Could be many reasons including tight ankles, hips or weakness in the calf…ETC) The heel contacts hard, leading to “braking” type forces and the runner “pulls” themselves thru instead of leaning forward more, landing their heel closer to the COG, and “pushing off” to propel themselves forward. The second is when runners “sit their hips back”, causing an anterior pelvic tilt (potentially related to tight hip flexors, weak gluteals...etc). While the heel strike itself distally doesn’t appear visibly as anterior as the “overstrider”, the proximal pelvic segment/COG are relatively more posterior. The outcome is the same – increased GRF at heel strike. This, of course, then has ramifications up the kinetic chain as well. For example, high vertical load rates can result in increasing sagittal plane forces at the patellofemoral joint leading to rising patellofemoral joint (PFJ) compression forces. Increased vertical loading causes greater rates of vertical arch deformation which in turn stresses the plantar fascia, first in the sagittal plane but as the arch collapses it does so concurrently in the traverse/frontal planes also. This contributes to overloading other tissues related to local shock absorption distally as well. In this study Johnson et al found plantar fasciitis group values of 52.4BW /s or higher for VALR associated with 11x increase in injury risk. This study, oddly, did not find increased GRF forces in the tibial bone stress runners subgroup. However, these runners had taken 1-2 months rest off as part of their treatment, prior to the study, and were allowed to run with a max of 2/10 pain, which possibly meant they were using altered/compensating mechanics. Mean vertical loading rates were not significantly higher in the ITB or achilles tendinopathy groups. These injuries have been linked with frontal and transverse plane weakness or excessive motion. Traditional PT often overlooks or misses these issues, like frontal plane stiffness in calcaneal eversion as a cause of distal foot overpronation (MTJ). Vertical stiffness during impact loading measures downward excursion of the COM per unit of force during the early stance. These “stiffer” joints are less able to dissipate external forces resulting in increased rate of injury. Higher knee joint stiffness and injury have been associated previously in other studies. Conversely, a decrease of vertical stiffness (ie. excessive collapse) is also a potential risk factor. Research has yet not pinpointed the exact amounts of stiffness necessary to prevent injury and properly dissipate forces. There is a likely safe range that is dependent on an individual’s biomechanics, strength and flexibility, etc. This study was retrospective. Therefore we’re uncertain whether it was capturing biomechanical factors that were causative of the injury. Studies do show that 86% of all runners will run through pain. This fact compels us as health care providers to carefully address running injury since runners who do, in fact, continue to train may be risking more severe or additional injury - leading to even more eventual disability, time off running, medical intervention and expenses downstream. This study differed in in that the runners here were rested for at least a month before being tested. Many prior studies looked at runners who were running their normal mileage while still in pain. This study had several limitations which the authors astutely noted. First, regarding external validity, because rearfoot strikers only were allowed to participate, the results cannot be extrapolated to fore- or midfoot strikers. It is important we caution against overgeneralizing these findings to runners in general especially as we more and more runners hearing about and attempting to utilize mid and forefoot strike patterns. The authors calculated risk thresholds (ie. VALR > 57.4BW in the patellofemoral pain group was linked to knee pain). These GRF injury risk thresholds (Table 4 in original article) are not intended to be definitive since this was not an experimental design study able to demonstrate causality. While it is accepted that increased force is associated with increased likelihood of injury down the road, it remains unclear what that time duration prior to symptom onset might be or the threshold for tissue overload that triggers inflammation and symptoms, especially regarding the level that alters function. It is impossible to establish whether the observed differences in this study are a cause or result of the recent injury. At what point do runners in pain modify their running mechanics, and to what degree, in order to decrease symptoms and continue to run? Johnson et al looked at runners after they were injured. Future prospective studies examining GRF patterns of asymptomatic runners and then following them over time to determine the relationship between many of these impact related variables and subsequent injury would be even more helpful to physicians and therapists clinically. Injured runners require skilled physical therapy capable of analyzing gait patterns that may contribute to increased GRF variables like Johnson et found in this study. Traditional or generic/protocol based therapy approaches often fail to identify functional biomechanical factors contributing to the “why” a runner is performing the skill or gross motor activity of running in the way they do. We must assume runners, like most athletes, are likely either utilizing the mechanics that inherently/naturally feel most efficient within their own body (based on the capabilities and the limitations they have) and/or are based on their interpretation of what they’ve learned or observed as “proper technique” that they are attempting to emulate. Running is a complex and integrated biomechanical skill. Not every injury has the same cause. There are internal biomechanical issues, training issues, and impact force issues among others. What caused the impact force to be intolerable on one side of the body when each foot took the same number of steps? Determining why one side had an increased force across the injured tissue is a key puzzle to be solved. It is imperative that therapy be capable of analyzing functional mechanics issues that my underlie abnormal running form and/or contribute to inefficiencies that lead to tissue overload. Thorough 3D testing and exercise progressions that resonate with the proprioceptive/neuromuscular system are key. For example, the hip abductors being trained to forcefully abduct the thigh is not “authentic” hip abductor force use. In running the abductors stabilize the pelvis and decelerate mild normal pelvic drop into hip adduction before concentrically contributing to re-leveling of the pelvis for push off. Concepts such as this are often missed with common clamshell or circle tubing abduction walk drills that do, in fact, “work” those muscles but are not authentic in their true preparation for running. Certainly GRF in runners is controllable to a significant degree by altering the forces at impact, in the case of runners, particularly with rearfoot strikers via increasing running cadence or steps/minute. Often in the clinic the injured runner is down around 75-80 steps per minute. They may think running slower is better for them, or easier...not realizing that when many runners lower their cadence they end up overstriding and thus increasing GRF. Recommending an increase in stride rate will actually move COM forward and decrease their impact forces through the heel, which, based on this study, may be helpful especially for runners with PFPS, plantar fasciitis, and achilles tendinopathy. PEAK PERFORMANCE PATIENT: Marley said: “ I didn’t know I would feel so much faster and more efficient when I run at the higher step count. This is the strongest I have ever felt!“ History: Marley was a collegiate runner training at 35-40 miles/week. She developed L hip symptoms that were diagnosed at school as hip bursitis. Rest was ordered but every time she tried to resume running the pain returned. We met Marley at a runners camp where she was assisting in coaching high school runners. Being around other runners only fueled her desire to run. Objective: Standing STJn showed leg length discrepancy. NWB and WB hip Abductor length testing showed tightness. FWB recovery from Hip Adduction was poorer. Asymm foot overpronation noted with esp SLB dynamic testing. Subsequent TM run test once painfree showed an 180 inclination angle at heel contact and a cadence of 78.steps/min on R foot. (See Fig A) Fig A Fig B Discharge Re-Evaluation: Marley’s running was again analyzed in 2D (Figure and her angle of inclination at foot contact was now 12 degrees. She had a cadence of 88-90 steps/min R LE. She was still a heel striker, but the contact point on her heel was slightly anterior to the original contact point. Her body lean was inclined forward, and she felt much stronger and able to push off easier. She self selected a comfortable speed of 6.5 mph on the second analysis. She has been running now for 6 weeks and has zero pain. Treatment: Initial: Shoe lift to address LLD. Functional dynamic stretching for her ITB/TFL along with WB based strengthening of hip Abd’s and ER’s as well. Dynamic balance exercises promoting pronation deceleration and the ability to resupinate were initiated and advanced. Superfeet OTC inserts were obtained and self-adhesive posting was added to semi-customize biomechanical demands. Subsequent – once symptoms gone: Cadence was increased for Marley to 84 and maintain that for 5 minutes in a 30/30 walk/run using a metronome app on her phone to ensure proper pace. She was taken up to 88-90 steps/min with the use of a metronome to ensure keeping the new cadence. Ran 3-4/week while also continuing her strengthening and functional stretching program. She did this for four weeks and gradually increased her run 5 seconds while decreasing her walking 5 seconds until she was running 5 minutes. When was then able to gradually maintain that new cadence she would increase the running by one min every three days. Once she hit ten minutes successfully, she used the metronome sporadically only and continued her gradual increase in time running. 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. Karen Napierala, PT, AT, MS, CAFS 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