Running Related Injuries: Should we rethink the use of treadmill biomechanical analysis? (Physician Update, April 2024)

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Peak Performance Physical Therapy & Sports Training

 

EVIDENCE-BASED PRACTICE UPDATE

April 2024

 

Running Related Injuries:  

Should we rethink the use of treadmill biomechanical analysis? 

 

by Karen Napierala MS, AT, PT, CAFS

 

What would you do? 

 

A 54 yo runner with persisting L knee lateral knee pain presents after running a 10k race with hills two months ago.  His normal weekly running volume was three times/week for two to three miles.  Once he warms up his knee soreness resolves but then symptoms exacerbate sometimes by late in the run but definitely within hours of finishing, sometimes lasting into the next day.  PMH includes L ITB syndrome and also recurrent (L) ankle sprains and associated chronic stiffness.  The patient denies any catching or giving way in his knee.  He has tenderness at the ITB over the LFC, no joint effusion, no joint line tenderness, (-) McMurray’s and Thessaly tests, and pain with single leg squatting.  Plain films show diffuse mild grade I degenerative changes.  

 

I would prescribe… 

1. Rest from running for two weeks along w/NSAID’s   
2. Physical Therapy for ITBS including a treadmill running biomechanics analysis  
3. MRI to R/O lateral meniscus pathology with FU in two weeks 
4. Home exercises handout including ITB stretches, other LE stretches, balance and step up exercises along with recommending cross training for two weeks and then gradually resume running.  FU if symptoms persist.     

 

CURRENT EVIDENCE:

Malisoux L, Gette P et al. Gait asymmetry in spatiotemporal and kinetic variables does not increase running-related injury risk in lower limbs: a secondary analysis of a randomized trial including 800 recreational runners.   BMJ Open Sport Exerc Med.  2024; 10(1) E001787

*** We modified the Newsletter format to better match your time constraints.  The more in-depth “Peak Perspective” will now be contained below in more “summary” form.  We invite you to reach out to us at PT@peakptrochester.com or call our office at 585-218-0240 to further discuss this article or specific patient needs if you wish.  The abstract can be found after the case study.

 

 

PEAK PERSPECTIVE SUMMARY 

Studies show that up to 79% or more runners sustain lower extremity injuries.  Orthopedic, primary care, and podiatric physicians along with physical therapists will see these athletes frequently for evaluation and determining best treatment approach.  This often has included the recommendation for a biomechanical running analysis, assessing for both general abnormality in mechanics/style but importantly also determining any key asymmetries present that may underlie overuse patterns.   

This study by Malisoux and Gette et al on the surface may seem to suggest that running gait analysis based asymmetry may not be the correct variable/factor actually underlying running injuries.  A deeper assessment of the study may caution providers to be slower in foregoing traditional treadmill running gait analysis for a number of reasons.  As with so many studies there is more than meets the eye from reviewing the abstract alone!

This study prospectively examined 874 recreational runners, as a part of a primary study looking at two different shoes cushioning sneaker types, and found 107 injuries over the 6 month study follow-up period, noting that there were no difference between leg asymmetries in kinetics or spatiotemporal variables measured for the injured runners group.  They concluded that gait asymmetries with spatiotemporal and kinetic variables were not associated with increased injury risk.  

Consider for a moment the analogy of MRI findings with degenerative meniscal tears, or degenerative rotator cuff or lumbar disc pathology or even osteoarthritis.  While past thinking early on revolved around identifying these abnormalities as definitive of injury and often receiving surgical treatment, current thinking has evolved based on newer research and better appreciation for the role MRI plays, and does not play, in defining a patient’s condition.  We now know there are (+) MRI findings in asymptomatic people or on the contralateral side that caution “over-reading” the importance.  The MRI, now more than ever before, is taken as key information but kept in context with the entirety of the history and clinical exam findings.     

Gait analysis according to this study is a similar case.  Kinetics alone, (GRF, COG displacement, step length) did not correlate or predict those recreational athletes that became injured during this running time period.   So, yes, this study suggests we take more caution in calling (certain) kinetic and spatiotemporal variable asymmetries between limbs as critical factors.  Does this study then make them unimportant?  Much like the vast number of MRI studies (+) for abnormality in contralateral limbs and asymptomatic populations - the answer is no, it is not unimportant.  But we must take it all in context. 

Asymmetry of those variables may not be the key factor.  Consider a runner with symmetrically excessive stride length causing poor heel strike and braking forces up the kinetic chain.  This study would not find that because there’s no “asymmetry” noted.  Same for the entire host of variables measured, which only looked for spatiotemporal and kinetic “asymmetry” - with the underlying hypothesis being that it is asymmetry that is the causative factor to eventual injury.  

Other studies have certainly demonstrated that asymmetry (i.e. unilateral weakness or tightness) can be related to injury and also poor performance.  Running studies in particular have also demonstrated the biomechanics differences between novices and more expert/experienced runners.  These kinetics based biomechanical findings also exist within each individual runner’s own kinematics factors and injury history, making even symmetric kinetic abnormalities “experienced” asymmetrically.  

Even if these kinetic measurements are not a direct predictor of injury, they are certainly not irrelevant. A key consideration not studied is how the forces of running (through the measured kinetics) are then absorbed and/or produced across the various joints and muscle groups.  Kinematic variables like this would help define the percentage of load, including any asymmetry present, with how the ankle, knee, and hip handled those forces.  This is also true for the triplanar nature of authentic function.  This study viewed sagittal plane variables yet we know that frontal and transverse plane function is also simultaneously occurring, whether that be from a “stabilization” demand or a force production/reduction standpoint.

Malisoux and Gette et al did not control for training load progressions, possibly the largest factor in expected injury.  The fact this data also involves the participants testing and training using different shoes than they normally wear, potentially impacting running style but also introducing a key shock absorption variable into the kinetics and spatiotemporal factors attempting to be studied.  “Injury” was also defined as causing a restriction or stopping of training for 7 days or more - meaning athletes who had to modify for shorter times and then able to resume, but then had symptoms return again may not have been included as having an “injury”.   

Our treadmill running analysis utilizes 2D video to capture not only sagittal plane but also frontal plane views for assessing kinetic (AND SPATIOTEMPORAL) variables.  This study reminds us to be cautious of placing excessive importance on asymmetry but because of the various limitations falls short of proving kinetic analysis unimportant or unnecessary.  Like MRI findings, the treadmill analysis becomes part of a larger battery of tests that help identify potential factors affecting the patient’s symptoms/function, leading to clinical decision making.  The use of functional weight bearing mobility, dynamic balance, strength, deceleration, and power testing provides some level of kinematics related information that helps paint a fuller picture of how that injured runner developed their condition and thus identifies targeted areas for functional rehab.  

 

THE PEAK PERFORMANCE EXPERIENCE

Jack said:  “After two weeks of doing the ankle and hip stretches, I am starting to run again! My knee feels looser.” 

History:  Left ITB pain at knee, not on the joint line. Running 2-3 /wk no more than 3 miles.

Subjective:  L knee pain with heel contact thru foot flat.  Able to warm up and run through pain with increase in pain once cooled down. Sore to touch on the ITB and was also painful with over 5 miles of biking at a time.

Objective:

(*=pain)	Initial Eval	Re-Eval 6 wks
Ankle dorsiflexion squat	L 19 / R 10	L 21 / R 17
Single leg squat knee angle	L 65 / R 85	L 78 / R 90
Calf raise in 15 sec	L 25/ R 14	L 25 / R 14
3” quad dom step down (eccentric) 2-10# DB FRONT RACK	L 24 / R 27	L 27 / R 28
Hip  flexion	L 85 / R 110	L 110 / R 120
Hip ER	L 30 / R 48 deg	L 42 / R 50
IKDC	59%	79 %

   

Key Findings:  Right ankle loss of dorsiflexion. Left hip limitations in external rotation and flexion.  Left calf and quad weakness. Tender palpation ITB at the joint line.  Gait analysis using 2D spark motion software revealed an increased step length on the L side and an increased tibial contact angle indicating increased GRF thru the L leg.  Frontal plane analysis revealed L hip drop increase in foot flat and increased knee valgus compensation.  Calcaneal eversion was the same, but the midfoot appeared to evert more on the L. 

Treatment:  Hip external rotation/flexion stretch and hip mobilization for posterior capsule.  Hip external rotation stretches with active frontal plane hip motion for strengthening and simultaneous posterior hip active stretch developing increased hip motion/concurrent strengthening in all planes.  Standing ankle dorsiflexion active stretch with knee flexion for soleus (rather than gastroc) stretch.  Progressive strengthening for left calf and quadriceps, quad dominant including step downs at 3 inches.  Standing hip external rotation strengthening using bands for low row (eccentric external rotation control from hip to foot).

Outcome:  Strength and ROM measures significantly improved.  Symptoms reduced to the point that the patient was running 3 miles 3/week pain free after four weeks of work.   His biking increased gradually to 8-10 miles 2/week pain free as long as he stretched. 

 

ABSTRACT  

Background:  Gait asymmetries in lower limbs during running are thought to generate differences in mechanical stress in a bilateral comparison and may expose runners to a higher injury risk.  There is no current consensus on ‘normal’ levels of asymmetry and when an asymmetry will create an injury.  We know that, when running, there is a wide variety of asymmetry in kinetic measurements such as stride length, ground Rx force, vertical displacement distance.  This study indicates that these kinetic measures alone are not associated with higher injury risk.  Also the variability between involved and uninvolved limbs in runners who sustained an injury was not correlated to the injury.  

Purpose:  To investigate asymmetry in spatiotemporal and kinetic variables in 800+ recreational runners identifying determinants of asymmetry.  Is greater asymmetry related to greater running injury risk with the kinetic variables between involved and uninvolved limb at baseline with treadmill analysis and a self-selected pace.  

Type:  Secondary analysis biomechanical running analysis at baseline and 6 month follow up on running exposure comparing two running shoe prototypes with different cushioning properties.

Methods:  874 recreational runners who were injury free from 18-65 years old and  who had run without orthopedic insoles for 12 months volunteered for the study.  They randomly received one of two running shoes differing only in their cushioning properties.  They were tested on a treadmill at their self-declared preferred running speed.  Three-dimensional ground reaction force (GRF) data was collected (step length, contact time, flight time, vertical oscillation of Centre of mass, peak GRF, peak braking force and propulsive force).  During the 6 month follow-up running related overuse injury was defined as “a running-related musculoskeletal pain in either of the lower limbs that caused a restriction in distance, speed, or duration, or stopping of running for 7 days or more. 

Findings:  107 participants reported at least one running-related injury using the predefined definition of injury (any musculoskeletal pain that causes a restriction in distance, speed or duration, or stoppage of running practice over the previous month).  Although leg length and other asymmetries were found, no between-limb differences were observed in runners having sustained an injury.

 Author's Conclusion: Gait asymmetry was not associated with higher injury risk for investigated spatiotemporal and kinetic variables. 

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. 

 

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