I work with lots of runners, both recreational and competitive, who are seeking to improve performance or overcome injuries. The most common issues I see are iliotibial band syndrome (ITBS) and patellofemoral knee pain (PFP).  With every runner, I routinely perform FMS and video analysis to get a better understanding of their movement patterns, gait mechanics and asymmetries.

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Without question, they tend to ask me if there is a better way to run.  Obviously, every accomplished runner has his/her own opinion on the matter.  Some prefer forefoot or midfoot strike, while other do just fine with a heel strike pattern.  In essence, we do not have any sound research or biomechanical evidence to declare one a winner.  Since I work with many injured runners, I am always seeking to find the most efficient ways to reduce injury risk and eliminate pain.

A paper just published in the September 2015 American Journal of Sports Medicine by Boyer and Derrick sought to answer the question of how shortening the stride length or altering foot strike pattern may impact certain variables.  Specifically, the authors sought to compare step width, free moment, ITB strain and strain rate, and select lower extremity frontal and transverse plane kinematics when stride length was shortened 5% and 10% in habitual rearfoot and habitual mid-/forefoot runners using both strike patterns while shod.

For the study, they used 42 healthy runners (21 habitual refract and 21 habitual mid-/forefoot) whose average age was 21 +/- 6 years.  Participants performed all testing in their own shoes.  They ran on a treadmill for 5 minutes at 3.35 m/s with their habitual stick pattern.  The time to complete 20 strides was timed after minutes 1 and 3 of the 5-minute run and the average was calculated.  This was used to determine preferred stride length and step rate.

Next, participants performed 7 overground running trials at 3.35 m/s landing with the right foot on the force platform. Following this, all participants ran on the treadmill again with a metronome to simulate a 5% and 10% shorter stride length. Again, this was followed by the same overground running trials at 3.35 m/s.  Once this was finished, brief instruction was given to each participant on how to run with the opposite strike pattern including a few seconds of slow motion video.  All of the experimental conditions were repeated on each runner now with the opposite strike pattern.

Effects of stride length

  • As stride length shortens step width increases
  • Pelvic drop, peak hip adduction, peak ankle eversion, peak ITB strain and strain rate and peak abductor free moment also decreased consistent with prior research
  • No decrease in adductor free moment was observed
  • While there were decreases in kinematic variables, all of these changes were approximately less than 1 degree.  according to research, ITBS and PFP are associated with about 2.5 to 4 degrees more hip adduction so shortening stride length may not alleviate pain with these conditions.  With that said, it will also not aggravate those issues.

Effects of foot strike pattern

  • Step width is wider for RFS compared to FFS and despite a narrower step width for FFS, peak ITB strain or strain rate did not increase.  As such, it does not appear using a RFS pattern instead of FFS would increase risk of ITB problems
  • Peak hip adduction angle was similar between RFS and FFS supporting similar ITBS and PFP injury rates seen in habitual rearfoot and mid-/forefoot runners.
  • Peak knee internal rotation and peak eversion angle was similar between styles
  • Free moment differed between foot strike styles as pattern was more consistent in FFS - authors speculate differences in early part of stance may be due to super body rotation (not measured) or foot rotation
  • Hypothesis that adductor free moment would blearier for FFS was not supported

Key takeaways

  1. Since none of the measured variables differed b/w habitual foot strike groups, the changes imposed by shortening the stride or using a different strike pattern can be generalized across the groups
  2. The lac of foot strike x stride length interaction indicates the the effects of stride length can be generalized to both FFS and RFS
  3. For injured runners, modestly shortening the stride length reduces several kinematic variables associated with ITBS and PFP, however it is not clear if these changes are really enough to impact pain.  With that said, shortening the stride length will not exacerbate said symptoms.
  4. There is still no clear winner in terms of FFS or RFS with respect to impacting injury predilection, so perhaps the body is best at self selecting the running pattern that is most suited and efficient for the person.  Clearly, we need continued research with respect to this question and whether making minor tweaks to running as investigated in this paper can or will have dramatic impact with respect to injury prevention and pain resolution for runners abroad.
  5. As therapists, trainers and running coaches, we must continue to seek the proper balance between proper physical training/preparation along with the right running form/mechanics to allow the client to run fast, efficiently and pain free.

If you are a runner and are looking for a comprehensive guide to help you balance your body and be physically prepared to run, be sure to check out my latest e-book titled ‘Fit for Running’ and download a free excerpt at www.fitforrunning.com.

Article reference: Boyer ER and Derrick TR. Select injury-related variables are affected by stride length and foot strike style during running. Am J Sports Med. 2015;43(9):2310-17.