Welcome to the Podiatry Arena forums

You are currently viewing our podiatry forum as a guest which gives you limited access to view all podiatry discussions and access our other features. By joining our free global community of Podiatrists and other interested foot health care professionals you will have access to post podiatry topics (answer and ask questions), communicate privately with other members, upload content, view attachments, receive a weekly email update of new discussions, access other special features. Registered users do not get displayed the advertisements in posted messages. Registration is fast, simple and absolutely free so please, join our global Podiatry community today!

  1. Everything that you are ever going to want to know about running shoes: Running Shoes Boot Camp Online, for taking it to the next level? See here for more.
    Dismiss Notice
  2. Have you considered the Critical Thinking and Skeptical Boot Camp, for taking it to the next level? See here for more.
    Dismiss Notice
  3. Have you considered the Clinical Biomechanics Boot Camp Online, for taking it to the next level? See here for more.
    Dismiss Notice
Dismiss Notice
Have you considered the Clinical Biomechanics Boot Camp Online, for taking it to the next level? See here for more.
Dismiss Notice
Have you liked us on Facebook to get our updates? Please do. Click here for our Facebook page.
Dismiss Notice
Do you get the weekly newsletter that Podiatry Arena sends out to update everybody? If not, click here to organise this.

Effects of step rate on running mechanics

Discussion in 'Biomechanics, Sports and Foot orthoses' started by Griff, Jul 4, 2010.

  1. Griff

    Griff Moderator

    Members do not see these Ads. Sign Up.
    Heiderscheit BC, Chumanov ES, Michalski MP, Wille CM, Ryan MB.
    Effects of Step Rate Manipulation on Joint Mechanics during Running.
    Med Sci Sports Exerc. 2010 Jun 23. [Epub ahead of print]

  2. Increased step rate = increased leg stiffness. Which will be OK for some of the people some of the time. If you already have high leg stiffness increasing step rate might just push you up above the zone of optimal leg stiffness (ZOOLS) = stress fracture, bone injury. On the other hand, it might form a useful form of therapy for a runner with decreased leg stiffness and soft tissue injury who is dropping below the ZOOLS. Decrease step length, increase cadence =increase leg stiffness in soft tissue running injury; obviously the opposite applies, so perhaps lengthen stride, decrease cadence in patients with bone related running injury.

    As you know Ian, running is effectively modelled as a spring mass system- a simple harmonic oscillator. There is a nice JAVA app. here:

    Increase the value of K (leg stiffness) and observe what happens to the frequency of the oscillation (step frequency if you like) . I know you'll enjoy playing with it, Ian.

    While were on the subject, there are some great resources for anyone who wants to improve their understanding of mechanics to underpin their biomechanics knowledge here: http://www.animations.physics.unsw.edu.au/mechanics/index.html
  3. BEN-HUR

    BEN-HUR Well-Known Member

    Does this study make any reference as to the running distance examined for the study? Or is it solely a study done on the effects of step/strike rates (over a short distance) relating to hip, knee & ankle joint loading forces with association to injury risk.

    What is stated may be conducive for long distance road running (i.e. possibly offsetting muscle fatigue/soreness in the marathon as well as reducing the accumulated forces gained from training) but I wouldn't think to be that conducive for shorter distances from a performance perspective... particularly track races.

    Putting aside the suggested benefits for injury reduction, I wonder what the implications would be on speed/performance on the whole. I presume strike cadence is a matter of balance (i.e. between vertical/horizontal excursion & energy/forces involved) & would differ between race distances... as well as running technique of the runner.

    This brings to mind something I've been thinking about for a while regarding orthotic therapy. Orthotics are commonly seen as a form of injury treatment product but how about a performance enhancement product... i.e. helping reduce ground reaction forces & reducing metabolic cost (reducing muscle tension/work) during a race... but not necessarily used for training (providing an underlying biomechanical issue is not present). I have been thinking of modifying a pair of racing flats with a custom orthotic. Has study been done regarding this area?... this however is probably another topic altogether.
  4. Matthew, this is a subject which I am very interested in. Can I suggest that you read this review paper first as it may answer many of your questions. Then, I should be more than happy to discuss this further.

    Attached Files:

  5. Griff

    Griff Moderator


    Glad you have pitched in on this. Annoyingly I can't seem to open the first link properly (the page opens but the java app won't run) - will try again later.

    If our current understanding of ZOOLS is correlated with injury as you state above is the following a reasonable summation?

    - Runner has history of soft tissue injury. They appear to be taking relatively long steps, showing increased joint kinematics (knee flexion for example) and marked CoM excursion. Potential management: Shorten stride length/increase cadence (thereby increasing leg stiffness)?

    In London a lot of 'running technique' coaches seem to have popped up of late. See here for the sort of theories they subscribe to: http://www.youtube.com/user/fitnessfootwear#p/u/6/Jio7DK15Q1E

    I have spoken to a few and essentially they give some postural and stride length re-education. Maybe they are onto something with out realising?

  6. Ian, try updating your java player, if you get no luck I'll e-mail it to you. Otherwise, you're probably on the money; as it seems are your running technique coaches, provided they are spotting those candidates that are too high in their ZOOLS and those that are too low and adjusting accordingly. Is this clinical take home?;)

    Maybe they're on to something with realisation.
  7. Griff

    Griff Moderator

    Will update it tonight squire - as soon as I have finished watching Ghostbusters.

  8. Annoyingly, I watched it on DVD last night- doh. Film!!!!!!!!
  9. Griff

    Griff Moderator

    Absolute classic. Bill Murray is a hero.
  10. RobinP

    RobinP Well-Known Member

    No 1 - gutted I missed Ghostbusters
    No2 - Simon thanks for the Java demo - it is a really great, simple model.
    No3 - Simon thanks for the stiffness paper
    No4 - I'm interested in this performance improvement thing - Are we talking about reduction in injury potential and therefore the ability to train harder or actually changing the mechanics of running to be individually more efficient?

    It is an area that very much interests me so I will be interested to hear any theories - not that I'll be able to understand all of it probably!


  11. Griff

    Griff Moderator


    I'm sure I've read a post of Simon's which mentioned an increase in leg stiffness directly improved performance/speed (assuming this individual was still within their ZOOLS for that given activity of course). Can't think of the reference off the top of my head - sure Simon will enlighten in the morning.

    Get yourself to Woodland Grange at the end of this month and hear it from the horses mouth: http://www.podiatry-arena.com/podiatry-forum/showpost.php?p=149725&postcount=2
  12. Griff

    Griff Moderator


    These two (which are also on the Leg Stiffness thread) discuss the relationship between leg stiffness and performance

  13. RobinP

    RobinP Well-Known Member

    I'd love to but I only have the time and budget to do 1 other thing besides the x ray course you suggested and I plumped for Craig's Biomechanics Bootcamp. Hopefully there will be some similar discussions there.

    Thanks for the papers

  14. Both. In general researchers have increased leg stiffness by manipulating surface stiffness. When we run on a compliant surface, the surface and the leg act like two springs in series. So we have an effective spring stiffness for the system made up from the stiffness of the leg "spring" (kleg) and the surface "spring" (Ksurf). The body wants to maintain centre of mass (COM) kinematics, i.e displacement, frequency of oscillation etc. so in response to a compliant surface it will increase the leg stiffness to compensate for the decrease in surface stiffness to maintain constant COM kinematics. Increasing leg stiffness in this way increases the elastic energy storeage and return, metabolic cost is reduced.

    Go back to the physics of springs.
  15. RobinP

    RobinP Well-Known Member

    Am I the only person appreciating the irony of the fact that this thread is talking about "Zones of Optimal Leg Stiffnesss -ZOOLS whilst concurrently discussing Ghostbusters in which Dana becomes possessed by ZUUL, the minion of Gozer the Gozarian?


  16. Know this, when I first thought of the acronym "ZOOLS", I had the film Ghostbusters in my head. Like I said earlier: film!!!!
  17. Griff

    Griff Moderator

    I reckon Drs Spengler, Venkman and Statz had reduced kleg...

  18. I reckon Venkman's approach to research is killer.
  19. BEN-HUR

    BEN-HUR Well-Known Member

    Hi Simon,

    Thanks for that PDF... I have skimmed through it & it looks very interesting. Some points stated have put a new perspective on the understanding of the topic.

    Once I have a closer read I will like to discuss further... particularly on the practical applications of it, which I have been looking into for a while & recently been putting into practice.

    If only my ideas had developed at the same time as my body... I would have more time to play around with them. Anyway, better late than never.
  20. BEN-HUR

    BEN-HUR Well-Known Member

    Big sigh... it seems this coach has taken a few pages from Professor Lieberman's premise in justifying how we apparently evolved to run :deadhorse::hammer: (I'll say no more).

    Yes, I don’t think their reasoning is the same... it is a different wavelength. So I've heard so many times before from Pose/Chi running convertees & barefooters... it is the fear of having that braking affect when (as they put it) "striking ahead COG". I think they believe it is an epidemic & that those of us who don’t follow their methods are striking too far ahead & thus subsequently are deemed ‘brakers’.

    The following are points I found interesting from the previously cited PDF...
    View attachment Lower Extremity Stiffness Implications PDF.pdf

    I suppose the above point helps support why in part that plyometrics are beneficial for runners. It may also support the idea of running with an added weighted extremity (i.e. ankle weights)... adding weight to the extremity would contribute to greater force imparted to the lower limb as well as invoking greater resistance to movements (i.e. heel kick during swing phase). Both methods would seem to be conducive to adopting & adapting to greater degrees of stiffness of the lower limb.

    This didn’t seem to resonate with me. I would have thought the opposite, that being... a longer stride length would induce greater leg stiffness as a result of the increased demands of the activity i.e. higher resistance needed. Maybe the key point here is... for a given velocity, a longer stride length is associated with lower stiffness”... as a result of overstriding (??).

    I suppose a good analogy here would be that of tyre pressures for your car... tyres with little pressure (lower stiffness) would be less economical than tyres with high pressure (higher stiffness) in regard to petrol economy.

    I wonder if this should have implications on stretching routines for runners... particularly before the event. I have read in the past that stretches (in particular static stretches) were not conducive before a race. Thus stretches may have an adverse impact on the state of lower limb stiffness.

  21. A better a
  22. Griff

    Griff Moderator

    Spooner - over 24 hours have passed and the suspense is killing me.

    What would a better analogy be??
  23. How do you know "a" was for analogy? ;)

    I was going to talk about springs, but changed my mind. I didn't realise I'd hit the send button and by the time I did, it was too late to edit. You'll find out in couple of weeks. You getting there on Thursday? Give me a bell, when you get there.
  24. Griff

    Griff Moderator

    Yep driving up after work Thursday night. Beer o'clock.
  25. The idea that increases in "step rate" can be beneficial for many runners is nothing new. This has been a coaching technique for distance runners ever since my high school running years (early 1970s).

    The more common and frequently used term is "stride frequency", not "step rate", for the number of running steps/strides per minute. In coaching runners, it is typical for many inexperienced runners to "overstride" or have an increased stride length versus their optimal stride length, so we tell the runners to "chop their stride" and "increase their stride frequency". While this would be expected to diminish the center of mass excursion and decrease joint loading for each running step, one must also consider that the accumulated loading force on the joints per unit of time spent running does not change nearly as dramatically since there are more foot collisions per minute when stride frequency is increased.

    Interesting research, however.:drinks

Share This Page