Priscah Jeptoo won a silver medal in today's Olympic Marathon, finishing in 2:23:12, 5 seconds behind Ethiopia's Tiki Gelana. An impressive time in wet slippery conditions. Yet it wasn't just her time that caught the eye. A few people noticed her unusual running form and the effect it had on her right knee. The way she swings her right leg is a little different from most elite runners – she seems to flick the right ankle out as the knee bends – but it's what happens on impact that would concern me;

The right hip adducts (comes in towards the midline) there is a valgus stress on the knee (the lower leg moves outward relative to the femur) and the right ankle appears to overpronate (although this is hard to tell).

If we add in guide lines it clarifies it a little;

It's not position that is necessarily of concern, but the difference between right and left. You might expect this running style to place more stress on lateral compartment of the knee (outside of the knee joint) and the patellofemoral joint. The ITB might tighten to compensate for the hip adduction. The inside of the ankle joint, Tibialis Posterior and Achilles tendons may be under greater load too. Higher up the chain, the hip and lower back might also suffer.

I couldn't tell what shoes she had on, @ThePhysioRooms has a keen eye and he suggested they might be Nike Flywire Racers. They certainly looked to be a minimalist shoe and you can bet your mum she wasn't wearing Brooks Beasts! (for non shoe-geeks and people who actually have a life they are a motion control shoe for overpronators). So it appears no attempt is made to correct her form from a footwear point of view, but then you'd expect racers in an event like this. But does her form even need correcting?

Jeptoo is an Olympic silver medalist, an elite athlete with a 2:20:14 PB for the marathon. In 2011 she won the Paris Marathon and came second at the World Championships. Priscah Jeptoo is part of an extreme talented group of Kenyan runners that are amongst the best in the world.

So does her unusual form really matter? It's likely she's always ran in this way. Her tissues will have adapted and strengthened in response to the stresses on them. It could be that she has an underlying biomechanical cause, for example a leg length difference, and what we see is actually a useful adaptation of the body to compensate.

More and more evidence seems to be emerging that even elite athletes have a host of biomechanical 'issues' and yet continue to compete at the highest level. Perhaps the issue is not what body you have but how you use it. Smart training with careful use of mileage prevents over stressing vulnerable tissues. Strength and conditioning work helps the muscles to absorb impact and reduce joint loading and rest is utilised as a valuable tool to allow tissues time to adapt.

So if you have somewhat unusual biomechanics, or form, you're really just like an Olympian and certainly one of many. In fact, are any of us actually biomechanically perfect? I highly doubt it.

My final thought is this, a little advice, if you google Jeptoo, you will get information about the highly decorated Kenyan runner. If you google Jetpoo you get something very, very different. Don't google Jetpoo!


  1. Yes, clearly she has all those problems mentioned yet apparently she still performs at a high level. My contention is that this will significantly reduce the length of her career and cause trouble for her later in life. I think that she could take steps to partially correct for some of these biomechanical issues despite her lifelong accomodation to them. This is not to mention the detriment of all that lateral motion to her forward progress.

  2. What a timely post! I was watching today and wondering how the heck she runs so fast with such a pronounced valgus alignment. It seemed also that the swing leg hip was internally rotating too. Everything looked off but those biomechanics certainly don’t seem to affect her speed. It’s really amazing to find out someone can run at such a high level like that. I’m curious to see, with all the running she’s done with that form, if there are any degenerative changes to her lateral compartment.

  3. Personally I do not subscribe to the philosophy that there is an ‘ideal’ alignment or biomechanical movement pattern for all. That said it is very difficult not to take notice when you see vast kinematic excursions from what was historically suggested to be ‘textbook’.

    There is a growing body of research which suggests that the human locomotor apparatus will self-select the most metabolically efficient way to ambulate (for a given individual performing a given activity). It is certainly well established that kinematic variations of the lower extremity are high and this is considered to be ‘normal’. Throw in the curve ball that the prospective relationship between skeletal alignment and overuse injury is not as black and white as we once thought, and those of us treating injured sportsmen and women find ourselves at a rather interesting crossroad.

    Benno Nigg’s theory on preferred movement pathways (although over a decade old now) is worth a read:

    Great topic for discussion Tom.

  4. How much of a role do you think her weight plays in being able to run like this? Say, she were 10 kg heavier, would she be more likely to experience injuries given such running form?

    • Thanks for your comments, I think her weight will play a part actaully, that’s a good point. Perhaps because she is a fairly light build she can get away with it to some degree, the extra 10kg could make a lot of difference.

  5. As a distance runner who has myriad of running related injuries, her bio-mechanics caught my attention and reminded me of Phoebe Buffay, character from sitcom Friends.

    Thanks for detailed analysis of her running style. For a runner it made interesting read.

  6. To be able to assess coronal alignment, the patella must be facing directly anteriorly. She does not have a valgus knee, she has increased femoral neck anteversion with the typical “eggbeater” run.

  7. I started running 29 years ago at the age of 42, and it soon occurred to me that the chief cause of injury was the modern running shoe with its huge built-up heel. The effect of this was to exaggerate the heel strike common to distance runners and accentuate any biomechanical oddities the runner might have. The human heel is specially designed by Dame Nature to cope with any sort of strange angle the foot might take when hitting the ground, and to transmit the shock right up the middle of the leg, whereas the “overhang” of the modern shoe extends a considerable distance to the rear and both sides, and thus the shock goes up the back or side of the leg and therefore causes problems. I discovered many years later that some athletes who were used to running in plimsoles complained about the cushioned shoes when they were first introduced, and subsequently the ‘barefoot running’ movement has gained much credibility, but bfor a long time I was regarded as very eccentric.
    Priscilla Jeptoo’s wonderful victory today might finally convince people that “nature knows best”. I don’t anticipate she will have any more injuries or long-standing problems than are experienced by athletes with a more normal gait.

  8. Good post!

    I agree with the opinion about it’s more an anteversion of the femoral neck what ellicits a valgus on her knee, specially on the left leg. The right leg show less femoral neck anteversion anda clear internal rotation of the femur, which compensates with external rotation of the lower leg and another external rotation of the ankle (which is part of the overpronation ‘complex’). And of course I agree if she was 10kg heavier she would be slower and much more injury-prone… But this is valid to all the athletes in the world!

    In my opinion she would be a little faster if she had a better running technique, and probably she would be more protected against injuries when she got used to and was able to run as fast as she does now with the new technique… The problem at this level (top elite) is… Do you have the time that she needs to modify some of the things of her technique? Would it be worth to spend some weeks, months or even years to change and cosolidate a new technique?

  9. I have the exact same “egg beater” leg swing and have had problems on and off with my knee since taking up running only 2 1/2 years ago.
    I remember when I was a child someone telling me that I ran funny so unfortunately, even though I loved sports, I steered clever of any sports that included running.
    Only yesterday I asked my Chiro about it and she suggested one reason that it may be just the way the bones in my hip have set as a child and whatever the reason there is probably nothing you can do about it other than mentally try and control it… However it naturally gets worse with fatigue.
    I am somewhat relieved to know that this is just the way I am am it’s not really that uncommon.

    • how funny Tania, I was just searching the same thing.
      I also swing my legs out when running and have done so since a young child running fun runs. Never really had any problems until now. I find that my right hip is always a little sensitive and I get lower back pain, which I think is from my glutes not being strong enough.
      Do I fix the glutes or the swing?

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