Once upon time, video gait analysis was something that only the elite would use as a tool for fine tuning their already near perfect running technique. Then one day, shoe shops realised that placing a runner on a treadmill and watching their feet move could be great way of prescribing footwear. Sadly, they got that all wrong (more on that later) but before long runners of all abilities found themselves being offered video gait analysis as a way of reducing injury and increasing performance. How effective is gait analysis in doing this? Let’s take a closer look…
3D Gait Analysis
The latest development to hit the market is ‘3D Gait Analysis’, a system that uses depth sensing cameras to record all sorts of movements that the naked eye could either miss or simply not be able to see. StrideUK (where I am based) was one of the first companies in the country to start offering this new 3D technology, so I am obviously biased when it comes to recommending it but I am also the first to warn runners that ANY form of gait analysis is only as good as its interpretation.
Now, don’t get me wrong: the technology behind 3D Gait Analysis is truly incredible and I am happy to say that with ten years experience of using 2D gait analysis for over 1000 runners, the new 3D technology allows me to offer a far superior service. However, that’s because I have learnt (often the hard way) the importance of knowing the limitations of gait analysis, the art of not jumping to unsubstantiated conclusions, and realising that when it comes to running injury & performance we do not have all the answers. Having access to a whole new load of data is awesome but it means very little if you fall prey to making tenuous links & weak assumptions.
Gait Analysis: The Essentials
When analysing a runner’s gait (or having your gait analysed), it is vital to have the following factors in mind:
• Despite what we may read and hear, there is still very little evidence that links specific movement patterns to running related injury.
• There is no one optimum way of running; we see too much variance in successful running forms to say ‘this is how you need to run.’ There are similarities between the most successful running forms but one look at an elite pack shows that they do not all run in the same way.
• Using technology that compares how one runner moves to stored ‘norms’ is a very grey area. The variance mentioned above means that there is no guarantee that the runner on your treadmill will benefit by moving in the same way as the majority of runners in a database.
For every injured runner I see exhibiting a certain running movement, there will be another later in the week exhibiting the same movement but not suffering from the same injury. It’s like the patient who comes in with neck pain and has one shoulder higher than the other – how can we blame the neck pain on the difference in shoulder height when we see hundreds of other patients with differences in shoulder height but no neck pain? Asymmetry is more common in human anatomy than symmetry. Any therapist, trainer or coach who blames a runner’s pain on uneven shoulders, hiked hips, anterior pelvic tilts or leg length discrepancies needs to take a long, hard look at the huge amount of asymmetrical runners out there who are not in pain, not to mention the hundreds of ‘perfectly symmetrical’ runners who are in pain. Chasing symmetry as part of gait analysis can be a slippery slope of red herrings.
Keeping An Eye On Other Factors
How you run will obviously play a large part in the way your body deals with the relative forces & loads. The problem is, research has yet to explain why some people running one way get injured but others running the same way do not. Until we know more, it is vital that we remember to also keep an eye on other factors that may be increasing risk of injury or inhibiting performance. The good news is studies have provided us with some pretty good data in other areas.
In the diagram below, the bottom part of the pyramid represents factors & interventions that are most supported by evidence; the top of the pyramid represents the least evidence. Let’s take a look at them one by one.
• Inappropriate Training Loads
Training load proudly fills the largest portion of the evidence pyramid, and rightfully so. Studies suggest that the key factor in 60-70% of running related injuries is inappropriate training volume (Hreljac et al. 2004: Impact & Overuse Injuries in Runners). A sudden increase in either running frequency (runs per week or day), intensity (speed, incline, etc.) or distance (time on feet) can lead to tissue overload and pain/injury. For this reason, gait analysis must include a thorough look at the training habits of the runner.
• Strength Training
If inappropriate training load is a key factor in running related injury, it makes sense that getting stronger so you can handle more load will be a good way of reducing risk of injury. The research supports this: studies show that strength training can reduce sports injuries to less than 1/3 and overuse injuries by almost 50% (Lauersen et al. 2013: The Effectiveness of Exercise to Prevent Sports Injuries). Any gait analysis that fails to take into account a runner’s strength could me missing out on a very large part of the jigsaw.
• Running Technique
As we have already stated, how someone runs will obviously affect what parts of the body are put under stress. If we define pain/injury as sign that the load threshold of a certain tissue has been exceeded, modifying that runner’s form so as to reduce the load to that particular tissue can provide a valuable way to break the pain cycle and allow recovery whilst running. The implications of this are actually quite huge when we take into account that pain is not just a product of tissue damage. Pain is an output from the brain & nervous system in response to a variety of sensory feedback. Tissue damage is just one form of sensory feedback and does even need to be present for pain to be experienced (people with an amputated limb often feel pain in the absent limb). Helping someone experience pain free running can help the nervous system recover. Any gait analysis that ignores what we refer to as the ‘biopsychosocial’ nature of pain is very likely to miss out on a larger part of the picture.
Basing shoe selection on how much you ‘pronate’ (a perfectly natural and vital part of foot mechanics) is not actually backed by any science. Though some runners wearing an ‘anti-pronation’ shoe may see pain disappear, others do not, and some see symptoms get worse. Research has clearly shown that categorising runners into three groups based on their foot arches (high/normal/low) once again ignores natural human variance. Different shoes (and insoles) will load tissues differently, it’s just a question of working out what works for your body. Modifying footwear can be a useful way of resting sensitised tissues and allowing recovery but as far as choosing which shoe is best for you, gait analysis will rarely provide the answers. For more information, do a search for ‘overpronation’ on my website (sportinjurymatt.co.uk).
• Other Stuff
The smallest part of the pyramid at the top is sadly a place where many runners (and therapists) spend too much time. Anything we haven’t mentioned yet sits here: stretching, foam rolling, kinesiology tape, acupuncture, etc. I am not saying these are all a waste of time but as far as running related injury goes they are the least supported by evidence. There will always be runners who swear by them of course but anecdotal evidence doesn’t really count for much. Devoting too much time at the top of the pyramid runs the risk of missing out on the evidence based bottom, staying injured and delaying recovery. You’ve been warned.
The effectiveness of using Gait Analysis rests heavily on realising that running technique is just one piece to the jigsaw. There is no doubt it plays a part but focussing solely on the biomechanics runs the risk of eclipsing a whole host of other factors that may be responsible for injury or inhibited performance. If you are considering video gait analysis (which I thoroughly recommend you do) make sure it includes a thorough assessment of all the levels of the pyramid, in particular training load and strength.
3D Gait Analysis with Matt Phillips can be booked on the Stride UK Website HERE.
Have you had an interesting experience connected with Gait Analysis? Have you used the latest 3D software yet? Whether you are giving or receiving the analysis, we would love to hear from you in the comments section below!