I have a long-term interest in orthotics, the custom inserts that reportedly ensure pain-free feet, stemming way back to my days as a PhD student. In the early and mid-1990s, I worked on T cell receptors and the mechanisms by which they transmit important signals into the cell interior, ultimately leading to cell proliferation – a critical component of our normal immune response. However, my own physiological response was that by the end of a long day in the lab, mostly standing and running biochemical assays, my feet ached.
The first course of action for sore feet is to rest. Popping off one's shoes or sandals, and propping up one's feet usually brings a degree of relief. And it did for me; at least for a while. But over time, I began to notice that upon awakening in the morning, my feet were already sore – and hadn't recovered from the previous day's aches. For those who haven't experienced this kind of feeling, in my case it was never acute pain – just a dull ache in the heel and metatarsal areas. But it was depressing to feel uncomfortable getting out of bed and standing up after a full night's rest.
It was my PhD adviser who first suggested custom orthotics – that my feet were probably flat, or had insufficient arches, and that custom orthotics would help. Being me, I resisted; I compromised and came to work in supportive training shoes, rather than sandals. That did not help. So I caved in, and went to see an orthotics expert. In those days, they had me step on a clay-based cast of some sort and it took about three weeks to make an actual plaster mold for my shoes. By the time I finally received the orthotics, I had managed to rest my poor feet a little more as I was entering the final stages of my PhD work, and spending more time writing papers and my dissertation. When I later left for my post-doc, I didn't even bring the orthotics with me – and though my feet were often sore, I grinned (or rather complained) and bore it.
Fast forward around 15 years, during which time chronic foot pain has dogged me – and then, we adopt a dog. Although I adhere to a rigid exercise regimen, the extra walks were probably what broke the scientist's metatarsal. Metaphorically, of course. It's amazing how such a modest change altered the balance from somehow bearable pain to pain that is almost debilitating. But it did. So my wife suggested that the new advances in orthotics might be worth a try – after all, she was the main target of my frequent complaints. And anyway, it's only money. And a lot of us would pay handsomely to make chronic pain go away. Many industries are built on that principle.
Herein is the catch; desperate people resort to desperate measures. A degree of the pseudo- and anti-science movement that is called homeopathy stems from suffering and the inability of modern medicine to completely address issues such as chronic pain. Of course, a large part of homeopathy and refusal to vaccinate children is simply related to ignorance. And so, desperate for a solution, and most atypically for me – as I almost always research and verify whatever I do – I made a spur of the moment decision to try one of the new orthotic companies that have been springing up across this country.
Did I research what qualifications the personnel in these companies have? Whether they are trained in podiatry? Physiotherapy? In orthopaedics? Did I look up their length of training? Degrees? Experience? The answer is no. I failed to do proper research. An expensive experiment, to say the least. But hope springs eternal, and I had been diagnosed with low arches and relatively flat feet. So it makes sense that lifting the arches would remove some of the pressure from the heel and metatarsal region, right? Perhaps.
In the orthotics shop, I stood barefoot on some inked paper that left an imprint – and the person taking care of me analysed my footprint and "confirmed" the suspicion that low arches were the cause of my pain. The system used by this particular company is to provide three sets of orthotics: 1) a high arch one for day-to-day use (the most aggressive arch for lifting the heel), 2) a less aggressive arch for walking/sport, and 3) a modest arch for relaxing around the house. The "custom" part of the orthotics was not a de novo designed arch support, but rather the availability of a huge selection of sizes, arches, degrees of firmness and flexibility and so on. So off I went with a trial set.
I found that the orthotic support for around the house did provide modest relief in my slippers/flip flops. But the pain did not go away. Over the next several months, I returned multiple times (8-10 times) for adjustments, replacing the day-to-day inserts and sports inserts until I returned full-circle. As my daughter would say when she was three years old, "No luck said the duck."
By this time, I had recovered my senses and began a systematic literature search to decide whether there was even any point continuing with my orthotics. I found that the jury was definitely still out on their efficacy, at least from a scientific standpoint. First, a recent article suggests that "there are many unscrupulous and shoddy suppliers of these products, and the science is complex and incomplete," and notes, "Only pedorthists are trained in both gait analysis, lower body anatomy and biomechanics and the actual fabrication of custom foot orthoses."
Research at the National Library of Medicine's website (PubMed) identified a plethora of articles addressing the efficacy of orthotics. On the one hand, there seems to be cumulative evidence that orthotics are frequently able to decrease foot pain for many people. But there also seemed to be little understanding of how this occurs. One article, entitled "Custom foot orthoses for running" points out in the abstract that "When designing custom foot orthoses for running, the differences between walking and running mechanics must be considered." This was not something I had carefully considered.
My own exercise regimen consists of brisk walking, but no running, as I have knee injuries incurred from years of marathon running when I was younger. In any case, I realised that the rather cursory foot impression done at the orthotics store in no way takes into consideration my gait when exercising – despite the fact that the second set of orthotics was specifically designated for exercising.
In 2011, Gina Kolata interviewed two experts on orthotics: Dr Nigg, a professor of biomechanics and co-director of the Human Performance Lab at the University of Calgary in Alberta, and Dr Hamill, professor of kinesiology and the director of the University of Massachusetts in Amherst biomechanics laboratory. Both experts agreed that it's entirely unclear how orthotics actually work for athletes. What this means is that choosing the right orthotics – particularly when gait and movement need to be taken into consideration – is more about trial and error than actual science. Indeed, in the same article, president of the American Academy of Orthotists and Prosthetists, Scott Cummings, noted that "the trade is only now moving toward becoming a science." Tell me about it!
It seems that even from a scientific standpoint, it will be extremely difficult to sort out efficacy trials. People with plantar fasciitis, a very specific instance of foot pain due to an inflamed ligament on the bottom of the sole – react very differently to orthotics than people with low arches. Compounded with such different problems that lead to foot pain are studies that while informative, may be limited in their usefulness for live subjects. For example, Meardon et al published a paper in Foot & Ankle International that tests bone strain in cadavers in the presence or absence of fitted orthotics. While clearly this type of rigorous experimentation is necessary, it highlights the difficulties in coming to conclusions about orthotics for your run-of-the-mill live person who suffers from foot pain.
As for me, I have found a tentative solution. I use my orthotics in day-to-day use and around the house. But for exercise, I merely employ a silica cushion insert. This seems to be a fair solution – perhaps lifting my heel and metatarsal area does help, but compounded with speed walking, the inserts do not work properly, at least in my case. So I have learned my lesson – there is no replacement for proper, rigorous, research, especially in making decisions about one's health and comfort. Next time, I will not sell my sole.
