Science based chiropractor, Dr. Alexander Jimenez demonstrates that foot injury as a consequence of the foot/pedal interface is amazingly common and under-reported...
Cycling injury research can be broadly collated into two groups: trauma-related, which happens as a consequence of a crash or collapse, and non-trauma-related, which entails overuse-type injuries. The epidemiology of collision/impact injuries in cycling has brought a relatively large amount attention from investigators, presumably because of their life- threatening possible. However, the data indicates that despite the acute dangers of accidents and drops, cyclists are more likely to suffer with accidents resulting from the action of biking. A 2006 research on cycling injuries reasoned that the prevalence of non-traumatic harm was as high as 85 percent(1).
Although coaches, chiropractors, physiotherapists and coaches can not do much about the former, overuse-type injuries are amenable to treatment and prevention. A survey of the literature about non-traumatic cycling injuries demonstrates that much of this research thus far has been focussed on injuries of the trunk, neck, arms, hands, buttocks, perineum and knees(two). This is perhaps understandable; cyclists interface with the bike at three distinct points -- the handlebars, the saddle and the pedals. Incorrect handlebar shape/settings, saddle design/height or framework geometry could lead to excessive loading on muscles and joints as well as undesirable motion biomechanics, significantly increasing the probability of harm (see Box 1).
Overlooked Foot
One area which may have been overlooked, however, is your pedal port, especially because it is the foot/pedal interface which typically encounters the greatest forces during cycling. Unlike other overuse biking accidents mentioned above, there's very little peer-reviewed research accessible on foot injuries, with those foot accidents that are reported in the literature being mainly descriptions of foot numbness, metatarsalgia, achilles tendonitis and plantar fasciitis(3-5).A study by Dettori and Novell (2006) reported about the prevalence and incidence of lower leg/foot cycling injuries collated by a meta-review of non-traumatic bicycling accidents(1). The data were presented as self-reported heights of pain gathered from cyclists engaging in tour rides, ranging from the shortest distance of 545km over a six-day occasion to the longest distance of 7242km within an 80-day event. The incidence of reduced leg/foot harms was reported to be 7 percent, 13 percent and 22% respectively, with an incidence rate of 24 percent.
Nonetheless, this data believed both the lower leg and the foot to be one homogeneous unit rather than separate anatomical regions, which consequently negates its usefulness as meaningful foot pain data for the wider cycling population. Simply speaking, there's very little research concerning the frequency, etiology and/or management of foot discomfort in cycling available to direct the clinician. The little amount of available literature that's available tends to be descriptive non-systematic literature reviews or view. Moreover, where data are reported, participants have yet to be sampled robustly and research have tended to concentrate only on elite cyclists instead of those engaged in club, recreational and fitness cycling (that the huge majority of cyclists).
New Research On Foot Pain Incidence
Given the abundance of anecdotal evidence suggesting that foot injuries in cyclists are more common than is often reported, a 2012 study set out to try and identify typical kinds of foot injuries suffered by cyclists and just how common these are(6) In the study, Australian researchers set out to answer the following questions about foot injuries in cyclists:
- what is the distribution of age, gender, foot/pedal interface use and distances cycled amongst cyclists who experience foot pain?
- what type of pain and in what region of the foot do cyclists typically experience pain?
- what techniques do cyclists use to try and cope with/overcome foot pain caused by cycling?
- are there key groups of cyclists at greater risk of foot pain than others?
A number of critical findings became evident, the first of which was that over half of the cyclists (53.9 percent) reported experiencing foot pain whilst biking. The cyclists normally described the pain as 'burning' or 'numbness.'
The most usual methods of dealing with this kind of pain comprised stopping for a period of time through the ride, shoe removal, walking round and massaging/ stretching the foot.
This analysis shows exactly how common foot pain may be among recreational cyclists. The fact that 'cleated-in' shoes increased the danger of pain is perhaps no surprise; studies have already shown that these types of shoe have a tendency to localize plantar pressures, which in turn can be detrimental to blood and nerve supply integrity in that area(2,7). Another implication that follows is that cycling shoe design and choice could be just as essential as saddle and saddle options for pain-free cycling.
Evaluation Of The Foot-Pedal Interface
The foot-pedal port is the sole guide website for energy transport from the fisherman into the bike. In a 'cleated-in' pedal port (one having clip less pedals and shoes or toe clips and straps), all of the body's power to make the bicycle move forward is moved to the pedal through a really small contact area (typically around 60mm2), and there is consistent anecdotal evidence that forefoot pain at this stage of energy transfer is common(2,7). The most obvious issue this raises therefore is if the use of particular sorts of biking shoe structure, insole substances or contoured surfaces can decrease the incidence of pressure hot spots by spreading the load more evenly. Indeed, this approach is embodied by specific cycling shoe makers like Specialized, who utilize a combination of particular material types and contoured surfaces to attempt to minimize forefoot distress.Looking at shoe building first, a current trend has been the movement towards stiffer and stiffer cycling shoe construction and especially the use of carbon fiber. The reasoning is that higher shoe stiffness contributes to less shoe bend and therefore less electricity wastage during the power transfer. To look into this specific query, US scientists conducted a study into cycling shoe stiffness on forefoot pressure(7).
Plantar pressure data have been recorded in two different shoe types to ascertain the effect of cycling shoe stiffness on peak plantar forefoot pressure in cyclists. Two pairs of shoes of the same size and manufacturer, indistinguishable except for outsole material and stiffness, were analyzed. Shoe stiffness measurements were gathered under controlled conditions and in two different configurations using a dynamic hydraulic tensile testing machine. Measurements of plantar pressure were assembled using 'Pedar' capacitive-based detector insoles while issues pedaled in a seated position in a restricted power output of 400 watts (hard!) . The pressure distribution in carbon fibre composite sneakers during cycling was compared to that of cycling shoes made with (cheaper) plastic soles.
Concerning stiffness, the carbon fibre sneakers were surely stiffer -- 42% and 55% more pliable than plastic sneakers when subjected to longitudinal bending and bending bending, respectively. During pedaling, the carbon fibre shoes generated peak plantar pressures 18 percent higher than people of plastic design, and the authors concluded that competitive cyclists afflicted by metatarsalgia or ischemia must be particularly careful when using carbon cycling shoes because the shoes increase peak plantar pressure, which might aggravate these foot ailments.
Jumping To Conclusions
However, more recent research suggests that assessing a shoe's possible to cause foot pain based purely on its structure may lead to incorrect decisions. This originates from an interesting study published annually by German researchers, who contrasted the effects of carbon fiber foot orthoses with standard cycling shoe inserts on plantar pressure distribution through biking(8). In the study, 11 pain-free triathletes were examined on a cycle ergometer at two different cadences (60 and 90 rpm) and at two unique workloads -- both 200 and 300 watts. These were:- a cycling shoe with its standard insole (control condition);
- the same shoe but with carbon fibre foot orthoses.
As Figure 1 reveals, peak pressures recorded in the total foot area ranged from 70-75kPa at 200 watts power output, and out of 85-110kPa in 300 watts. Regardless of being stiffer, the carbon fibre foot orthoses reduced peak pressures by approximately 4.1 percent compared to the standard insole. Within separate foot regions, back foot peak pressure was decreased by 16.6 percent, mid foot strain by 20.0 percent and forefoot strain by 5.9 percent. It was mentioned, however, that in the toe region, peak pressure with the carbon orthoses was raised by approximately 16%. Regardless of which fit was utilized, when it came into the forefoot it also had been the lateral forefoot that showed the maximum peak pressures when compared to lateral and lateral forefoot (34 percent and 59% greater for the carbon and standard inserts respectively).
Conclusions & Recommendations
The US researchers mentioned previously concluded from their study that the plantar pressures recorded during seated biking were within the range listed for ordinary walking, despite cycling being considered an extremely low impact game(7). If a fisherman poses with foot pain, consequently, the problem of plantar pressures in biking shouldn't be dismissed as the potential origin. This is particularly true for competitive cyclists that will potentially 'push' around 40 million pedal cycles throughout their career!Excessive plantar pressure is not something that happens in isolation, and much more study is needed about the use of other factors in precipitating foot discomfort during cycling. These include bicycle set-up (saddle height, saddle distance, cleat position), type of cycling shoe (type of cleat, material of sole), shoe fit (too tight, too narrow, attached too tightly), foot type of the cyclist (pes planus, pes cavus), presence of any lower limb biomechanical or structural deformities (genu varum, forefoot supinatus, ankle joint equinus), differences in body mass, the typical cycling terrain (hills or flat terrain) the preferred pedaling cadence and use of low/high gearing, as well as the experience and fitness of the cyclist.
For now, however, coaches, physiotherapists, chiropractors and coaches must know that foot discomfort during cycling is surprisingly common and much more likely associated with plantar pressure issues. Box 2 gives some practical recommendations that can be offered to cyclists in their own care.
1. Sports Med. 2006;36(1):7-18.
2. J Bodywork Movement Therapies 2005; 9:226-236.
3. Sports Medicine 1994; 17:117-131 .
4. Sports Medicine 1991; 11:52-70.
5. American Podiatric Medical Association 2000; 90:354-376.
6. Journal of Science and Cycling 2012; 1(2): 28-34.
7. Foot and Ankle International 2003; 24:784-788.
8. Sportverletz Sportschaden. 2012 Mar;26(1):12-7.