Monday, December 17, 2012
Understanding the Structure of Your Feet: A Critical Element for Staying Injury-Free
In recent years, a great deal of research has been published that suggests a possible link between arch development and injury patterns in runners and athletes. Due to the change in mechanics associated with varying arch heights, understanding how your arch is potentially affecting the biomechanics of your leg is crucial for athletes wishing to stay injury-free and prevent painful, chronic conditions and deformities that negatively impact athletic performance.
The relationship between arch height and injury pattern is fairly straightforward; feet with low-arches tend to be hypermobile and are more susceptible to medial injuries of the leg and ankle, while high-arched feet tend to be rigid and stiff, more frequently leading to stress fractures and injuries on the lateral side of the leg. As demonstrated in a 2001 study by Williams and McClay, this discrepancy is largely due to altered mechanics associated with different arch structures and types. In their study they were able to demonstrate that individuals with low arches tend to display a greater degree of rearfoot inversion upon initial ground contact, followed by a significantly faster rate of calcaneus eversion when compared to individuals with higher arches. This rapid motion is dampened by supporting muscles and ligaments, and often places a great deal of stress on these structures, thereby aiding in the development of related injuries. This excessive pronation tends to force the shin to rotate internally, which in turn forces the thigh to rotate outwardly to compensate for this structural change. In this sense, the altered mechanics and subsequent structural compensation travels up the entire kinetic chain, causing an increase in the amount of strain placed on the ACL, as well as the hip and pelvis.
Understanding these biomechanical interactions is useful not only for health practitioners, but also for athletes of all abilities wishing to improve their athletic performance and prevent injury development and recurrence. In addition to making sure you are getting enough rest and recovery while training, a significant body of research strongly supports a link between properly warming-up before engaging in rigorous physical activity and a decreased incidence of injury. Being too aggressive with training progression frequently leads to injuries in even the most experienced athletes; as a general rule of thumb, make sure you are not increasing your weekly mileage by more than 20%. Slightly less talked about are the benefits barefoot activity may have on arch development and strength. The physical stimulation that occurs while barefoot theoretically helps to produce a protective increase in surface muscle tone, helping to elevate the arch and strengthen the involved muscles and tendons. This may be particularly relevant and useful for individuals with lower foot arches as it theoretically helps to diminish some of the less desirable mechanical aspects of having low-arches. As always, be sure that you are wearing proper shoes that fit your foot-type and meet your needs. For helpful tips on selecting a shoe, check out our Guide to Buying Running Shoes here!