Structural Adaptations

In a previous post, we discussed how the foot is made up of bones specially stacked to form three arches that are very good at bearing the weight of our whole body. The keystone bones sit on top of the arches, creating a wedge and aiding the strength of the structure. The alignment of these bones plays an important role in aligning the rest of our body and our ability to balance. So, what happens when these bones are out of alignment? It doesn’t mean we fall over, right?

Every time I talk about alignment, I think about optimization. How can I move my body with harmony and structural integrity, more efficiently and pain free? Optimization is about finding the best solution, but the definition of best is not fixed. Even in mathematical optimization when working with data models, there is a concept of local versus global optima. While a global optimum is the best, most optimal solution for the whole system, a local optimum, is the best solution in its immediate vicinity. In other words, there could be lots of optimal solutions over a data set, just like there are lots of optimal solutions for our body over the course of a life time.

So when we think about alignment and the best way to move our body, there isn’t necessarily one correct answer for all situations, but there are optimizations we can make. Our daily activities, our physical or sedentary pursuits, our athletic obsessions, play a role in how we organize and align our body. For example, there are specialized adaptations of the foot structure for specific sports and activities that are not necessarily the result of a pathology.

Here is a ballet dancer’s foot in a pointe shoe that makes unique use of the arch structure. Notice the position of the talus bone, the keystone of the medial arch, on the x-ray. It now aligns over the toes and comes together with the tibia (shin bone) and calcaneus (heel bone) to bear the full body weight of the dancer. The specific alignment of the arch is supported by paste, cardboard, and leather of the shoe to maintain the upright position of the foot.

That can’t be good for your feet. The extreme positioning of the bones is asking for an injury. If not a sprained ankle, surely a bunion will occur from cramming the toes into a pointe shoe. However, as this article explains, having a bunion is not necessarily related to dancing on pointe, but more so to a genetic predisposition coupled with improper technique and poor alignment. And as this article outlines, dancing on pointe is not only possible, but also safe given correct alignment and sufficient strength for the task. Of course, the optimal alignment for pointe work is quite different than for say running or walking, and years of training will bring along changes to the overall foot structure.

Next, here is a comparison of the foot of a high level wrestler (1) with someone who is active, but without a sport specific focus (2). As the side view image shows, the bones of the medial arch of the wrestler appear to make contact with the ground while standing. This is commonly referred to as flat feet or pes planus. In this case, this foot structure was acquired due to excessive flattening of the arch while wrestling. As this study shows, the greater the number of years wrestled, the greater the likelihood of acquiring flat feet. This is due to repeatedly maximizing foot contact with the mat in order to maintain balance and to disturb the balance of the opponent by forcefully pushing into the medial arch.

Excessive and repeated pressure to the inside of the foot caused the big toe joint to angle in and form a bunion as may be seen in the image of the view from the top. The talus bone became rotated inward. In order to stay balanced and to offset the inward rotation of the foot, the angle of the shin bone, which sits on top of the talus, adapted to lean slightly outward. This in turn affects the alignment of the knee, which is likely to develop some wear and tear in the meniscus. However, as this article suggests, wrestling is not known to be easy on the joints.

For comparison, the second image shows a foot with a high arch and very active toes. The space under the arch is clearly visible, the big toe extends straight out. The shin also sits directly on top of the ankle as the bones of the arch are in an optimal position. This is a foot structure that does not show a specific adaptation and is considered to be in excellent overall alignment. Must be nice!

The structural changes that occur from years of training are optimal for the specific sport or activity, but are not necessarily optimal overall. Many such adaptations place greater stress and consequent wear and tear on the joints. Additionally, these specific adaptations are less transferable to other activities. Flat feet may be useful for wrestling, but would be a hinderance for dancing on pointe. Both wrestlers and dancers would have a hard time taking up running due to the respective changes to their foot and body alignment.

That being said, those invested in serious training are not doomed to have misshapen feet and bad joints. Wear and tear injuries can be prevented by improving strength and coordination, and maintaining the optimal alignment for the specific activity. There is likely a postural predisposition and a fault in technique that contribute to some extreme structural adaptations. Therefore, my perpetual focus is on acquiring and practicing perfect technique with correct alignment in favor of injury prevention.

We must note that these structural adaptations are not unique to elite level athletes and dancers. We all have some alignment issues that are a result of our daily activities that we can all improve for more efficiency and harmony in our movement. It’s about taking ownership of our body. I believe that awareness of what good alignment and proper technique feel like for our favorite activities will greatly contribute toward our optimal well-being.

Experiment:

  • Next time you are at the beach, or walk across a wet floor, take a look at your footprint. Of the ones shown below, which one does your foot look like?
  • If you wish to be a bit more scientific about it, step on a piece of paper with a wet foot. Trace the outline with a pencil and compare to the footprints in the image.
  • If your footprint looks closer to the one on the left, compare your footprint with weight on your foot while standing to one while sitting. You may notice a change in the size and shape of your foot as you place weight on it.
  • This check distinguishes between a flexible and a rigid flat foot. In the case of a flexible flat foot, there is clearly an arch when not bearing weight, but the foot appears to be flat while standing. This is in contrast to a rigid flat foot where the shape of the arch does not change whether or not it is bearing weight.

Takeaways:

  • Good alignment is relative to our chosen activity and lifestyle; our body adapts to the demands we place on it.
  • Sport specific adaptations are likely to occur with greater focus on one sport, and are likely to lead to greater wear and tear on the joints. This does not mean that this is the end of the world and we shouldn’t pursue what we love.
  • Structural adaptations happen to every one of us based on our daily activities, and it’s up to us to practice good alignment to prevent injury.

Comment below if you checked your footprint and learned something new about your foot structure. Do you have any structural adaptations from years of practicing the same activity?