What is a Bunion?

One of the most notable features of a bunion is an apparent enlargement of the bone at the base of the big toe on the inside of the foot. Describing a bunion as only an abnormal bone growth though would not be a complete or accurate explanation of the problem.

Bunion

The medical term for the common bunion is hallux valgus. Hallux refers to the big toe. Valgus is a term that means outward angle.  A bunion occurs when the position of the bones in the big toe shift in a manner that causes it to point in the direction of the other toes. This displacement causes the end of the first metatarsal bone to appear more prominent on the inside of the foot. This subjects the joint to increased irritation that then leads to inflammation and swelling of the surrounding tissue. Prolonged irritation causes additional bone to start forming at the joint. Over time this will make the bunion appear larger.

Bunion Formation

The exact cause of bunions in unknown. There is controversy regarding the effects genetics and shoe wear have on the condition. Hallux valgus is reportedly rare in populations that habitually go barefoot. Heredity certainly appears to play a role in the formation of bunions, particularly in younger individuals. The other suspected causative factors can be grouped into 4 categories:

  1. Biomechanical problems such as excessive pronation or hypermobile joints
  2. Systemic or neuromuscular diseases included rheumatoid arthritis, cerebral palsy, and connective tissue disorders
  3. Traumatic injuries such as a nonunion fracture or dislocation of the joint
  4. Pre-existing structural abnormalities 

Bunions and Footwear

My personal feeling is that choice of footwear plays a major role in the development of the problem and is not simply an irritating factor. Here is a photograph from a study by an orthopedist named Dr. Phil Hoffman back in 1905, comparing the foot of an adult that had never worn shoes (B) to a child who had worn shoes for only a few months (A).

Fig 11

 

Notice the position of the big toe with the rest of the foot. Previous studies have shown shoes affect the development of the arch, so it makes sense that shoes would play a role in hallux valgus.

In 1912, not long after the Hoffman study, Edward Lyman Munson wrote a book called The Soldiers Foot and The Military Shoe. The book was intended as a guide to the Army for providing soldiers with footwear that would allow them to march effectively and without injury. The book has many insightful points about improper footwear and I’m surprised it didn’t have a larger impact on shoe design in the years after its publication. Here is a picture from the book comparing an x-rays taken of a foot both with and without a shoe. 

 

Foot Without Shoe Foot With Shoe

Given that both of the works cited above are over 100 years old, it’s clear that the issue of the effect shoes can have on foot health have been known and discussed for a while. It seems logical that shoes could be a direct cause of bunions either by:

  • having a narrow toe box that forces that bones of the toes together or
  • indirectly encouraging excessive pronation or flattening of the arch which would then put additional pressure on the big toe
This is an issue that involves a number of variables with a lot of conflicting research so I’m going to cover it in two parts. The second part of this series will go into further detail about the factors contributing to hallux valgus and what might be done to decrease the risk of developing a bunion. Before I end this section I went to mention a story that seems fitting for this discussion. 
 
I have a friend who i first met when her and her husband came to the US on an extended business trip from India. She never wore shoes, always sandals (which is not that uncommon in San Diego) and has a space between her first and second toes similar to the figure B in photo posted earlier. This is not something I would have normally noticed or paid attention to, except she also has the habit, when she sits, of fitting the big toe of the opposite foot in that gap. 
 
To be honest, when I first saw her doing it I almost wanted to tell her to stop because I thought maybe that was the reason there was such a wide space there. I was reminded of this while writing the post about the best positions for sleeping. One of the articles I referenced mentioned that one particular posture was ideal for allowing the Achilles of one side to fit between the toes on the other to treat a bunion. 
 
This was way before I had done much research on the topic so I was making the mistake of thinking the Western foot (for lack of a better name) was the norm. Now I realize that having separation is actually better alignment. Her feet were probably that way because she hadn’t worn, and therefore hadn’t been affected much, by shoes  growing up.
 
I don’t know what the effectiveness is of using your heel or your other big toe to maintain that spacing or prevent bunions, but on the surface it seems like a sound idea. There is a product I see advertised frequently called Yoga toes which works on the same concept. I’ve even recommended to patients before who were trying to alleviate hallux valgus related pain. I used to view that device as more of a gimmick. Now I’m starting to rethink that as well. 
 
Stay tuned for Part 2 which I should get to within the next week. In the meantime if anyone has had experience dealing with bunions or related problems before please feel free to share. 
 

References

  1. Robinson D, Hasharoni A, Halperin N, Yayon A, Nevo Z. Mesenchymal cells and growth factors in bunions. Foot Ankle Int. 1999 Nov;20(11):727-32.
  2. Hoffman, P. Conclusion drawn from a comparative study of the feet of barefooted and shoe-wearing peoples. J Bone Joint Surg Am. 1905;s2-3:105-136. 
  3. Banks A, McGlamry E. McGlamry’s comprehensive textbook of foot and ankle surgery. 3 rd ed. Philadelphia: Lippincott Williams and Wilkins; 2001. 
  4. Nix S, Vicenzino B, Collins N, Smith M. Characteristics of foot structure and footwear associated with hallux valgus: a systematicreview. Osteoarthritis Cartilage. 2012 Oct;20(10):1059-74. Epub 2012 Jul 5.
  5. Munson, E. The soldiers foot and the military shoe. Fort Levenworth: George Banta Publishing Co; 1912.

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