Bunions – Hallus Abductor Valgus
Bunions (Hallus Abducto Valgus) are a common foot problem that affects the joint at the base of the big toe (first metatarsophalangeal joint). In Latin “bunion” means enlargement, while “hallux abducto valgus (HAV)” refers to a bending inwards of the big toe.
When the big toe bends in towards the other toes while the bone behind it (1st metatarsal) pushes outward, this can create a considerable amount of stress on the joint (first metatarsophalangeal joint). Due to this bending inwards, a sharp angle at the big toe joint is created, resulting in the formation of a bunion. Initially, this enlargement is composed of swollen tissue which becomes irritated by any external pressure (for example tight shoes). Eventually this swollen tissue thickens to form a very large lump or bunion.
There is an obvious relationship between bunions and shoes, since bunions do not occur in cultures that go barefoot. High heels, pointed shoes, ballet shoes, excessively tight shoes, and even cowboy boots often lead to the development of bunions.
Anatomy and Biomechanics
From a biomechanical perspective, bunion formation creates a cycle of dysfunction. As the bone behind the big toe (1st metatarsal bone) moves outwards, the inner arch of the foot becomes unstable and starts to collapse. This instability, or lack of support in the arch, increases stress on the angle at the point where the bunion is forming. This stress accelerates the formation of the bunion, which in turn further destabilizes the arch of the foot. To truly deal with this problem, you must address both the foot instability and joint angle.
In addition to the stresses caused by poor shoes, simply walking with your feet in a turned out position can also lead to bunion formation from the stress it puts on two particular muscles. This “turned out” position leads to an imbalance between two muscles – the adductor hallicus and the abductor hallicus.
The adductor hallicus is an interesting muscle which is shaped like the number seven. The adductor hallicus transverses from several of the lateral toes into your big toe. When the adductor hallicus contracts, it pulls the big toe towards the 2nd toe.
When the adductor hallicus muscle becomes tight and restricted, it continually pulls the big toe towards the second toe (even without contracting). The adductor hallicus tends to become restricted in individuals who excessively pronate or walk with their feet turned outwards (a huge percentage of runners and dancers).
This pulling action of the adductor hallicus disrupts a key balance in muscle tension, which normally keeps the big toe in a neutral or straight position. This balance occurs between the adductor hallicus and the abductor hallicus muscles.
The abductor hallucis normally resists the pulling action of the adductor hallicus. The abductor hallucis runs from your heel (calcaneus) to your big toe (proximal phalanx). Constant pulling from the adductor hallicus weakens and overstretches the abductor hallucis. Without the appropriate counter-balancing action of the abductor hallucis, the big toe moves inward, and bunion formation accelerates.
In the first stages of bunion formation, bunions are often not painful until there is a significant inward deviation of the big toe. Some of the symptoms commonly associated with bunions include localized pain near the joint (often only with palpation), redness, swelling and restricted motion.
In diagnosing bunions a complete physical examination and patient history report are required, as well as X-rays. These enable the physician to measure joint angles in order to determine the severity of the condition. It also allows the physician to rule out fractures or other pathological processes.
Treatment of Bunions
Treatment can be divided into non-surgical (conservative) and surgical treatments.
Exercise is Essential
Exercise is an essential component in the treatment of bunions, it should not be optional. Soft-tissue therapy without exercise can only achieve a certain level of results, and the probability of the bunion returning becomes very high.
Just as the kinetic chain must be considered when determining treatment therapy (ART, Graston, Massage, etc.), the kinetic chain must also be evaluated to identify weak links which can be strengthened through exercises. For example, it has been well established that weak hip muscles are directly related to an increase in abnormal foot pronation, and abnormal pronation has been shown to accelerate the formation of bunions. In such cases, to prevent a recurrence of the bunion, you need to do exercises to strengthen and correct the weak hip muscle.
In most cases surgery is not necessary for the treatment of bunions. Conservative treatment can be very successful in the treatment of bunions, but you must ensure that your selected practitioner has a good understanding of anatomy, biomechanics, and the various factors causing bunion formation.
The objective of conservative treatment is to prevent the progression of the bunion by correcting the biomechanical stress on the foot, realigning the joint as much as possible, and increasing the intrinsic strength of the foot.
Fortunately, in most cases surgery is not necessary, and conservative treatment can be very successful, especially when the following factors are addressed:
Shoes: Sorry – but those high heels will have to go (except on the rarest of occasion) – especially when the bunion is extremely painful. The best shoes for bunions are flat shoes with a wide toe box. If you wear shoes that rub against your bunion it will only get larger. Some of the best choices are: wide athletic shoes, crocs, and sandals. The only problem with sandals is that you will not be able to wear orthotics within them to correct excessive pronation (if over-pronation is part of the problem). You can also try a shoe stretcher to increase the space in your current shoes.
Soft Tissue Restrictions: It is essential to remove soft tissue restrictions in order to bring the big toe back into its neutral position. Without addressing these restrictions, the bunion will continue to expand. There are various techniques that can be used to break up these restrictions such as Active Release Techniques, Graston Techniques, Massage Therapy, or various types of fascial manipulation. The exact area of restriction will vary for each individual case. Using a golf ball on the bottom of your foot and performing self-massage can also be of great benefit.
Foot Stability: Besides the obvious restrictions that may be found in the Adductor Hallucis, we also have to consider the other muscles that are involved in stabilizing the entire foot. Think of your foot the same way you would think of your car. Your car has four tires, each of which must be kept in alignment. If one of your tires is out-of-alignment, it affects the motion of the entire vehicle. The same thing occurs with the muscles of your feet. It only takes a restriction in one muscle to affect the stability of the entire foot.
Surgery is sometimes necessary when the pain from a bunion is extremely severe, or when a bunion has grown past certain limits.
The success rate for bunion surgery is very high, especially when measured in terms of performing your ADL’s (activities of daily living) and pain reduction. Complications from surgery include: infections, nerve damage, scar tissue formation, over or under-correction, and blood clots. It is also import to note that the bunion can reoccur if the underlying factors that caused the initial bunion formation are not properly dealt with. The surgery it self may alter the pressure pattern on the bottom of the foot (alignment), causing certain biomechanical imbalances.
Please Note: Something to keep in mind for professional dancers; a bunion surgery will often be the end of that dancer’s career. This is because most dancer cannot return to their pre-operative state.