Treatment of Bunions with Orthotics

 

 

Hallux Abducto Valgus is the medical name for a condition more often referred to as ‘bunions’, and bunion occur so frequently that most podiatrists examine at least one case of this affliction per day.

One question that patients usually ask is if their choice of footwear has caused their bunions to develop, and the answer to that is quite complicated.

In-depth research reporting by renowned podiatrist F.D Ross (The Relationship of Abnormal Foot Pronation to Hallux Abducto Valgus—A Pilot Study, F.D Ross et al., Prosthetics and Orthotics International, 1986) concluded that while a person’s biomechanics are the base cause of the development of bunions, constrictive shoes can tip the scales toward full-blow development of hallux abducto valgus, and worsen existing conditions as well.

What researchers have discovered is that excessive pronation of the foot is a major factor in the development of bunions.

When further pursued it became clear that excessive pronation of the feet is due to abnormal foot mechanics, the most common abnormality being a subtalar joint that remains in a pronated position for too long a time during the mid-stance and propulsion point of the moving process. This in turn causes hyper-mobility in the first ray of the foot (a series of foot bones that includes the big toe) which then causes a partial dislocation of the first metatarshophalangeal joint (joints in the big toe). It is this partial dislocation and the subsequent uneven distribution of pressure that causes bunions to develop.

Extremely flexible feet and feet with a short metatarsal are considered to be more vulnerable to the processes that cause bunions to develop, and these two factors are hereditary.

(The Relationship of Abnormal Foot Pronation to Hallux Abducto Valgus—A Pilot Study, F.D Ross et al., Prosthetics and Orthotics International, 1986)

(Lorimer et al, 1997; Selner et al, 1992; De Valentine, 1992).

Stages of Bunion Development

There are 3 stages of bunion development, and fortunately, there exists the opportunity at every stage to introduce orthoses and thus prevent the next deterioration from occurring.

1. The Primary Stage: The primary stage of bunion development generally occurs between adolescence and 25 years of age. At this stage the bunion usually appears as a very slight bump on the side of the toe.

2. The Secondary Stage: The secondary stage of bunion development generally occurs between 25 and 55 years of age. The first metatarsal head is already leaning to the inside toes and the hallux has moved outward, putting pressure on the second digit. Calluses may have developed on the joint situated at the base of the toe as well as the toe itself.

If orthoses are not introduced and the foot is allowed to continue over-pronating the toe will continue to abduct and the muscles (specifically the hallucis longus) will continue to tighten, which then pulls the hallux further out of alignment.

3. Tertiary Stage: If the misalignment of bones and joints is not properly treated at the second stage the bunion will progress to the third, or tertiary, stage. When this occurs the big toe overlaps with the second toe by either tucking under it or laying over it. Wearing shoes often becomes a problem as most footwear does not comfortably accommodate this type of deformity.

Treatment in the tertiary stage is problematic and the patient will likely be experiencing great pain. Orthodpedic surgery to remove or correct the bunion may be needed, and the patient will be prescribed orthoses to wear in order to correct the underlying biomechanical condition and to prevent the bunion from redeveloping.

Specifics on the Treatment of Bunions with Orthotics

In the research study published by F. D Ross it was found that while excessive pronation of the feet is quite common in children foot morphology is relatively unchanging after the age of eight, so a marked abnormality in childhood is likely to translate into a serious problem in adulthood. Furthermore, serious mechanical abnormalities or hyper mobility in the foot during childhood can also interfere with normal bone formation. The good news according to Ross, however, is that immediate pathology and delayed onset of pathology can be prevented by the use of orthotics ‘as early as possible.’

It was also discovered that the use of functional orthotics reduced or eliminated over-pronation by a significant amount (Bates et al, 1979) and that “hallux abducto valgus deformity can either be decreased or its development arrested by treatment with functional orthotics.” (Root et al, 1977).

The treatment of bunions with orthotics clearly works and has been accepted as such by the podiatric community. It is essential that the patient be familiar with the three stages of development and has a clear understanding of why using the orthotic device in the prescribed manner is so important. It is also beneficial if the patient understands the progression of the three stages so that the significance of prevention is fully understood.

Aside from prescribing an orthotic to realign the foot and correct or minimize pronation of the foot, intrinsic foot-strengthening exercises should be given in order to strengthen the aponeurosis. These exercises usually consist of scrunching a towel with the toes or picking up marbles with the feet. And while bunion strapping is also an option it is only effective in the first stage of development and will not be effective if the bunion develops beyond this level.

Treating Hallux Abducto Valgus with orthotic therapy means that the bunion must be closely monitored for a progression of symptoms or an increase in the level of pain experienced. If either of these conditions occurs the orthotic device will have to be evaluated to ensure that it is providing enough control and to verify if the patient is still able to over-pronate while wearing the device. If this is the case a firmer density orthotic will be required. In cases where the patient has a short first metatarsal a Morton’s Extension can be added to the orthotic.

Conclusion

The treatment of bunions with orthotics is clearly advantageous, especially when the problem is found early on and treated as soon as possible.

View Orthotics to Treat Bunions

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