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Department
of Podiatry
Forefoot
Valgus
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Definition
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a congenital, fixed osseus deformity where the forefoot is everted
relative to the rearfoot, when the subtalar joint (STJ) is in
the neutral position and the midtarsal joint (MTJ) is fully
pronated / locked. (see left)
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- theoretically due to excessive valgus torsion of the head and neck
of the talus during foetal development, but this has not been well
supported
Incidence
- 44.8%
of 116 female subjects (McPoil et al, 1988)
- 9% of 120 male and female subjects (Garbalosa et al, 1994)
- 70% of 552 male and female subjects (Burns, 1977)
Classification
total forefoot valgus
- flexible
- rigid
plantarflexed 1st ray
- hypermobile
- rigid
NB: regardless whether the valgus position is total or due to a PF1st,
the foot will function similarly
- the flexible type is reportedly the most common presentation (Burns,
1977)
Compensation
- dependent
on range of motion of MTJ and STJ and the degree of deformity
- 'spectrum' of compensation
Flexible forefoot valgus
- sufficient
MTJROM to bring entire FF to ground
- requires inversion to make foot plantigrade
- inversion occurs around longitudinal axis of midtarsal joint
- unlocking of midtarsal joint
- forefoot hypermobility
- associated pathology
Appearance
- high arch non-WB, flattens on WB
- may be HK sub 2nd MPJ
- forefoot splay on WB
- normal or hypermobile MTJ
Associated pathology
- HAV, particularly in children
- Morton's neuroma
- lesser toe deformities
- plantar fasciitis
- 1st met-cuneiform exostosis
Rigid forefoot valgus
- no
MTJROM available
- requires inversion to make foot plantigrade
- inadequate ROM at midtarsal joint
- STJ compensatory supination
- supinatory 'rock' to lateral aspect
- excessive shock-induced pathology and lateral instability
- in some cases, the STJ may be excessively supinated prior to HC
Appearance ('pes cavus')
- high arch WB and non-WB
- heel inverted
- restricted MTJ ROM
- retracted lesser digits
- may be HK sub 1st and 5th MPJs, lateral aspect of heel
- anterior displacement of fat pad
Associated pathology
- tibial sesamoiditis
- chronic inversion sprains
- medial knee pain
- lower back pain
- plantar fasciitis
- tibial stress fracture
NB: Michaud (1997) also includes a 'hyperflexible' category where
there is excessive motion available around the LAMTJ
Summary
- fixed,
osseus congenital deformity
- requires inversion to make foot plantigrade
- two patterns of compensation
- flexible: compensatory LAMTJ supination
- rigid: compensatory STJ supination
- associated with a number of lower limb pathologies
- flexible: forefoot hypermobility
- rigid: inadequate shock attenuation and lateral instability
 References
Bowden
PD (1983) The pathomechanics of forefoot valgus. The Chiropodist
38(12):445-450.
McPoil TG, Cameron JA, Adrian MJ (1987) Anatomical characteristics
of the talus in relation to forefoot deformities. J Am Podiatr
Med Assoc 77(2): 77-81.
Michaud TC (1993) Foot orthoses and other forms of conservative
foot care. Williams and Wilkins, Baltimore, p. 77-91.
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