The Effects of Different Types of Foot Orthosis in Adults With Compensatory Forefoot Varus

Forefoot varus is a type of foot deformities. It is asociate with subtalar joint hyperpronation, and cause too much stress over tissues around foot and lower leg during weight bearing activities.

One of the common interventions for forefoot varus is to use foot orthosis with medial forefoot wedge to accommodate the forefoot deformity. Forefoot varus has been considered as an osseus deformity and caused by insufficient talar torsion during development. However, recent studies have reported forefoot varus may not be an osseus deformity. They might be a result of soft tissue adaption. For example, subtalar joint hyperpronation and ankle equinus could lead to forefoot supination/compensatory forefoot varus, which could be mistaken for osseus forefoot varus after a long period of time. If compensatory forefoot varus is caused by soft tissue adaptions, these adaptions may have a chance to reverse.

Nowadays, orthoses which applying medial forefoot wedge to accommodate the deformity for forefoot varus deformity, and the other type orthoses which applying rearfoot medial wedge and arch support are both used in subject with forefoot varus deformity.

However, some colleges claims that using medial forefoot wedge to accommodate the deformity of forefoot varus, the deformity may be fixed after a long-term period. However, there were no studies compare the effect of arch support orthosis that with and without medial forefoot wedge.

Forefoot varus is a type of foot deformities. It is asociate with subtalar joint hyperpronation, and cause too much stress over tissues around foot and lower leg during weight bearing activities.

One of the common interventions for forefoot varus is to use foot orthosis with medial forefoot wedge to accommodate the forefoot deformity. Forefoot varus has been considered as an osseus deformity and caused by insufficient talar torsion during development. However, recent studies have reported forefoot varus may not be an osseus deformity. They might be a result of soft tissue adaption. For example, subtalar joint hyperpronation and ankle equinus could lead to forefoot supination/compensatory forefoot varus, which could be mistaken for osseus forefoot varus after a long period of time. If compensatory forefoot varus is caused by soft tissue adaptions, these adaptions may have a chance to reverse.

Nowadays, orthoses which applying medial forefoot wedge to accommodate the deformity for forefoot varus deformity, and the other type orthoses which applying rearfoot medial wedge and arch support are both used in subject with forefoot varus deformity.

However, some colleges claims that using medial forefoot wedge to accommodate the deformity of forefoot varus, the deformity may be fixed after a long-term period. However, there were no studies compare the effect of arch support orthosis that with and without medial forefoot wedge.

In consideration of few studies have been done for investigating the effects of different orthoses in subjects with flat foot combined forefoot varus. Thus, the purpose of this study is to investigate the effect of different foot orthoses designs on improving pain, muscle activity and displacement of center of pressure. We hypothesized that both orthoses will have the better effect on improving pain than placebo orthoses ,and muscle activity and displacement of center of pressure of arch support orthoses group will have change which close to normal foot.

Eligibility Criteria:
Inclusion Criteria:

* Flexible flatfoot
* Angle of forefoot varus \> 6 degree
* Feel leg or foot pain when walking or exercising, and pain visual analogue scale \> 3 points
* The duration of wearing shoes \> 30 he per week

Exclusion Criteria:

* Rigid flatfoot
* Leg length discrepancy \> 1cm
* Angle of Hallux valgus \> 20 degree
* With any nerve problem or disease
* Used to have trauma over lower limbs
* Had any severe joint deformity or osteoarthritis over lower limbs
* Had any acute injury (in two weeks and inflammation)
* Had wearing insole for 6 months
* Can't follow order