what-when-how
In Depth Tutorials and Information
providing them that foot orthoses for patients with RA include these main
groups:
1.
Simple cushioning insoles.
2.
Insoles to which padding or other additions can be applied.
3.
Contoured insoles intended to change the function of leg and foot
joints, either:
• custom made to a cast of the patient's foot,
or
• supplied off the shelf.
There is no formal classification of foot orthoses, but the clinical choice
appears to be based on the degree of deformity, the symptoms and the
ability of the patient's footwear to accommodate the orthoses. The
boundaries between the modes of action of the types are not always
exact and an individual device may include elements of more than one
type or mode of action.
Clark et al (2006)
in their critical review of the
literature concluded that there is limited and often conflicting evidence on
which to base clinical practice. However, they further concluded that there
are indications from the available research that:
•
foot orthoses reduce pain and improve functional ability
•
both hard and soft orthoses have the potential to reduce forefoot
pain
•
hard orthoses have the potential to reduce rearfoot pain in patients
with early RA
•
hard orthoses have the potential to reduce hallux abductovalgus.
The premise of simple cushioning insoles is that the addition of a com-
pressible padded material under the weight-bearing surface of the foot
can reduce symptoms and so improve comfort and function. In their
simplest form, simple insoles comprise one or more lat layers of com-
pressible material that provides a softer interface than that normally found
inside the shoe.
Although simple insoles can provide some pressure reduction at the
interface of the foot and shoe, where loads need to be modified more
systematically (typically where the structure or function of the foot is
altered in some way), modular additions can be added to the basic simple
insole design. One of the more common modular additions is an arch
'iller' that aims to redistribute load away from the forefoot and is reported
anecdotally to reduce symptoms. A similar principle underpins the use of
a forefoot plantar metatarsal pad that is intended to support the trans-
verse arch across the ball of the foot. Two small studies indicate that
metatarsal 'dome' and 'bar' pads reduce mean peak plantar foot pressure
