Footwear options - Footwear and Foot Orthoses - page 107

Figure 7.5 Elongated heel
(elevation) at the front of the shoe, distal to the metatarsal heads ( Figure
7.3 ). The principal is that as load is transferred from the heel to the fore-
foot, the stiffness of the sole prevents the midfoot and toes from flexing.
This reduces the transfer of load to the forefoot and maintains loading in
the midfoot area (also the heel area in some rocker shoe designs). In the
propulsive phase of gait, the shape of the toe spring allows the wearer
to 'roll off' more efficiently as the next step is started on the opposite side.
There is a multitude of different designs of rocker sole. They may be
curved or angled in profile (angled ones are often called a metatarsal bar)
( Figure 7.6 ) and include toe only, heel to toe, negative heel, severe angle
and double rocker. They must be matched with the patient's needs, the
condition and the desired effect. The variations are based on the mid-
stance section, the apex of the rocker (the pivot point), the profile and the
severity of the rocker, which can be between 20 and 30 degrees. Studies
support the use of rocker soles but highlight that the practitioner needs
to be aware of loading other areas of the foot as this may cause other
problems. This is particularly evident in the diabetic neuropathic foot
( Cavanagh 2004 ). Van Schie et al (2000) illustrated the precision required
for the placement of the rocker in order to achieve the maximum pressure
relief of up to 60 per cent at the metatarsals and 65 per cent at the toes.