Cuboid Notch

A cuboid notch or raise is a more specific form of lateral column support in a foot orthotic that is specific to the location of the cuboid bone. It could be incorporated intrinsically into the foot orthotic shell or added extrinsically as a cuboid pad out of material such as cork, poron or EVA adhered to the dorsal surface of the foot orthotic.

cuboid notch

Typical location of a cuboid notch

Traditionally the cuboid notch would be incorporated into the custom foot orthotic by shaving off or scooping out plaster under the cuboid in the preparation of the plaster positive model of the foot. Using the CAD systems the orthotic shell would be designed to be elevated under the area of the cuboid. Most foot orthotic manufacturing facilities accept prescriptions of a cuboid notch in millimetres (or fractions of an inch). A cuboid pad from materials like EVA could be added as an extrinsic addition to the orthotic shell. The padding used for metatarsal dome could also be modified and used for this. A number of prefabricated foot orthotic brands use a cuboid notch as part of their standard design. The Feehery Modification is when the cuboid notch is extended more posterior to also support the anterior lateral aspect of the calcaneus.

There is no research on the use of a cuboid notch on foot orthotics and no clear consensus on its indications and use. Some of the uses that get mentioned are:

  • To support the cuboid in cuboid syndrome and calcaneocuboid fault syndrome. The notch provides an upward force that resists any plantar subluxation or movement of the cuboid.
  • To facilitate movement of the centre of pressure medially during midstance to make use of Bojsson-Mollor’s high gear propulsion concept.
  • The cuboid notch will provide a pronatory moment at the subtalar and midtarsal joints.
  • The notch can help elevate the inclination angle of the calcaneus.
  • The notch will also help to pronate the putative oblique axis of the midtarsal joint and plantarflex the fourth and fifth rays – this is claimed to give the peroneus longus a mechanical advantage to stabilize the first ray.
  • To help prevent the foot sliding laterally off the foot orthotic if a lot of design features are incorporated into the foot orthotic to increase the supinatory moments on the foot (eg medial skive).
  • Clinicians are more likely to use a cuboid notch if they use a weightbearing or a semi-weightbearing negative modelling method as this modelling method lowers the lateral column.
  • They are also more likely to be used in traditional plaster based manufacturing systems as the standard for the addition of plaster to the lateral column to allow for foot expansion will lower the lateral arch profile in the foot orthotic.

Sometimes cuboid notches increase the symptoms in those with pain around the cuboid. It has been suggested that the traditional location of the cuboid notch or pad is too lateral and because of that location it places an eversion moment on the cuboid when the cuboid might need an inversion moment. In this situation the notch or pad should be moved more to be under the medial plantar aspect of the cuboid to try and invert the cuboid. The cuboid does not “drop” in a plantar direction, it rotates (everts as it “drops”) as part of calcaneocuboid joint motion, so using a cuboid pad to rotate (invert) rather than “support” the cuboid does make sense.

Cuboid notches or raises incorporated into the orthotic shell can not be removed. If they are used on an EVA type of foot orthotic, a grinder can be used to reduce the height of the cuboid notch. A cuboid pad adhered to the foot orthotic as an extrinsic modification can easily be removed.

A cuboid pad from a variety of different materials can be added extrinsically after a foot orthotic has been dispensed to get the desired clinical effects.

A treatment direction test using something like adhesive felt padding on the foot as a cuboid pad can be used to determine if a cuboid notch might be useful in the foot orthotic design.


See also:
Denton modification | Feehery Modification | Fettig modification | Varus Cuboid Pad

Page last updated: Aug 11, 2022 @ 5:02 am

 
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