orthosis (plural: orthoses)

orthosis (plural: orthoses)

device for straightening deformity (Table 1)
  • accommodative orthoses bespoke, semibespoke or 'off-the-shelf' orthoses; used to gain symptomatic relief, but not to correct, foot problems

  • functional orthoses bespoke, moulded insoles made to an adapted cast of the patient's foot; prescribed to improve foot and lower-limb function, and reduce local, proximal skeletal and soft-tissue misalignment

Table 1: Adaptations to orthoses
AdaptationRationale
First metatarsal cutoutA section of the orthotic shell is cut away proximal to the head of the first MTPJ to provide adequate space for sesamoid function and facilitate sagittal-plane motion
Low firstA groove (2-5mm deep) is skived into the upper surface of the orthotic immediately beneath the shaft of the first metatarsal to accommodate a plantarflexed first ray
First ray cutoutA section of the orthotic shell is cut away from beneath the first ray to facilitate first-ray movement
Fascial grooveA groove skived out of the shell in the area that lies immediately beneath the plantar fascia, to accommodate a tight plantar fascia or prominent flexor hallucis longus tendon
Flange outAn extension at the medial border of the orthotic to provide additional support for the MLA area, especially for cases of posterior tibial dysfunction
Morton's extensionA distal extension beyond the first MTPJ to limit movement at the first MTPJ and transfer load to the IPJ of the hallux
Lateral clipAn extension to the lateral side of the heel cup to control the rearfoot motion associated with excess pronation
Heel (Kirby) skiveAn addition to the medial or lateral side of the heel cup
Heel raiseAdditional height added to the plantar area of the heel cup to compensate for a mild leg length discrepancy
Pegasus rockerA rocker added to the proximal heel area in order to increase sagittal-plane motion at the ankle joint

MTPJ, metatarsophalangeal joint; MLA, medial longitudinal arch; IPJ, interphalangeal joint.