Selection of an above or below-ankle orthosis for individuals with neuropathic partial foot amputation: a pilot study

Background: Little evidence exists for the orthotic management for individuals diagnosed with diabetic neuropathy and partial foot amputation. Objective: This pilot study examined differences in balance and pressure distribution while individuals wore foot orthoses inside shoes (BA) and this same orthosis combined with an above-ankle (AABA) orthosis. Study Design: Within-group repeated measures crossover design. Methods: Participants with transmetatarsal amputation were assessed during randomized visits with the two interventions. Using a motion analysis system and force plates, we computed the instantaneous inclination angle between the center of mass and center of pressure to quantify balance. The F-Scan in-shoe sensor system was used to measure plantar pressures. Results: Improvement in balance was measured with the use of the AABA orthosis for the participant who had the greatest time from the timed up and go test (TUG). Plantar pressure during terminal stance did not change between the two conditions. And, lack of ankle mobility appears to lead to less compliance. Conclusion: Only individuals with reduced mobility may have improved balance with an orthosis that extends above the ankle. The TUG score may be an effective clinical exam to differentiate those individuals who may benefit from an AABA design as compared to a BA design. Clinical relevance Orthotic interventions aim to improve balance and distribute plantar pressures. This study suggests that the different effects on balance while walking with the BA and AABA devices are individually specific and the TUG outcome measure may provide a useful means to determine the appropriate intervention.