A model to predict the effect of ankle joint misalignment on calf band movement in ankle-foot orthoses

Stefania Fatone, Andrew H. Hansen

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


Accurate alignment of anatomical and mechanical joint axes is one of the major biomechanical principles pertaining to articulated orthoses, yet knowledge of the potential effects of axis misalignment is limited. The purpose of this project was to model the effects of systematic linear (proximal-distal and anterior-posterior) misalignments of single axis mechanical ankle joints in an ankle-foot orthosis (AFO) in order to determine the degree and direction of calf band travel that would occur over a functional range of motion. Sagittal plane misalignments of the ankle joint centres of an AFO were simulated using a simple two-dimensional model for both a range of ankle angles and a typical able-bodied ankle kinematic curve for self-selected normal walking speed. The model assumed that no movement occurred between the foot and the foot-plate of the AFO. The model predicted that for anterior (positive horizontal) misalignments, dorsiflexion movements would cause the calf band to travel proximally (i.e., up the leg) and plantar flexion movements would cause the calf band to travel distally (i.e., down the leg). The opposite was predicted for posterior (negative horizontal) misalignments. Proximal (positive vertical) misalignments would cause only distal movements of the calf band while distal (negative vertical) misalignments would cause only proximal movements of the calf band. Anterior-posterior misalignments were found to have a much larger effect on the amount of calf band travel than proximal-distal misalignments.

Original languageEnglish (US)
Pages (from-to)76-87
Number of pages12
JournalProsthetics and Orthotics International
Issue number1
StatePublished - Mar 2007

Bibliographical note

Funding Information:
This work was funded by the National Institute on Disability and Rehabilitation Research (NIDRR) of the U.S. Department of Education under Grant No. H133E030030. The opinions contained in this publication are those of the grantee and do not necessarily reflect those of the Department of Education. The authors wish to acknowledge Michael Brncick for his insight and clinical guidance on this project.


  • AFO
  • Ankle joint misalignment
  • Calf band movement


Dive into the research topics of 'A model to predict the effect of ankle joint misalignment on calf band movement in ankle-foot orthoses'. Together they form a unique fingerprint.

Cite this