Design of a stiffness-adjustable ankle-foot orthosis and its effect on ankle joint kinematics in patients with stroke

Toshiki Kobayashi, Kam Lun Leung, Yasushi Akazawa, Stephen W. Hutchins

Research output: Journal article publicationJournal articleAcademic researchpeer-review

31 Citations (Scopus)


Ankle-foot orthoses (AFOs) are commonly prescribed to improve gait. The stiffness of an AFO is central for successful prescription; however, the recommended level of stiffness is currently based on the experience of clinicians. Therefore, the aim of this study was to design an experimental AFO (EAFO) whose stiffness was adjustable using commercially available oil-damper joints, and to demonstrate its potential capability in investigating the effects of altering AFO stiffness on gait. The influence of the EAFO stiffness on ankle joint kinematics in sagittal plane was evaluated in 10 patients with stroke by altering the stiffness of its oil-damper- type orthotic ankle joints using the four levels pre-set and defined by the manufacturer in dorsi- and plantarflexion directions independently. The mean peak plantarflexion angle was reduced by 105%, showing a change from 8.18 (3.14) degrees of plantarflexion to 0.38 (4.17) degrees of dorsiflexion, whilst the mean peak dorsiflexion angle was reduced by 44%, showing a change from 11.46 (5.57) degrees of dorsiflexion to 6.47 (5.23) degrees of dorsiflexion by altering the EAFO stiffness. The EAFO would therefore serve as a convenient tool when investigating the influence of AFO stiffness on gait in both clinical and research settings.
Original languageEnglish
Pages (from-to)721-723
Number of pages3
JournalGait and Posture
Issue number4
Publication statusPublished - 1 Apr 2011


  • Ankle-foot orthosis (AFO)
  • Gait
  • Kinematics
  • Stiffness
  • Stroke

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine
  • Rehabilitation
  • Biophysics

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