Stiffness of the arizona ankle-foot orthosis before and after modification for gait analysis

Stacie I. Ringleb, Theodore Armstrong, Lawrence J. Berglund, Harold B. Kitaoka, Kenton R Kaufman

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

The purpose of this project was to measure the stiffness of the Arizona ankle-foot orthosis (AFO) before and after it was modified for gait analysis with a foot specific marker set. Five Arizona AFOs were tested in the intact condition in a custom testing device in the sagittal and coronal planes. After testing in the intact condition, 2.5-cm diameter holes were drilled in the malleoli and the medial, lateral, and posterior aspects of the calcaneus. Three cycles of loading in each plane were averaged for analysis. The slope of the load-displacement curve was calculated to determine the brace stiffness. The coefficient of repeatability was ±0.17 Nm per degree in plantarflexion, ±0.16 Nm per degree in dorsiflexion, ±0.38 Nm per degree in inversion, and ±0.18 Nm per degree in eversion. The stiffness decreased significantly in plantarflexion and dorsiflexion but not in the coronal plane motions. The change in stiffness in plantarflexion increased with an increase in the height of the medial malleolus holes. This relationship was significant, as determined by the Hotellings t test (p = 0.04), which suggests that the Arizona AFO should be reinforced on the medial side before it can be used in gait analysis studies. 2009 American Academy of Orthotists and Prosthetists.

Original languageEnglish (US)
Pages (from-to)204-207
Number of pages4
JournalJournal of Prosthetics and Orthotics
Volume21
Issue number4
DOIs
StatePublished - Oct 2009

Fingerprint

Foot Orthoses
Gait analysis
Gait
Ankle
Stiffness
Calcaneus
Braces
Foot
Testing
Equipment and Supplies

Keywords

  • Arizona AFO
  • Biomechanics
  • Gait analysis
  • Stiffness

ASJC Scopus subject areas

  • Biomedical Engineering
  • Rehabilitation
  • Orthopedics and Sports Medicine

Cite this

Stiffness of the arizona ankle-foot orthosis before and after modification for gait analysis. / Ringleb, Stacie I.; Armstrong, Theodore; Berglund, Lawrence J.; Kitaoka, Harold B.; Kaufman, Kenton R.

In: Journal of Prosthetics and Orthotics, Vol. 21, No. 4, 10.2009, p. 204-207.

Research output: Contribution to journalArticle

Ringleb, Stacie I. ; Armstrong, Theodore ; Berglund, Lawrence J. ; Kitaoka, Harold B. ; Kaufman, Kenton R. / Stiffness of the arizona ankle-foot orthosis before and after modification for gait analysis. In: Journal of Prosthetics and Orthotics. 2009 ; Vol. 21, No. 4. pp. 204-207.
@article{542b9ded5a5545a7b2202e29f14d2838,
title = "Stiffness of the arizona ankle-foot orthosis before and after modification for gait analysis",
abstract = "The purpose of this project was to measure the stiffness of the Arizona ankle-foot orthosis (AFO) before and after it was modified for gait analysis with a foot specific marker set. Five Arizona AFOs were tested in the intact condition in a custom testing device in the sagittal and coronal planes. After testing in the intact condition, 2.5-cm diameter holes were drilled in the malleoli and the medial, lateral, and posterior aspects of the calcaneus. Three cycles of loading in each plane were averaged for analysis. The slope of the load-displacement curve was calculated to determine the brace stiffness. The coefficient of repeatability was ±0.17 Nm per degree in plantarflexion, ±0.16 Nm per degree in dorsiflexion, ±0.38 Nm per degree in inversion, and ±0.18 Nm per degree in eversion. The stiffness decreased significantly in plantarflexion and dorsiflexion but not in the coronal plane motions. The change in stiffness in plantarflexion increased with an increase in the height of the medial malleolus holes. This relationship was significant, as determined by the Hotellings t test (p = 0.04), which suggests that the Arizona AFO should be reinforced on the medial side before it can be used in gait analysis studies. 2009 American Academy of Orthotists and Prosthetists.",
keywords = "Arizona AFO, Biomechanics, Gait analysis, Stiffness",
author = "Ringleb, {Stacie I.} and Theodore Armstrong and Berglund, {Lawrence J.} and Kitaoka, {Harold B.} and Kaufman, {Kenton R}",
year = "2009",
month = "10",
doi = "10.1097/JPO.0b013e3181bfb28e",
language = "English (US)",
volume = "21",
pages = "204--207",
journal = "Journal of Prosthetics and Orthotics",
issn = "1040-8800",
publisher = "American Academy of Orthotists and Prosthetists (AAOP)",
number = "4",

}

TY - JOUR

T1 - Stiffness of the arizona ankle-foot orthosis before and after modification for gait analysis

AU - Ringleb, Stacie I.

AU - Armstrong, Theodore

AU - Berglund, Lawrence J.

AU - Kitaoka, Harold B.

AU - Kaufman, Kenton R

PY - 2009/10

Y1 - 2009/10

N2 - The purpose of this project was to measure the stiffness of the Arizona ankle-foot orthosis (AFO) before and after it was modified for gait analysis with a foot specific marker set. Five Arizona AFOs were tested in the intact condition in a custom testing device in the sagittal and coronal planes. After testing in the intact condition, 2.5-cm diameter holes were drilled in the malleoli and the medial, lateral, and posterior aspects of the calcaneus. Three cycles of loading in each plane were averaged for analysis. The slope of the load-displacement curve was calculated to determine the brace stiffness. The coefficient of repeatability was ±0.17 Nm per degree in plantarflexion, ±0.16 Nm per degree in dorsiflexion, ±0.38 Nm per degree in inversion, and ±0.18 Nm per degree in eversion. The stiffness decreased significantly in plantarflexion and dorsiflexion but not in the coronal plane motions. The change in stiffness in plantarflexion increased with an increase in the height of the medial malleolus holes. This relationship was significant, as determined by the Hotellings t test (p = 0.04), which suggests that the Arizona AFO should be reinforced on the medial side before it can be used in gait analysis studies. 2009 American Academy of Orthotists and Prosthetists.

AB - The purpose of this project was to measure the stiffness of the Arizona ankle-foot orthosis (AFO) before and after it was modified for gait analysis with a foot specific marker set. Five Arizona AFOs were tested in the intact condition in a custom testing device in the sagittal and coronal planes. After testing in the intact condition, 2.5-cm diameter holes were drilled in the malleoli and the medial, lateral, and posterior aspects of the calcaneus. Three cycles of loading in each plane were averaged for analysis. The slope of the load-displacement curve was calculated to determine the brace stiffness. The coefficient of repeatability was ±0.17 Nm per degree in plantarflexion, ±0.16 Nm per degree in dorsiflexion, ±0.38 Nm per degree in inversion, and ±0.18 Nm per degree in eversion. The stiffness decreased significantly in plantarflexion and dorsiflexion but not in the coronal plane motions. The change in stiffness in plantarflexion increased with an increase in the height of the medial malleolus holes. This relationship was significant, as determined by the Hotellings t test (p = 0.04), which suggests that the Arizona AFO should be reinforced on the medial side before it can be used in gait analysis studies. 2009 American Academy of Orthotists and Prosthetists.

KW - Arizona AFO

KW - Biomechanics

KW - Gait analysis

KW - Stiffness

UR - http://www.scopus.com/inward/record.url?scp=70349767057&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=70349767057&partnerID=8YFLogxK

U2 - 10.1097/JPO.0b013e3181bfb28e

DO - 10.1097/JPO.0b013e3181bfb28e

M3 - Article

AN - SCOPUS:70349767057

VL - 21

SP - 204

EP - 207

JO - Journal of Prosthetics and Orthotics

JF - Journal of Prosthetics and Orthotics

SN - 1040-8800

IS - 4

ER -