Development Activities


Biplanar Fluoroscopic System for Dynamic, in vivo Foot and Ankle Motion Analysis

This project is structured to develop a unique biplanar (3-D) fluoroscopic imaging system for in vivo motion analysis of the foot and ankle during walking.This imaging technology will allow real-time assessment of internal bony motion during ambulation.This technology will be coupled with an existing segmental foot and ankle model (Milwaukee Foot Model) for assessment of segmental hindfoot kinetics. Anticipated development results include new knowledge of in vivo bony motion in the foot during ambulation; better information for future footwear; and orthotic and prosthetic development.

  • PI
    • Taly Gilat Schmidt, Ph.D.
  • Patient population
    • Other: 5 (children aged 10 – 18 yrs.)
  • Project goal
    •  Develop a biplane x-ray fluoroscopy system for analyzing in vivo motion of the bare or shod foot

D3 Update: May 2013

Presentation by Alex Griffin at GCMAS Annual Conference


Most current gait analysis techniques rely on external markers to quantify segmental foot and ankle motion. Because of the use of external markers, multi-segmental foot models are also unable to accurately analyze the shod foot. This presents a significant challenge to the clinician and engineer interested in quantifying foot kinematics during the shod condition. Those interested in quantifying barefoot motion face similar challenges with the use of external markers, which are subject to motion artifact, model repeatability and external validation requirements, and rigid body motion assumptions. Fluoroscopic analysis, by comparison, eliminates the need for external markers by utilizing images of in vivo bony geometry to create segment/coordinate systems. This process circumvents soft tissue artifact error, and allows for analysis of the shod foot, providing more relevant clinical data to assist in the assessment of orthotics and footwear.

Audio Powerpoint:


D3 Update: 2012 Annual Meeting

  • Progress
  • Challenges & Solutions
  • Accomplishments
  • Opportunities
  • Plans for Year 3

D3 2012 Annual Update (Powerpoint) (1.7 MB)

D3 Update: October 2012

Poster presentation by Alex Griffin at the annual Medical College Research Day.

Fluoroscopic Assessment of Hindfoot Kinematics During Gait: Comparison of Barefoot and Shod Motion (1.7 MB)

D3 Specific Aim

  • To develop a prototype biplane fluoroscopy system and manual feature extraction method for in vivo studies of subtalar hindfoot kinematics

D3 Conceptual Model

  • Proposed 3D biplane fluoroscopy system will be constructed by adding a second gantry to our existing 2D system
  • Proposed biplane fluoroscopy system and analysis method
    • 3D localization is possible in the region irradiated by both gantries
    • Elevated walkway contains a force plate to enable kinetic analysis
  • Dynamic biplane x-ray images will be acquired during ambulation

Photograph shows a single-plane fluoroscopy system.

Diagram shows the configuration of a proposed biplane fluoroscopy system and analysis method.

D3 Tasks

  1. Phantom studies to quantify localization accuracy
  2. Biplane fluoroscopy hardware and software development
  3. Dynamic phantom studies to validate biplane localization accuracy
  4. Pilot studies with 5 children age 10–18 yrs.

An x-ray of a shod foot phantom acquired with single-plane system

D3 Anticipated Timeline

Activity Year 1 Year 2 Year 3 Year 4 Year 5
Phase 1: Phantom studies with 2D fluoroscopy system Q1Q2Q3Q4
Phase 2: Construct biplane fluoroscopy system Q1Q2Q3Q4 Q1Q2Q3Q4
Phase 3: Develop feature extraction software Q1Q2Q3Q4 Q1Q2Q3Q4
Phase 3: Dynamic phantom study Q1Q2Q3Q4
Phase 3: Pilot patient studies (5 children aged 10–18) Q1Q2Q3Q4