Bi-planar x-ray imaging of the human foot
Research type
Research Study
Full title
Quantifying the internal motion of the healthy human foot using integrated bi-planar x-ray videography: a preliminary study
IRAS ID
163391
Contact name
Karl Thomas Bates
Contact email
Sponsor organisation
University of Liverpool
Duration of Study in the UK
2 years, 0 months, 0 days
Research summary
Summary of Research
The human foot is an extremely complex structure, being composed of 26 bones, +80 ligaments and muscles. Measuring how it moves during locomotion is crucial to understanding how it functions when healthy, and subsequently how best to diagnose and treat foot disorders. To-date the only direct measurements of motion within the foot during walking have come from invasive ‘bone-pin’ studies, where the movements of metal pins drilled into the foot bones of anesthetized volunteers are tracked by cameras. The highly invasive nature of this method makes it logistically challenging, and not surprisingly only a small number of individuals have been studied. However, the recent development of high-resolution bi-planar x-ray systems makes it possible to track the three-dimensional motion of foot bones directly and non-invasively in unparalleled detail. Furthermore, radiation dosages are low enough for several repeat trials per subject (e.g. level of ionising radiation exposure is equivalent to a uniform whole body exposure [effective dose] of approximately ~ 0.15 mSv for a full study on one volunteer versus 10mSv in a whole body CT scan in[1]), and to-date it has been used to study movement in the human knee joint during running and turning, as well as in a number of animal studies. In this pilot project we will collect integrated bi-planar x-ray videography data on the feet of a small number of healthy human volunteers (N=15) in our purpose built bi-planar x-ray facility. This novel data will be integrated with traditional measurements of locomotion (motion capture, pressure and force plate recordings) and magnetic resonance imaging (MRI) data of the subject’s lower limbs. The proposed research therefore brings together unique and cutting edge experimental and imaging techniques. It is hoped that the knowledge gained from the work proposed here will provide the basis for a larger study using these techniques, with the ultimate goal being a major improvement in our understanding of how the human foot functions.References: [1] Miranda et al. 2008, NEBEC 2008: 1-3.
Summary of Results
Measuring how the human foot moves during locomotion is crucial to understanding how it functions when healthy, and subsequently how best to diagnose and treat foot disorders. However, to-date the only direct measurements of motion within the foot during walking have come from invasive ‘bone-pin’ studies, where the movements of metal pins drilled into the foot bones of anesthetized volunteers are tracked by cameras. The highly invasive nature of this method makes it logistically challenging, and not surprisingly only a small number of individuals have been studied. This research, and indeed recent and on-going work by the investigators now suggests standard indirect measures (e.g. skin marker motions, plantar pressure measurements) of human foot function lead to important over-simplifications and some in cases flawed conclusions about how the healthy human foot works. The recent development of high-resolution bi-planar x-ray systems provides the new method required. These systems allow us to track the three-dimensional motion of foot bones directly and non-invasively in unparalleled detail. Furthermore, radiation dosages are low enough for several repeat trials per subject. Our primary objective in this project was to quantify the three-dimensional motion of bones within the human foot (in 15 young, healthy volunteers) as it contacts the ground during walking using biplanar x-ray videography.During the project we were able to successfully collect biplanar x-ray data on the feet of five young, healthy volunteers. This required extensive modification of our standard data collection set-up to visibly image all foot bones simultaneously, which caused delays to initial timeline of the project. Having collected high-quality data on these five subjects, we paused data collection to ensure that appropriate data processing could be carried to achieve the overall aim of the project. First, attempted to utilise automated image registration algorithm developed specifically for rapid processing biplanar x-ray data of the human foot by researchers at Keio University. These algorithms had been previously validated based on cadaveric human foot trials at Keio University. Unfortunately, our work has suggested that these algorithms do not currently produce accurate enough data to be used as a standalone tool. We were therefore forced to resort to manual processing of the data, which is at least one order of magnitude more time-consuming than automated approaches. At present we have processed a small number of trials from one human volunteer. Given the challenge of processing this data efficiently, and lab shutdowns during the COVID-19 pandemic, we made the decision not to collect data on outstanding 10 subjects.
REC name
North West - Greater Manchester East Research Ethics Committee
REC reference
15/NW/0851
Date of REC Opinion
29 Dec 2015
REC opinion
Further Information Favourable Opinion