Touching Lives - October 2013
The Oxford Foot Model: Helping children to walk
Action Medical Research has funded numerous projects that have helped change the lives of children. One project in Oxford has enabled surgeons, doctors and scientists to develop a way to assess foot deformity to help improve treatment and minimise pain for children who have problems walking.
For the many thousands of children with cerebral palsy and other foot problems, walking can be extremely painful. This has a major impact on their lives and can exclude them from taking part in activities their friends or schoolmates might enjoy.
Cerebral palsy (CP) affects movement and posture and is caused by damage to a baby’s developing brain, which occurs in around one in every 400 babies during pregnancy, birth or infancy.
Nearly all children with CP (90 per cent) go on to develop deformities in their feet which are caused by unusual forces on the foot during a child’s early development. There are also other causes of foot deformity, such as club foot, that can affect a child’s ability to walk and some require surgery.
In the late 1990s there was limited understanding of foot movement and how forces are applied on the skeleton during walking. Doctors could only make decisions about how to treat foot deformities in children with CP through clinical observations, so the results and outcomes were often unpredictable.
Action funded research to help improve understanding of foot problems and this established a set of criteria to help doctors decide on the best types of treatment. This has helped reduce pain and improve walking for children with CP.
In 2001 Action Medical Research awarded a grant of £140,982 to Mr Tim Theologis and his research team at the Nuffield Orthopaedic Centre in Oxford and the University of Oxford. Their aim was to develop a sophisticated new tool to improve doctors’ understanding of problems leading to foot abnormalities and deformity in children with CP. The team collaborated with the Istituto Superiore di Sanità in Rome, Italy, Vicon Motion Systems and Vaquita Software, who provided hardware and software for some of the data collection and analysis.
This led to the discovery of a new way to analyse movement patterns within specific parts of the foot, which became known as the Oxford Foot Model (OFM). Around 4,000 children a year are benefiting from having their foot movement assessed while walking with the OFM. The OFM uses gait analysis to help doctors make an assessment. Gait is the pattern or way someone walks, so when this is analysed it gives doctors information that helps them understand the cause of possible abnormalities that can occur when walking and potential treatments.
The analysis is made using motion capture technology which is commonly used to assess how athletes run, to help them run more efficiently and to identify posture related or movement related problems. Markers are placed on various parts of the feet and legs and specialised motion capture cameras track the movement of the feet and legs while walking. To detect muscle activity, electrodes can also be placed on the surface of the skin.
Understanding the way feet move while walking using the OFM rather than just clinical examinations gives doctors, surgeons and therapists information about the various forces that are occurring across the foot as well as movement in specific parts of the feet.
The OFM has led to a greater knowledge of how foot deformities occur, including high arch, low arch, club foot, amputation and when part of the foot is missing through inherited conditions or accidents, stiff feet, feet that are too flexible and bunions – anything where there’s a mechanical problem with the foot.
Movement of the whole ankle joint as well as motion at the mid-foot and big toe can be measured using the OFM and adults as well as children are benefiting from this.
Today, the OFM is now the standard way doctors make accurate decisions to help treat people with foot problems. It is used across the UK in clinics, hospitals and universities.