Gait lab research
New methods to make gait analysis more accurateConventional methods of gait analysis are known to be heavily dependant on the physiotherapist conducting the study. Several studies have shown even with the most experienced physios different results have come from different labs. This study is trying to develop a technique that’s less dependant on placement of the markers by the physiotherapists and should therefore give the same results wherever it is tested. The early work of this study is currently being done at the Hugh Williamson Gait Analysis Laboratory at the Royal Children’s Hospital, further testing will be conducted at other laboratories within the Gait CCRE. A study has just been completed on 10 healthy children that repeated the gait analysis 4 times in one afternoon, using our two most experienced physiotherapists. The study found that repeatability of the two physiotherapists was quite high with the old technique, though it also found that the new technique was even higher. All children seen at the Gait Laboratory take part in a gait analysis will have markers to allow both old and new technique to be used for comparison. We are working very closely with VICON, who are the leading manufacturers of gait analysis systems internationally and hope that they will adopt these new techniques for laboratories all over the world. Staff involved:
What is a 3-Dimensional joint angle?Gait analysis measures how joint angles change during walking. A joint angle is how one bone is held in respect to another bone, e.g. the knee joint angle looks at how the shin bone is held with respect to the thigh bone. In 2-Dimensional this is all very simple. In 3-Dimensions joint angles becomes more complex and there is still a debate on exactly how these angles should be calculated. This project is trying to find a rigorous definition of joint angles. The answer needs to be consistent with how a Doctor thinks about the body.
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How effective is orthopaedic surgery for children with Cerebral palsy?Most orthopaedic surgeons are convinced that surgery has significant benefits for children with cerebral palsy, though no one has yet been able to prove this rigorously. In this research a group of 19 children who all needed surgery sometime within the year were studied. The group was divided randomly into two groups, one group had the surgery immediately and the second group had the surgery at the end of the year. A comparison was then made of how both groups progressed during the year, using gait analysis as measurements. The study found that patients that didn’t have the surgery, and tended to get a little worse over the year. Patients who did have surgery were slightly better at the end of the year and showed even more improvement the following year. This showed quite clearly that there is a benefit from orthopaedic surgery for children with cerebral palsy. Staff involved:
Classification of walking patterns in children with cerebral palsy.This research project was carried out to gain a better understanding of the range of characteristics and abnormalities of walking patterns in children with hemiplegic cerebral palsy (CP). The project was also designed to develop a new system for classifying walking patterns that can be used to better identify and treat walking disorders in children with hemiplegic CP. It attempted to test all children with hemiplegic CP born in This research was carried using three-dimensional motion analysis. Walking patterns were judged by a panel of expert clinicians from many different walking laboratories around the world. A new method of multidimensional classification of walking patterns in children with hemiplegic CP based on three clinically meaningful dimensions has now been proposed. Additional studies are now required to further validate the developed classification system so it can be used to facilitate clinical decision making for the management of walking disorders for children with hemiplegic CP. Staff involved:
Can more regular Botox injections stop the calf muscle from getting to tight?This project is about understanding how often to use Botox and perhaps why some children respond less to Botox injections over time. Botox helps to relax tight muscles and keep them long in children with cerebral palsy, but it only lasts around 3 months. Children may get Botox once or more often in a year. What this project is trying to find out is how often Botox should be used to keep muscles as long as possible. To answer this, we will do tests that measure calf length and strength, take ultrasound pictures of the calf muscles, and do some questionnaires. Some children get less effect from the Botox over time and it is unsure why. It may be because they are ‘stiffer’ and the Botox can’t work as well, or it may be because they develop resistance (antibodies) to the Botox. The project will be studying genetics and blood samples to help understand this issue. This project will study 60 young children with cerebral palsy who are able to walk. There will be two groups: 30 children will receive Botox injections once a year, the other 30 children will get Botox 3 times a year. The results of these two study groups will be compared. The project will be conducted at the Royal Children’s Hospital and Monash Medical Centre, Southern Health. Recruitment will begin towards the end of 2007 and continue for 2 years. Staff involved:
Does making some changes to standard test of measuring calf length make the test more reliable in children with cerebral palsy?This project was created to find out whether a new technique of assessing calf tightness in children with cerebral palsy was more accurate and reliable than standard measures used. The normal technique to assess calf muscle length involves stretching the foot back towards the shin, and measuring the angle either by looking or using a measuring stick (goniometer). This is known to be reasonably reliable, however it may be less accurate depending on how strong the examiner pushes, how loose the child’s muscles are to start with, and how much the child tries to resist the movement. The new technique is performed with the child lying on their back and a flat board placed against the sole of the foot, connected to a cord and spring balance for the examiner to pull with. The spring balance enables a safe, known force of half the child’s weight and therefore uses the same force on each child to stretch the calf. Once the leg is in its correct position a digital photo is taken. The angle between the foot and leg is measured using software applied to the photo to determine the length of the calf muscle.(add diagram) The research project involved 34 children with cerebral palsy (15 boys and 19 girls) that were able to walk, between the ages of 3-9 years of age. The children were tested twice, once while they were awake and once when they were under a light anaesthesia (eg when a child is having a Botox injection). The research project found that the new technique compares well and a little better to previously used measures of calf length. It also found that the newer technique was more reliable when the children were asleep under a light anaesthetic, indicating that perhaps the anaesthetic state produces the most reliable calf length measure. Staff involved:
Does using different marker location decrease error in information from skin and muscle movement during gait analysis?Gait analysis is a way to get information about the way people walk. Some people have difficulty with walking, and through the use of gait analysis it is possible to plan various types of treatment aimed at improving their ability to walk. The information is obtained by measuring the position of markers attached to the skin over bony structures. These areas of skin however are known to move in relation to those structures as the subject is walking and this limits the accuracy of this technique. There are a number of methods which have been developed in the past to try to minimize the effect of this error. Many of these methods are invasive and inappropriate for normal routine clinical motion capture. This research project was designed to find the best marker positions and the best combination of markers that are not affected by the movement of skin or muscle, when used in gait analysis. A variety of locations on the lower limb were used to identify a more reliable position to place markers. In addition the study was designed to find out whether minimizing this effect has any impact on results in the routine clinical setting. A group of 20 healthy adults between the ages of 18-60 participated in this study. The results found that certain areas on the lower leg were least affected by movement of the skin. This information can now be used in the future to develop a new model to be tested on a variety of ages and populations from children with cerebral palsy to adults with Parkinson’s, which will hopefully prove more accurate and reliable results and help clinical decision making in gait analysis. Staff involved:
How strong do muscles have to be for normal walking?This project was created to find out what muscle strength was needed for normal walking. In many motor disorders a significant factor limiting walking and other functional abilities is muscle weakness. Finding out the strength needed for normal walking may be useful in future research to help understand the level of strength required for individuals with motor disorders such as cerebral palsy. The project consisted of 11 able-bodied children who had a regular walking pattern. Normal, maximal muscle strength can be graded as grade 5. Grade 3 muscle strength can be regarded as fair, where the individual can hold the test position against gravity but they can not resist additional pressure. The major muscle groups of the legs were manually tested for maximum strength i.e. grade 5 and for their ability to resist gravity alone i.e. grade 3. The procedure consisted of practice trials until the child demonstrated the correct muscle action. Three maximal test trials were then performed for about 5 s in which the assessor aimed to ‘break’ the child’s maximal effort. The results were then processed and presented in a way that allowed direct comparison with the muscle forces collected during normal routine clinical motion capture. Each session was conducted at the one time by a single physiotherapist, using a random selection of dominant and non dominant legs. The results indicated that although maximal grade 5 muscle strength was not recorded and thus needed during walking, grade 3 muscle strength was nowhere near a satisfactory strength level for normal walking either. The researchers acknowledged that there may have been some limitations with this type of strength testing for some muscle groups but overall they were confident that the results gave reliable estimates of true muscle strength required for walking in normal children. Staff involved:
What are the common movement problems amongst SUFE patients?SUFE (Slipped Upper Femoral Epiphysis) is a problem of the hip joint. This joint consists of a bony ball and socket which is connected to the thigh bone (femur) by a bony strut known as the femoral neck. In SUFE patients, the bony ball (epiphysis) slips off the femoral neck. The slip can only occur in growing children because it occurs through the growth plate. There are varying degrees of slip and thus varying symptoms including pain, limited hip joint movement and limping, In the long term, problems such as degeneration of the joint can occur, which can lead to early hip replacements. In order to hopefully avoid this outcome, reconstructive surgery is often offered to patients to improve the congruity of their hip joint, Specific X-ray tests are used to assess the degree and severity of the slip. Gait analysis is also commonly used to examine the movement problems associated with the walking pattern of SUFE patients. The information from these two sources can then be combined to determine the best type of re-constructive surgery to perform. Research in this topic will have three broad aims: 1. To characterise the common gait abnormalities in SUFE patients 2. Identify a clinical test to mimic the re-constructive effects of hip surgery and 3. Compare the results of patients before and after surgery using gait analysis. Staff involved:
Novel approach to clinical gait analysis.Gaitabase has been established to provide a web-accessible repository of gait analysis data. It has been developed to allow sharing of data across national centres but access is open to the international clinical and research community. There are at least three areas in which this is useful: Clinical consultation: Gait analysis is conducted because patients have specific gait problems that are clinically challenging. Gait analysis offers the potential to accurately specify a patient’s condition and consult with others regarding clinical decision-making. Sharing knowledge with other experts is now easier thanks to Gaitabase that provide the mechanism for sharing the data online either of individual patients or of patients with similar gait data. Collaborative work: Because of the difficulty in collecting gait data, many gait clinics rely on small sample size to make important decisions. Gaitabase addresses this through collaborative work, which is based on a sharing large sampled gait data to improve decision-making. Quality assurance: The quality of gait data is crucial for clinical decision-making. Gaitabase assists by providing novel procedures and functionality that are essential component to ensure the quality of the data. The best clinical gait centres in Europe and the Staff involved:
How similar or different is walking when we measure it on different occasions?In clinical gait analysis services, we often measure a person’s walking on more than one occasion. It is known that repeated measurements from the same person can show large variability but not whether this arises from measurement error or the real (inherent) variability of walking patterns from one test to anther. This research project is currently looking at how healthy people’s walking patterns vary when measured with three-dimensional motion analysis systems across hours, a day, or a week.. It was designed to to see how much variability is typical in young adults and how repeatable the measures are. Data for this project was captured at the Knowledge from this project will give us a clearer understanding of how much people vary their walking over time. Staff involved:
Using GAITABASE and Gait Reliability Profiles to calculate the.reliability of 3-Dimensional Gait Analysis (3DGA)Determining how much measurement error occurs when we repeat 3DGA measures is important in maintaining the quality of Gait Laboratory data and for interpreting clinical gait data. GAITABASE uses a statistical approach to estimate the repeatability of repeated 3DGA measures and to produce Gait Reliability Profiles. These are simple graphs that illustrate how repeatable gait analysis data are. These profiles can show how repeatable gait analysis data are from a single assessor or from a team of staff within a gait laboratory. The profiles provide clinicians with useful information about the quality of their measures. Staff involved:
Validating the Functional Mobility Scale (FMS)The functional mobility scale was constructed in 2004; it is designed to classify functional mobility in children between the age of 4 -18 years old, taking into account the use of assistive devices needed by the child. The functional mobility scale can also be used to document if any change occurs in a child over time and to see if any change occurs after certain interventions have been implemented. The assessment is done by a clinician on the basis of questions asked of the child/parent. The child’s walking ability is rated at 3 different levels at 5m, 50m and 500m according to what assistive devices are needed, such as crutches, walkers or wheelchair. The current research being conducted on the FMS is determining it’s reliability and validity . The different ways this has been done involve;
The research has so far found that the FMS has good reliability. Most forms of validity have been supported, indicating that the FMS can be used in confidence as a functional mobility scale tool. This research will allow the FMS to accurately monitor change in mobility over time as well as after surgery.
Below is a picture of the Functional Mobility Scale.
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Changes in gait in children with Dravet SyndromeChildren with Dravet Syndrome have a severe form of epilepsy that begins in infancy. Seizure control and cognitive and developmental delay are the main issues in the first decade of life. It has been noticed that gait deterioration occurs later in the teenage years and mobility becomes compromised. This study involves people of all ages with Dravet Syndrome and identifies their gait pattern, how their ability to walk is affected at school/work and in the community and any changes seen physically and on x ray. The results have shown that before the age of ten years some children are already showing signs of an alteration in gait pattern known as crouch gait. This means that they are beginning to bend at their hips, knees and ankles when walking. Most of the children tend to have some degree of flat feet. The crouch gait becomes more pronounced in most cases, during adolescence and adulthood and the ability to walk community distances becomes harder with some opting for a wheelchair in the community. However all remain able to walk in the home or at school/work. Some physical and x ray changes also occur. Having identified these changes in gait in Dravet Syndrome, we now need to identify the cause(s) of these changes so that crouch gait can be prevented.
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Can severe crouch gait in cerebral palsy be corrected by a programme of orthopaedic surgery?When a child walks with their hips, knees and ankles excessively bent, the gait pattern is called severe crouch gait. Some children with cerebral palsy have both of their legs involved, and may walk in severe crouch gait. Eventually with time these children have great difficulty walking due to knee pain, fatigue, and falls. Fractures of the knee cap can also develop. These symptoms often cause the child to limit their walking and to use sticks, crutches or a wheelchair to get around. Surgery to correct the tight muscles and bony abnormalities that are present in severe crouch gait is extensive involving often more than six operations in the one surgical session. The post-operative management is intensive and involves physiotherapy, orthotics and various walking aids during rehabilitation. This study looked at the results of the surgical programme used to correct severe crouch gait at one and five years post- operation. The surgery to correct the excessively bent posture of the knee and ankle was successful and maintained at five years. However surgery did not affect the hip and so surgical intervention has now been altered to assist in increasing hip extension and a normal alignment of the pelvis. This change in the type of surgery so far has shown positive results.
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Classifying gait in children with cerebral palsy, who have both legs involved.Children with cerebral palsy who have both legs involved, do not all walk the same way. Some may walk on fairly straight legs but on their toes, whilst others may walk with bent hips, knees and ankles with feet flat on the floor. Because these children walk differently, they can not be managed with the same orthotics, spasticity management or surgical interventions. The aim of this study was to identify the main gait patterns that these children exhibit and explore the implications for management stategies for each gait pattern. The gait patterns were categorised by video observation and three dimensional gait analysis using the sagittal plane data from mid stance to toe off. Four gait patterns were identified (see Figure below), with a fifth one comprising a different gait pattern for the left and right legs (asymmetric gait pattern). Appropriate management stategies were also developed as guidelines on which to begin to tailor individual treatment plans for each particular child. This classification of gait patterns for these children with bilateral leg involvement in cerebral palsy is a handy tool for communication amongst peers, for teaching the newcomer to the field of cerebral palsy and can be used to define subject groups in research. Staff involved:
The use of bilateral 8 plates in the management of flexed knee gait.Walking with bent knees can be a long term threat to sustained walking in later life as the bent knee is subjected to increased forces that lead to stretching of the tendon at the knee cap, eventual knee pain and even stress fractures of the knee cap. Therefore the presence of a contracture at the knee that prohibits complete straightening of the knee is a concern. Past surgical intervention to correct minor knee contracture in young children who have not completed their skeletal growth, has been by the insertion of staples at the growth plate of the knee to slow down growth at the front of the knee and allow normal growth at the back and thereby balance the knee contracture. However the ability to reverse this procedure has been difficult to assess. This study looks at a new procedure using 8 plates to control the growth plate at the knee for minor knee contracture in children who are still skeletally immature and have a neurological condition. The study will be conducted over three years and aims to recruit thirty patients. Outcomes measures will include radiology of the knee, range of motion of the knee, gait pattern and functional mobility at baseline and then at regular intervals until 8 plate removal.
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