Interview with Aurélie Canal and Laurent Servais
For several years the Institute of Myology has been carrying out evaluations of motor function in humans within the framework of clinical trials. The ULENAP (Upper Limb Assessment in Non Ambulatory Patients) clinical trial to evaluate non-ambulatory patients suffering from neuromuscular diseases began in January. Aurélie Canal, physiotherapist form the center of neurophysiology and muscle evaluation (Director: JY Hogrel) and Laurent Servais, neuropediatrician at the IM, have developed Moviplate, a tool for measuring motor function in these patients.
What is the purpose of this clinical trial?
It is a somewhat unusual trial that has been initiated to validate a tool to evaluate the upper limbs of non-ambulatory patients, regardless of the neuromuscular disease, but mainly Duchenne patients. Here we assess the reliability, feasibility, reproducibility of this test and then its sensitivity in the natural history of this dystrophy; to ultimately be able to assess the effects of therapy on the upper limbs.
We have therefore been asked to develop a tool for the evaluation of non-ambulatory patients to serve as a measurement tool for future clinical trials. It would be a 6-minute walk test, a reliable test ... for patients who walk. The prospect of clinical trials in ambulatory patients is continuously comparable. For the time being, ULENAP must include 100 non-ambulatory neuromuscular patients and 60 controls from 8 to 30 years, and test both upper limbs.
It is a somewhat unusual trial that has been initiated to validate a tool to evaluate the upper limbs of non-ambulatory patients, regardless of the neuromuscular disease, but mainly Duchenne patients. Here we assess the reliability, feasibility, reproducibility of this test and then its sensitivity in the natural history of this dystrophy; to ultimately be able to assess the effects of therapy on the upper limbs.
We have therefore been asked to develop a tool for the evaluation of non-ambulatory patients to serve as a measurement tool for future clinical trials. It would be a 6-minute walk test, a reliable test ... for patients who walk. The prospect of clinical trials in ambulatory patients is continuously comparable. For the time being, ULENAP must include 100 non-ambulatory neuromuscular patients and 60 controls from 8 to 30 years, and test both upper limbs.
What was your progress to accomplish Moviplate?
We first established a list of constraints concerning this tool: it should be simple, painless, reproducible, easy to understand and use, enjoyable... The device should be applicable both to persons with normal strength and extremely weak subjects, thus neither a lower limit effect nor upper limit effect; it had to be possible for patients with contractures; it had to be on a sufficiently broad scale to be discriminating; it had to be reproducible, automated, simple, inexpensive, rapid, not tiring, not painful, not boring, challenging, not too bulky ... We originally considered several tools that we subjected to our list of constraints. We imposed a long list on ourselves! By testing our ideas with patients in consultation, watching their reactions ... eureka! The concept of Moviplate emerged.
We first established a list of constraints concerning this tool: it should be simple, painless, reproducible, easy to understand and use, enjoyable... The device should be applicable both to persons with normal strength and extremely weak subjects, thus neither a lower limit effect nor upper limit effect; it had to be possible for patients with contractures; it had to be on a sufficiently broad scale to be discriminating; it had to be reproducible, automated, simple, inexpensive, rapid, not tiring, not painful, not boring, challenging, not too bulky ... We originally considered several tools that we subjected to our list of constraints. We imposed a long list on ourselves! By testing our ideas with patients in consultation, watching their reactions ... eureka! The concept of Moviplate emerged.
Precisely, what does Moviplate consist of?
The device has two platforms. The goal is simply to touch each of them alternately. These platforms are connected to force transducers to directly measure the force developed. A counter shows the number of contacts and a stopwatch counts down the time over thirty seconds. For now, the design is fairly austere, but it is planned to decorate it with drawings! Moreover, patients appreciate this test (and their parents who sometimes ask to try it). Young patients are very motivated to do the maximum and try to exceed their scores.
The device has two platforms. The goal is simply to touch each of them alternately. These platforms are connected to force transducers to directly measure the force developed. A counter shows the number of contacts and a stopwatch counts down the time over thirty seconds. For now, the design is fairly austere, but it is planned to decorate it with drawings! Moreover, patients appreciate this test (and their parents who sometimes ask to try it). Young patients are very motivated to do the maximum and try to exceed their scores.
You insist on the attractiveness of the device...
It is actually very important that it is motivating. The target patient is the 12 year-old boy suffering from DMD. You cannot ask him to pass a boring, off-putting, painful and long test. Furthermore, when we’re more advanced, we can imagine creating software and connecting the sensors to a computer to make a video game where the movement would be associated with something enjoyable.
It is actually very important that it is motivating. The target patient is the 12 year-old boy suffering from DMD. You cannot ask him to pass a boring, off-putting, painful and long test. Furthermore, when we’re more advanced, we can imagine creating software and connecting the sensors to a computer to make a video game where the movement would be associated with something enjoyable.
Will the test include other tests?
Four other tests of function and strength are also part of the test: ‘taping’, an endurance test that is relatively unpleasant and difficult to achieve for children with contractures because of the arm’s position during the test. The ‘wrist flexion and extension’ that concerns the wrist also poses problems for these patients. The grip test using the ‘handgrip’ is really good, very sensitive, effective and motivating. Finally there is the ‘pinch’, which measures the strength between the thumb and forefinger. In addition to these mechanical tests, we have a functional quality of life questionnaire based on the activities of the hands in everyday life (Do you brush your teeth? Do you button up your shirt? Can you turn a key in a lock ? etc.). The battery of tests ends with a MFM (measure of motor function comprising 32 items divided into three dimensions: D1 standing and transfers, D2 axial and proximal motor function, D3 distal motor function).
Four other tests of function and strength are also part of the test: ‘taping’, an endurance test that is relatively unpleasant and difficult to achieve for children with contractures because of the arm’s position during the test. The ‘wrist flexion and extension’ that concerns the wrist also poses problems for these patients. The grip test using the ‘handgrip’ is really good, very sensitive, effective and motivating. Finally there is the ‘pinch’, which measures the strength between the thumb and forefinger. In addition to these mechanical tests, we have a functional quality of life questionnaire based on the activities of the hands in everyday life (Do you brush your teeth? Do you button up your shirt? Can you turn a key in a lock ? etc.). The battery of tests ends with a MFM (measure of motor function comprising 32 items divided into three dimensions: D1 standing and transfers, D2 axial and proximal motor function, D3 distal motor function).
Will the patients be evaluated at the Institute?
Only for some of them: the multicentre trial involves five centres: the Institute of Myology, the hospitals Trousseau, Necker, Garches-Raymond Poincaré and Gant in Belgium. A. Canal is regularly present at Garches to train physiotherapists who will carry out the tests and for which we have made another Moviplate. The equipment will be made available to the team at Gant for a month in order to test all of its patients. Finally, we will go to the Trousseau and Necker hospital to assess patients from these two sites.
Only for some of them: the multicentre trial involves five centres: the Institute of Myology, the hospitals Trousseau, Necker, Garches-Raymond Poincaré and Gant in Belgium. A. Canal is regularly present at Garches to train physiotherapists who will carry out the tests and for which we have made another Moviplate. The equipment will be made available to the team at Gant for a month in order to test all of its patients. Finally, we will go to the Trousseau and Necker hospital to assess patients from these two sites.
Next step: actimetry
The measurement of patients’ upper limbs is like squaring the circle! Moviplate is one of the tools developed to evaluate their motor function. Here is another that will soon be valid, actimetry, i.e., the recording of the subject in his home, during his daily life. The technology is not yet optimized: we need a device that is sufficiently small and light that can provide analysable data, know how to analyze them and how to correlate them. However, we have just found the equation that relates the effectiveness of a task and the acceleration that must be produced to achieve this task. Now that we know which data we need, it is possible to size the sensor. Once the prototype is built, it needs to be calibrated, verify that the equations highlighted on control subjects are valid for patients with muscular dystrophy. Then, follow the same progress and evaluate the sensitivity and reproducibility. So, for the patients, it is unnecessary to come to take measurements at the Institute at a given point and time; he can live his daily life at home and the recorded measurements will be even more reliable.
The measurement of patients’ upper limbs is like squaring the circle! Moviplate is one of the tools developed to evaluate their motor function. Here is another that will soon be valid, actimetry, i.e., the recording of the subject in his home, during his daily life. The technology is not yet optimized: we need a device that is sufficiently small and light that can provide analysable data, know how to analyze them and how to correlate them. However, we have just found the equation that relates the effectiveness of a task and the acceleration that must be produced to achieve this task. Now that we know which data we need, it is possible to size the sensor. Once the prototype is built, it needs to be calibrated, verify that the equations highlighted on control subjects are valid for patients with muscular dystrophy. Then, follow the same progress and evaluate the sensitivity and reproducibility. So, for the patients, it is unnecessary to come to take measurements at the Institute at a given point and time; he can live his daily life at home and the recorded measurements will be even more reliable.
March 2010
Interview by Anne Berthomier, translation by Racquel N. Cooper
Interview by Anne Berthomier, translation by Racquel N. Cooper
