Analysis of the Psychometric Properties of Kinematic Parameters of Locomotion Measured by Inertial Measurement Units. Validation in Healthy Children and Children with Cerebral Palsy

Cerebral palsy (CP) is currently one of the major causes of disability in children. The presence of various disorders (muscle stiffness, architectural bone defects, spasticity) leads to a number of functional impacts, including severe impairment of mobility, particularly locomotion. Locomotion can be assessed using a motion capture system that enables 3-dimensional analysis, in order to help make treatment decisions and quantify them. Although these systems are currently considered to be the gold standard, the fact remains that they cause a certain amount of patient fatigue (long set-up times) and that walking is assessed in a laboratory rather than in real life.

Today, technological advances have brought to the fore other gait analysis devices, such as inertial measurement units (IMUs). Various systems incorporating IMUs in the feet, for example, respond to these problems of analysing walking in real-life situations. The IMUs record the movements and orientation of the foot in space; the data is then processed by algorithms to recognise walking steps and calculate the spatio-temporal parameters of locomotion. Additional IMUs positioned on the body can be grafted onto this system to provide a more precise analysis of locomotion, in particular by calculating the movements of the various joints of the lower limb. However, before such devices can be used in a pathological paediatric population, they must be validated in a healthy population. This validation must be conducted using a precise method that has been widely documented in the COSMIN recommendations (Consensus-based Standards for the selection of health Measurement Instruments). The first stage will assess the safety of the IMU devices in a healthy paediatric population, and the validity of the spatio-temporal parameters. If these properties are deemed to be compliant, these same parameters will be assessed in a paediatric population with cerebral palsy in the second stage.