Gait analysis using inertial and magnetic sensors in children with cerebral palsy

Cerebral Palsy (CP) is the problem of greatest interest among all child motor
disabilities.
Gait Analysis (GA) is nowadays considered as the most refined tool available
for the documentation
and the functional assessment of the gait, especially in CP children. The GA is
widely used to classify
different forms of CP and to evaluate the effectiveness of rehabilitation
treatments. Optoelectronic
measurements systems are currently the only systems used to obtain GA. However,
such specialized
equipment limits the clinical use of this exam only to dedicated laboratory.
Alternatively, an inertial and
magnetic measurement system (IMMS) can be used. Such systems are increasingly
relevant in
clinical practice but need to be validated on CP children.

The aims of the study are 1) to upgrade an existing GA protocol based on
inertial system
(developed at the INAIL Prostheses Centre in collaboration with the University
of Bologna) in terms of
finding out which calibration procedures result suitable to the different kind
of patients with CP, and 2)
to evaluate the validity and the reliability of this protocol with respect to a
reference system and
protocol, in measuring joint kinematics during gait.

This is a pilot study. Walking trials and measurements will be performed partly
in the gait laboratory of the VU University Medical Center in Amsterdam, the
Netherlands, and partly into a edicated reserved area in the same location. 10
CP children will be measured in a first session using the IMMS and the
reference optoelectronic system to calibrate the systems on the subject*s body;
then they will be measured inside the laboratory to investigate the validity of
hardware and protocol; thirdly, the children will be measured in the reserved
area outside the laboratory to determine the influence on the gait patterns of
the laboratory setting itself; and finally the calibration procedures will be
executed once more inside the laboratory to determine the reliability of the
protocol.

Patients will be asked to walk a 10m walkway and a 50m walkway at self-selected
speed, wearing the IMMS sensors and marker clusters attached to the segments of
the lower extremities. The measurements are non-invasive. Markers and inertial
sensors have cables and may somehow increase the burden during the measurements
compared to normal walking. During walking, pain and fatigue could occur,
however, the risk of pain will be minimal. Patients can quit the measurements
if pain will occur. The practical relevance of this study is that validation of
the IMMS in a clinical situation may help to introduce such systems in clinical
practice in order to increase the use of the GA technique and to simplify and
improve its application in CP children.