Three Dimensional Ultrasound Reconstruction of the Medial Gastrocnemius in Children with Cerebral Palsy

Cerebral palsy (CP) is the most common cause of motor disorder in children. 80
per cent of the reported cases of CP are predominantly spastic. In
rehabilitation, most of the commonly applied therapeutic interventions are
directed at lengthening of the spastic muscles. Effectiveness of intervention
requires a fundamental knowledge of the mechanisms underlying the reduced
muscle force and muscle length range of active force exertion as well as how
the interventions change muscle force and length.
The aim of this project is to further develop and optimize a non-invasive
method which allows for quantifying morphological parameter of muscles in vivo.
Recent developments have made it possible to extend normal 2D B-scan ultrasound
analysis of a plane to a 3D reconstruction of a volume. Based on this approach
a 3D ultrasound reconstruction technique will be used to measure morphological
muscle parameters such as muscle belly length, fiber length, and pennation
angle. To relate these morphological muscle parameters to mechanical muscle
properties such as passive muscle force and net joint moment a dynamometer will
be used.

To optimize the 3D ultrasound reconstruction and dynamometer as a clinical tool
for measurement of morphological and mechanical muscle properties, and to
compare the m .gastrocnemius medialis of healthy children to the m
.gastrocnemius medialis of children with SDCP using the 3D ultrasound and the
dynamometer.

- Part A: a pilot study to investigate the reproducibility of the 3D ultrasound
and of
the dynamometer on healthy children.
- Part B: Investigate the reproducibility of the 3D ultrasound and the
dynamometer
on children with SDCP and a descriptive study to compare healthy
children to children with SDCP using the 3D ultrasound and the
dynamometer.

The reconstruction of the m gastrocnemius medialis is expected to give a better
understanding of the morphology of spastic muscles. And in the (near) future,
this method can improve diagnosis and treatment of spastic muscles. The
additional risks of the current study for the subjects are negligible and the
burdens minimal. The measurements are non-invasive. Subjects will have to lie
prone on a bench, whilst undergoing the ultrasound scans and passive
dynamometer measurements, watching a video. For this study it is necessary that
the subjects do not move during the measurements. This will ask for some
patience of the subjects. We believe the benefits clearly outweigh the risks or
burdens for the subjects.