Biomedical Engineering Reference
In-Depth Information
functioning of the upper limb, such as hemiplegia,
Friedreich's ataxia or even brachial plexus.
5.3. Mobility of a healthy cervical spine
There are many
in vivo
studies on the three-dimensional
mobility of the cervical spine in healthy subjects. Several use
a specific goniometer, the Cervical Range of Motion and
provide the amplitudes of the main movements, with good
reproducibility, over large populations [NIL 96, YOU 92].
However, for a truly three-dimensional analysis, describing
in particular the reciprocal coupling between lateral bending
and axial rotation, other devices must be used. Medical
imaging - CT scan [SAL 13], MRI [TAK 11],
stereoradiography [ROU 11] - present the disadvantage of
basing the analysis on extreme static postures, which do not
correctly reproduce the coordination of the actual movement
observed [TSA 13]. Electromagnetic devices such as the
Spine Motion Analyzer [FEI 99], ultrasound [DEM 07] or
even optoelectronic devices [FER 02, SFO 02] are also used
to monitor the movement of the cervical spine. Nevertheless,
it is difficult to synthesize the results of all these studies
given the diversity of the experimental protocols and
calculation methods used.
5.3.1.
Materials and methods
The aim of the study described here, which was part of the
Ph.D. thesis by Luc Boussion [BOU 08], is an analysis of the
three-dimensional mobility of the cervical spine in healthy
subjects using an original experimental protocol exploiting
the Motion Analysis® system with passive markers. An
adjustable seat helps position the subjects in a sitting
position, with support of the lower back and strapping of the
pelvis. A device with a vertically adjustable bracket (to align
its center with the vision axis) is situated at 0.65 m from the
