Summary
Dysfunctions of the
cervical spine are extremely common in the general population and their chronic
nature represents a high cost. In spite of this major problem of public health,
cervical pathology presents difficulties in terms of diagnosis and treatment.
Evaluation of the muscle strength of the neck is an important part of the
overall study of cervical musculature. Most of these studies have described
simple evaluation methods of isometric neck muscle strength, but its dynamic
function during voluntary maximal contractions is little-known. Moreover, few
studies have attempted to combine these strength measurements with other
parameters (EMG analysis, cinematic or morphological).
Main aim
Using an integrative approach taking into
account biomechanical, neuromuscular and morphological parameters, the main
objective is to characterize the dysfunctions of the cervical spine in function
of their etiology.
Secondary aims
Using quantitative data, this analysis
should facilitate the therapeutic management and the follow-up of cervical
affections.
At different levels, the methods set up could be a help for
medical evidence expertise.
The data concerning muscle morphology will lead
to participation in the conception of a predictive behaviour model of the muscle
mechanism of the cervical spine developed at the Laboratory of Biomechanics of
ENSAM (UMR CNRS 8005). Muscle strength and EMGs activity parameters will allow
this model to be validated.
Experimental protocol
The first stage of the project
concerns the conception and construction of the measurement system, adaptable to
different dynamometers in terms of structure, material and design. The second
stage concerns the definition of the protocol of strength measurement and its
reproducibility based on 15 healthy subjects. The test-retest reproducibility of
the measurement system will be tested. Isometric and isokinetic tests will be
carried out for the lateral incline, flexing and extension functions. For the
isometric tests, different cervical positions corresponding to different muscle
lengths will be tested. For the isokinetic tests, each function will be tested
at different angular speeds. The electromyographic and cinematic measurements
will be done at the same time. Simultaneously, the surface of the transversal
section of the neck muscles will be determined by the magnetic resonance imaging
(MRI) technique. The third and final stage of this work will concern the
characterisation of the muscle function of subjects submitted to different
cervical constraints and patients whose cervical spine is post-traumatic,
post-operative, rheumatological or affected with a neuromuscular dysfunction
(approx. 15 subjects per group). This project should lead to the
characterisation of the cervical spine in different healthy or affected
populations in terms of strength, as well as in electromyographic, cinematic and
muscle geometry terms.
