Could Cervical Postural Changes Affect the Long Thoracic Nerve Electromyographic Findings?

Inclusion Criteria: * Patient whose age is \> to 18 years and \<40 yo * Patient presenting a chronic neck pain (symptoms over 3 months) * No neurological deficit * Asymptomatic volunteers (for control group) * Obtaining the enlightened consent of the patient Exclusion Criteria: * Patient having refused to sign his consent * Patients whose age is \< to 18 years or \>40 yo. * Patients with neurologic deficits * Patients presenting history of allergy * History of cervical spine surgery * Patient presenting an anticoagulant or salicylated treatment which can not be interrupted. * Pregnant woman. * Patient with acute head and neck trauma * Patient with a contra-indication to radiography. * Patient with a psychiatric pathology preventing a clinical evaluation. * Patient with contra-indication (cutaneous or different) to needle electromyography. * Surgery contra-indication (cardiac failure, respiratory…) * Patient without health coverage.