KINESIOLOGICAL EMG AND CONTROL OF MOVEMENTS WITH A VIRTUAL REALITY SYSTEM ENABLE A RELIABLE DIAGNOSIS OF FUNCTIONAL DISTURBANCES AFTER QTF GRADE II WHIPLASH INJURIES

Abstract

Introduction: After whiplash injuries the majority of patients complain of pain, muscular dysfunctions and restricted movement of the cervical spine, however, the cause of these symptoms cannot be diagnosed.

Against this background, the hypothesis is formulated that functional disturbances in the form of pathological activities of the neck muscles occur as a result of a whiplash injury of the cervical spine. These pathological muscle activities can be demonstrated electromyographically and differ from the patterns of activity of healthy subjects.

Study Objective: Thus, the aim of this study was to establish an electromyographical method for the diagnosis of functional disturbances of the neck muscles after whiplash injuries of the cervical spine.

Material/Method: Primarily, an intramuscular recording of the electromyographical activity of the semispinalis capitis muscle was performed during flexion/extension and axial rotation in 46 patients with chronic symptoms after a whiplash injury of the cervical spine (QTF grade II) and 29 healthy subjects. The movement was controlled with techniques of virtual reality. The subject is immersed into a virtual outer space environment with a head-mounted display (HMD). In this virtual scene, the patient follows paths of motion of a signal (globe) with his/her gaze.

A subsequent study was conducted to validate the results that had been obtained. For this purpose, the electromyographical activity of the semispinalis capitis muscle was recorded in another subject group (n=20) and patients with acute symptoms as a result of a whiplash injury of the cervical spine (QTF grade II) (n=35).

Results: Compared to the physiological muscle activities that were established in the first subject group, changes could be observed in the chronic patient group.

Subjects in our study, for instance, show a decrease in electrical activity during flexion and the resulting stretching of the semispinalis capitis muscle, while the same movement causes an increase in activity in patients. On the basis of these differences, 93 % of subjects (specificity) and 83 % of patients (sensitivity) could be classified correctly with a discriminance analysis.

In the second study, the specificity was 88 % while a sensitivity of 86 % was determined in the acute patient population.

Conclusion: The results of these investigations enable a highly specific and sensitive diagnosis of muscular dysfunctions on the basis of the intramuscular recordings of the electromyographical patterns of activity of the semispinalis capitis muscle.