Interaction between the muscles of the neck and the extraocular muscles of the myopic eye. An electromyographic study.

The functional relationships between the extraocular muscles of the myopic eye and the muscles of the neck were studied by means of electromyography, with the aim of demonstrating a possible alteration of the posture of the head due to abnormal tonus of the trapezius and sternocleidomastoid mm. in subjects with defective vision. The study was conducted in a group of 10 subjects with normal vision and a group of 10 myopic subjects, between the ages of 20 and 40 years. Electromyographic recordings of the relevant muscles were made during varied eye movements. Analysis of the results demonstrated a marked difference in tonic activity of the named muscles between the myopic and the normal groups. The findings suggest that, in the correction of visual defects, attention should be paid to postural adjustment of the neck by means of a series of programmed exercises directed towards the trapezius and sternocleidomastoid mm.