Data from electromyography of vertically acting extraocular muscles during head tilting, confirms that the superior oblique and superior rectus muscles are increasingly activated with head tilt to the ipsilateral side. The inferior rectus and inferior oblique muscles are increasingly inhibited with head tilt to the ipsilateral side. A reverse pattern of muscle activity is seen with head tilt to the contralateral side. The absence of these changes with tilting of the head while the subject lies in the supine position, indicates that the neck muscles play little or no part in generating the torsional movements of the eye.
Scott AB. Extraocular Muscles and Head TiltingElectromyographic Measurement of Activity of Individual Muscles. Arch Ophthalmol. 1967;78(3):397-399. doi:10.1001/archopht.1967.00980030399024