Semirhythmic, Jerky, and Sustained Movements of the Right Scapula, Neck, and Head

Needle electromyography of the right rhomboids demonstrating semirhythmic, 3- to 4-Hz, 0.1- to 0.2-second bursts of grouped, normal motor unit potentials recruited in a crescendo-decrescendo pattern while sitting. Surface electromyography showing similar activity in the right rhomboids/midtrapezius and infraspinatus regions.