Location and intensity of focal and referred pain provoked by maintained extreme rotation position of the cervical spine in healthy females

Situations with rotated positions of the cervical spine often occur in working life. The aim of this study was to find out whether maintained extreme positions of joint rotation in the cervical spine could induce pain, and if so to locate the pain. Two postures of the cervical spine were investigated, one sitting with active rotation, and the other prone with passive rotation. The ten healthy females participating in our study rated the perceived intensity of experimentally induced pain, and indicated its location and quality. Pressure pain thresholds were measured before and directly after each experiment. Extreme positions of joint rotation caused pain in all subjects within 9 min. Pain increased with time, and disappeared within 30 min after the end of provocation. Pain was located in the dorsal part of the neck, and in several subjects, it was referred to head- and/or shoulder regions. Other symptoms were dizziness and nausea. Pressure pain thresholds showed a tendency to increase after provocation compared to before. Ergonomic analyses of work postures should, therefore, include the study of extreme rotation of the cervical spine to help avoid the pain induced by such positions.