Ability to reproduce head position after whiplash injury

Study Design. A two-group design with repeated measures. Objectives. To determine if there is loss of the ability to reproduce target position of the cervical spine in individuals who have sustained a whiplash injury. Summary of Background Data. The ability to sense position is a prerequisite for functional movement. Injury may have a deleterious effect on this ability, resulting in inaccurate positioning of the head and neck with respect to the body coordinates and to the environment. Methods. Eleven subjects with history of whiplash injury (age, 42 +/- 8.7 years) and 11 age-matched asymptomatic subjects (age, 43 +/- 3.1 years) participated in the study. Effects of whiplash injury on the ability to replicate a target position of the head were assessed. Maximum rotation of the neck and ability to reproduce the target angle were measured using a standard cervical range-of-motion device. Subjects' perception of ''neutral'' position was also assessed. Results. Analysis of variance indicated the whiplash subjects were less accurate in reproducing the targe angle than were control subjects. These whiplash subjects tended to overshoot the target. In addition, the subjects in the whiplash group were often inaccurate in their assessment of neutral position. Conclusions. Subjects who have experience a whiplash injury demonstrate a deficit in their ability to reproduce a target position of the neck. These data are consistent with the hypothesis that these subjects possess an inaccurate perception of head position secondary to their injury. This study has implications for the rehabilitation of individuals with whiplash injury.