Predictive and discriminative value of shoulder proprioception tests for patients with whiplash-associated disorders

Objective: To evaluate whether patients suffering from whiplash-associated disorders have impaired shoulder proprioception and whether the acuity of shoulder proprioception is reflected in the patients' symptoms and self-rated function. Design: A comparative group design, including a correlation design for the patient group. Subjects: Patients with chronic whiplash-associated disorders (n = 37) and healthy subjects (n = 41). The groups were matched for age and gender. Methods: All subjects underwent a shoulder proprioception test involving active ipsilateral arm position-matching. Group difference was evaluated by multiple analysis of variance and analysis of variance. The patient group completed questionnaires addressing functioning and health and performed pain ratings. Associations between proprioceptive acuity and self-rated functioning and symptoms were studied by correlation and regression analyses. Results: The patient group showed significantly lower acuity of shoulder proprioception. Moderate correlations were found between proprioceptive acuity and questionnaire scores representing physical functioning, so that low proprioceptive acuity was associated with low self-rated physical functioning. Scores representing pain-intensity did not correlate with proprioceptive acuity. Conclusion: The results show that, at the group level, patients with whiplash-associated disorders have impaired shoulder proprioception. The clinical relevance of this finding is strongly supported by the association between shoulder proprioceptive acuity and self-rated functioning in the patient group.