Arch Phys Med Rehabil. 2002 Mar; 83(3): 412-5.

Effect of neck pain on verticality perception: a cohort study.

Grod JP, Diakow PR.

Canadian Memorial Chiropractic College, 1900 Bayview Avenue, Toronto, Ontario M4G 3E6, Canada. jgrod@cmcc.ca

OBJECTIVE: To use the Rod-and-Frame Test (RFT) as a quantification of the perception of verticality in subjects with and without neck pain. DESIGN: Cohort study comparing perception of verticality in symptomatic subjects with neck pain versus a control group. SETTING: Both groups were selected from 2 urban chiropractic offices treating typical neuromusculoskeletal conditions from the general community in Canada. PATIENTS: Nineteen subjects (11 women, 8 men) with uncomplicated mechanical neck pain and 17 (7 women, 10 men) asymptomatic subjects. INTERVENTION: The RFT offers a noninvasive method of measuring spatial orientation or the perception of verticality. Studies of the RFT indicate that performance is reliable. The RFT requires subjects to set a luminescent rod to the true vertical in the presence and absence of a luminescent background frame. MAIN OUTCOME MEASURE: The amount of rotation was measured and recorded by a dial on the back of the device. RESULTS: Two-way analysis of variance showed statistically significant differences in judging vertical between symptomatic and asymptomatic subjects. Unpaired t tests for each test situation and the Tukey post hoc test showed statistical differences for both groups. CONCLUSION: There may be a direct connection between the structures that provide internal cues for the body's ability to sense verticality and nociceptive influences affecting the afference of these structures. The overshoot of the symptomatic group could indicate the search for additional proprioceptive information.Copyright 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation