Background: Increased postural sway has been detected in people with chronic low back pain. Studies done on neck pain indicate that neck torsion increases the postural sway and therefore is a possible test to identify proprioceptive impairments in the neck. It has, to our knowledge, not been investigated if lumbar torsion has the same effect on postural control.

Objective: to investigate the reliability of a test using torsion of the lumbar spine when measuring postural sway.

Design: cross-sectional design, test-retest study.

Methods: Postural sway was measured in neutral and torsion left and right in 30 participants with low back pain (LBP) and 28 controls. A rotation board was constructed upon which a Wii Balance Board (WBB) was placed, connected to a personal computer via Bluetooth. Measures were obtained with a custom-made program, WBB vibration program Julia Treleaven 1.3.

Result: For path velocity Intraclass Correlation Coefficient (ICC) ranged from 0,88 to 0,94 and Standard Error of Measurement (SEM) varied from 7,1% to 12,0%, with a significant between trials difference. In anteroposterior amplitude ICC ranged from 0,63 to 0,88 with SEM varying from 11,2% to 16,8% and in mediolateral amplitude ICC ranged from 0,77 to 0,93 with SEM varying from 11,8% to 25,2%.

Conclusion: the test shows high relative reliability and acceptable absolute reliability. There is a decrease in mean path velocity from the first to the second test, indicating a possible learning effect. Torsion needs to be better directed to the lumbar spine and the test procedure needs to be simplified for the test to be used in the clinic.