This study was designed cross-sectional controlled study. Thirty-two patients with CDH related chronic neck pain and twenty-three age and sex-matched asymptomatic controls participated in this study.~The Neck Disability Index (NDI) was used to assess neck pain related disability. The Biodex Balance System (BBS; Biodex Medical Systems, Shirley, New York, USA) was used to assess postural control. This system allows individuals to measure their stability limits. It also examines the control of the center of gravity on the support surface and balance abilities when trying to move it. The evaluated parameters of this system are presented below; modified clinical test of sensory integration of balance (mCTSIB), athletic single leg test (ASLT), limits of stability (LOS), and fall risk assessment were performed with and without a cognitive task. Dual-task interference (DTI) was assessed.~In order to avoid the order bias of postural control measurements during Single-task and Dual-task for each case, the order of the measurements was determined by randomization on the first day by using sealed envelope method. After single/double task randomization was made, the order of tests was also randomized by using sealed envelopes containing two different orders (1-mCTSIB, 2-ASLT, 3-Fall test, 4-LOS and 1- LOS, 2- Fall test, 3- ASLT, 4-mCTSIB).~Before starting the evaluations, the participants were informed about the tests. Considering methodological bias, the same investigator performed all assessments and all participants received standardized and identical instructions.~Single and dual task measurements were made as follows:~Single task measurements involved the measurement of balance parameters by using Biodex Balance System without any additional cognitive task. For assessment of dual task performance, the participants were asked to perform an additional cognitive task (counting backwards from 200 by three or seven) during measurements .~DTI values were calculated for all balance parameters using the formulas below :~DTI %= (Dual Task-Single Task)/Single Task*100
Intense pain and moderate disability are seen most patients with symptomatic cervical disc herniation (CDH). Since neck motion and motor control are associated with changes in neck pain and disability, it is highly likely that patients with neck pain related disability would display dual-task interference (DTI) during postural control with a cognitive task.~It is very important for patients with cervical disk herniation to perform more than one task at the same time for many activities of daily living. Therefore, the aim of this study was to compare balance performance in dual task between patients with CDH related chronic neck pain and asymptomatic controls.