Sherafat Shiva, Salavati Mahyar, Takamjani Ismail Ebrahimi, Akhbari Behnam, Rad Shahrzad Mohammadi, Mazaheri Masood, Negahben Hossein, Lali Pezhman
PhD Student in Physical Therapy, Physiotherapy Department, Iran University of Medical Science, Tehran, Iran.
Professor, Physiotherapy Department, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.
J Manipulative Physiol Ther. 2014 Mar-Apr;37(3):170-9. doi: 10.1016/j.jmpt.2014.02.003. Epub 2014 Mar 15.
The purpose of this study was to compare the effect of dual tasking on postural and cognitive performance between participants with and without nonspecific chronic low back pain.
In this 3-factor mixed-design study, dynamic postural stability was assessed in 15 patients with chronic nonspecific low back pain and 15 age-, sex-, and size-matched asymptomatic participants. Bilateral stance on a Biodex Balance System was investigated at 3 levels of postural task difficulty (different platform stabilities levels with eyes open and closed) and 2 levels of cognitive task difficulty (with or without auditory Stroop test). We measured anterior-posterior, medial-lateral, and overall indices for postural performance. Average reaction time and error ratio of a modified auditory Stroop test were calculated as measures of the cognitive task performance.
Mixed-design 3-way analyses of variance revealed significant interactions. Post hoc 2-way analyses of variance showed significant group by cognitive task difficulty for anterior-posterior (P < .001), medial-lateral (P = .003), and overall stability indices (P < .001) on a stiffness level of 5 with eyes closed. At this level, there were significant differences between single- and dual-task conditions for anterior-posterior (P < .001), medial-lateral (P = .02), and overall stability indices (P < .001) only in the chronic low back pain group. Also, at the most difficult postural conditions, participants with chronic low back pain increased their error ratio (P = .002), whereas matched asymptomatic individuals increased their reaction time (P < .01) of the auditory Stroop test.
Postural task performance is attenuated by cognitive loading at a moderate level of postural task difficulty. Therefore, to observe the effect of attentional demands of postural control, task difficulty should be considered.
本研究旨在比较非特异性慢性下腰痛患者与无下腰痛患者在双重任务对姿势和认知表现方面的影响。
在这项三因素混合设计研究中，对15例慢性非特异性下腰痛患者以及15例年龄、性别和体型匹配的无症状参与者进行了动态姿势稳定性评估。在姿势任务难度的3个水平（睁眼和闭眼时不同的平台稳定水平）和认知任务难度的2个水平（有或无听觉Stroop测试）下，对在Biodex平衡系统上的双侧站立进行了研究。我们测量了姿势表现的前后、内外侧和整体指标。计算改良听觉Stroop测试的平均反应时间和错误率作为认知任务表现的指标。
混合设计的三因素方差分析显示存在显著的交互作用。事后的双因素方差分析表明，在闭眼且刚度水平为5时，前后（P <.001）、内外侧（P =.003）和整体稳定性指标（P <.001）在认知任务难度方面存在显著的组间差异。在此水平上，仅在慢性下腰痛组中，单任务和双任务条件下的前后（P <.001）、内外侧（P =.02）和整体稳定性指标（P <.001）存在显著差异。此外，在最困难的姿势条件下，慢性下腰痛患者的错误率增加（P =.002），而匹配的无症状个体的听觉Stroop测试反应时间增加（P <.01）。
在中等姿势任务难度水平下，认知负荷会削弱姿势任务表现。因此，为观察姿势控制的注意力需求的影响，应考虑任务难度。
