Rudolfsson Thomas, Björklund Martin, Svedmark Åsa, Srinivasan Divya, Djupsjöbacka Mats
Centre for Musculoskeletal Research, University of Gävle, Umeå, Sweden.
Department of Community Medicine and Rehabilitation, Physiotherapy, Umeå University, Umeå, Sweden.
PLoS One. 2017 Jan 18;12(1):e0170274. doi: 10.1371/journal.pone.0170274. eCollection 2017.
Cervical range of motion (ROM) is commonly assessed in clinical practice and research. In a previous study we decomposed active cervical sagittal ROM into contributions from lower and upper levels of the cervical spine and found level- and direction-specific impairments in women with chronic non-specific neck pain. The present study aimed to validate these results and investigate if the specific impairments can be explained by the neutral posture (defining zero flexion/extension) or a movement strategy to avoid large gravitationally induced torques on the cervical spine.
Kinematics of the head and thorax was assessed in sitting during maximal sagittal cervical flexion/extension (high torque condition) and maximal protraction (low torque condition) in 120 women with chronic non-specific neck pain and 40 controls. We derived the lower and upper cervical angles, and the head centre of mass (HCM), from a 3-segment kinematic model. Neutral head posture was assessed using a standardized procedure.
Previous findings of level- and direction-specific impairments in neck pain were confirmed. Neutral head posture was equal between groups and did not explain the direction-specific impairments. The relative magnitude of group difference in HCM migration did not differ between high and low torques conditions, lending no support for our hypothesis that impairments in sagittal ROM are due to torque avoidance behaviour.
The direction- and level-specific impairments in cervical sagittal ROM can be generalised to the population of women with non-specific neck pain. Further research is necessary to clarify if torque avoidance behaviour can explain the impairments.
颈椎活动范围（ROM）在临床实践和研究中通常会被评估。在之前的一项研究中，我们将颈椎矢状面的主动活动范围分解为颈椎上下节段的贡献，并发现慢性非特异性颈部疼痛女性存在节段和方向特异性的功能障碍。本研究旨在验证这些结果，并调查这些特定的功能障碍是否可以由中立姿势（定义为零屈伸）或一种避免颈椎受到大的重力诱导扭矩的运动策略来解释。
对120名慢性非特异性颈部疼痛女性和40名对照组女性在坐位时进行最大矢状面颈椎屈伸（高扭矩条件）和最大前伸（低扭矩条件）时的头部和胸部运动学评估。我们从一个三段运动学模型中得出下颈椎和上颈椎角度以及头部重心（HCM）。使用标准化程序评估中立头部姿势。
颈部疼痛中节段和方向特异性功能障碍的先前发现得到了证实。两组之间的中立头部姿势相同，并且无法解释方向特异性功能障碍。HCM迁移的组间差异相对大小在高扭矩和低扭矩条件下没有差异，这并不支持我们关于矢状面ROM功能障碍是由于扭矩回避行为的假设。
颈椎矢状面ROM的方向和节段特异性功能障碍可以推广到非特异性颈部疼痛的女性人群。有必要进行进一步研究以阐明扭矩回避行为是否可以解释这些功能障碍。
