Direction-Specific Impairments in Cervical Range of Motion in Women with Chronic Neck Pain: Influence of Head Posture and Gravitationally Induced Torque.

Thomas Rudolfsson,Mats Djupsjöbacka,Åsa Svedmark,Divya Srinivasan,Martin Björklund,Johannes Fleckenstein

doi:10.1371/journal.pone.0170274

Thomas Rudolfsson, Mats Djupsjöbacka + Show 4 more

Open Access

https://doi.org/10.1371/journal.pone.0170274

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Journal: PloS one	Publication Date: Jan 18, 2017
Citations: 8	License type: CC BY 4.0

Affiliation: University of Gävle, Umeå University

Abstract

BackgroundCervical 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.MethodsKinematics 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.FindingsPrevious 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.InterpretationThe 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.

Highlights

Cervical function is important for activities of daily living involving stabilizing and orientating the head
We found that women with chronic non-specific neck pain had direction- and level-specific impairments compared to controls; reduced extension in the upper, and reduced flexion in the lower cervical levels
These confirmations of previous findings support that the direction- and level-specific impairments in range of motion (ROM) for active sagittal cervical flexion/extension can be generalised to the population of women with non-specific neck pain

Summary

Introduction

Cervical function is important for activities of daily living involving stabilizing and orientating the head. We found that women with chronic non-specific neck pain had direction- and level-specific impairments compared to controls; reduced extension in the upper-, and reduced flexion in the lower cervical levels. We found that the lower levels contributed to a lesser extent to the total sagittal ROM in women with neck pain compared to controls Those results suggest that a separation of upper and lower cervical contributions to sagittal ROM give more detailed information about impairments than traditional single-joint models and such information can allow for more specific treatment interventions. 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.

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