The Effect of Spinal Orthoses on Immobilizing the Cervical Spine: A Systematic Review of Research Methodologies

Introduction
The purpose of this article is to review the literature on the effect of immobilization of the cervical spine using orthotic devices. The review focused on the methodologies of the studies to see if this might be a contributing factor to the lack of available clinical guidelines on spinal immobilization using orthoses.

Methods
This review was conducted using PRISMA guidelines (PLoS Med. 2009;6:e1000097). The search was conducted in August 2019 within all major databases using relevant phrases. No date restrictions were applied, but the search was restricted to full manuscripts published in English. These searches were then supplemented by tracking all key references from the appropriate articles identified. Articles were selected according to a priori–defined criteria. Initially, data were extracted regarding publication details, orthosis name and group, spinal level studied, and whether cervical range of motion was measured.

Results
A total of 52 articles fulfilled the inclusion criteria. This article discusses the methodology of the included studies.

Conclusions
There is a clear paucity of well-designed research on immobilization of the cervical spine using orthotic devices. Comparing the results of studies using different types of orthoses is difficult due to the type and age of the participants involved (healthy, pathological, cadaver) and the different techniques of measurement used. This lack of standardization prevents meta-analyses from being performed and may be a contributing factor to the lack of available clinical guidelines. An agreed structured methodology is required to enable meta-analyses and determine clinical guidelines for the prescription of spinal orthoses for cervical spine pathology.