Defining and measuring objective and subjective spinal stiffness: a scoping review

Abstract

Purpose

Examine and identify the breadth of definitions and measures of objective and subjective spinal stiffness in the literature, with a focus on clinical implications.

Methods

A scoping review was conducted to determine what is known about definitions and measures of the specific term of spinal stiffness. Following the framework by Arksey and O’Malley, eligible peer-reviewed studies identified using PubMed, Ebsco health, and Scopus were included if they reported definitions or measures of spinal stiffness. Using a data abstraction form, the studies were classified into four themes: biomechanical, surgical, pathophysiological, and segmental spinal assessment. To identify similarities and differences between studies, sixteen categories were generated.

Results

In total, 2426 records were identified, and 410 met the eligibility criteria. There were 350 measures (132 subjective; 218 objective measures) and 93 indicators of spinal stiffness. The majority of studies (n = 69%) did not define stiffness.

Conclusion

This review highlights the breadth of objective and subjective measures that are both clinically and methodologically diverse. There is no consensus regarding a standardised definition of stiffness in the reviewed literature.

Implications for Rehabilitation

• There is a need for a consensus definition of stiffness, as we did not find a consensus definition of stiffness in the reviewed literature.

• Definitions of stiffness should be included alongside self-reported or patient-reported outcome measures.

• There is a need to establish the relationship between subjective and objective measures in future studies.

• Clinicians should be aware that stiffness is a symptom that may indicate the presence of underlying pathophysiology.

Keywords:

• Spinal
• stiffness
• biomechanics
• outcome measures
• patient reported outcomes

Disclosure statement

No potential conflict of interest was reported by the author(s).