The breath-back connection: A systematic review

Abstract

Background: Recent research studies highlight a complex interplay between respiratory function and spinal stability, particularly involving the diaphragm and core stabilizing muscles in individuals with low back pain (LBP).

Objective: This systematic review aimed to investigate diaphragm and stabilizer muscle thickness and function in individuals with LBP compared to healthy subjects during breathing.

Methods: A comprehensive literature search was conducted in Web of Science, Science Direct, PubMed, Scopus, and Medline databases up to April 2024. Studies assessing the function and thickness of the diaphragm, abdominal muscles, and lumbar multifidus during breathing in individuals with LBP and healthy subjects were included. The Critical Appraisal Skills Program (CASP) checklist was used to assess study quality.

Results: A total of 14 studies met the inclusion criteria, comprising eight case-control and six cross-sectional studies. Findings indicated variations in diaphragm thickness, excursion, and fatigability among LBP patients, with inconsistent evidence regarding its function. Abdominal muscle activity and recruitment patterns differed significantly between LBP patients and healthy controls, with altered transversus abdominis (TrA) and internal oblique (IO) activation. Some studies reported increased TrA and IO thickness in LBP patients, potentially compensating for diaphragm dysfunction, while others observed reduced thickness and activity. Lumbar multifidus size showed no significant differences during breathing.

Conclusion: This review highlights altered diaphragm and abdominal muscle function in individuals with LBP, supporting the theory of a breath-back connection influencing spinal stability. However, inconsistencies in findings suggest a need for further research focusing on LBP subgroups. Understanding these interactions may contribute to improved rehabilitation strategies targeting core muscle function and respiratory mechanics in LBP management.