Contributions of patient-generated mental and emotional health status to diaphragm function in young males with low back pain

Abstract

Background

Individuals with low back pain (LBP) exhibit altered diaphragm function and poor psychological health. Chronic maladaptation of diaphragm activity has been linked to impaired emotional and physical well-being; however, no study has directly examined whether self-reported disability contributes to diaphragm function in LBP.

Objective

To compare ultrasonographic measures of diaphragm function in the standing position between young male participants with and without LBP and examine the associations between patient-oriented measures of physical function and psychological status and diaphragm function in those with LBP.

Methods

A cross-sectional comparative study was conducted involving 22 young males with LBP and 17 healthy controls. Six validated questionnaires assessed physical and psychological status. Ultrasonography quantified bilateral diaphragmatic contractility and right hemidiaphragm excursion in the standing position.

Results

Participants with LBP exhibited significantly lower contractility in both hemidiaphragms than controls (p < 0.05). The strongest predictor of right hemidiaphragm contractility was the mental component summary of the Short Form-36 (R² = 0.356, p = 0.003). The combination of social life dysfunction and pain-related disorder domains in the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire explained 25.0% of the variance in left hemidiaphragm contractility (R² = 0.250, p = 0.065). While the regression model of the left hemidiaphragm contractility approached statistical significance (p = 0.065), it did not meet our criterion alpha (0.05).

Conclusion

Reduced diaphragm contractility in standing posture may be associated with poorer psychological health in young males with LBP. These findings suggest diaphragm dysfunction as a potential contributor to the multidimensional burden of LBP. Larger, prospective studies including females are warranted to clarify these associations.