Abdominal Hollowing vs. Abdominal Bracing: A Scoping Review of Clinical Trials on Effectiveness for Trunk Stability and Rehabilitation.

Objectives: This scoping review explores the effectiveness of abdominal hollowing (AH) and abdominal bracing (AB) techniques in enhancing trunk stability and facilitating rehabilitation, particularly for individuals with lower back pain (LBP). Methods: The review synthesizes findings from 22 randomized controlled trials (RCTs) that assessed these techniques' impacts on muscle activation, pain reduction, and functional outcomes. Results: The results demonstrate that both techniques can significantly improve trunk stability, muscle thickness, balance, and gait. However, a notable gap exists in studies directly comparing AH and AB, raising questions about whether they are equally effective. While AH is often associated with selective activation of the transversus abdominis, AB promotes a broader co-contraction of trunk muscles, contributing to robust spinal stability. Conclusions: This review underscores the need for further research to directly compare these techniques and refine their application in clinical practice. The findings suggest that personalized rehabilitation programs incorporating both AH and AB, tailored to individual patient needs and rehabilitation goals, can be effective in managing and preventing LBP.