Synergistic imbalance in lumbar core muscles and novel targeted interventions for intervertebral disc degeneration

Abstract

BACKGROUND: Research on the mechanical stability imbalance mechanism in intervertebral disc degeneration has long focused on the paraspinal muscles, with insufficient attention paid to the anterior/posterior abdominal wall and hip core muscle groups. There is a particular lack of systematic analysis of the synergistic actions of multiple muscle groups, and the link between molecular mechanisms and muscle function remains unclear. OBJECTIVE: To integrate evidence on the association between the anterior/posterior abdominal wall, paraspinal, and hip core muscle groups and intervertebral disc degeneration, to elucidate interaction of synergistic muscle imbalance with molecular pathways such as Piezo1–YAP, and to propose targeted prevention and treatment strategies. METHODS: A search was conducted in CNKI, WanFang, PubMed and Web of Science using a combination of MeSH terms (e.g., transversus abdominis[MeSH]) and free terms (e.g., TrA, IVDD) connected by Boolean operators (AND/OR) for muscle anatomy terms (transversus abdominis, gluteus maximus, etc.), disease terms (intervertebral disc degeneration, low back pain, etc.), and study types (RCT, cohort study, etc.). Finally, 61 articles were selected according to preset criteria for analysis. RESULTS AND CONCLUSION: There is a complex association between lumbar core muscles and intervertebral disc degeneration. The transversus abdominis maintains lumbar stability by regulating intra-abdominal pressure and thoracolumbar fascia tension; its decompensation (inhibition/atrophy) is an important pathological feature of intervertebral disc degeneration. Meanwhile, patients with intervertebral disc degeneration exhibit characteristic synergistic dysfunction of core muscles: (1) antagonistic compensation of abdominal wall muscles (overactivation of internal/external oblique to compensate for transversus abdominis dysfunction); (2) dual compensation in the quadratus lumborum region (intra-regional psoas-quadratus lumborum synergistic reorganization, inter-regional erector spinae-quadratus lumborum/psoas compensation); (3) gluteal muscle imbalance (gluteus maximus fatty infiltration/inhibition, gluteus medius protective compensation on the dominant side). These synergistic dysfunctions are core links in disrupting spinal stability and accelerating intervertebral disc degeneration. Multi-muscle synergistic imbalance (e.g., disruption of the gluteus-psoas-abdominal muscle kinetic chain) not only exacerbates local mechanical abnormalities but also affects overall spine-pelvic biomechanical balance through systemic compensation, and causes dysregulation of intra-abdominal pressure. Molecular mechanism studies indicate that abnormal mechanical loading activates the Piezo1-Ca²⁺-F-actin-YAP signaling axis, promoting extracellular matrix degradation and inflammatory responses; meanwhile, imbalance of the nuclear factor E2-related factor 2/nuclear factor κB pathway exacerbates oxidative stress and inflammatory microenvironment, forming a mechanical-biological vicious cycle. Intervention strategies targeting recovery of core muscle synergistic function (e.g., transversus abdominis targeted training, gluteal strengthening, correction of abnormal activation patterns) and their combination with molecular targeted drugs have important clinical potential. Future research should delve into the mechanisms of interaction among muscle groups and compensation patterns to optimize prevention and treatment strategies for intervertebral disc degeneration.

1. Introduction

Intervertebral disc degeneration, as one of the main causes of chronic low back pain, is closely related to the imbalance of lumbar mechanical stability. Traditional research has mainly focused on the role of paraspinal muscles (multifidus, erector spinae) in intervertebral disc degeneration, confirming that fatty infiltration and atrophy of paraspinal muscles are positively correlated with the degenerative process [1-2]. However, the maintenance of lumbar stability depends on the synergistic network of core muscles—including the anterior abdominal wall muscles (transversus abdominis, obliques), posterior abdominal wall muscles (quadratus lumborum), and hip muscles (gluteus maximus, gluteus medius)—in dynamic balance. Existing studies have shown that the asymmetry of rectus abdominis reaction time in patients with intervertebral disc degeneration is significantly higher than that in healthy individuals [3], and abdominal wall muscle asymmetry is independently associated with low back pain (independent of handedness) [4], suggesting that dysfunction of the anterior abdominal wall and hip core muscles may be a key pathological link in intervertebral disc degeneration. Unfortunately, current research still has significant gaps: most literature focuses on paraspinal muscles [2,5-6], while empirical studies on the role of anterolateral abdominal wall muscles (transversus abdominis/obliques) and hip muscles in intervertebral disc degeneration are scarce, especially lacking systematic analysis of multi-muscle synergistic dysfunction.

This review aims to fill this research gap and will be conducted from three aspects: first, systematically integrate evidence on the association between anterior abdominal wall muscles (rectus abdominis, transversus abdominis, obliques), paraspinal muscles (psoas, quadratus lumborum), and hip muscles (gluteus maximus, gluteus medius) with intervertebral disc degeneration; second, reveal the key role of core muscle synergistic imbalance (e.g., transversus abdominis inhibition/oblique compensation, gluteus medius dominant-side protection) in the progression of intervertebral disc degeneration; finally, propose targeted prevention and treatment strategies based on synergistic functional reconstruction of muscle groups and molecular targeted interventions.