PrevalenceofMyofascialTriggerPointsinPatientswithRadiatingandNon-RadiatingLowBackPain:ASystematicReview

Low back pain is one of the most common conditions affecting adults worldwide, with up to 90% of cases classified as "non-specific" — meaning no clear structural cause can be identified. Among the potential sources of this pain, muscles are increasingly recognized as important contributors. Within muscle tissue, myofascial trigger points (MTrPs) — hyperirritable spots in skeletal muscle that can produce local and referred pain — are considered one of the most common sources of symptoms in non-specific low back pain. Despite their clinical importance, the true scope of MTrPs in low back pain populations has remained unclear.

Previous reviews on spinal pain were conducted over a decade ago and did not specifically focus on low back pain or distinguish between patients with pain that radiates to the leg versus pain that stays in the back. Additionally, examining patients for MTrPs is time-consuming, taking at least 15 minutes to assess all major muscle groups. Without knowing which muscles most commonly harbor active trigger points, clinicians may waste valuable time examining low-yield areas. This systematic review aimed to synthesize current knowledge on how common MTrPs are in people with low back pain and identify which specific muscles are most frequently affected.

The researchers conducted a systematic review following PRISMA guidelines, searching three major databases (PubMed, Cochrane, and Web of Science) plus manual journal searches for relevant studies published any time up to February 2025. They included descriptive, observational, or experimental studies that reported the prevalence of active or latent MTrPs in individuals with non-specific low back pain, using manual palpation methods that adhered to established Delphi consensus guidelines. Two independent reviewers screened articles and extracted data using a standardized form. They assessed methodological quality using a checklist derived from the Dutch Cochrane Centre, scoring studies on seven criteria including description of patient groups, control groups, selection bias, exposure measurement, blinding, confounders, and outcome reporting.

Each criterion was rated as fulfilled (+), not fulfilled (−), or insufficient information (0). From an initial 139 records, they removed 26 duplicates, excluded 80 based on title and abstract screening, and eliminated 24 more after full-text review, ultimately including nine articles in the final analysis.

The nine included studies involved a total of 1,187 participants, with 790 having some form of low back pain: acute (less than 2 months, n=61), chronic non-specific (n=192), or associated with radiculopathy/radiating pain (n=537). The methodological quality scores ranged from 4 to 6 out of 7, with a mean of 5.5, indicating moderate to high quality overall. However, only four studies included control groups, three implemented any blinding, and four controlled for confounding factors.

For active MTrPs in patients with low back pain, the quadratus lumborum showed prevalence ranging from 30% to 55% across studies. The gluteus medius ranged from 34% to 45%, with one study finding 93% prevalence in posterior and superior fibers specifically. The piriformis had 42% prevalence, the psoas ranged from 5% to 10%, and the lumbar iliocostalis ranged from 33% to 38%. Notably, patients with radiating low back pain showed particularly high rates in the gluteal region — 76.4% in one study and 74.1% in another for the gluteus medius area — suggesting a potential neurogenic component to MTrP development.

For latent MTrPs, the gluteus medius showed 74% prevalence in one study, while the quadratus lumborum showed 14–17% prevalence. Other muscles including the piriformis (19–22%), psoas (26–36%), and lumbar iliocostalis (19%) also demonstrated latent trigger points in symptomatic patients, generally at higher rates than in asymptomatic controls.

One study on gluteus medius found that posterior and superior fibers were most affected (93%), followed by anterosuperior and middle fibers (77%). Another study found that MTrPs in the superolateral quadrant of the gluteus had 91.4% specificity for predicting radicular involvement, suggesting potential diagnostic utility.

Inter-examiner reliability for MTrP identification varied substantially by muscle, with kappa values ranging from 0.42 for the quadratus lumborum to 0.83 for the gluteus medius. Additionally, 57% of MTrPs identified by one examiner were not confirmed by another within a 50 mm margin, highlighting significant localization variability.

This review establishes that active and latent myofascial trigger points are common in patients with low back pain, particularly in the quadratus lumborum, gluteus medius, and iliocostalis muscles. The findings suggest that clinicians should prioritize examining these muscles, especially in initial assessments, to improve diagnostic efficiency. The higher prevalence of gluteal trigger points in patients with radiating pain suggests that nerve root irritation may contribute to trigger point development through reflex mechanisms or biomechanical compensations — this has implications for differentiating radicular from non-radicular pain.

However, the substantial variability in prevalence estimates and the subjectivity of manual palpation remain important limitations. The finding that inter-examiner agreement varies considerably by muscle, with deeper muscles like the psoas and quadratus lumborum showing lower reliability, suggests that clinical examination protocols may need refinement. The authors recommend developing more objective diagnostic tools such as ultrasound elastography or electromyography to complement manual examination.

For patients, this review supports that muscle-related pain mechanisms are relevant in low back pain and that targeted assessment of specific muscles may help guide treatment. The evidence also supports interventions targeting MTrPs, such as dry needling, as potentially beneficial for this population. Future research should standardize diagnostic criteria, systematically record pain duration and intensity, and explore the pathophysiological significance of MTrPs to enhance therapeutic approaches for low back pain.